Producing Potassium Sulfate From Phosphogypsum And Potassium Chloride By Solvent Method

In this paper, some technical conditions of producing potassium sulfate with phosphogypsum and potassium chloride by adding proper solvent are studied.Some main variables affecting the yield of potassium oxide are researched in ammonium solution. The optimized reaction conditions are: initial ammonia solution 35%(wt), reaction temperature 5℃, reaction time 60min, weight ratio of solution to phosphogypsum 6.5 : 1, and mol ratio of phosphogypsum to duple potassium chloride 1.05 : 1. At which the yield of potassium oxide is about 90%, and the quality of the obtained potassium sulfate can not reach related standards.Based on some organic solvents can improve the property of reactant in reaction system and accelerate the rate of reaction, some organic solvents, such as methanol etc, are added into the reaction system, and their effect on the yield of potassium oxide are studied. Results show that methanol, alcohol, isopropanol and acetone can effectively enhance the yield of potassium oxide.The yield of potassium oxide in different reaction system of ammonia-methanol, ammonia-alcohol, ammonia-isopropanol and ammonia-acetone are investigated respectively. Results show that ammonia-isopropanol is the most proper solvent to improve the technical conditions and enhance the yield of potassium oxide. The optimum technical conditions are: initial ammonia solution 30%, isopropanol 7%, reaction temperature 20℃, reaction time 60min, weight ratio of solution to phosphogypsum 5.5 : 1, and mol ratio of phosphogypsum to duple potassium chloride 1.05 : 1, the yield of potassium oxide is over 95%. The quality of the obtained product also reaches related standards, the producing process is simpler and the operational condition is milder than others. Additionally, the solvent can be recycled and reused.In the end, in order to perfect the theory of technology, the actions of solvent that affect solubility of reactant are studied,...