Title of Invention	A PROCESS FOR THE SEPARATION OF CHROMIUM FROM CHROME TANNED COLLAGEN MATERIAL
Abstract	A process for the separation of chromium from chrome tanned collagen material by treating chrome tanned collagen material with 2% w/w of alkali at a float of 300% w/v, at pH 8 for a period of one hour at a temperature of 25° C, followed by separation by known method to get alkali treated chrome collagen, treating the alkali treated chrome collagen with 4% v/w, of acid at a float of 300% w/v, at a pH 6 for a period of one hour followed by separation by known method to get chromium in the form of salt.

Title of Invention

A PROCESS FOR THE SEPARATION OF CHROMIUM FROM CHROME TANNED COLLAGEN MATERIAL

Abstract

A process for the separation of chromium from chrome tanned collagen material by treating chrome tanned collagen material with 2% w/w of alkali at a float of 300% w/v, at pH 8 for a period of one hour at a temperature of 25° C, followed by separation by known method to get alkali treated chrome collagen, treating the alkali treated chrome collagen with 4% v/w, of acid at a float of 300% w/v, at a pH 6 for a period of one hour followed by separation by known method to get chromium in the form of salt.

Full Text	The present invention relates to a process for the separation of chromium from chrome tanned collagen material. Field of the Invention This process has potential application in leather processing industry for effective chrome management by way of recovering chromium from chrome tanned solid wastes like shaving, trimming, buffing dust etc. for possible reuse, thereby providing a viable solution for the environmental pollution associated therewith. Background of the Invention As reported in the document (International consultation meeting on technology and environmental upgradation in leather sector, 29-30 November 1999), trimmings and shavings of various types form about 35% of all tannery solid wastes generated by the leather processing industry. About 20,000 tons of chrome shavings are generated per annum in India. Chrome shavings are regarded as hazardous waste due to their chromium content, which is in the range of 1-3% of dry weight. In many places due to the unavailability of landfill sites and proper collection and disposal arrangements, solid wastes mostly consisting of wet blue trimmings, shaving remain unattended and finds its ultimate disposal along the wastewater channel and open plots and it is a source of breeding place for insects, pests and rodents, with serious aesthetic as well as public health and environmental implications. Efforts are therefore being made to explore possibilities of disposing these chrome containing solid wastes in cost effective way. Conventionally, these chrome containing solids are subjected to whereby re-usable chrome cake and protein by-product are formed. Cabeza et al (Journal of the Society of Leather Technologists and Chemists, 83,Page 14-19,1999) subjected the chromium containing leather wastes to alkaline hydrolysis at a pH in the range of 8.0 with pepsin and magnesium oxide at 70°C for 3 hours followed by filtration to separate the chromium from the protein fraction. Taylor etal (Journal of American Leather Chemist Association, 87(10), 380, 1992) digested chrome shaving at 67-69°C for 3 hrs with the addition of alkaline protease and allowed the resulting mixture to settle overnight. The protein hydrolysate layer was decanted and the settled chrome containing cake was filtered through Whatman 1 paper. The chrome contents of the protein hydrolysates were found to be less than 1 ppm. Reference may be made to Taylor et al (Journal of American Leather Chemist Association, vol.88, page 358-366, 1993), who subjected the chrome containing solids to highly alkaline conditions at 70-72°C for 6 hrs followed by separation of the gelable protein fraction and subsequent enzymatic treatment of the remaining chrome sludge at 70-72°C followed by filtration to isolate hydrolysed protein fraction with 10,000-20,000 molecular weight distribution and a recyclable chromium cake. As reported by Cabeza et al (Proceedings of the XXV IULTCS Congress, page 465-472, 1999) chrome shavings are treated, at a float of 500% with 1.5% sodium bicarbonate for 2hrs and subsequently filtered to get gelable protein, which is treated with 0.0125% alkaline protease to separate hydrolysable protein. Taylor et al (Journal of American Leather Chemist Association, volume 85,page 264-274, 1990), subjected the chrome shavings to proteolytic treatment at a temperature of 60-65°C in the presence of 5-6% of lime and 1-12% Enzeco Alkaline protease-L enzyme obtained from Enzyme Development Corporation, New York followed by filtration to separate chromium cake and protein fraction. Extraction of the chromium cake with sulfuric acid may be directly used in the pickle bath. As reported by Sastry et al (Proceedings of the XXV IULCS Congress, page 513-519,1999), the bovine pancreatic homogenate showed proteolytic activity against the substrate casein at a pH between 8.5-9.0. The extractability of gelatine was found to be more than 50%. Berry et al (Waste management 22,761-772, 2002) treated leather shavings produced as a waste with lime, MgO etc at 90°C for 6hrs in the presence of enzyme and filtered the resulting mixture using whatman 1 filter paper to separate protein and chrome cake. Using the chrome cake the pigments were prepared. Cabeza et al (Journal of American Leather Chemist Association, volume 94,page 268-286,1999) digested Chrome shavings, mixed with 6% magnesium oxide at 72°C for six hours and centrifuged to isolate gelatin. In the second step the chrome sludge was mixed with water, 2 % MgO and 0.0125% alkaline protease and digested at 72° C for 1.5 hours. The mixture was centrifuged to separate the hydrolysed protein from the chrome cake. Thus, all the above enzymatic studies were essentially done by treating the collagen with alkalis in the presence of enzymes and heating the mixture to about 60-90 °C for 4 to 6 hours. The major limitation associated with this enzymatic technology is that it requires special infrastructure suitable for handling different enzymes. Another limitation associated with the processes is that a temperature in the range of 60-90 °C is required for the enzyme activation, implying thereby additional cost towards providing heating arrangement. Yet another limitation associated with the processes is that the enzymatic hydrolysis requires not less than 4hours. No prior art is available on non-enzymatic process for the separation of chromium from chrome tanned collagen material. Objects of the Invention The main objective of the present invention is to provide a process for the separation of chromium from chrome tanned collagen material which obviates the limitations as detailed above. Another objective of the present invention is to provide a non-enzymatic process for the separation of chromium from chrome tanned collagen material. Yet another objective of the present invention is to provide a process that may be conducted at a temperature as low as 25 °C. Still another objective of the present invention is to provide a process to separate chromium from the chrome tanned collagen material in a period as low as one hour. Summary of the Invention Accordingly the present invention provides a process for the separation of chromium from chrome tanned collagen material which comprises i. treating chrome tanned collagen material with known alkali at a float of not less than 300% w/v, at pH not less than 8 for a period of not less than one hour at a temperature of not less than 25 ° C , followed by separation by known method to get alkali treated chrome tanned collagen material, ii. treating the above material as obtained in step(i),with