The features of clay-saline (potassium and sodium chlorides) dispersions flocculation using polyacrylamide and its cationic and anionic copolymers are described, including the effect of flocculant concentration, solid concentration in dispersion, method of polymer dissolution in water or saline solution on the sedimentation rate and flocculation density. It is shown that polyacrylamide has the highest flocculating ability towards clay-saline dispersion, and cationic copolymers – the lowest effect. It is shown that in concentrated clay dispersions flocculation starts at lower flocculant dose rate and occurs in a narrow range of polymer concentrations. The sedimentation rate of clay in salt dispersion increases by 15–20% with the introduction of flocculant in two stages, and by 50% times – with consequent dosing of cationic and anionic flocculant. It is also stated that polymer solutions prepared using concentrated salt solutions of potassium and sodium chlorides provide a higher efficiency of clay flocculation in comparison with solutions of polymers prepared in water.

The process of potassium sulfate crystallization from aqueous solutions in the presence of organic modifiers containing phosphonic, phosphate, sulfonic, sulfate and carboxyl functional groups has been studied. It is shown that the introduction of organic substances has an inhibitory effect on the formation of potassium sulfate crystals. Modifiers containing sulfonic, sulfate and phosphonic functional groups have the greatest inhibitory effect. The effectiveness of modifiers containing carboxyl groups is significantly lower. The formation of stable supersaturated solutions of potassium sulfate is achieved by introducing organic modifiers in an amount of 0.25 – 0.50%.