Title of Invention

"A PROCESS FOR THE PREPARATION OF FIRED TILES AND SLABS FROM WASTE SLAG OF FOUNDRY CUPOLA USING CLAY"

Abstract The present invention provides a process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay which comprises crushing and grinding the cupola slag, sieving through a sieve to give a fineness in the range of 100-315 microns particle size, mixing the above said sieved cupola slag with 25 to 45% by weight of powdered clay, adding water to the above mixture, pouring the mixture in steel die and applying pressure in the range of 130 to 170 kg / cm2, ejecting out the molded product from the steel die and subjecting for air drying for a period of about 24 hours, firing the air dried product at a temperature in the range of 1050 to 11500c for a period in the range of one to two hours, cooling and followed by polishing of the tiles and slabs if so required.
Full Text This invention relates to a process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay.
Cupola slag is a waste generated from fire -clay lined cupola furnaces during production of iron castings . Large quantity of cupola furnaces slags to the tune of a quarter million tonnes per year is generated in India alone and it does not find any use at present, on the contrary to blast furnaces slag which is extensively utilised primarily for cement production. With increasing demand and production of iron castings year after year, there is going to be further increase in generation of this waste slag.
The slag after being separated out from Cupola furnaces is transported and dumped outside foundry areas. This not only occupies important land space but more importantly adds to the solid waste pollution around foundries. Lack of availability of dumping sites nearby foundries due to fast urbanisation has necessitated transportation to far away places which has enhanced cost of handling this waste material while pollution problem remains as such. Main constituents of the cupola slag are generally found in the following ranges :
SiO2 40-60%, A12O3 10-20%, Fe2O3 2-5%, CaO 10-30%, Others 1-5%.
Against this background, efforts-were initiated for fruitful utilisation of this industrial waste product which has hitherto not been exploited to its fullest potential. The slag was found to hold a good promise for being utilised for making some value added products for building applications viz. tiles and slabs for wall, floor, platform, facade, roof etc. useful in housing including kitchen, bathroom and laboratories. In our copending application no. 2637/D/96, We have described and claimed a process for preparation of tiles and slabs from waste slag of foundry cupola . cement binders have been used in this process.
The object of the present invention is to provide a process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay, useful in building construction for various applications.
Accordingly, the present invention provides a process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay which comprises crushing and grinding the cupola slag, sieving through a sieve to give a fineness in the range of 100-315 microns particle size, mixing the above said sieved cupola slag with 25 to 45% by weight of powdered clay, adding water to the above mixture, pouring the mixture in steel die and applying pressure in the range of 130 to 170 kg / cm2, ejecting out the molded product from the steel die and subjecting for air drying for a period of about 24 hours, firing the air dried product at a temperature in the
range of 1050 to 1150°C for a period in the range of one to two hours, cooling up to temperature of 400°C and finally to room temperature, polishing if required.
Slag lumps collected from the dumps are crushed and ground. The ground slag is passed through sieve of size 100 to 315 microns and the powder collected under this sieve size is mixed thoroughly with 25 to 45% by weight of powdered clay. Water is added to this blend to prepare a thick paste suitable for moulding. The mix is packed in steel die by pressing. The moulded product is ejected out of the die and subjected to air drying and subsequently fired at a temperature of 1050-1150°C. The product is retained at this temperature for one to two hours and then slowly cooled upto 400°C then it is taken out for further cooling upto room temperature . The product so obtained is polished with silicon carbide grinding wheels to obtain very fine finish and appeal. If required some pigments can also be added to bring desired colours and shades. The product obtained is tested as per IS : 1478-1969 for clay flooring tiles. Water absorption and flexural strength etc. are found to be within prescribed limits.
The tiles and slabs prepared by this process of this invention are useful for floor and wall tiles and slabs used in building construction. The slabs and tiles thus prepared have adequate strength, good finish, shade and appeal.
The following example are given by way of illustration and should not be construed to limit of the scope of the invention.
Example 1 : Cupola slag having a composition SiO265.5%, A12O3 18%, Fe2O3 4.5%, CaO 11%, MgO 1% was mixed with 35% clay by weight of 10x10x1.2 CMS and pressed at 150Kg Cm2. The tile is removed and air dried for 24 hrs. The tiles are heated in the furnace to 1050°C and held for 1 hour. The tiles are cooled inside the furnace with the power switched off.
Example! rCupola slag having a composition SiO2 66%, Al2O3 18%, Fe2O3 4%, CaO 11%, MgO 1%, was mixed with 40% clay by weight and water to suitable consistency. It is packed in steel die of 10x10x1.2 CMS and pressed at 160Kg Cm2. The tile is removed and air dried for 24 hrs. The tiles are heated in the furnace to 1100°C and held for 1 hour. The tiles are cooled inside the furnace with the power switched off.
Examples : Cupola slag having a composition SiO2 66% A12O3 19%, Fe2O3 4%, CaO 10 %, MgO 1%, was mixed with 45% clay by weight and water to suitable consistency. It is packed in steel die of 10x10x1.2 CMS and pressed at 155 Kg Cm2. The tile is removed and air dried for 24 hrs. The tiles are heated in the furnace to 1150°C and held for 1 hour. The tiles are cooled inside the furnace with the power switched off.
The main advantages of the process of the present invention are :
1. The process relates to exploitation of a hitherto usefully unutilised
industrial waste, posing disposal and environmental pollution problem for
preparing value added products useful in building application.
2. Total amount of the waste slag is processed without rejecting any fraction
of it.
3. The process leads to formation of new products which can be used as
floor and wall tiles and slabs for platforms in houses and laboratories.
4. The process does not require grinding to very fine sizes and thus saves
considerably on grinding energy and cost.
5. The process is simple and does not involve use of expensive raw
materials.





We Claim:
1. A process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay which comprises crushing and grinding the cupola slag, sieving through a sieve to give a fineness in the range of 100-315 microns particle size, mixing the above said sieved cupola slag with 25 to 45% by weight of powdered clay, adding water to the above mixture, pouring the mixture in steel die and applying pressure in the range of 130 to 170 Kg / Cm2, ejecting out the molded product from the steel die and subjecting for air drying for a period of about 24 hours, firing the air dried product at a temperature in the range of 1050 to 1150°C for a period in the range of one to two hours, cooling and followed by polishing of the tiles and slabs if so required.
2. A process for preparation of fired tiles and slabs from waste slag of foundry cupola using clay substantially as here in described with reference to the examples.



Documents:

1970-del-1998-abstract.pdf

1970-del-1998-claims.pdf

1970-del-1998-correspondence-others.pdf

1970-del-1998-correspondence-po.pdf

1970-del-1998-description (complete).pdf

1970-del-1998-form-1.pdf

1970-del-1998-form-19.pdf

1970-del-1998-form-3.pdf


Patent Number 215173
Indian Patent Application Number 1970/DEL/1998
PG Journal Number 10/2008
Publication Date 07-Mar-2008
Grant Date 21-Feb-2008
Date of Filing 10-Jul-1998
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI- 110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 LAKSHMI NARAYANA CHANDRAMOHAN NATIONAL RESEARCH LABORATORY (C.S.I.R.) HABIBGANJ NAKA, BHOPAL - 462 026,
2 RAKESH KUMAR RAWLLEY NATIONAL RESEARCH LABORATORY (C.S.I.R.) HABIBGANJ NAKA, BHOPAL - 452 026,
PCT International Classification Number C21B 3/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA