Title of Invention

ACTIVE FOAMED MAGNETIC CERAMIC/METAL COMPOSITE SUBSTRATE FROM REDMUD AND PROCESS FOR THE PREPARATION THEREOF

Abstract The method of the present invention utilizes red mud an industrial wastes as resources materials which inherently contains the phases of oxides of iron, titanium which on reduction by low density oil get converted to the carbides, lower oxide and metal phases of iron and titanium, which helps and are responsible for providing observed activity and high strength to the active foamed ceramic substrate materials prepared by the method of the present invention. The method of the present invention enables through homogenization of industrial waste from aluminum production industry namely red mud with liquid state reducing and foaming agent viz., low-density oil namely furnace oil/waste oil from automobile industry by making use of absorption/adsorption mechanism. The uniform and highly homogenous mixing of ores with liquid reducing and foaming agent viz., low density oil enables the reaction to take place at a considerably lower temperature in the range of 1000- 1300°C in a duration of 1 to 2 hours and thus saving considerable energy.
Full Text Field of the Invention
The present invention relates to active foamed magnetic ceramic/metal composite substrate from redmud and a process for the preparation thereof. The invention in particular relates to a novel method for making active foamed magnetic ceramic/metal composite substrate from red mud useful for multifunctional potential applications.
Background of the Invention
The active foamed magnetic ceramic/metal composite substrate possesses characteristics suitable for numerous potential applications ranging from automobile (as microrecator catalyst and catalytic support), effluent treatment (as microseparator of toxic ions from waste water e.g. copper, lead etc) to adsorption of gaseous products (removal of sulphur dioxide and hydrogen sulphide) from the chemical industry to acoustic absorption etc. The unique characteristic features, of the active foamed magnetic ceramic/metal composite substrate made using red mud, which enables multifunctional applications, are :
a) Active i.e. amenability of the foamed magnetic ceramic / metal composite substrate for
deposition with noble and non - noble metals e.g. platinum, silver, gold and copper,
lead etc respectively, by using simple electro less deposition method
b) Magnetic
c) Fire resistance
d) Composite pore structure - the size of the various pores ranges from micron to
millimeters and thus imparting very high surface area to the foamed substrate
e) Mechanical strength of the foamed ceramic structure.
Description of the Prior Art
Reference may be made to the patented work of K.Schwartzwalder etal (US Patent no. 3090094,May 1963) for making ceramic foam using the polyurethane foam replica technique which involves soaking of slurry of desired ceramic materials in reticulate polyurethane foam. The soaked foam is then burnt of above 500 °C and the resulting material is then sintered to required high temperature depending on the nature of ceramic materials used for obtaining mechanical strength. The main drawbacks of this process is that the ceramic foam made using this process has poor mechanical strength due to the formation of cracks during processing.
Recent work of N. Claussen Etal (J.Eur.Ceram.Soc.1994,14,97 -109) has shown that use of reaction bonded alumina powder instead of conventional alumina helps in obtaining higher strength in the foamed ceramics, but the drawbacks of this process is that it requires the intensive milling of Aluminum and alumina mixture and use of polyurethane foam.
A research paper by S.Dhara etal (Advances. Appld.Ceram. 104,1, 9-21,2005) has mentioned that the burnout of polyurethane perform produces a large volume of toxic combustion products. Depending on the specific application foamed ceramics are prepared using various materials such as mullite, coorderite, alumina, silicon carbide, partially stabilized zirconia etc (L. Montananro et al, J.Euro.Ceram.soc.1998 18,1339 - 50 and K.Lannguth, Ceram. Intl, 1995,21,237-242).
A research paper by C.Zolfrank etal (J.Eur.Ceram.Soc. 2004,24,495) mentioned the use of dried wood as templates for producing ceramic foam, but the properties of the wood based templates keeps on varying based on the nature and geological conditions were the plants have grown. Similarly the use of egg white and soap nut extract are utilized for their natural foaming ability (S.Dhara etal (Advances. Appld.Ceram. 104,1, 9-21,2005) but again the consistency properties of these foaming agents is of considerable concern.
Recently research work on making foamed glass ceramic by polymeric sponge process is reported but the process suffers from drawbacks such as the use of polyurethane and the need of melting parent glass composition at high temperature of 1500 °C (E. Sousa et al Advan. Appld. Ceram. 2005,104,1, 22 - 29.). The use of catalyst loaded open cell ceramic foam has been demonstrated and found superior in comparison to classical heterogeneous catalysts for many reactions such as cleaning of hydrogen for fuel cell applications, exhaust gas cleaning and oxidative dehydrogeneation of alkanes processes (F. Scheffler etal Advan. Appld. Ceram. 2005,104,1, 43-48).
