Process for preparing detergent builder zeolite-a from kimberlite tailings

A process for preparing detergent builder Zeolite-A from Kimberlite tailing generated as solid waste during diamond mining and having chemical constituents in the range SiO2 30-32%, Al2O3 2-5%, TiO2 5-8%, CaO 8-10%, MgO 20-24%, Fe2O3 5-11% and loss on ignition 13-15%, the process comprising passing Kimberlite tailing through 60 mesh screen and treating the sieved fraction with 1 to 10 N hydrochloric or nitric acid at temperature in the range of 75 to 100° C. for a specified period in the range of 1 to 6 hours to remove acid soluble impurities, recovering acid treated Kimberlite tailing after washing with demineralized water till free from acid and digesting acid treated Kimberlite tailing having chemical composition in the range of SiO2 73-77%, R2O3 3-4%, TiO2 10-13%, CaO+MgO 0.5-1.0% and loss on ignition 5-6% with an alkali comprising a sodium hydroxide solution having concentration in the range 6 to 10 percent at 95-200° C. for a period of 1 to 6 hours either in an open vessel or in a closed system to prepare sodium silicate having 13-21% SiO2 and 4-7% Na2O with molar ratio of SiO2:Na2O=2.8-3.3, adjusting the Na2O/SiO2 mole ratio in the range of 0.5 to 0.8 and H2O/Na2O mole ratio in the range of 30 to 40 by adding sodium hydroxide solution, dosing a sodium aluminate solution prepared separately by dissolving required quantity of aluminum trihydrate in sodium hydroxide solution at 70 to 100° C. so as to obtain Na2O/Al2O3 mole ratio in the range of 1.8 to 2.2 and H2O/Na2O mole ratio in the range 25 to 30, to the sodium silicate solution under continuous sting at ambient temperature in the range of 25 to 40° C. and in a specified period in the range of 30 to 120 minutes to form aluminosilicate gel, heating the gel having a composition 3.2±0.1 Na2O:

• 2.0±0.2 SiO2:
• Al2O3:
• 105±10 H2O in a temperature range of 70 to 100° C. for a time in the range of 1 to 5 hours there by converting the amorphous aluminosilicate gel to crystalline Zeolite-A, cooling the product slurry to <50° C. and separating product by filtration, washing the wet cake of the product with demineralized water till pH of wash water is between 11 and 10.5, drying washed wet cake of product containing 40 to 50% moisture in a dryer at 110° C. for 5 to 7 hours followed by pulverizing dried lumps of the product using micro or impact type pulverizer to obtain Zeolite A as a fine powder.