known acid, at a float of not less than 300% w/v, at a pH not exceeding 6 for a period of not less than one hour followed by separation by known method to get chromium in the form of salt. In an embodiment of the present invention, the chrome tanned collagen material used may be selected from chrome shaving, chrome leather trimming, chrome tanned leather, chrome split. In another embodiment of the present invention, the alkali used may be selected from calcium hydroxide, magnesium oxide, sodium hydroxide, either individually or in any combination. In yet another embodiment of the present invention, the acid used may be selected from sulphuric acid, nitric acid, hydrochloric acid, oxalic acid, formic acid, acetic acid, either individually or in any combination. In still another embodiment of the present invention, the treatment of Chrome tanned collagen with alkali and that of alkali treated chrome collagen with acid may be carried out preferably under dynamic condition In yet another embodiment of the present invention, the known method of separation may be selected from filtration, centrifugation, decantation. In still another embodiment of the present invention, the salt of Chromium produced may be such as sulphate, nitrate, chloride, oxalate, formate, acetate. In yet another embodiment of the present invention, the recovery of Chromium may be upto 90%. Detailed description The present invention is described below in detail. Chrome tanned collagen materials are treated with known alkali, preferably under dynamic condition, at a float of not less than 300%w/V at a temperature of not less than 25 ° C for a period of not less than one hour. pH is maintained at not less than 8. The resulting mixture is separated by known method to get alkali treated chrome collagen. This is treated with known acid, at a float of not less than 300% w/v, preferably under dynamic condition, at a pH not exceeding 6 for a period of not less than one hour and the resulting mixture is subjected to separation by known method to get chromium. The inventive step of the present invention lies in the use of alkali and acid to extract chromium from the chrome tanned collagen material by non-enzymatic process. The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention EXAMPLE -1 In a 5 L capacity container, 2.5L of water was taken and 500g of chrome shaving was added to it. 30 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to that.100 ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3 The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 86% EXAMPLE -2 In a 5 L capacity container, 2 5L of water was taken and 500g of chrome shaving was added to it 24 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 11 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 30°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 2 5I_ of water was added to that 50 ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3 The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 60% EXAMPLE -3 In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 8 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 10 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 16 ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 45% EXAMPLE -4 In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it. 6 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 9 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 31°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 9 5 ml of 90% formic acid was then added to the beaker with continuous shaking. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 37%. EXAMPLE -5 In a 2 L capacity container, 1,0L of water was taken and 200g of chrome shaving was added to it. 4 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 8. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that.8 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 20%. EXAMPLE -6 In a 5 L capacity container, 1.5L of water was taken and 500g of chrome shaving was added to it. 29 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1 5L of water was added to that 95 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 64%. EXAMPLE 7 In a 2 L capacity container, 1 6L of water was taken and 200g of chrome shaving was added to it 13 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 30 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 90%. EXAMPLE -8 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 12.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that20 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 6. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 8%. EXAMPLE -9 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 11 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 11. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 25°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 24 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 4. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 50%. EXAMPLE-10 In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it. 12 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 28°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 24 ml of sulfunc acid was then added to the beaker with continuous stirring. pH was adjusted at 2. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as sulfate. The percentage recovery of chromium from the chrome shaving was estimated to be 47%. EXAMPLE-11 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 12 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at29°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 48 ml of Nitric acid was then added to the beaker with continuous stirring. pH was adjusted at 1. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as nitrate. The percentage recovery of chromium from the chrome shaving was estimated to be 65%. EXAMPLE-12 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 33 gms of magnesium oxide was added to the container with stirring. pH was adjusted to 10. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C. during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1 OL of water was added to that 17ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3 The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 58% EXAMPLE-13 In a 2 L capacity container, 1 OL of water was taken and 200g of chrome shaving was added to it 18 gms of magnesium oxide was added to the container with stirring pH was adjusted to 9. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 OL of water was added to that 10 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3 The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 45% EXAMPLE-14 In a 2 L capacity container, 1 .OL of water was taken and 200g of chrome shaving was added to it. 2.0gms of magnesium oxide was added to the container with stirring. pH was adjusted to 8.0. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1 .OL of water was added to that8.0 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 28%. EXAMPLE-15 In a 2 L capacity container, 1 .OL of water was taken and 200g of chrome shaving was added to it. 20 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 11. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 26 of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 50%. EXAMPLE-16 In a5L capacity container, 2.5 L of water was taken and 500g of chrome shaving was added to it. 18 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 9.0. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to thatiO ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 36%. EXAMPLE-17 In a 5 L capacity container, 2.0 L of water was taken and 400g of chrome shaving was added to it. 12 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 8. