Title of Invention

"A PROCESS FOR THE PRODUCTION OF CERAMIC TILES USEFUL FOR WALL AND FLOOR"

Abstract

A process for the production of wall and floor tiles from a single ceramic body, which comprises: intimate blending of mass percent of 30 to 90 powdered pyrophyllite and 10 to 70 beneficiated common clay powders, passing the said powdered pyrophyllite and the said clay powder blend through 100 mesh B.S sieve, mixing the sieved batch with mass percent of 3 to 10 water and 0.5 to 1 organic binders, followed by granulation by known methods; compacting the granules to form flat tiles, drying the green tiles so obtained at a temperature in the range of 110 ± 5 °C to reduce the moisture content of the tiles below 0.5%; firing the resultant tiles at a temperature in the range of 1075 to 1225°C for a soaking period of< 2 hours..

Full Text

The present invention relates to a process for the production of wall and floor tiles from a single ceramic body. The present invention is useful for the production of wall and floor tiles from a single ceramic body for application in building industries. The present day method of making wall and floor tiles utilizes different kinds of ceramic bodies. The body essentially consisting of clay, silica sand or quartz and feldspathic minerals have been the normal practice in producing floor tiles over the years: On the other hand a body consisting of clay, limestone, dolomite, wollastonite have been the normal practice in producing wall tiles. The tiles are produced by the hitherto known ceramic processing methods of mixing, granulation, pressing, glazing and firing. However, the fact remains that a vitrified body cannot be used as a wall tile because of its high shrinkage or a wall tile composition cannot be fired at high temperature to get vitrified product because of its quick and uncontrollable melting. To overcome such type of complex problems many attempts are continually being made by researchers working in this field to develop a single body composition which can fulfill the requirements of both floor and wall tile utilizing the knowledge on raw materials research. Reference may be made to the work of Bursa, A and Bresciani A. "Using a multipurpose tile body", in Am. Ceram. Soc. Bull., 74,9(1995), pp.59-63 and "Floor & Wall tile production through a multipurpose body", in Ceram. Engg. Sci. Proc, 17,1(1996), pp. 50-59 where the authors reported several determing parameters for designing multipurpose body. Use of stable raw materials with low ignition loss, controlled process condition such as fine grinding and higher forming pressure, optimal Si02 : AI203 ratio and CaO content are some of the suggestions to develop a single body. The authors discussed two types of body formulations based on feldspar and pyrophyllite for wall and floor tiles. The technological parameters obtained by them fall well within EN standard classifications for both floor and wall tiles. These experimental bodies resulted almost nil shrinkage and 12 % water absorption at 1120°C and less that 1% shrinkage and 5% water absorption at 1160°C. It was possible to obtain such extra ordinary properties by optimizing the chemical and mineralogical composition of the body and controlling the processing conditions. Reference may also be made to the work of Dana K. and Das S.K., "Some studies on ceramic body composition for wall and floor tiles", in Trans. Ind. Ceram. Soc, 61,2(2002), pp. 83-86. They observed less variation in shrinkage (0.14 to 1.06%) and water absorption (15.15 to 21.20%) value within a wide temperature range (1060°C to 1180°C) from a body consisting of pyrophyllite, clay and wollastonite which is highly suitable for wall tile composition. With slight modification the same wall tile body was converted to floor tile composition and promising results were obtained. Many researchers observed advantageous effect of pyrophyllite in tile body. References may be made to Ibanez, P., Pena, F., Sandoval, F. and Pena, J.M.G., "Modification of inert component in wall tiles bodies", in Am. Cer. Soc. Bull., 71 (1992), pp.1661-68, Prasad, C.S., Maiti, K.N. and Venugopal, R., "Thermal behavious of whiteware bodies containing sericitic pyrophyllite ", in Interceram, 46 (1997), pp.154-61, Prasad, C.S., Mukhopadhyay, T.K. and Maiti, K.N., "Characterization and utilisation of some Indian Pyrophyllite'" in Trans. Ind. Ceram. Soc, 48 (1989), pp. 96, Prasad, C.S., Maiti, K.N. and Venugopal, R., "Replacement of quartz and potash feldspar with sericitic pyarophyllite in whiteware composition", in Interceram, 