Title of Invention	"AN IMPROVED CORDIERITE BASED KILN FURNITURE AND A PROCESS FOR PREPARING THE SAME"
Abstract	The present invention relates to improved cordierite based kiln furniture comprising spent catalyst as a replacement for refractory grog and a process for preparing the same. More particularly, the present invention relates to a process for utilization of spent catalyst rich in silica and alumina as raw material in the manufacture of cordierite based kiln furniture.

Full Text

FIELD OF INVENTION The present invention relates to an improved cordierite based kiln furniture and a process for preparing the same. More particularly, the present invention relates to a process for utilization of spent catalyst rich in silica and alumina as raw material as a replacement for refractory grog to manufacture an improved cordierite based kiln furniture comprising spent catalyst. BACKGROUND OF THE INVENTION Fluid Catalytic Cracking (FCC) is one of the largest secondary refining process in which over 500,000 MT catalysts per year is consumed. In this process catalyst particles are in continuous motion from reactor to regenerator via cyclone and encounter collision with each other and hardware body. As a result of collision some catalyst particles break in to fines and are lost from the system, which is known as attrition loss. In the process of cracking the catalyst gradually gets deactivated which is caused by the loss of crystallinity of zeolite component. Loss of crystallinity may be due to several accounts such as thermal/hydrothermal destruction of zeolite in the regions such as regenerator and steam stripper of FCC unit. FCC feeds are not free of vanadium salts and during processing of metal laden feeds vanadium gradually deposits on the catalyst and destroys zeolite by reacting with structural aluminum and rare earth component. This demands periodic withdrawal of catalyst and substitution with fresh. The attrition loss is in the range of 0.5-3 wt% of inventory/day while withdrawal of spent catalyst is almost 50% of total catalyst consumed per annum. Quantum of spent catalyst generated world wide in the process of FCC is mind-boggling and is in the range of 200,000-250,000 MT per annum. From environmental point of view, disposal of spent catalyst is of great concern. Metals Trading International (MTI) finds a home for metal-bearing spent catalysts after they are no longer useful to the catalyst applicant. Metal bearing catalysts such as reforming, isomerization, hydrotreating, hydrocracking catalysts contain high value metals such as nickel, cobalt, rhenium, palladium and platinum. MTI works with a number of industries using metal-bearing products as raw materials for the production of primary metals, steel, and chemicals. Recovery of these metals from spent catalysts is attractive on account of cost of recovered material. However, FCC catalysts do not contain such precious metals in them and hence required to be contended with value contained in silica and alumina. The disposal route of spent catalyst not containing heavy metals, or low in heavy metals, e.g. spent FCCU catalyst, depends very much on whether this type of waste is considered hazardous or not. In either case, land filling is a suitable option, but for hazardous waste the landfill should have proper containment control in place. FCC catalysts are prepared from clay, zeolite and silica-alumina based binder and contain from 25-45 wt% of alumina and 40-50 wt% of silica. Spent FCC catalyst may additionally contain vanadium and nickel in the range 0.4 to 1.0 wt% and 0.1 to 0.5 wt% respectively. These catalysts have attracted the attention of industries such as ceramic and cement as a cheap raw material due to common composition. One way to dispose of catalytic cracking catalyst particles is to use them as an ingredient in other compositions. This would avoid costly disposal practices and in addition give the particles a commercial value of their own. U.S. Pat. 5,5032,548 provides for utilizing particles of FCC catalyst together with a small amount of binder as a composition capable of functioning as a load-bearing layer in environments where it is subjected to compressive loads, such as in a road base or levee. Here particles are present in amount, by dry weight of the composition, in the range of 80% to 96%, and the binder is present in the range of 4% to 20%, by dry weight of the composition. GENERAL PROCEDURE FOR PREPARATION OF REFRACTORY MATERIAL Clay and talc are mixed together and wet milled for 24 hours. After wet milling, the excess water is removed either with the help of filter press or using plaster of Paris moulds. The dried cakes are crushed and mixed with grog either manually or in the mixer. Calculated amount of water is added to this mix. The mix is then given the desired shape in the hand press or mechanical press. The shape is dried and fired in the kiln. Thus, there is a constant need to provide new and cost effective ways to dispose waste catalyst which also do not pose an environment hazard. OBJECTS OF THE PRESENT INVENTION The main object of the present invention is to improved cordieritc based kiln furniture comprising spent catalyst as a replacement for refractory grog. Another object of the present invention is to provide a process for preparing cordieritc based kiln furniture comprising spent catalyst as a replacement