Salt is almost always treated with additives (magnesium carbonate, magnesium oxide, calcium silicate) to prevent it from absorbing moisture and ensure that it remains free flowing and granular.
Three theories were put forward by some researcher. 1 low nutrition and low calcium 2 free radical 3 magnesium theory.
最近有学者指出地氟病的发病机制主要有以下三方面学说：1低营养低钙学说，2自由基学说，3镁学说。
3
This paper mainly solved the extraction of sodium salt, potassium salt and the calcium salt by conducting research on the technique of comprehensive utilization of magnesium-free mother liquor.