40 ( 1991), pp. 94-98, Higashi, Shoji " Ammonium bearing mica and mica/smaectite of several pottery stone and pyrophyllite deposits in Japan : their mineralogical properties and utilisation", in Applied clay science, 16(3&4) (2000)., 171-184, Lintz, E.H., "Use of talc & pyrophyllite in semi-vitreous dinner ware bodies", in J. Am. Ceram. Soc, 21 (1938), pp 229-237, Sproat, I.E., "Use of pyrophyllite in wall tile bodies", J. Am. Ceram. Soc, 19(1936), pp. 135-42. The extent of pyrophyllite utilization in all these studies was limited to maximum 40 mass % only along with a number of others raw materials. In all the hitherto known prior art processes, the main drawbacks are: 1. Use is made of a large number of raw materials and need more controls in selecting them. 2. The present normal practice is to use separate bodies for wall and floor tiles and makes the process more complex. 3. In the present practice, processing of different bodies for wall and floor tiles need separate equipment facilities, more extra space which all add to extra capital investment. 4. The present hitherto known processes produce wall and floor tiles with higher dimensional defects, more size variations, higher shrinkage which all leads to lower economic benefits. 5. The present hitherto known processes consume higher thermal energy due to higher firing temperature. The main object of the present invention is to provide a process for the production of wall and floor tiles from a single ceramic body, which obviates the drawbacks of the hitherto known processes as detailed above. Another object of the present invention is to provide a process wherein pyrophyllite is used as one of the major raw materials which is abundantly available but have a limited use. Still another object of the present invention is to provide a process for the production of wall and floor tiles from a single ceramic body utilising less number of raw materials. Yet another object of the present invention is to provide a process for the production of a product having less shrinkage and better physicomechanical properties. Still yet another object of the present invention is to provide a process for the production of wall and floor tiles from a single ceramic body which utilizes lower thermal energy. In the present invention there is provided a process for the production of wall and floor tiles from a single ceramic body, utilizing pyrophyllite and common clay. The tiles produced from the single body and fired in the temperature range of 1175 to 1225°C are suitable for multipurpose application in wall and floor of the buildings. Some of the advantages of the single body are: use of less number of low cost materials, simple processes of manufacturing, easy quality control, less shrinkage and dimensional defects and saving in thermal energy. The physico mechanical properties obtained in the end product produced by the process of the present invention are found to be superior or at par with the properties of such commercially produced tiles. Accordingly, the present invention provides a process for the production of wall and floor tiles from a single ceramic body, which comprises: intimate blending of mass percent of 30 to 90 powdered pyrophyllite and 10 to 70 beneficiated common clay powders, passing the said powdered pyrophyllite and the said clay powder blend through 100 mesh B.S sieve, mixing the sieved batch with mass percent of 3 to 10 water and 0.5 to 1 organic binders, followed by granulation by known methods; compacting the granules to form flat tiles, drying the green tiles so obtained at a temperature in the range of 110 ± 5 °C to reduce the moisture content of the tiles below 0.5%; firing the resultant tiles at a temperature in the range of 1075 to 1225°C for a soaking period of In an embodiment of the present invention, the powdered pyrophyllite is obtained by crushing and grinding by known methods of ball milling, vibro milling and passing through 100 mesh B.S. sieve. In another embodiment of the present invention, the mass percent of major chemical constituents of pyrophyllite is in the range of SiO2 : 58 to 60, Al2O3 : 29 to 31, TiO2 below 0.5 , Fe2O3 below 1.0, MgO below 1.0 , K2O :1.0 to 2.0, Na2O below 1. In still another embodiment of the present invention, the mass percent of major chemical constituents of the common clay is in the range of SiO2: 50 to 62, AI2O3:14 to 22, no, : 0.5 to 1.5, Fe2O3:4 to 9, CaO :1 to 4, MgO : 1 to 4, K2O : 0.5 to 4, Na2O :0.5 to 3. In yet another embodiment of the present invention, the blending time