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 2.0L of water was added to that7 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 25%. EXAMPLE-18 In a 7 L capacity container, 2.0L of water was taken and 400g of chrome shaving was added to it. 23 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 2.0L of water was added to that 70 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes in 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 89%. EXAMPLE-19 In a 75 L capacity container, 25 L of water was taken and 5000g of chrome shaving was added to it. 230 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 25°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 25L of water was added to that 700 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 88%. EXAMPLE -20 In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 12 5 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 10 ml of sulfunc acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as sulfateThe percentage recovery of chromium from the chrome shaving was estimated to be 38% EXAMPLE -21 In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 13 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 28°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 40ml of acetic acid was then added to the beaker with continuous stirring pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as acetate. The percentage recovery of chromium from the chrome shaving was estimated to be 45%. EXAMPLE -22 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 13.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 20 ml of hydrochloric acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as chloride. The percentage recovery of chromium from the chrome shaving was estimated to be 44%. EXAMPLE-23 In a 5 L capacity container, 1 4L of water was taken and 200g of chrome trimming was added to it 35 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome trimming was taken in another beaker and 1 4L of water was added to that 100ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3 The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 85%. EXAMPLE-24 In a 7 L capacity container, 2 4L of water was taken and 300g of chrome trimming was added to it. 45 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome trimming was taken in another beaker and 2 4L of water was added to that 130 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 86%. EXAMPLE -25 In a 75 L capacity container, 40 L of water was taken and 5000g of chrome trimming was added to it. 900 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum Temperature was maintained at 30°C during the process. After a period of 75 minutes, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome trimming was taken in another beaker and 40 L of water was added to that 2200 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 89%. EXAMPLE -26 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 2 gms of Magnesium oxide and 10.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of two hours, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 29 ml of formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 88%. EXAMPLE -27 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 4 gms of sodium hydroxide, 2.5 gms of Magnesium oxide and 9.0 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 2ml of sulfuric acid, 10 ml of hydrochloric acid and 4 ml of nitric acid were then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of 90 minutes, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. The percentage recovery of chromium from the chrome shaving was estimated to be 41%. EXAMPLE -28 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 2.5 gms of Magnesium oxide and 10.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 20 ml of acetic acid and 14 ml of formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of two hours, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. The percentage recovery of chromium from the chrome shaving was estimated to be 60%. EXAMPLE -29 In a 5 L capacity container, 2.5L of water was taken and 500g of chrome shaving was added to it. 30 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to that.300 ml of 20% oxalic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.5. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 21%. EXAMPLE 30 In a 2 L capacity container, 1.6L of water was taken and 200g of chrome shaving was added to it. 12.8 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process. After a period of one hour, the mixture was centrifuged. The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 29 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were centnfuged to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 94%. EXAMPLE 31 In a 2 L capacity container, 1.6L of water was taken and 200g of chrome shaving was added to it 13 2 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process After a period of one hour, the alkali treated chrome shaving was separated after decantation of the liquor. The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 31 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, chrome liquor was separated by decantation from the mixture Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 85%. EXAMPLE -32 In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 13 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag. The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that23 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 5. The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 17%. Advantages The main advantage of the present invention are the following: • This process is very simple and economically viable to adopt even by small- scale tanners. • Since the process is conducted at a temperature as low as 25° C, expenditure on raising temperature may be saved. • Addition of proteolytic enzyme is not needed. • Process duration for the alkaline hydrolysis (detanning) is one hour as compared with to a minimum of 6hours for enzymatic hydrolysis. • Process duration the separation of chromium is one hour as compared with to a minimum of 6hours for enzymatic process. • Ground water is protected from the leaching of the waste due to indiscriminate dumping of the waste in the open land. • After the separation of chromium, the collagen may be used for the production of bioenergy or the recovery of protein • The recovered chromium may be directly used in the tanning operation We claim 1. A process for the separation of chromium from chrome tanned collagen material which comprises i. characterised in that treating chrome tanned collagen material with 2% w/w of alkali such as herein described at a float of 300% w/v, at pH 8 for a period of one hour at a temperature of 25° C, followed by separation by known method to get alkali treated chrome collagen, ii. treating the above alkali treated chrome collagen as obtained in step (i), with 4% v/w, of acid, such as herein described at a float of 300% w/v, at a pH 6 for a period of one hour followed by separation by known method to get chromium in the form of salt. 2. A process, as claimed in claim 1, wherein the chrome tanned collagen material used is selected from chrome shaving, chrome leather trimming, chrome tanned leather, chrome split. 3. A process, as claimed in claim 1 to 2, wherein the alkali used is selected from calcium hydroxide, magnesium hydroxide, sodium hydroxide, either individually or in any combination. 4. A process, as claimed in claim 1 to 3, wherein the acid used is selected from sulphuric acid, nitric acid, hydrochloric acid, oxalic acid, formic acid, acetic acid, either individually or in any combination. 5. A process for the separation of chromium from chrome tanned collagen material, substantially as herein described with reference to the examples.