The use of foamed ceramic support so far was considered to be inert but now very recently the use of foamed ceramic matrix as reactive support has also been reported by F. Scheffler etal (Advan. Appld. Ceram. 2005,104, 1, 43 -48) for crystallization of zeolite on Si -O -C based foamed materials. The drawback of this process is the i) use of poly silesquioxane polymer for the preparation of Si-O-C foam from the mixture of Silicon and silicon carbide and ii) requiring high temperature of sintering ceramic foam i.e. Si and SiC.
The novelty of the present invention with respect to prior art lies in the fact that (i) the method of the present invention obviates the need of conventionally used foaming agent such as toxic polyurethane, dried wood, egg white, soap nut extract and sucrose etc as templates for producing ceramic foam (ii) the method of the present invention enables through homogenization of red mud - a industrial waste with liquid state reducing and foaming agent viz., low density oil by making use of absorption/adsorption mechanism.
The uniform and highly homogenous mixing of red mud powder with liquid reducing and foaming agent viz., low density oil enables the synergistic and simultaneous reaction of reduction and foaming of various mineral phases present in the red mud, to take place vigorously at lower temperature in the range of 1000 - 1300°C in a duration of 1 to 2 hours and thus saving considerable energy (iii) the method of the present invention overcomes the problem of burnout of polyurethane perform which produces a large volume of toxic combustion products (iv) The method of the present invention utilizes red mud - a waste which is generated in powder form aluminium production industry and thus helps in saving grinding energy, otherwise required in conventional process for grinding of raw materials for making foamed ceramic materials (v) The method of the present invention utilizes red mud -a waste form aluminium production industry , which inherently contains the phases of iron, aluminium and sodium aluminum carbonate silicate in the form of hydrates which enables the foaming of red mud (vi) The method of the present invention utilizes red mud - a waste form aluminium production industry, which inherently contains the phases of oxides of iron, titanium which on reduction by low density oil get converted to the carbides, lower oxide and metal phases, responsible for providing observed activity, magnetic property and high strength to the active foamed magnetic ceramic/metal composite substrate materials.
Objects of the Invention
Thus the main object of the present invention is to provide active foamed magnetic ceramic/metal composite substrate from red mud useful for multifunctional potential applications and a process for the preparation thereof, which obviates the drawbacks of the hitherto known prior art as detailed above.
Another object of the present invention is to provide a novel method, which utilizes low-density oil as novel foaming and reducing agent for making active foamed magnetic ceramic/metal composite substrate from red mud useful for multifunctional potential applications.
A further object of the present invention is to provide a process that uses liquid state low density oil, which enables through homogenization and a close contact between the two reactant entities thus helping in making active foamed ceramic substrate by synergistic reaction of various mineral phases present in red mud with foaming and reducing content present in low density oil.
Summary of the Invention
Accordingly, the present invention provides active foamed magnetic ceramic/metal composite substrates from redmud comprising red mud and low density oil in the ratio of 10 to 50 % w/w.
The said ceramic substrates are useful for multifunctional potential applications e.g. a) in effluent treatment i.e. microseparator for removal of toxic ions namely copper and lead from waste water, b) removal of sulphur dixide and hydrogen sulphide gases in the chemical industries and c) as a catalytic support in automobile industry etc.
In an embodiment of the present invention, an active magnetic foamed ceramic/metal composite substrate is obtained from red mud - which is a huge waste and is generated in powder form in aluminium production industry. The generation of red mud waste in powder form obviates the grinding and thus helps in saving on the account of grinding of raw materials in conventional methods.
In another embodiment of the present invention the low-density oil used is preferably selected from the group consisting of furnace oil and waste oils from automobile industry.
In still another embodiment of the present invention low-density oil has been used as a liquid state reducing and foaming agent for making an active magnetic foamed ceramic/metal composite substrate from red mud.
In yet another embodiment of the present invention, the homogenized mixture of red mud with low-density oil is then loaded in a graphite crucible and is heated in a temperature range of 1000 -1300°C for a period ranging from one to two hours.
Detailed Description of the Invention
The present invention provides a novel method for making active foamed magnetic ceramic/metal composite substrate from red mud useful for multifunctional potential applications, using low density oil, which comprises of the homogenization of the red mud powder with 10-50% (w/w) low density oil as a liquid state reducing and foaming agent, which is then loaded in a graphite crucible and heated in a temperature range of 1000 -1300°C for a period ranging from one to two hours where after the graphite crucible is allowed to cool to ambient temperature under reducing environment prevailing inside the crucible and then the active foamed magnetic ceramic/metal composite substrate thus formed by synergistic reaction between the various mineral and foaming phases present in
