<p>The subject of the invention is method of NPK and PK fertilizers production by feeding to the granulation process superphosphate slurry, so-called MSP slurry, together with MAP slurry or instead of MAP slurry, in amount to 100% by weight of P 2 O 5 contained in fertilizer. Total participation of MAP and MSP slurry amounts from 5 to 80 % by weight of fertilizer. MSP slurry is a suspension containing mixture of mono- and dicalcium phosphates and calcium sulphate in saturated solution by above salts above mentioned and free phosphoric acid. MSP superphosphate slurry is obtained in the reaction between phosphate rock and mixture of phosphoric and sulfuric acids in mutual ratio: from 40 to 63% by weight of phosphate rock, from 37 to 60% by weight of mixture of phosphoric and sulfuric acids. The amounts of the acids are given as 100-percent acids.</p>