Full Text

The present invention relates to a process for the separation of chromium from chrome tanned collagen material. Field of the Invention
This process has potential application in leather processing industry for effective chrome management by way of recovering chromium from chrome tanned solid wastes like shaving, trimming, buffing dust etc. for possible reuse, thereby providing a viable solution for the environmental pollution associated therewith. Background of the Invention
As reported in the document (International consultation meeting on technology and environmental upgradation in leather sector, 29-30 November 1999), trimmings and shavings of various types form about 35% of all tannery solid wastes generated by the leather processing industry. About 20,000 tons of chrome shavings are generated per annum in India. Chrome shavings are regarded as hazardous waste due to their chromium content, which is in the range of 1-3% of dry weight. In many places due to the unavailability of landfill sites and proper collection and disposal arrangements, solid wastes mostly consisting of wet blue trimmings, shaving remain unattended and finds its ultimate disposal along the wastewater channel and open plots and it is a source of breeding place for insects, pests and rodents, with serious aesthetic as well as public health and environmental implications. Efforts are therefore being made to explore possibilities of disposing these chrome containing solid wastes in cost effective way. Conventionally, these chrome containing solids are subjected to whereby re-usable chrome cake and protein by-product are formed.
Cabeza et al (Journal of the Society of Leather Technologists and Chemists, 83,Page 14-19,1999) subjected the chromium containing leather wastes to alkaline hydrolysis at

