Potassium salts e.g. potassium chloride or sulphate purificn. - by compacting to uniform density, comminuting, and washing with potassium salt soln. less than 50 per cent satd. with sodium chloride

摘要

Process reduces the NaCl content of a potassium salt in the form of a crystalline aggregate contg. an excess of ca 0.8 wt.% CaCl as embedded crystals or enclosed NaCl soln. The crystalline aggregate is compressed or compacted to produce a cake of uniform density, then the crystalline material (with a particle dia. less than ca 1.5mm) is introduced into a leaching zone in admixture with a soln. which contains a further amt. of the potassium salt and is less than 50% satd. with CaCl. in order to extract the NaCl from thepotassium salt crystal aggregates and yield a crystalline potassium salt prod. contg. less than ca 0.35 wt.% NaCl, the crystalline potassium salt prod. being subsequently removed from the leaching zone and sepd. from the soln. Conversion of agricultural grade potassium salts (esp. potassium chloride and potassium sulphate) into industrial grade salts without the need for recrystallisation.