for refractory grog. SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for employing catalyst waste in the manufacture of cordierite based kiln furniture in refractory industry, further method of employing spent catalyst in refractory industry makes new avenue for disposal of a catalyst waste. Further, present method of disposal of catalyst waste generates useful material and is of economic advantage. DETAILED DESCRIPTION OF THE PRESENT INVENTION Accordingly, the present invention provides a method for employing spent catalyst in the preparation of refractory. The physico-chemical characteristics and higher silica and alumina content of catalyst waste is considered adequate for its use as part replacement of some raw materials used in refractory industry. Accordingly, the experiment was designed to replace refractory grog in the body mix of refractory from 15-35 wt% with spent catalyst. The performance of final refractory was studied carefully. From the physical performance property of refractory prepared partly with spent catalyst it is evident performance of finished product is not sacrificed due to the use of catalyst waste which is a disposable industrial waste. During a study conducted by the Applicants, it was noticed that Refractory industry uses raw materials such as clay, talc and refractory grog (IS - 6 grade) for preparing refractory kilns. In refractory, clays are used mainly as a source of alumina and silica. The plastic nature of some of the clays has added advantage during use as they provide green strength to the product. Depending upon the chemical composition, level of impurities. cost and availability, the combination of two to three types of clays are used in the manufacture of kiln furniture. Crushed fire clay refractory grog (IS - 6 quality) is added to control the firing shrinkage of the product. The size fraction of refractory grog is maintained as 100 % passing through 16mesh sieve and 100 % retained on 40mesh sieve. Talc is used as a source of MgO. A preferred end use for spent catalyst particles would be one in which large quantities of the particles are required and more preferably one, which requires composition similar to that of spent catalyst composition. After careful study of several industries such as cement, ceramic and refractory the last two appear to be ideal whose raw material composition nearly matches that of spent catalyst. Spent FCC catalyst has alumina in the range 25-45 wt% and silica in the range 40-50 wt% and total alkali and alkali earth metal oxide is less than 1 wt%. In accordance with the first object, the present invention provides an improved cordierite based kiln furniture comprising 10 to 30% by weight of clay, 5 to 30% by weight of talc, 5 to 70% by weight of refractory grog and 1 to 40% by weight of spent catalyst. In an embodiment of the present invention, the clay used is a naturally occurring mineral having 45 to 65% by weight of SiO2, 25 to 40% by weight of A12O3, and 2 to 4% by weight of elemental oxides seleced from Na2O, CaO, TiO2 and K2O. In another embodiment of the present invention, the talc used is a naturally occurring mineral having 90 to 99% by weight of MgO, 0.1 to 1.0% by weight of A12O3, and 0.5 to 2.0% by weight of elemental oxides seleced from Na2O, CaO, TiO2 and K2O. In yet another embodiment of the present invention, the spent catalyst is obtained from Fluid Catalytic Cracking (FCC) process, Deep Catalytic Cracking (DCC) process, Reforming, Hydro-treating and Hydrocracking. In still another embodiment of the present invention, the spent catalyst consists of 45 to 70% by weight of SiO2, 30 to 95% by weight of A12O3, 0.1 to 1.0% by weight of Fe2O3, 0.1 to 1.0% by weight of CaO, 0.1 to 0.5% by weight of MgO, 0.1 to 0.7% by weight of Na2O, 0.1 to 2.0% by weight of TiO2, 0.01 to 2.0% by weight of Vanadium and 0.01 to 1.0% by weight of Nickel. In a further embodiment of the present invention, the refractory grog consists of Al2O3 in the weight range of about 38 wt%, SiO2 in the weight range of about 52% and Fe2O3 in the weight range of about 4 wt%. In accordance with the second object, the present invention provides a process for the preparing cordierite based kiln furniture from clays, talc, refractory grog and spent catalyst, said process comprising the steps of: (a) mixing clay, refractory grog and talc and milling in presence of water to obtain a slurry; (b) sieving the slurry of step (a); (c) dewatering the sieved slurry of step (b) with the help of plaster of Paris moulds to obtain dewatered cakes; (d) mixing spent catalyst with the dewatered cake and kneading the same; (e) giving desired shape to the mixture obtained in (d); (f) air drying the shaped product of step (e), firing the air dried product and cooling the same to obtain cordierite based kiln furniture. In an embodiemnt of the present invention, wherein for the preparation of slurry, clay is taken in the range 10-30 wt%, talc is added in the range 5-30 wt%, refractory grog taken in the range 5-70 wt% and spent catalyst in range 1-40 wt%. In another embodiment of the present invention, wherein clay is a naturally occurring mineral with SiO2 in the range 45-65 wt%, Al2O3 in the range 25-40 wt%, and other elemental oxides such as Na2O, CaO, TiO2, K.2O in the range 2-4 wt%. In yet another embodiment of the present invention, wherein talc is a naturally occurring