Abstract: The tail salt and wastewater in potassium chloride production with drying mining method in the sylvine potash mine in the plain area were unable to deal with.In order to solve this problem，a new cycle evaporation and hot-melt crystallization method to produce potassium chloride was proposed.The process route，control indicators，and selection of main equipment were studied through theoretical analysis and practical experiment.Process and equipment conditions which could produce high quality potassium chloride products were achieved in engineering stage.Through the field test，high quality products had been produced.This method will become a new technology for the production of high quality potassium chloride in China and abroad.

Key words: potassium chloride；cycle evaporation and hot-melt crystallization；equipment selection