for pyrophyllite and clay is in the range of 5 to 8 hours. In still yet another embodiment of the present invention, the organic binders is such as selected from polyvinyl alcohol(PVA), carbo methoxy cellulose(CMC), dextrin. In a further embodiment of the present invention, the compacting of the granules to form flat tiles is effected by hydraulic pressing at a pressure in the range of 350 to 400 kg/cm2. In a still further embodiment of the present invention, the firing of the dried tiles is effected in an electrically heated furnace at a temperature below 1200°C for a soaking period in the range of 0.5 to 2.0 hours. The details of process steps of the present invention are given below: a) Pyrophyllite is first crushed and ground by conventional methods of ball milling, vibro milling and passed through 100 mesh B.S sieve. b) Mass percent of 30 to 90 ground and sieved pyrophyllite of step 'a' is intimately blended with 10 to 70 of beneficiated common clay powder for a duration of 5 to 8 hours. c) The blended batch of step 'b' is passed through 100 mesh B.S sieve. d) The mixed powder of step 'c' is moistened with mass percent of 3 to 10 water and 0.5 to 1 organic binders and granulated by known method. e) The ready material of step 'd' is compacted in the form of flat tiles under hydraulic pressure in the range of 350 to 400 kg/cm2 . f) The pressed tile of step 'e' are dried at 110±5 °C to reduce the moisture content of the tiles below 0.5%. g) The dried tiles of step f are fired at a temperature in the range of 1075 to 1225°C for a period in the range of 0.5 to 2 hours. h) Tiles of step 'g' are evaluated for physico-mechanical properties. The process of the present invention produces a single body containing pyrophyllite and clay in the ratio 90 :. 10 exhibited wall tile properties at 1100°C (0.86% linear shrinkage, 14.16% water absorption and 16.2 mPa flexural strength) and floor tiles properties at 1175 °C ( 4.00% linear shrinkage, 4.00 % water absorption and 38.7 mPa flexural strength). Similarly, another single body containing pyrophyllite and clay in the ratio 50 : 50 exhibited floor tile properties at 1125°C (4.85% linear shrinkage, 2.00 % water absorption and 42.5 mPa flexural strength ) and synthetic granite tile properties at 1175°C (3.75% linear shrinkage, 0.23 % water absorption and 60.0 mPa flexural strength ). In another single body X-ray diffraction analysis conducted on the sintered vitrified samples confirms the presence of quartz and mullite as major phases. The intensity of mullite peaks increase with increase in pyrophyllite content. Presence of mullite phase was responsible for the development of higher flexural strength. The present invention shows a good promise towards designing a single body from series of combinations of pyrophyllite and common clay for multipurpose applications as wall, floor and synthetic granito tiles in building industries. Due to inherent capabilities of pyrophyllite in reducing shrinkage, thermal expansion and increasing mullite content and higher strength at lower temperature of firing, it is worth to consider the potentialities of this presently developed multipurpose bodies which offers many advantages in comparison to presently used commercial compositions. In the hitherto existing system, clay-quartz-feldspar, potash feldspar acts as a flux for reducing firing temperature and increasing the alkali level in the glassy phase. This viscous liquid phase reacts with other body constituents and gradually permeates the microstructure leading to its densification. In commercial product, coarser grains of quartz tends to dissolve in the feldspathic melt but sizable proportion of undissolved quartz phase remains in the system. This undissolved quartz is responsible for deterioration in mechanical properties due to a (3 quartz inversion. The dehydroxylated clay relicts also tends to dissolve in the glassy phase and helps in the recrystalization of secondary mullite. Silica released from the decomposition of clay is in very fine form and dissolve in the glassy melt. The growth of mullite crystal is very much dependent on the matrix viscosity arising from dissolution of both quartz and clay. The overall reaction leading to end product at a particular temperature is very slow and time dependent. In the process of the present invention, pyrophyllite and common clay, the illite-chlorite mineral transforms to glassy phase at a much lower temperature due to presence of more Fe203, CaO and MgO. The viscosity of the liquid phase also reduces very sharply. Since