The Study Of The Conversion Between Potassium Sulfate And Sulfuric Acid To Prepare Potassium Sulfate

Experiment is carried out on the reaction between potassium chloride and potassium bisulfate in both liquid phase and solid phase contraposing the reaction of second step of the mechanism of the art of Mannheim. Combining the results of experiment with thermodynamics proves that the two kinds of material can react with each other in solid phase at room temperature, and the conversion rate of potassium bisulfate increases with the temperature increasing and the granularity diminishing, and the results obtained are different if the temperature is different during the process of preparing potassium sulfate through solid reaction.A process is designed to prepare a kind of fertilizer containing N, K, S, in liquid phase and through two steps, using potassium chloride and sulfuric acid as materiel. This process first produces potassium bisulfate, the middle production, then neutralization the potassium bisulfate liquid with ammonia to produce potassium sulfate and ammonium sulfate. The finally product, compounding fertilizer containing N, K, S, is high enough to be used as non-chloride potassic fertilizer for its much low chloride.In order to probe into the art of separating potassium sulfate and ammonium sulfate, equilibrium studies of the K2SO4-(NH4)2S04-H2O system at 25 are conducted. This obtains that the graph of the system contains the crystal sections of pure potassium sulfate and pure ammonium sulfate. Besides, relevancy and calculation are made based on the equilibrium data of the system using Pitzer theory.Equilibrium studies of NH3-K2SO4-(NH4)2SO4-H2O system at 25 are conducted. Based on the phase diagram, analysis is made on the art of separating potassium sulfate and ammonium sulfate using ammonium as the regent of salting out, and theoretic calculation is also made.In order to discuss the effect of Urea added in the K2SO4-(NH4)2SO4-H2O system on the composition of salted out and regular of solubility, equilibrium studies of the CO(NH2)2-K2SO4-(NH4)2SO4-H2O system at 25 are also conducted. The result shows that the three substances can not form compounds, and the adding of Urea benefits the salting out of pure potassium sulfate. Besides, relevancy and calculation are made based on the equilibrium data of the system.