The difference between the three kinds of salt is as follows: mineral salt: as the name suggests, it is salt mined from salt mines. Mineral salt has been deposited underground for thousands of years, and the ancient industry was underdeveloped and the pollution was less, so the purity of mineral salt was good and the impurities were less.
Sea salt: It comes from the sea, and the sea water is dried after certain treatment. Because human pollution affects the ocean, its purity is not as good as mineral salt. Sea salt is also rich in minerals and trace elements.
Salt: It is the most stable salt for acid and alkali plants. In addition, if the concentration of salt is high enough, it can play a bactericidal role.
At present, the proportion of sea salt and mineral salt in China is about 46% and 44%, and the rest 10% is lake salt.
Salt: NaCl, the main component of salt, ionic compound. Pure sodium chloride crystal is a colorless and transparent cubic crystal. Due to the existence of impurities, sodium chloride is generally a white cubic crystal or a fine-grained powder with a specific gravity of 2. 165(25/4℃), a melting point of 80 1℃, a boiling point of 1442℃ and a relative density of 2. 165g/cm3. Soluble in water or glycerol, insoluble in ethanol and hydrochloric acid, neutral and conductive in aqueous solution. Solid sodium chloride is not conductive, but molten sodium chloride is conductive. With the increase of temperature, the solubility in water increased slightly. When the temperature is lower than 0. 15℃, NaCl dihydrate can be obtained. Sodium chloride is abundant in seawater and natural salt lakes, and can be used to produce chlorine, hydrogen, hydrochloric acid, sodium hydroxide, chlorate, hypochlorite, bleaching powder and metallic sodium. It is an important chemical raw material. It can be used for seasoning food and curing fish and vegetables, as well as salting out soap and tanning leather. Highly refined sodium chloride can be made into physiological saline for clinical treatment and physiological experiments, such as sodium loss, water loss and blood loss. Sodium chloride can be prepared by concentrating crystallized seawater or natural salt lake or salt well water.
Salt has a wide range of functions: sterilization, tooth protection, beauty, skin cleaning, decontamination, medical treatment, important chemical raw materials, and eating.