关键词: 磷石膏钙渣, 不溶性含钾岩石, 钾钙肥, 正交法

Abstract: Taking the insoluble potassium-containing rock and phosphogypsum calcium slag as raw materials，potassium-calcium fertilizer product was prepared after mixing them well，briquetting，pulverizing，and high-temperature calcining etc.Nine experiments designed by orthogonal test were carried out for exploring the influencing factors of potassium-calcium fertilizer preparation，and the optimal process conditions were obtained as follows：the raw material（insoluble potassium-containing rock and phosphogypsum calcium slag） mass ratio was 1∶1.45，calcining time was 30 min，and calcining temperature was 160 ℃.Meanwhile，the reaction process was analyzed with thermal analyzer，so as to get to know the relevant reactions and reaction course.The quality analysis indicated the quality of the product was better than that specified for Grade One in the Enterprise Standard.

Key words: phosphogypsum calcium slag, insoluble potassium-containing rock, potassium-calcium fertilizer, orthogonal design test