It turns out that Anning is an ancient salt capital, and even the name "Anning" is derived from salt. It is said that a cowherd named "A Ning" found salt here, so he named this place "Anning" after him.
The underground salt zone in Anning stretches for dozens of kilometers, and the underground from Zhangjiaba to the salt mine is all salt zone. The salt we eat is vacuum salt, which is made by the unique and advanced salt and nitrate co-production process in Kunming Salt Mine.
There is a video in the exhibition area, where I finally figured out the whole production process through repeated watching:
First, insert the shaft into the underground salt layer, then inject high-pressure water into the salt layer to dissolve the original salt, and then pump out the brine. Sodium carbonate and caustic soda are added to the brine to decompose refined brine and calcium and magnesium ions. The refined brine enters the multi-effect vacuum evaporation device, and the salt and nitrate are quickly separated in the system. Liquefied substances are centrifugally dehydrated by the high-speed operation of the equipment, and a part of solidified solid substances are attached to the inner wall of the equipment in granular form, which is salt. Finally, they are transported to a fluidized bed for drying, cooling and cooling.
Does it sound that simple? But we eat salt every day, but we don't know how it is made. Today we finally figured it out, full of sense of accomplishment! Hmm. How interesting