Refined salt, common salt includes coarse salt and sun-cured fine salt. That is, refined salt is based on underground natural brine, brine obtained from rock salt water solution mining and brine made of dissolved coarse salt as raw materials, and the soluble impurities are removed by chemical methods, after clarification, and then through evaporation, crystallization, dehydration, drying, and screening. Sun-cured fine salt refers to the process of new brine, thin drying, short-term crystallization, regular activity brine and salt ballast to produce fine salt with uniform particles according to the characteristics of high temperature and frequent precipitation in the sea salt area of southern China.