Study On Preparation Of Instant Dissolved Potassium Sulfate

The market demand and price space of instant potassium sulphate are very large and have high added value.The suitable process conditions were obtained after the experiments of purifying agricultural potassium sulfate by the method of “heat dissolution and cold crystallization”: dissolving at 80? for 10 minutes with the initial liquid-solid ratio of 4.5:1 and the cycle liquid-solid ratio of 11.8:1,crystallization at 25? for 12 hours.Under this experimental condition,the once yield was nearly 34% and the cycle yield was about 90%.After purification,the purity of potassium sulfate product was improved from 92.6% to 99%,and water-insoluble content was decreased to less than 0.1%.The instant dissolved potassium sulfate was developed by using the purified potassium sulfate as raw material.Through a lot of screening experiments,the environment-friendly additives combination “0.5%STPP + 4%UP” and additives adding system was determined.At the dissolution conditions of room temperature(25-29?),stirring speed of 150r/min,and liquid-solid ratio of 10:1,the dissolving time of instant samples was 4.5 minutes,with appropriate particle size prepared by wether the solvent method or the mechanical mixing method.The product was dissolved in 100%,leaving the transparent solution.Solubility of the product was the same with other international high quality products.