Title of Invention

"A PROCESS FOR THE PRODUCTION OF CERAMIC TILES"

Abstract

Present invention provide a process to prepare ceramic tiles using industrial wastes such as iron ore slime, fly ash and blast furnace slag . In the process of present invention , liquid phase sintering of iron ore slime , fly ash and blast furnace slag takes place in the presence of alumino-silicate minerals. Additive is added during raw material mixing to promote the reaction sintering at lower temperature (1100 ° to 1250° C) as against the sintering temperature of 1150 ° to 1300° C in hitherto known process. The iron ore slime used in the present invention contain iron oxide and silica , fly ash contain silica, alumina ,iron oxide , blastfurnace slag contain calcium oxide , silica , alumina and magnesium oxide.

Full Text

The invention relates to an improved process for the production of cerninic tiles. The invention particularly relates to an improved process for the production of ceramic tiles using industrial wastes such as iron ore slime, fly ash and blast furnace slag. The products produced by the process of present invention may be of different shapes and sizes, in the glazed or unglazed forms as per requirement. The near impervious unglazed tiles shall be useful for laying floor of industries, godowns, buildings, etc. where the floors are subjected to scratch and abrasion. The glazed tiles with matty finish shall be useful for making decorative floors while the glaze tiles with glossy finish shall be useful for making decorative walls of buildings. The hitherto known processes use costly minerals such as kaolin, feldspar, quartz, talc, pyrophillite, etc. to produce ceramic tiles. The existing processes to produce ceramic tiles consisted of wet mixing for 1 0 to 20 hours of raw materials, spray drying, compacting at 250 to 300 kg/cm2 load, drying at 110° to 120°C, glazing and firing at 1150 to 1300°C. The raw materials are wet mixed in mills. The wet slurry obtained is filter pressed to squeeze the water out and then spray dried to get very small nodules of raw material for better compaction. The ready powder is compacted in tile shape by hydraulic pressing then dried and fired to get unglazed tiles. To get the glazed tiles first engob is applied to hide the body colour then glaze is applied on the surface of unbaked tiles and then fired. The existing process also require double firing for high quality glossy glazing of tiles for walls. Another known process use iron ore tailings in combination with other minerals like kaoline, feldspar, quartz, talc, etc. to produce ceramic tiles. The raw materials are wet mixed in mills, filter pressed to squeeze the water out and then spray dried to get small nodules of raw material for better compaction. The ready powder is compacted in tile shape by hydraulic pressing then dried and fired to get unglazed tiles. To get the glazed tiles first engob then glaze is applied on the surface of unbaked tiles and then fired. The hitherto known process have the following limitations: a. The floor made of the product of the known processes are not capable of withstanding scratch and high abrasion required in a number of industrial applications as they have relatively low scratch hardness (around 5 in Moh's Scale) and compressive strength. b. The production cost of sintered tiles made from the costly minerals is relatively high. c. The raw materials used for the production of existing ceramic floor and wall tiles require 10 to 20 hours of grinding to achieve fineness as they are found in lump forms, leading to the consumption of more energy. d. The sintering has to be carried out at 1150° to 1300°C for 1 to 2 hours leading to the consumption of more energy. According to literature survey and available information, it may be mentioned that at present no process is available to produce ceramic tiles from iron ore slime, fly ash and blast furnace slag. The purpose of this development is to use abundantly available waste materials such as iron ore slime, fly ash and blast furnace slag which are causing environmental pollution, as raw material to produce value added products such as ceramic tiles. The main object of the present investigation is to provide a process to produce ceramic tiles in glazed and unglazed form using industrial wastes such as from iron ore slime, fly ash , blast furnace slag and other low cost minerals. Another object of the present invention is to provide an improved process to produce unglazed and glazed ceramic tiles using industrial wastes such as from iron ore slime, fly ash , blast furnace slag and other low cost minerals whereby the cost of production is appreciably lowered and the properties of the product is improved. Yet another object of the present invention is to provide an improved process to produce unglazed and glazed ceramic tiles using industrial wastes such as from iron ore slime, fly ash and blast furnace slag whereby the energy consumption is significantly reduced. Still yet another object of the present invention is to provide an improved process to produce