a pH in the range of 8.0 with pepsin and magnesium oxide at 70°C for 3 hours followed by filtration to separate the chromium from the protein fraction.
Taylor etal (Journal of American Leather Chemist Association, 87(10), 380, 1992) digested chrome shaving at 67-69°C for 3 hrs with the addition of alkaline protease and allowed the resulting mixture to settle overnight. The protein hydrolysate layer was decanted and the settled chrome containing cake was filtered through Whatman 1 paper. The chrome contents of the protein hydrolysates were found to be less than 1 ppm.
Reference may be made to Taylor et al (Journal of American Leather Chemist Association, vol.88, page 358-366, 1993), who subjected the chrome containing solids to highly alkaline conditions at 70-72°C for 6 hrs followed by separation of the gelable protein fraction and subsequent enzymatic treatment of the remaining chrome sludge at 70-72°C followed by filtration to isolate hydrolysed protein fraction with 10,000-20,000 molecular weight distribution and a recyclable chromium cake.
As reported by Cabeza et al (Proceedings of the XXV IULTCS Congress, page 465-472, 1999) chrome shavings are treated, at a float of 500% with 1.5% sodium bicarbonate for 2hrs and subsequently filtered to get gelable protein, which is treated with 0.0125% alkaline protease to separate hydrolysable protein.
Taylor et al (Journal of American Leather Chemist Association, volume 85,page 264-274, 1990), subjected the chrome shavings to proteolytic treatment at a temperature of 60-65°C in the presence of 5-6% of lime and 1-12% Enzeco Alkaline protease-L enzyme obtained from Enzyme Development Corporation, New York followed by filtration to separate chromium cake and protein fraction. Extraction of the chromium cake with

sulfuric acid may be directly used in the pickle bath.
As reported by Sastry et al (Proceedings of the XXV IULCS Congress, page 513-519,1999), the bovine pancreatic homogenate showed proteolytic activity against the substrate casein at a pH between 8.5-9.0. The extractability of gelatine was found to be more than 50%.
Berry et al (Waste management 22,761-772, 2002) treated leather shavings produced as a waste with lime, MgO etc at 90°C for 6hrs in the presence of enzyme and filtered the resulting mixture using whatman 1 filter paper to separate protein and chrome cake. Using the chrome cake the pigments were prepared.
Cabeza et al (Journal of American Leather Chemist Association, volume 94,page 268-286,1999) digested Chrome shavings, mixed with 6% magnesium oxide at 72°C for six hours and centrifuged to isolate gelatin. In the second step the chrome sludge was mixed with water, 2 % MgO and 0.0125% alkaline protease and digested at 72° C for 1.5 hours. The mixture was centrifuged to separate the hydrolysed protein from the chrome cake.
Thus, all the above enzymatic studies were essentially done by treating the collagen with alkalis in the presence of enzymes and heating the mixture to about 60-90 °C for 4 to 6 hours.
The major limitation associated with this enzymatic technology is that it requires special infrastructure suitable for handling different enzymes.
Another limitation associated with the processes is that a temperature in the range of 60-90 °C is required for the enzyme activation, implying thereby additional cost towards

providing heating arrangement.
Yet another limitation associated with the processes is that the enzymatic hydrolysis requires not less than 4hours.
No prior art is available on non-enzymatic process for the separation of chromium from chrome tanned collagen material.
Objects of the Invention
The main objective of the present invention is to provide a process for the separation of chromium from chrome tanned collagen material which obviates the limitations as detailed above.
Another objective of the present invention is to provide a non-enzymatic process for the separation of chromium from chrome tanned collagen material.
Yet another objective of the present invention is to provide a process that may be conducted at a temperature as low as 25 °C.
Still another objective of the present invention is to provide a process to separate chromium from the chrome tanned collagen material in a period as low as one hour.
Summary of the Invention
Accordingly the present invention provides a process for the separation of chromium from chrome tanned collagen material which comprises
i. treating chrome tanned collagen material with known alkali at a float of not less than 300% w/v, at pH not less than 8 for a period of not less than one hour at a

