Lake salt washing and dehydration process The primary salt is hard in texture and large in particle size, with an average particle size of 3.93 mm, which is easy to wash and dehydrate. The commonly used processes are: hydraulic pipeline transportation → hydrocyclone → vibrating screen → scraper of stone casting tank → vibrating centrifuge. The regenerated salt is soft in texture and large in particle size, with an average particle size of 1.84 mm, which is fragile and difficult to recover without dehydration. Generally, spiral grading salt washer → scraper classifier → piston centrifuge is used for washing and dehydration; At the same time, the overflow liquid of each part can be recovered and clarified centrally to reduce the loss of powder salt.

(II) Processing technology of decalcification and salt washing Decalcification and salt washing are unique lake salt products in China. It basically removes gypsum (CaSO4 2H2O), the main impurity in primary lake salt, by roasting first, then soaking and washing, so as to reduce its content to the range allowed by national standards. The technological principle is that when the ore is roasted to 200 ~ 260℃, calcium sulfate dihydrate will be dehydrated into calcium sulfate hemihydrate, and then the roasted ore will be soaked in saturated brine. After friction, calcium sulfate hemihydrate will be dispersed into fine particles (particle size less than 0.08 mm), suspended on the surface of salt water, and then discharged through overflow. Although the particles of sodium salt were also broken at this time, most of them were still at 65438+.

(3) Process of making brine from lake salt for vacuum salt making The raw materials used for vacuum salt making in lake salt production plant (field) are powdered salt, salt cover and corner salt from garbage dump. Powder salt and corner salt contain gypsum and other impurities, while salt cover contains more mud sand and magnesium chloride. Powder salt and primary salt salt cover can be mixed at the ratio of 2: 1, powder salt and regenerated salt salt cover can be mixed at the ratio of 4: 1, and the above raw materials can also be used independently. There are three main processes for making brine from lake salt for vacuum salt making: salt barrel, long salt pond and spiral stirring salt tank.