unglazed and glazed ceramic tiles using industrial wastes such as from iron ore slime, fly ash and blast furnace slug which are waste materials'and thereby reducing the *. ' pollution in the environment. In the process of present invention, liquid phase sintering of iron ore slime, fly ash and blast furnace slag takes place in the presence of alumino-silicate minerals. Additive is added during raw material mixing to promote the reaction sintering at lower temperature (1100° to 1250°C) as against the sintering temperature of 1150° to 1300°C in hitherto known process. The iron ore slime used in the present invention contains iron oxide and silica, the fly ash used in present invention contains silica, alumina and iron oxide, the blast furnace slag used in the present invention contains calcium oxide, silica, alumina and magnesium oxide. Silica is the most important constituent for any ceramic tile composition to form crystalline as well as glassy phase. The three waste material used in the present invention contains silica along with alumina, iron oxideA calcium oxide and magnesium oxide. These constituents reacts together during heating and forms mullite, fayalite, anorthite and other crystalline phases on reaction sintering. The crystalline phase is uniformly distributed and reinforced in glassy matrix. As a result, a strong, dense and compact microstructure is achieved which contribute to the high scratch hardness and strength. The thermal expansion of the present tile body is kept equal or marginally higher than thermal expansion of the glaze, so that glaze materials remains under compression to the body to avoid microcracking and chipping of the glaze. Accordingly, the present invention provides a process for the production of ceramic tiles using industrial wastes characterized in that comprising Iron ore slime in the range of : 30 - 50% by weight Fly ash in the range of : 10 - 30% by weight Blast furnace slag in the range of : 5 - 20% by weight Alumino-silicate mineral in the range of : 25 - 50% by weight Additives in the range of : 5 - 15% by weight & water in the range of : 70 - 90% by weight of the total raw materials the said process comprises mixing the above defined ingradients for a period in the range of 6 to 10 hours, drying of wet slurry by conventional manner to obtain powder, granulating the dried powder using organic liquid binder such as herein described, compacting the granulated powder by hydraulic press having pressure in the range 200 - 300 kg/cm2 into desirable size, further drying slowly the compacted tiles at a temperature range of 90° -120°C for a period in range of 10 - 20 hours, firing the compacted tiles in an electric/gas operated furnace in the temperature range of 1100° - to 1300°C for a period in range of 30 to 60 minutes to produce unglazed tiles, engobing and glazing the dried compacted tiles by conventional spray technique to produce glazed tiles. According to the feature of the invention, the iron ore slime, fly ash, blast furnace slag and alumino silicate minerals may be selected from the following composition range:- (Table Removed) The alumino silicate mineral may be selected from kaolin, bentonite, illite, pyrophillite and the like. The additives may be selected from talc, soapstone, feldspar and the like. According to yet another feature of the invention, organic binder may be selected from, polyvinyl alcohol, methyl cellulose, carbomet- The tiles produced by the process of present invention have the following range of properties : • Dimension stability : Within 0.5% variation • Surface quality : 95% free from visible defects • Percent water absorption : 2 to 5% for floor and 14 to 16% for wall tiles • Scratch hardness : 6 to 7 (Moh's scale) • Modulus of rupture :> 250 kg/cm2 • Compression strength : 350 to 500 kg/cm2 The following examples are given by way of illustration and should not be construed to limit the scope of invention. EXAMPLE -1 300 grams of iron ore slime, 250 grams of fly ash, 80 grams of blast furnace slag, 300 grams of kaolin and 70 grams of feldspar were uniformly mixed with 750 cc of water in a pot mill for a duration of 10 hours. The slurry was dried in an electric oven at 105°C. 60 cc of polyvinyl alcohol was sprayed on the dried powder uniformly. Marketable size tiles of 112 X 112X7 mm dimensions were produced by compacting at 260 kg/cm2 pressure. The tiles were then oven dried at 110°C for 14 hours. Finally the unglazcd tiles were obtained by sintering the product at 1240°C for 45 minutes. The properties obtained are furnished in table 1. EXAMPLE-2 70 grams of iron ore slime, 200 grams of fly ash, 120 grams of blast furnace slag, 250 grams of illite and 70 grams of talc were uniformly mixed with 850 cc of water in a pot mill for a duration of 9 hours. De-watering of slurry was done in an oven at 110°C. 50 cc of carboxymethyl cellulose was sprayed on the powder thoroughly. Square shape tiles of 112 X 112 X 8 mm dimensions were compacted at 300 kg/cm2 pressure. The tiles were then dried in oven at 110°C for 15 hours. Finally the vitrified unglazed tiles were obtained by sintering the product at 1225°C for 1 hour. The properties obtained are furnished in table 1. EXAMPLE - 3 320 grams of iron ore slime, 150 grams of fly ash, 150 grams of blast furnace slag, 300 grams of pyrophillite and 80 grams of feldspar were thoroughly mixed with 800 cc of water in a pot mill for a duration of 8 hours. De-watering of slurry was done by drying in an oven at 110°C. 55 cc of polyvinyl alcohol was sprayed uniformly on the powder. 