temperature of not less than 25 ° C , followed by separation by known method to get alkali treated chrome tanned collagen material,
ii. treating the above material as obtained in step(i),with known acid, at a float of not less than 300% w/v, at a pH not exceeding 6 for a period of not less than one hour followed by separation by known method to get chromium in the form of salt.
In an embodiment of the present invention, the chrome tanned collagen material used may be selected from chrome shaving, chrome leather trimming, chrome tanned leather, chrome split.
In another embodiment of the present invention, the alkali used may be selected from calcium hydroxide, magnesium oxide, sodium hydroxide, either individually or in any combination.
In yet another embodiment of the present invention, the acid used may be selected from sulphuric acid, nitric acid, hydrochloric acid, oxalic acid, formic acid, acetic acid, either individually or in any combination.
In still another embodiment of the present invention, the treatment of Chrome tanned
collagen with alkali and that of alkali treated chrome collagen with acid may be carried
out preferably under dynamic condition
In yet another embodiment of the present invention, the known method of separation
may be selected from filtration, centrifugation, decantation.
In still another embodiment of the present invention, the salt of Chromium produced
may be such as sulphate, nitrate, chloride, oxalate, formate, acetate.
In yet another embodiment of the present invention, the recovery of Chromium may be
upto 90%.

Detailed description
The present invention is described below in detail.
Chrome tanned collagen materials are treated with known alkali, preferably under dynamic condition, at a float of not less than 300%w/V at a temperature of not less than 25 ° C for a period of not less than one hour. pH is maintained at not less than 8. The resulting mixture is separated by known method to get alkali treated chrome collagen. This is treated with known acid, at a float of not less than 300% w/v, preferably under dynamic condition, at a pH not exceeding 6 for a period of not less than one hour and the resulting mixture is subjected to separation by known method to get chromium.
The inventive step of the present invention lies in the use of alkali and acid to extract chromium from the chrome tanned collagen material by non-enzymatic process. The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention
EXAMPLE -1
In a 5 L capacity container, 2.5L of water was taken and 500g of chrome shaving was added to it. 30 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to that.100 ml of 90% formic acid was then added to the beaker with continuous

stirring pH was adjusted at 3
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 86%
EXAMPLE -2
In a 5 L capacity container, 2 5L of water was taken and 500g of chrome shaving was added to it 24 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 11 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 30°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 2 5I_ of water was added to that 50 ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 60%
EXAMPLE -3
In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 8 gms of calcium hydroxide was added to the container with stirring pH was

adjusted to 10 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 16 ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 45%
EXAMPLE -4
In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it. 6 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 9 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 31°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag
The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 9 5 ml of 90% formic acid was then added to the beaker with continuous shaking. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was

separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 37%.
EXAMPLE -5
In a 2 L capacity container, 1,0L of water was taken and 200g of chrome shaving was added to it. 4 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 8. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that.8 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 20%.
EXAMPLE -6
In a 5 L capacity container, 1.5L of water was taken and 500g of chrome shaving was added to it. 29 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.

The alkali treated chrome shaving was taken in another beaker and 1 5L of water was added to that 95 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 64%.
EXAMPLE 7
In a 2 L capacity container, 1 6L of water was taken and 200g of chrome shaving was added to it 13 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag
The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 30 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 90%.

EXAMPLE -8
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 12.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that20 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 6.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 8%.
EXAMPLE -9
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 11 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 11. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 25°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 24 ml of 90% formic acid was then added to the beaker with continuous

stirring. pH was adjusted at 4.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 50%.
EXAMPLE-10
In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it. 12 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 28°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 24 ml of sulfunc acid was then added to the beaker with continuous stirring. pH was adjusted at 2.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as sulfate. The percentage recovery of chromium from the chrome shaving was estimated to be 47%.

EXAMPLE-11
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 12 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at29°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 48 ml of Nitric acid was then added to the beaker with continuous stirring. pH was adjusted at 1.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as nitrate. The percentage recovery of chromium from the chrome shaving was estimated to be 65%.
EXAMPLE-12
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 33 gms of magnesium oxide was added to the container with stirring. pH was adjusted to 10. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C. during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.

The alkali treated chrome shaving was taken in another beaker and 1 OL of water was added to that 17ml of 90% formic acid was then added to the beaker with continuous stirring pH was adjusted at 3
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 58%
EXAMPLE-13
In a 2 L capacity container, 1 OL of water was taken and 200g of chrome shaving was added to it 18 gms of magnesium oxide was added to the container with stirring pH was adjusted to 9. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag
The alkali treated chrome shaving was taken in another beaker and 1 OL of water was added to that 10 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 45%

EXAMPLE-14
In a 2 L capacity container, 1 .OL of water was taken and 200g of chrome shaving was added to it. 2.0gms of magnesium oxide was added to the container with stirring. pH was adjusted to 8.0. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1 .OL of water was added to that8.0 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 28%.
EXAMPLE-15
In a 2 L capacity container, 1 .OL of water was taken and 200g of chrome shaving was added to it. 20 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 11. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 26 of 90% formic acid was then added to the beaker with continuous

stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 50%.
EXAMPLE-16
In a5L capacity container, 2.5 L of water was taken and 500g of chrome shaving was added to it. 18 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 9.0. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to thatiO ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 36%.

