Technology for the Production of Sulphate of Potash and Refractory Grade Magnesia from Sea Bittern

Novel improved processes of preparing sulphate of potash & refractory grade magnesia from sea bittern are given.

CSIR-CSMCRI has developed a technology whereby Potassium Sulphate (SOP) can be recovered from mixed salt produced from bittern and MOP as raw material. This technology is suitable for implementation in low humidity (arid) regions

• SOP is a premium two nutrient fertilizer (50% K2O and 18% S) with the highest total nutrient value (68%) and the lowest salt index (46.1) which lowers osmotic effect and thereby reduces the dehydration of plants.
• SOP (K2SO4) offers an advantage over MOP (KCl) currently used by farmers with special focus on Chloride sensitive crops, Dryland agriculture, Sulphur responsive crops, Drip irrigation and areas deficient in K & S.
• Low cost than the present import price to promote its use for better soil and crop management
• Conversion of liquid effluent into value added products such as low sodium salt and magnesia.
• No floatation is used for NaCl separation and recycle system designed leaches away NaCl with simultaneous increase in potash recovery.
• The sea bittern and many of subsoil bitterns in the country are sulphate rich and hence the potash is recovered in form of SOP which is agronomically better fertilizer
• The recovery/yield of potash is high because of integration and recycle of intermediate streams
• The unit operations used are simple and most of the operations are carried out at ambient temperature except drying and calcinations of magnesium hydroxide to form MgO
• The technology developed is environmentally benign.