red mud and foaming and reducing phases present in low density oil, is taken out from the graphite crucible and used for desired multifunctional potential applications.
Thus the novel process for making active magnetic foamed ceramic/metal composite substrate, which is useful for many functional potential applications, from red mud - a industrial wastes, comprises of the homogenization of the powder of red mud with 10-50 (w/w) low density oil as a liquid state reducing agent using a Y mixer for 15-30 minutes. The homogenized mix is then placed in a graphite crucible, which is fitted with a tubular outlet with stopper valve to permit the escape of emanating carbon dioxide gas during reduction of various phases present in red mud - an industrial waste with low-density oil. The graphite crucible is then placed in an electric/oil/gas fired furnace and heated in the temperature range of 1000 - 1300°C for duration of one to two hours. At the end of the heating period, the furnace is switched off; the graphite crucible is allowed to remain in the furnace and out let valves is closed to maintain the reducing atmosphere inside the graphite crucible. The graphite crucible, containing active foamed magnetic ceramic/metal composite substrate is allowed to cool to ambient temperature, where after the substrate material is removed from the graphite crucible and is used for various desired multifunctional potential applications.
The following examples are given by way of illustration of the working of the invention in actual practice and therefore should not be construed to limit the scope of the present invention.
EXAMPLE-1
The active foamed magnetic ceramic/metal composite substrate material was prepared from the red mud a waste from aluminum industry and waste low-density oil. A 600 g of red mud powder was thoroughly homogenized with 300 g of low-density oil. The homogenized mix so obtained was then placed in a graphite crucible and heat treated at 1300°C for one hour in an electrical muffle furnace. After the heat treatment, the graphite crucible was cooled to ambient temperature. The active foamed magnetic ceramic/metal composite substrate materials thus obtained was then used as microseprator for removal of copper from the copper sulphate solution by simply dipping the active foamed ceramic/metal composite substrate in the copper sulphate solution (This metal deposition/removal phenomenon is called and governed by simple electro less deposition method). For this the active foamed ceramic/metal composite substrate weighing 30.16 g was immersed in 500ml solution of 1 %
copper sulphate and it was observed that after 5 minutes duration the whole substrate of the foamed ceramic/metal composite material was coated with copper. The chemical analysis of the copper in the copper sulphate solution after removal of copper using active foamed ceramic/metal composite substrate was carried out using atomic absorption spectrophotometer and it was found that the presence of copper ions in the left over solution was well the below detection limit. The example has confirmed that i) foamed ceramic/metal composite substrate materials is active and can be used as microseparator for the removal of copper ions from aqueous solution and ii) the substrate materials is getting simultaneously coated with copper during removal of copper and therefore can be used for many catalytic reactions as microreader.
EXAMPLE-2
The active foamed magnetic ceramic/metal composite substrate was prepared from the red mud a waste from aluminum industry and waste low-density oil. A 130 g of red mud powder was thoroughly homogenized with 52 g of low-density oil. The homogenized mix so obtained was then placed in a graphite crucible and heat treated at 1200°C for one hour in an electrical muffle furnace. After the heat treatment, the graphite crucible was cooled to ambient temperature. The active foamed magnetic ceramic/metal composite substrate materials thus obtained was then used as microseparator for removal of silver from the silver sulphate solution by simply dipping the active foamed ceramic/metal composite substrate in the silver sulphate solution (This phenomenon of metal deposition is called and governed by simple electro less deposition method). For this the active foamed ceramic substrate weighing 10.35 g was immersed in 500ml solution of 0.5 % silver sulphate and it was observed that after 10 minutes duration the whole substrate of the foamed ceramic/metal composite material was coated with silver. The chemical analysis of the silver in the silver sulphate solution after removal of silver using active foamed magnetic ceramic/metal composite substrate was carried out using titration method and it was found that the presence of silver ions in the left over solution was found to be 0.0025 % The example has confirmed that i) foamed ceramic substrate materials is active and can be used as microseprator for the removal of silver ions from aqueous solution and ii) the substrate materials is getting simultaneously coated with silver during removal of silver and therefore can be used for many catalytic reactions as microreactor.