EXAMPLE-17
In a 5 L capacity container, 2.0 L of water was taken and 400g of chrome shaving was added to it. 12 gms of sodium hydroxide was added to the container with stirring. pH was adjusted to 8. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 2.0L of water was added to that7 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 25%.
EXAMPLE-18
In a 7 L capacity container, 2.0L of water was taken and 400g of chrome shaving was added to it. 23 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 2.0L of water was added to that 70 ml of 90% formic acid was then added to the beaker with continuous

stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes in 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 89%.
EXAMPLE-19
In a 75 L capacity container, 25 L of water was taken and 5000g of chrome shaving was added to it. 230 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 25°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 25L of water was added to that 700 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 88%.

EXAMPLE -20
In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 12 5 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 10 ml of sulfunc acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as sulfateThe percentage recovery of chromium from the chrome shaving was estimated to be 38%
EXAMPLE -21
In a 2 L capacity container, 1 0L of water was taken and 200g of chrome shaving was added to it 13 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 28°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1 0L of water was added to that 40ml of acetic acid was then added to the beaker with continuous stirring

pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as acetate. The percentage recovery of chromium from the chrome shaving was estimated to be 45%.
EXAMPLE -22
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 13.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 20 ml of hydrochloric acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as chloride. The percentage recovery of chromium from the chrome shaving was estimated to be 44%.

EXAMPLE-23
In a 5 L capacity container, 1 4L of water was taken and 200g of chrome trimming was added to it 35 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 29°C during the process After a period of one hour, the mixture was filtered through 5-micron polypropylene bag
The alkali treated chrome trimming was taken in another beaker and 1 4L of water was added to that 100ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 85%.
EXAMPLE-24
In a 7 L capacity container, 2 4L of water was taken and 300g of chrome trimming was added to it. 45 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome trimming was taken in another beaker and 2 4L of water was added to that 130 ml of 90% formic acid was then added to the beaker with continuous

stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 86%.
EXAMPLE -25
In a 75 L capacity container, 40 L of water was taken and 5000g of chrome trimming was added to it. 900 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum Temperature was maintained at 30°C during the process. After a period of 75 minutes, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome trimming was taken in another beaker and 40 L of water was added to that 2200 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes at 15rpm in a vertical rotating drum. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 89%.

EXAMPLE -26
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 2 gms of Magnesium oxide and 10.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of two hours, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 29 ml of formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 88%.
EXAMPLE -27
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 4 gms of sodium hydroxide, 2.5 gms of Magnesium oxide and 9.0 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was

added to that 2ml of sulfuric acid, 10 ml of hydrochloric acid and 4 ml of nitric acid were then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of 90 minutes, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. The percentage recovery of chromium from the chrome shaving was estimated to be 41%.
EXAMPLE -28
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 2.5 gms of Magnesium oxide and 10.5 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that 20 ml of acetic acid and 14 ml of formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of two hours, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. The percentage recovery of chromium from the chrome shaving was estimated to be 60%.

EXAMPLE -29
In a 5 L capacity container, 2.5L of water was taken and 500g of chrome shaving was added to it. 30 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 30°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 2.5L of water was added to that.300 ml of 20% oxalic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.5.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate. The percentage recovery of chromium from the chrome shaving was estimated to be 21%.
EXAMPLE 30
In a 2 L capacity container, 1.6L of water was taken and 200g of chrome shaving was added to it. 12.8 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process. After a period of one hour, the mixture was centrifuged.

The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 29 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were centnfuged to separate chrome liquor from the collagen Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 94%.
EXAMPLE 31
In a 2 L capacity container, 1.6L of water was taken and 200g of chrome shaving was added to it 13 2 gms of calcium hydroxide was added to the container with stirring pH was adjusted to 12 The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 27°C during the process After a period of one hour, the alkali treated chrome shaving was separated after decantation of the liquor.
The alkali treated chrome shaving was taken in another beaker and 1 6L of water was added to that 31 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 3.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, chrome liquor was separated by decantation from the mixture Chromium was separated as formate The percentage recovery of chromium from the chrome shaving was estimated to be 85%.

