The word "salt" originally meant "salt water boiled in a container". It is recorded in Shuowen that raw food is called brine and cooked food is called salt. Legend has it that there was a warlord named Su Sha in the era of the Yellow Emperor who boiled brine with seawater and fried it into blue, yellow, white, black and purple salt. Around the time of Shennong (Emperor Yan) and Huangdi, people in China began to make salt. In ancient China, salt was boiled in sea water.
In industry, salt is dried with seawater (also called salt field method) or boiled with well water or salt lake water to precipitate salt crystals. The salt made in this way has many impurities and is called raw salt. Crude salt can be dissolved, precipitated, filtered and evaporated to produce refined salt. In order to eliminate the harm of iodine deficiency and protect the health of citizens, the state adopts comprehensive prevention and control measures based on long-term supply of iodized salt (hereinafter referred to as iodized salt).
Extended data
use
Salt has a wide range of functions: sterilization, tooth protection, beauty, skin cleaning, decontamination, medical treatment, important chemical raw materials, and eating.
chemical property
1. It can react with silver nitrate to generate silver chloride precipitate;
2. The solid salt can be heated with concentrated sulfuric acid to obtain hydrogen chloride gas;
3. Chlorine, hydrogen and sodium hydroxide can be obtained by electrolysis of sodium chloride solution;
4. Sodium and chlorine can be obtained by electrolytic melting of sodium chloride.
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