mineral with MgO in the range 90-99 wt%, Al2O3 in the range 0.1-1 wt%, and other elemental oxides such as K2O, Na2O, CaO, TiO2 in the range 0.5-2 wt%. A process as claimed in claim 1, where in spent catalyst is a inorganic waste catalyst sourced from Fluid Catalytic Cracking (FCC) process, Deep Catalytic Cracking (DCC), Reforming, Hydrotreating and Hydrocracking. In still another embodiment of the present invention, wherein spent catalyst has a composition of SiO2 from 45 wt% to 70 wt%, A12O3 from 30 wt% to 95 wt%, Fe2O3 from 0.1 wt% to 1 wt% CaO from 0.1 wt% to 1 wt%, MgO from 0.1 wt% to 0.5 wt%, Na2O 0.1 wt% to 0.7 wt% , TiO2 0.1 to 2 wt%, Vanadium from 0.01 wt% to 2 wt%, Nickel from 0.01 wt% to 1 wt%. In one more embodiment of the present invention, wherein for the preparation of clay and talc water is used in the range 30-40 wt%. In one another embodiment of the present invention wherein in step (f), air drying temperature is carried out at temperature in the range 10-45 °C. In a further embodiment of the present invention wherein in step (g), the firing temperature for the air dried refractory material is in the range 1000-1500 °C. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS In the drawings accompanying the specification, Figure 1 represents the photographs showing kiln furniture manufactured using catalyst waste. Figure 2 represents the X-ray diffractogram of kiln furniture sample. RAW MATERIALS Clays Two types of clays were employed in the present investigation and they were obtained from the user industry. These clays were characterized for their chemical analysis. These clays contain 10-15 wt% LOI, 50-65wt% SiO2, 22-28 wt% A12O3 and 0.5-1.5 wt% Fe2O3 besides other minor impurities such as CaO, MgO, K2O, Na2O and TiO2. Spent catalyst The chemical analysis of spent FCC catalyst sourced from one of RFCC unit indicates that it contains 1.15 percent LOI, 60.35 percent SiO2, 33.12 percent A12O3 and 0.96 percent Fe2O3 besides other minor impurities. The content of Ni and V was estimated to be 0.34 percent and 0.95 percent respectively. The X-Ray diffraction analysis was carried out to identify the mineral phases present in a used catalyst. The investigations reveal that main mineral phases present in spent catalyst are Na2Al2Si4.7O13.4. x H2O and Mg2Al4Si5O13. It was observed that the catalyst looses its crystallinity during use and tends to become more and more amorphous in nature. The physical/thermal characterization of the used catalyst waste sample reveal that the bulk density and specific gravity of the material is 0.998 g/cc and 2.426 respectively. The catalyst waste sample is highly non-plastic in nature and showed no fusion tendency up to 1450 °C. The results of physical/thermal characterization and sieve analysis are given in Table 1. TABLE 1: Physical/thermal properties of waste catalyst sample (Table Removed) The presence of TiO2, Fe2C>3, Ni and V in the catalyst waste make it very sensitive for fired color. The catalyst waste sample was fired at 900, 1100 and 1250 °C to see the fired color of this material. It is observed that the color at 900 °C is light brown which changes to light yellow at 1100 °C and at 1250 °C changes to brown. The chemical analysis coupled with non plastic nature and high temperature stability of this material make it suitable for use in pottery and refractory bodies. Example 1: Preparation of Mullite Based Refractory Bodies This example illustrates a formulation for utilization of spent catalyst in preparing mullite refractory bodies by adding additional alumina-to-alumina deficient spent catalyst. Accordingly four sets of compositions were designed using catalyst waste and alumina as per details given in Table 2. TABLE 2: Details of mullite batches prepared using used catalyst waste and alumina (Table Removed) These mixes were mixed and experimental pellets were prepared using suitable binder. The pellets were dried in electric oven at 120 °C for 24 hours and then fired at a temperature of 1450 °C in Muffle furnace. The fired pellets were examined using X-Ray diffractometry for identification and semi quantitative estimation of mineral phase developed. The results of XRD analysis are given in Table 3. TABLE 3: Semi-quantitative mineralogical analysis of mullite trial batches fired at 1450 °C (Table Removed) The interpretation of the results indicates that Mullite phase has developed in all four cases ranging from 25-30%. Example 2: Preparation of Cordierite-Mullite Based Kiln Furniture from Spent Catalyst In this example procedure is explained for preparing Cordierite-Mullite based refractory bodies by employing spent catalyst in place of refractory grog. A typical and conventional batch composition for the manufacture of kiln furniture is given below in Table 4. TABLE 4: A typical conventional batch composition for the manufacture of kiln furniture (Table Removed) In the above batch mix, the refractory grog was considered for part / full replacement with catalyst waste. Accordingly, two batch mixes was prepared replacing refractory grog with catalytic waste. Two Batches mixes of 50 kg each were' prepared as per weight composition given in Table 5. TABLE 5: Weight composition for preparing two batches of 50 Kg (Table Removed) Both the clays along with Talc were wet milled in the ball mill for 24 hours. The addition of water was of the order of 40 %. The slurry after milling was sieved through 10-mesh sieve for proper mixing of the materials. The sieved slurry was dewatered with the help of plaster of Paris moulds and then dried. The plastic mass was then aged for 72 hours. The dried cake was crushed and mixed with catalytic waste and water and manual kneading was carried out. The quantity of water at this stage was maintained around 20 %. A hand press was used to manufacture kiln furniture of the desired shape. DRYING AND FIRING OF SHAPED BODIES The kiln furniture was dried in the open atmosphere for removal of the water. These green products were loaded in the shuttle kiln for firing in an industrial unit. The products were fired at a temperature of 1250 °C with a soaking time of 2 hours. The furnace oil was used as fuel. The heating rate was maintained at around 80 °C per hour. After the soaking period, the oil firing was stopped and the exhaust blowers were put on. The blowers were on till the temperature dropped to 900 °C. At this temperature the blowers were also put off and the kiln was allowed to cool naturally. Fig. 1 shows some of the samples of kiln furniture thus manufactured from spent catalyst. The evaluation of samples of both the batches was carried using XRD technique ( Fig. 2). The results indicate that the desired phase has developed in both the batch mixes, relatively higher in batch 2. PERFORMANCE OF REFRACTORY PREPARED FROM SPENT CATALYST Two samples of refractory material prepared employing 15 wt% and 25 wt% of spent catalyst in place of refractory grog were subjected to 50 number of cyclic thermal shocks at 1000 °C from room temperature of 30 °C. Results of performance and physical properties of refractory material are shown in Table 6. TABLE 6: Performance results and physical properties of refractory material prepared with spent catalyst along with reference material. (Table Removed) We claim: 1. An improved cordierite based kiln furniture comprising; a. 10 to 30% by weight of clay, having 45 to 65% by weight of Si02, 25 to 40% by weight of A12O3, and 2 to 4% by weight of Na20, CaO, Ti02 and K20, b. 5 to 30% by weight of talc, having 90 to 99% by weight of MgO, 0.1 to 1.0% by weight of A12O3, and 0.5 to 2.0% by weight of Na20, CaO, Ti02 and K20, c. 5 to 70% by weight of refractory grog, having A12O3 in the weight range of about 38 wt%, Si02 in the weight range of about 52% and Fe203 in the weight range of about 4 wt%, and d. 1 to 40% by weight of spent catalyst. 2. An improved cordierite based kiln furniture as claimed in claim 1, wherein the spent catalyst is obtained from Fluid Catalytic Cracking (FCC) process, Deep Catalytic Cracking (DCC) process, Reforming, Hydro-treating and Hydrocracking and more specifically the spent catalyst consists of 45 to 70% by weight of Si02, 30 to 95% by weight of A1203, 0.1 to 1.0% by weight of Fe203, 0.1 to 1.0% by weight of CaO, 0.1 to 0.5% by weight of MgO, 0.1 to 0.7% by weight of Na20, 0.1 to 2.0% by weight of Ti02, 0.01 to 2.0% by weight of Vanadium and 0.01 to 1.0% by weight of Nickel. 3. A process for the preparing cordierite based kiln furniture of claim 1 from clays, talc, refractory grog and spent catalyst, said process comprising the steps of: a. mixing clay, refractory grog and talc, and milling the obtained mixture in presence of water to obtain a slurry; b. sieving the slurry of step (a); c. dewatering the sieved slurry of step (b) with plaster of Paris moulds to obtain dewatered cakes; d. mixing spent catalyst with the dewatered cake and kneading the same; e. giving desired shape to the mixture obtained in (d); and f. air drying the shaped product of step (e), firing the air dried product and cooling the same to obtain cordierite based kiln furniture. 4. A process as claimed in claim 3, where in for the preparation of slurry, clay is in the range 10-30 wt%, talc is in the range 5-30 wt%, refractory grog is in the range 5-70 wt% and spent catalyst in the range of 1-40 wt%. 5. A process as claimed in claim 3, where in clay is a naturally occurring mineral with SiO2 in the range 45-65 wt%, A12O3 in the range 25-40 wt%, and other elemental oxides such as Na20, CaO, TiO2 and K2O in the range 2-4 wt% and more specifically talc is a naturally occurring mineral with MgO in the range 90-99 wt%, A12O3 in the range 0.1-1 wt%, and other elemental oxides such as K2O, Na20, CaO, TiO2 in the range 0.5-2 wt%. 6. A process as claimed in claim 3, where in spent catalyst is a inorganic waste catalyst sourced from Fluid Catalytic Cracking (FCC) process, Deep Catalytic Cracking (DCC), Reforming, Hydrotreating and Hydrocracking which has a composition of Si02 from 45 wt% to 70 wt%, A1203 from 30 wt% to 95 wt%, Fe203 from 0.1 wt% to 1 wt% CaO from 0.1 wt% to 1 wt%, MgO from 0.1 wt% to 0.5 wt%, Na20 from 0.1 wt% to 0.7 wt% , Ti02 from 0.1 to 2 wt%, Vanadium from 0.01 wt% to 2 wt%, Nickel from 0.01 wt% to 1 wt%. 7. A process as claimed in claim 3, wherein in step (f) air drying temperature is carried out at temperature in the range 10-45°C and firing temperature for the air dried refractory material is in the range 1000-1500°C. 8.An improved cordierite based kiln furniture, substantially as herein described with reference to the aforesaid examples. 9.A process for preparing an improved cordierite based kiln furniture, substantially as herein described with reference to the aforesaid examples.

