Study On Production Process For Potassium Sulfate From Phosphogypsum By Two Step Conversion

In the article comprehensive utilization of phosphogypsum was summarized ,and the existent problem,the production process,the process conditions of potassium sulfate from phosphogypsum by two step conversion were studied, the best process conditions were ascertained through orthogonal and individual experiments in this article. Potassium sulfate is the central kind of nonchlor- potassium fertilizer especially used by many economical plants. Potassium sulfate is mainly abtained by inlet in china. Because the large number of phosphogypsum exist, the way of potassium sulfate from phosphogypsum by two step conversion is widely studied. But the technological application is very rare.In the article potassium sulfate from phosphogypsum by two step conversion was studied. During the first process, the effects of the reaction time,the reaction temperature,the raw material mole ratio(2NH4+:SO42-),the theoretical concentration of ammonium sulfate ((NH4)2SO4),the amount of water on the conversion of the raw matetial and the loss of ammonium were studied. The optimal conditions were attained through orthogonal and individual experiments: the reaction temperatur was 28℃,the reaction time was 60-90min,2NH4+:SO42- was 1:0.9,the theoretical concentration of ammonium sulfate was 60(g/100g water),the amount of water was 45-52.5(g/100 raw materials).During the second process, the affects of the reaction temperature,the reaction time,the original concentration of ammonium sulfate,the raw matetial mole ratio(SO42-:2K+) on the obtention of potassium Pk+%,Cl-%,NH4+% in the K2SO4 were studied. The optimal conditions were attained through orthogonal and individual experiments: the reaction temperature was 50℃, the reaction time was 60-80min, the original concentration of ammonium sulfate was 60(g/100 water),SO42-:2K+ was 1:1,the amount of water was 10ml.Under these best conditions, the conversion of phosphogypsum was 93.41%, the loss of ammonium was 4.72%, the obtention of potassium was 72.10%, NH4+% was 4.38%,Cl-% was 1.72% in the production.