pyrophyllite does not contain any free quartz, it tends to dissolve in the glassy phase which leads to considerable energy saving. Absence of quartz also reduces the possibility of undisolved quartz grains remaining in the matrix and thus eliminating the hysteresis loop of quartz in the thermal expansion curve of the product. In other words the thermal expansion of the product is generally reduced. Pyrophyllite by its inherent nature reduces the firing shrinkage and enchances crystallization of mullite from the melt due to over all higher AI2O3 content. The overall fired strength of the product is expected to increase. The clay-pyrophyllite system is therefore superior to that of clay-quartz-feldspar system. The novelty of the present invention resides in obtaining a material capable to be used as both floor and wall tiles replacing commercially available separate materials for those separate applications. This not only reduces the cost of the material but also increases the aesthetics of the constructed place. This novelty has been achieved by the non-obvious inventive step of providing a process wherein a naturally occurring material, pyrophyllite is used, which acts as pre-treated synthetic raw material which not only reduces the cost of the production but also improves other requirements such as shrinkage, thermal expansion and strength, as discussed in the above discussions for application as mentioned above. The following examples are given by way of illustration of the process of the present invention in actual practice and should not be construed to limit the scope of the present invention. Example 1 100 gms of beneficiated common clay powder was blended with 900 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 100 c.c. of water and 10 gms of dextrin and granulated by known method. The granulated material was pressed in the form of tiles at 400 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1100°C for 2 hours. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 2 100 gms of beneficiated common clay powder was blended with 900 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 100 c.c. of water and 10 gms of dextrin and granulated by known method. The granulated material was pressed in the form of tiles at 400 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1150°C for 2 hours. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 3 100 gms of beneficiated common clay powder was blended with 900 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 100 c.c. of water and 10 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 400 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1175°C for 0.5 hours. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 4 200 gms of beneficiated common clay powder was blended with 800 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 100 c.c. of water and 10 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 400 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1075°C for 2 hours. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 5 200 gms of beneficiated common clay powder was blended with 800 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 100 c.c. of water and 10 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 400 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1225°C for 0.5 hour. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 6 500 gms of beneficiated common clay powder was blended with 500 gms of pyrophyllite powder and dry mixed for a duration of 8 hours. The dried batch was mixed with 50 c.c. of water and 7 gms of CMC and granulated by known method. The granulated material was pressed in the form of tiles at 350 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1125°C for 2 hours. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 7 500 gms of beneficiated common clay powder was blended with 500 gms of pyrophyllite powder and dry mixed for a duration of 8 hours. The dried batch was mixed with 50 c.c. of water and 7 gms of CMC and granulated by known method. The granulated material was pressed in the form of tiles at 350 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1175°C for 1 hour. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 8 700 gms of beneficiated common clay powder was blended with 300 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 30 c.c. of water and 5 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 350 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1100°C for 1 hour. