Can be use for cooking and make-up. Although many refined salts are also derived from sea salt, they are not marked as sea salt, and the particles are fine. Generally, sea salt particles on the market are larger and much more expensive than ordinary salt. Compared with refined salt, the main component of sea salt is also sodium chloride, and there is no evidence that it has special benefits to human body. Moreover, there may be iodine deficiency in sea salt, so it is not suitable to completely replace iodized salt.
Extended data
Salt making is one of the oldest chemical processes in the world.
Salt can be divided into sea salt, lake salt, well salt and rock salt according to their sources.
Among the sources of salt production in the world, rock salt accounts for 465,438+0%, underground brine and salt lake account for 29%, and sea salt accounts for 26%.
Among them, seawater and halite are two main sources.
Rock salt is a mineral, which is formed by evaporation and deposition of closed lakes in internal flowing basins.
The bedrock of rock salt can extend in a wide area underground, with a thickness of 350 meters.
There is a huge bedrock in the underground of the United States and Canada, starting from the Appalachian Basin in western New York, passing through the underground of Ontario, and covering most underground areas of Michigan.
There are underground salt mines around Cheshire and Worcestershire in England.
Salzburg, Austria, is called "Yancheng" because of its salt mines.
There is a salt mine with a thickness of 100-200m underground in Huai 'an City, Jiangsu Province, China, and its reserves rank first in the world.
The salinity of seawater is about 35‰, which is an inexhaustible salt source.
Sea salt can be produced naturally or through processing technology, which can be divided into seawater evaporation and ion exchange membrane electrodialysis (EDI).
Seawater evaporation is a traditional construction method, which is affected by sunshine or rainfall and needs to occupy a wide salt field.
Ion-exchange membrane electrodialysis is a kind of seawater desalination technology, which needs a lot of energy, but it can have a stable output.
In marine countries with large evaporation and small rainfall, seawater evaporation is the first choice for salt production.
Let the salt pan be filled with seawater first, and salt crystals can be obtained from it after seawater evaporates.
Because some algae and microorganisms grow well in high salinity environment, sometimes these salt fields have very bright colors.
The annual output of crude salt in Yanchang, the largest Yantian Road in China, is more than 2.4 million tons, accounting for 7% of the total national crude salt output and 1/4 of the total sea salt output.
The production of well salt in China began at the end of the Warring States period, and Li Bing was the founder. Salt in other places is obtained by mining huge sediments that evaporated from oceans and lakes millions of years ago.
These salt mines can be mined directly as rock salt, or they can be pumped into the deposit and dissolved into solution before refining.
The salt collected in the above two cases can be purified by mechanical evaporation of salt.
Traditionally, this process is carried out in an open pot, and the evaporation rate is increased by heating.
Recently, this process will be carried out in a vacuum pot.
Baidu encyclopedia-Haiyan