Documents:

267-DEL-2004-Abstract-(06-05-2009).pdf

267-DEL-2004-Abstract-(12-08-2008).pdf

267-del-2004-abstract.pdf

267-DEL-2004-Claims-(08-05-2009).pdf

267-DEL-2004-Claims-(12-08-2008).pdf

267-del-2004-claims.pdf

267-del-2004-correspondence-other.pdf

267-DEL-2004-Correspondence-Others-(08-05-2009).pdf

267-DEL-2004-Correspondence-Others-(12-08-2008).pdf

267-del-2004-correspondence-po.pdf

267-DEL-2004-Description (Complete)-(06-05-2009).pdf

267-del-2004-description (complete)-12-08-2008.pdf

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

267-DEL-2004-Drawings-(12-08-2008).pdf

267-del-2004-drawings.pdf

267-DEL-2004-Form-1-(08-05-2009).pdf

267-DEL-2004-Form-1-(12-08-2008).pdf

267-del-2004-form-1.pdf

267-del-2004-form-13-(12-08-2008).pdf

267-del-2004-form-18.pdf

267-DEL-2004-Form-2-(06-05-2009).pdf

267-DEL-2004-Form-2-(12-08-2008).pdf

267-del-2004-form-2.pdf

267-DEL-2004-Form-26-(08-05-2009).pdf

267-DEL-2004-Form-3-(12-08-2008).pdf

267-del-2004-form-3.pdf

267-DEL-2004-Form-5-(08-05-2009).pdf

267-DEL-2004-Form-5-(12-08-2008).pdf

267-del-2004-form-5.pdf

267-del-2004-gpa.pdf