We claim:
1. Active foamed magnetic ceramic/metal composite substrates from redmud
comprising red mud and low density oil in the ratio of 2:1 to 3:1.
2. The ceramic substrates as claimed in claim 1, useful for multifunctional potential applications such as in effluent treatment, removal of sulphur dixide and hydrogen sulphide gases in the chemical industries and as a catalytic support in automobile industry.
3. A process for the preparation of active foamed magnetic ceramic/metal composite substrates from red mud using low density oil as claimed in claim 1, wherein the process steps comprise:
(a) homogenizing the red mud powder with low density oil as a
liquid state reducing and foaming agent in the ratio of 2:1 to 3:1.
(b) heating the homogenized red mud powder obtained from step (a) in a graphite crucible at a temperature ranging from 1000 to 1300 degree C for a period ranging from one to two hours;
(c) cooling the heated red mud obtained from step (b) to ambient temperature to obtain the desired active foamed magnetic ceramic/metal composite substrates.
4. A process as claimed in claim 3, wherein the low-density oil used is preferably selected from the group consisting of furnace oil and waste oils from automobile industry.

Documents:

738-del-2006-738-del-2006-Claims-(07-01-2013).pdf

738-del-2006-738-del-2006-Correspondence Others-(07-01-2013).pdf

738-del-2006-738-del-2006-Description (Complete)-(07-01-2013).pdf

738-del-2006-738-del-2006-Form-3-(07-01-2013).pdf

738-del-2006-abstract.pdf

738-del-2006-claims.pdf

738-del-2006-correspondence-others-1.pdf

738-del-2006-correspondence-others.pdf

738-del-2006-description (complete).pdf

738-del-2006-description (provisional).pdf

738-del-2006-form-1.pdf

738-del-2006-form-18.pdf

738-del-2006-form-2.pdf

738-del-2006-form-3.pdf

738-del-2006-form-5.pdf


Patent Number 256252
Indian Patent Application Number 738/DEL/2006
PG Journal Number 21/2013
Publication Date 24-May-2013
Grant Date 22-May-2013
Date of Filing 20-Mar-2006
Name of Patentee COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
Applicant Address ANUSANDHAN BHAWAN, RAFI MARG, NEW DELHI - 110001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 ANSHUL AVNEESH REGIONAL RESEARCH LABORATORY (CSIR), HABIBGANJ NAKA, BHOPAL-462026, INDIA
2 AMRITPHALE SUDHIR SITARAM REGIONAL RESEARCH LABORATORY (CSIR), HABIBGANJ NAKA, BHOPAL-462026, INDIA.
3 CHANDRA NAVIN REGIONAL RESEARCH LABORATORY (CSIR), HABIBGANJ NAKA, BHOPAL-462026, INDIA
4 RAMAKRISHNAN NARAYANRAO REGIONAL RESEARCH LABORATORY (CSIR), HABIBGANJ NAKA, BHOPAL-462026, INDIA
PCT International Classification Number C04B 35/100
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA