METHOD AND DEVICE FOR REMOVAL OF CRYSTALLITE IN COMMON SALT PRODUCING PROCESS

摘要

PROBLEM TO BE SOLVED: To efficiently and continuously remove crystallite such as potassium chloride and gypsum except for sodium chloride in a common salt producing mother liquid and bittern. SOLUTION: A porous plate 7 is attached to a filter device 1 to separate a filtrate layer 5 from the mother liquid layer 3, and common salt crystal is supplied to form a filter layer 4. The mother liquid is supplied through a mother liquid supply pipe 2 from the upper part of the filter device 1 and the common salt crystal suspending in the mother liquid is settled to be deposited on the filter layer 4 to form the filter layer together with the preliminarily deposited common salt crystal so as to filter out the crystallite such as potassium chloride and gypsum suspending and floating in the mother liquid. The filtered mother liquid is passed through the filtrate layer 5 and a liquid discharge pipe 6 to be returned to the salt producing process. When the common salt crystal depositing on the filter layer 4 reaches a certain level and detected by a level detector 8, the filter process is stopped and water or brine is supplied through a backward wash water supply pipe 10 to the filter layer 4 to dissolve the common salt crystal and crystallite such as potassium chloride as well as to allow the gypsum particles in the filter layer 4 to be floated by a rising flow and be to discharged through a backward wash discharge pipe 9.