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 9 700 gms of beneficiated common clay powder was blended with 300 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 30 c.c. of water and 5 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 350 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1150°C for 1 hour. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. Example 10 700 gms of beneficiated common clay powder was blended with 300 gms of pyrophyllite powder and dry mixed for a duration of 6 hours. The dried batch was mixed with 30 c.c. of water and 5 gms of PVA and granulated by known method. The granulated material was pressed in the form of tiles at 350 kg/cm2 pressure by hydraulic press. The pressed tiles were dried at 110°C for 8 hours. The dried tiles were fired at 1175°C for 1 hour. The fired tiles were tested for physico mechanical properties. The results are given in Table I below. The summary of the results of phsico-mechanical properties of the tiles produced under examples are given in Table I below. Table 1 The main advantages of the present invention are : 1. The present process utilizes less number of low cost materials. 2. The present process utilizes pyrophyllite as one of the major raw materials which is abundantly available but have a limited use. 3. The present process produces a single body for multipurpose applications, hence makes the process simple & easy to control. 4. The present process reduces the cost of capital investment. 5. The present process reduces dimensional defects by reducing shrinkage with all other superior properties. 6. The present process offers many economic benefits with respect to cost of production and thermal energy. We claim: 1. A process for the production of wall and floor tiles from a single ceramic body, which comprises: intimate blending of mass percent of 30 to 90 powdered pyrophyllite and 10 to 70 beneficiated common clay powders, passing the said powdered pyrophyllite and the said clay powder blend through 100 mesh B.S sieve, mixing the sieved batch with mass percent of 3 to 10 water and 0.5 to 1 organic binders, followed by granulation by known methods; compacting the granules to form flat tiles, drying the green tiles so obtained at a temperature in the range of 110 ± 5 °C to reduce the moisture content of the tiles below 0.5%; firing the resultant tiles at a temperature in the range of 1075 to 1225°C for a soaking period of 2. A process as claimed in claim 1, wherein the powdered pyrophyllite is obtained by crushing and grinding by known methods of ball milling , vibro milling and passing through 100 mesh B.S. sieve . 3. A process as claimed in claim 1 & 2 wherein the mass percent of major chemical constituents of pyrophyllite is in the range of SiO2 : 58 to 60, Al2O3:29 to 31, TiO2 below 0.5, Fe2O3 below 1, MgO below 1, K2O: 1.0 to 2.0, Na2O below 1. 4. A process as claimed in claim 1 and 3 wherein the mass percent of major chemical constituents of pyrophyllite used is in the range of SiO2 50 to 62, Al2O3 :14 to 22, TiO2 :0.5 to 1.5 , Fe2O3 :4 to 9, CaO : 1 to 4, MgO :1 to 4, K2O : 0.5 to 4, Na2O : 0.5 to 3. 5. A process as claimed in claim 1 to 4 wherein the blending time for pyrophyllite and clay used is in the range of 5 to 8 hours. 6. A process as claimed in claim 1 to 5 wherein the organic binders used are selected from polyvinyl alcohol (PVA), carbo methoxy cellulose (CMC), dextrin. 7. A process as claimed in claim 1 to 6 wherein the compacting of the granules to form flat tiles is effected by hydraulic pressing at a pressure in the range of 350 to 400 kg/cm2. 8. A process as claimed in claim 1 to 7 wherein the firing temperature of the dried tiles used is in the range of 1075°C to 1125°C for a soaking period in the range of 0.5 to 9. A process for the production of wall and floor tiles from a single ceramic body substantially as herein described with reference to the examples.

Documents:

1758-del-2004-Abstract-(11-07-2014).pdf

1758-DEL-2004-Abstract-(16-03-2011).pdf

1758-del-2004-abstract.pdf

1758-del-2004-Claims-(11-07-2014).pdf

1758-DEL-2004-Claims-(16-03-2011).pdf

1758-del-2004-claims.pdf

1758-del-2004-Correspondence Others-(11-07-2014).pdf

1758-DEL-2004-Correspondence Others-(16-03-2011).pdf

1758-del-2004-correspondence-others.pdf

1758-DEL-2004-Description (Complete)-(16-03-2011).pdf

1758-del-2004-description (complete).pdf

1758-DEL-2004-Form-1-(16-03-2011).pdf

1758-del-2004-form-1.pdf

1758-del-2004-form-18.pdf

1758-del-2004-Form-2-(11-07-2014).pdf

1758-del-2004-form-2.pdf

1758-DEL-2004-Form-3-(16-03-2011).pdf

1758-del-2004-form-3.pdf

1758-del-2004-form-5.pdf