Sea salt in coastal areas, salt fields in the vicinity of the return. Put the seawater in the back and surround it. The sun will evaporate water, and the salt will naturally precipitate and then take the salt.
Inland are mainly salt wells. Brine with high salt content is taken from a well, and the water is evaporated by cooking to get salt.
Ancient salt making
Introduction: Ancient people did not regard natural salt as salt, but called it halogen. The earliest salt collected by ancient people may be sea salt. According to ancient records, when Emperor Yan (referring to Shennong), Su Sha was the first to make salt with seawater, which was called "Su Sha as edible salt" in history. Su Sha is just a legend. In fact, making salt with seawater should be created by ancient ancestors living by the sea after long-term exploration and practice. Perhaps Su Sha popularized the method of making salt, and later generations put the invention right of collecting sea salt on his head.
Pool salt: Lake salt, also known as pool salt, is an inland salt lake. Due to the influence of dry climate, it can naturally generate crystalline salt. The ancient Hedong Salt Pond in history naturally produces salt by wind, sun and evaporation, which is called "Xie Yan", "Luyan" or "Hedong Salt" in history. Hedong salt pond appeared in historical records very early, and the history of salt mining in salt pond may not be later than sea salt.
Now Chaerhan Salt Lake and Chaka Salt Lake in Qinghai Province are rich in this kind of pool salt. Pool salt has the characteristics of natural crystallization. The book "Luo Du Fu" written by the king of Jin Dynasty says that "Hedong Salt Pond is clean and fresh, but natural without cooking", which means that the salt in the pond can be obtained naturally without cooking with fire. Hedong salt pond is located in the Yellow River basin, so it can be seen that ancient ancestors living in the Yellow River basin should have been exposed to this natural pond salt long ago.
It is difficult to determine which comes first, the discovery and consumption of pool salt and sea salt, because sea salt can also crystallize naturally by evaporation from the seawater in stagnant shoals. Ancient ancestors living by the sea also discovered and ate this natural sea salt produced by natural crystallization very early.
Naturally occurring pool salt and sea salt, as well as exposed rock salt on the surface, salt springs leaked by natural overflow and soil salt available everywhere, as long as there are human activities in the areas where these natural salts are produced, ancestors will always find them sooner or later. Just because of the long time, it is difficult to judge the time sequence of pond salt and sea salt discovery.
Well salt: Well salt may appear a little later. According to documents, it first appeared in Bashu area during the Warring States Period. "Huayang Guozhi" said that Li Bing, who is familiar with astronomy, geography and water veins, invented the technology of digging salt wells. While controlling water, libing surveyed the distribution of underground brine and dug a salt well. A number of portrait bricks of salt wells have been unearthed in Chengdu and other places, vividly reappearing the ancient well salt production.