EXAMPLE -32
In a 2 L capacity container, 1.0L of water was taken and 200g of chrome shaving was added to it. 13 gms of calcium hydroxide was added to the container with stirring. pH was adjusted to 12. The contents were intermittently mixed for every 10 minutes at 70rpm in a horizontal shaker. Temperature was maintained at 26°C during the process. After a period of one hour, the mixture was filtered through 5-micron polypropylene bag.
The alkali treated chrome shaving was taken in another beaker and 1.0L of water was added to that23 ml of 90% formic acid was then added to the beaker with continuous stirring. pH was adjusted at 5.
The contents were intermittently mixed for every 10 minutes 70rpm in a horizontal shaker. After a period of one hour, the contents were filtered using 5-micron polypropylene bag to separate chrome liquor from the collagen. Chromium was separated as formate.The percentage recovery of chromium from the chrome shaving was estimated to be 17%.
Advantages
The main advantage of the present invention are the following:
• This process is very simple and economically viable to adopt even by small-
scale tanners.
• Since the process is conducted at a temperature as low as 25° C, expenditure on
raising temperature may be saved.
• Addition of proteolytic enzyme is not needed.

• Process duration for the alkaline hydrolysis (detanning) is one hour as compared
with to a minimum of 6hours for enzymatic hydrolysis.
• Process duration the separation of chromium is one hour as compared with to a
minimum of 6hours for enzymatic process.
• Ground water is protected from the leaching of the waste due to indiscriminate
dumping of the waste in the open land.
• After the separation of chromium, the collagen may be used for the production of
bioenergy or the recovery of protein
• The recovered chromium may be directly used in the tanning operation

We claim
1. A process for the separation of chromium from chrome tanned collagen
material which comprises
i. characterised in that treating chrome tanned collagen material with 2% w/w of alkali such as herein described at a float of 300% w/v, at pH 8 for a period of one hour at a temperature of 25° C, followed by separation by known method to get alkali treated chrome collagen,
ii. treating the above alkali treated chrome collagen as obtained in step (i), with 4% v/w, of acid, such as herein described at a float of 300% w/v, at a pH 6 for a period of one hour followed by separation by known method to get chromium in the form of salt.
2. A process, as claimed in claim 1, wherein the chrome tanned collagen
material used is selected from chrome shaving, chrome leather trimming,
chrome tanned leather, chrome split.
3. A process, as claimed in claim 1 to 2, wherein the alkali used is selected
from calcium hydroxide, magnesium hydroxide, sodium hydroxide, either
individually or in any combination.
4. A process, as claimed in claim 1 to 3, wherein the acid used is selected
from sulphuric acid, nitric acid, hydrochloric acid, oxalic acid, formic acid,
acetic acid, either individually or in any combination.
5. A process for the separation of chromium from chrome tanned collagen
material, substantially as herein described with reference to the examples.

Documents:

526-del-2004-Abstract-(02-12-2010).pdf

526-del-2004-abstract.pdf

526-del-2004-Claims-(02-12-2010).pdf

526-del-2004-claims.pdf

526-del-2004-Correspondence-Others-(02-12-2010).pdf

526-del-2004-correspondence.pdf

526-del-2004-description.pdf

526-DEL-2004-Form-18-(21-09-2006).pdf

526-del-2004-form1.pdf

526-del-2004-form2.pdf

526-del-2004-form3.pdf

526-del-2004-form5.pdf

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Patent Number

245160

Indian Patent Application Number

526/DEL/2004

PG Journal Number

01/2011

Publication Date

07-Jan-2011

Grant Date

05-Jan-2011

Date of Filing

19-Mar-2004

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	RANGASAMY SUTHANTHARARAJAN	CENTRAL LEATHER RESEARCH INSTITUTE, ADYAR, CHENNAI-600020, INDIA.
2	KALYANARAMAN CHITRA	CENTRAL LEATHER RESEARCH INSTITUTE, ADYAR, CHENNAI-600020, INDIA.
3	ETHIRAJULU RAVINDRANATH	CENTRAL LEATHER RESEARCH INSTITUTE, ADYAR, CHENNAI-600020, INDIA.
4	BALASUBRAMANIAN UMAMAHESWARI	CENTRAL LEATHER RESEARCH INSTITUTE, ADYAR, CHENNAI-600020, INDIA.
5	SENGODAGOUNDER RAJAMANI	CENTRAL LEATHER RESEARCH INSTITUTE, ADYAR, CHENNAI-600020, INDIA.

PCT International Classification Number

B 09 B 3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA