Study On Optimum Technical Conditions And Kinetics Of Production Of Potassium Sulphate From Phosphogypsum

In this paper,the technical conditions and kinetics of the production of potassium sulphate from phosphogypsum by two-step method are studied.The factors affecting the ratio of conversion of calcium oxide and potassium oxide in the process of the production of potassium sulphate are examined. With orthogonal experiments,the optimum the technical conditions are obtained under the following conditions:reaction temperature30,reaction time30 min,ratio of ammonium carbonate to gypsum (mol/mol) 1.15,ratio of liquid to solid20:1,ammonia initial mole concentration110%-120%;reaction temperature 15,reaction time100 min,ratio of potassium chloride to ammonium sulphate (mol/mol) 1.05,ammonia initial concentration 27%(wt.) .Meanwhile,the optimum feeding condition of the latter reaction is also studied.The reaction model and the kinetics for the process of the production of ammonium sulphate from phosphogypsum are studied. The results indicate that the leaching kinetics of calcium oxide can be represented by the shrinking core model,the leaching rate expression isthe reaction energy is about39.10kJ/mol.