Abstract: A method of producing soda ash and ammonium sulphate by recycling by-products of Merseberg and Solvay processes includes treating brine with soda ash distiller waste for desulphatation of the brine to obtain gypsum, recovering pure salt from the desulphated brine and utilizing it in manufacture of soda ash in a Solvay process, washing the gypsum and reacting it with liquor ammonia and carbon dioxide to obtain CaCO3 and ammonium sulphate, separating the CaCO3 from the ammonium sulphate solution and recovering solid ammonium sulphate, washing the CaCO3 followed by calcination to generate CO2 and lime, recycling the CO2 in the Solvay process to obtain soda ash, recycling the lime with ammonium chloride generated in the Solvay process to recover ammonia and obtain distiller waste containing CaCl2 as a by-product, recycling the by-product distiller waste for the desulphatation of the brine, and recycling the ammonia recovered.

Abstract: A method of producing soda ash and ammonium sulphate by recycling by-products of Merseberg and Solvay processes includes treating brine with soda ash distiller waste for desulphatation of the brine to obtain gypsum, recovering pure salt from the desulphated brine and utilizing it in manufacture of soda ash in a Solvay process, washing the gypsum and reacting it with liquor ammonia and carbon dioxide to obtain CaCO3 and ammonium sulphate, separating the CaCO3 from the ammonium sulphate solution and recovering solid ammonium sulphate, washing the CaCO3 followed by calcination to generate CO2 and lime, recycling the CO2 in the Solvay process to obtain soda ash, recycling the lime with ammonium chloride generated in the Solvay process to recover ammonia and obtain distiller waste containing CaCl2 as a by-product, recycling the by-product distiller waste for the desulphatation of the brine, and recycling the ammonia recovered.

Abstract: Kainite mixed salt is treated with water to obtain solid schoenite and a schoenite end liquor. The latter is desulphated using recycled CaCl2 and thereafter evaporated to obtain camallite crystals, from which KCl is recovered, and a liquor rich in MgCl2. Gypsum produced during desulphatation is reacted with aqueous ammonia and CO2 to produce ammonium sulphate and calcium carbonate. The calcium carbonate is calcined to obtained CaO and CO2. The CaO is slaked and reacted with the MgCl2-rich liquor generated above to produce slurry of Mg(OH)2 in aqueous CaCl2. To this surface modifying agent is added while hot and, after cooling, the slurry yields surface modified Mg(OH)2. The filtrate rich in CaCl2 is recycled for desulphatation process above. The solid surface modified Mg(OH)2 may he calcined to produced MgO. The schoenite and KCl are reacted to produce solid sulphate of potash.

Abstract: The present invention provides an integrated process for the recovery of sulphate of potash (SOP), ammonium sulphate and surface modified magnesium hydroxide and/or magnesium oxide utilizing kainite mixed salt and ammonia as the only consumable raw materials. The process involves treating kainite mixed salt with water to obtain solid schoenite and a schoenite end liquor. The latter is desulphated using CaCl2 generated in the process itself and thereafter evaporated to obtain carnallite crystals from which KCl is recovered while the liquor rich in MgCl2 serves as a source of MgCL. The gypsum produced during desulphatation is reacted with aqueous ammonia and CO2 to produce ammonium sulphate and calcium carbonate. The calcium carbonate so obtained is then calcined to obtained CaO and CO2. The CaO is then slaked in decarbonated water and reacted with the MgCl2-rich liquor generated above to produce slurry of Mg(OH)2 in aqueous CaCl2.

Abstract: The present invention provides a process for the preparation of finely divided precipitated silica. Finely divided precipitated silica is prepared by neutralization of alkali silicate solution, under continuous stirring, at 60° to 90° C. in presence of alkali metal salt as coagulating agent, in various neutralization steps during which neutralization is interrupted for specific time. Further acidic silica sol, is added until 60 to 80% of total alkali is neutralized. The reaction mixture is then aged at least for 3 minute under continuous agitation, followed by circulation through centrifugal pump at an appropriate rate.

Abstract: The present invention provides a process for the preparation of detergent builder Zeolite-A from Kimberlite tailing generated as solid waste during diamond mining is disclosed. The process comprises, reacting an acid treated Kimberlite tailing with alkali solution to obtain sodium silicate and reacting it with alkaline aluminum source at room temperature and crystallizing at higher temperature to obtain Zeolite-A. The product is useful as builder in detergent formulation.

Abstract: The present invention provides a process for the preparation of finely divided precipitated silica. Finely divided precipitated silica is prepared by neutralization of alkali silicate solution, under continuous stirring, at 60° to 90° C. in presence of alkali metal salt as coagulating agent, in various neutralization steps during which neutralization is interrupted for specific time. Further acidic silica sol, is added until 60 to 80% of total alkali is neutralized. The reaction mixture is then aged at least for 3 minute under continuous agitation, followed by circulation through centrifugal pump at an appropriate rate.

Abstract: In the present invention a process for the preparation of sodium silicate from Kimberlite tailing generated as solid waste during diamond mining is disclosed. The process comprises, reacting Kimberlite tailing with mineral acid to remove acid soluble impurities followed by digesting acid treated Kimberlite tailing with alkali solution in a open or closed system to obtain sodium silicate useful for commercial applications.

Abstract: A new process is described for the preparation of free flowing hydrated amorphous silica from kimberlite tailing—a waste in diamond mining. The process comprises treating of kimberlite with acid, further reacting it with alkali solution to obtain soluble metal silicate solution, which is subsequently neutralized with mineral acid to polymerize silica as insoluble precipitates. The products is useful in rubber, paints as abrasive etc.