PROCESS OF PRODUCTION OF POTASSIUM SULFATE AND COMPLEX FERTILIZER Russian patent published in 2007 - IPC C01D5/08 C05D1/02 C05G1/10 

FIELD: mineral fertilizers.

SUBSTANCE: invention relates to manufacture of mineral fertilizers and can be used in technology of producing potassium sulfate from potassium chloride and ammonium sulfate in aqueous medium further processing excess solutions into complex fertilizers. Process comprises interaction of ammonium sulfate with potassium chloride slurry to form potassium-ammonium sulfate double salt, treating it with 5-15% potassium salt solution, separating resulting potassium sulfate from mother liquor and returning mother liquor to double salt preparation stage, washing potassium sulfate with potassium salt solution, concentrating solution from potassium-ammonium sulfate double salt preparation stage to form complex fertilizer. Solution is concentrated in shell-tube evaporators at atmospheric pressure to achieve content of salts in solution being concentrated no higher than 50% and then under vacuum at content of solid phase in solution being concentrated 5-20%. Thus obtained slurry is subjected hydroclassification and filtration to separated solid phase, which is used as fertilizer, while liquid phase is returned to concentration stage. Above-mentioned potassium salt solution is, in particular, potassium chloride or potassium sulfate solution.

EFFECT: simplified manufacturing technology.

2 cl, 1 tbl, 3 ex