112 X 112X6 mm size tiles were produced by compacting at 250 kg/cm2 pressure. The tiles were then dried at 110°C for 15 hours. First engob than glaze was sprayed on the surface of the tiles uniformly. Finally firing was done at 1150°C for a period of 30 minutes. The properties obtained are furnished in table 1. EXAMPLE - 4 400 grams of iron ore slime, 150 grams of fly ash, 100 grams of blast furnace slag, 250 grams of kaolin and 100 grams of talc were wet mixed in a pot mill for 10 hours using 750 cc of water. De-watering of slurry was done by drying in an oven at 110°C. Then 60 cc of polyvinyl alcohol was sprayed on the dried powder uniformly. Market size tiles of 112 X 112 X 7 mm dimensions were produced by compacting at 280 kg/cm2 pressure. The tiles were then dried at 110°C for 15 hours. Engob and glaze was sprayed on the surface of the tiles uniformly. Finally sintering was done at 1000°C for a period of 30 minutes to get the glazed tiles. The properties obtained are furnished in table 1. Table - 1: Properties of various tiles discussed above (Table Removed) The main advantages of the present invention arc : 1. The process utilises abundantly available industrial wastes as major raw materials to produce tiles, thereby the cost of production is considerably reduced in comparison to the known process. 2. The present invention saves energy in terms of grinding time of raw materials required in the conventional process. 3. The products produced by the present invention are superior in terms of scratch hardness, modulus of rupture and compressive strength then the products produced by the existing process. This is obtained by the formation of mullite, fayalite, anorthite and other crystalline phases uniformly distributed and reinforced in glassy matrix. 4. The process of the present invention is helpful in solving the pollution problem by utilising industrial wastes. We Claim: 1 . A process for the production of ceramic tiles using industrial wastes characterized in that comprising Iron ore slime in the range of : 30 - 50% by weight Fly ash in the range of : 10-30% by weight Blast furnace slag in the range of : 5 - 20% by weight Alumino-silicate mineral in the range of : 25 - 50% by weight Additives in the range of : 5 - 15% by weight & water in the range of : 70 - 90% by weight of the total raw materials the said process comprises mixing the above defined ingradients for a period in the range of 6 to 10 hours, drying of wet slurry by conventional manner to obtain powder, granulating the dried powder using organic liquid binder such as herein described, compacting the granulated powder by hydraulic press having pressure in the range 200 - 300 kg/cm2 into desirable size, further drying slowly the compacted tiles at a temperature range of 90° - 120°C for a period in range of 10 -20 hours, firing the compacted tiles in an electric/gas operated furnace in the temperature range of 1100° - to 1300°C for a period in range of 30 to 60 minutes to produce unglazed tiles, engobing and glazing the dried compacted tiles by conventional spray technique to produce glazed tiles, 2. A process as claimed in claim 1 wherein iron ore slime/used is contained SiO2 - 1 to 2%, AI2O3 -1 to 10%, Fe2O3 -75 to 95%, CaO - trace, MgO - trace, TiO2 -0.01 to 2%, LOI -1 to 5%. 3. A process as claimed in claims 1 & 2, wherein fly ash used is contained Si02 -45 to 65%, AI2O3 -15 to 30%, Fe2O3 -3 to 6%, CaO - 1 to 4%, MgO -0.01 to 2%, TiO2 -1 to 2% , LOI -1 to 5%. 4. A process as claimed in claims 1 to 3, wherein blast furnace slag used is contained Si02 -25 to 45%, AI2O3 -15 to 30%, Fe203 -0.01 to 2%, CaO -25 to 40%, MgO -5 to 15%, TiO2 -1 to 2%, LOI -1 to 3%. 5. A process as claimed in claims 1 to 4, wherein alumino silicate mineral used is contained Si02 - 40 -65%, AI2O3 -15 to 25%, Fe2O3 -1 to 5%, CaO -2 to 5%, MgO - Trace, TiO2 -0.01 to 2%, LOI-8 to 15%. 6. A process as claimed in claims 1 to 5, wherein the additives used is selected from talc, soapstone, feldspar and the like. 7. A process as claimed in claims 1 to 6 wherein organic binder used is selected from polyvinyl alcohol, methyl cellusose, carbo-methoxy cellusose, dextrine and in the range of 3 to 8%. 8. A process for preparation ceramic tiles using industrial wastes substantially as herein described with reference to the examples.

Documents:

1488-del-1999-abstract.pdf

1488-del-1999-claims.pdf

1488-del-1999-correspondence-others.pdf

1488-del-1999-correspondence-po.pdf

1488-del-1999-description (complete).pdf

1488-del-1999-form-1.pdf

1488-del-1999-form-19.pdf

1488-del-1999-form-2.pdf

1488-del-1999-form-3.pdf