The salt used in food production is the end product of a two-step process of extraction and refinement called Solution Mining and Brine Evaporation. Most of the artificial brines are obtained by pumping water into underground salt beds. A considerable amount of brine itself is used directly in industrial countries. Evaporation is the reverse of this process. When an aqueous solution of several salts (seawater, for example) is evaporated, each salt precipitates as it reaches its point of saturation in the solution. Thus, the different salts in seawater will precipitate at different times, forming layers on the bottom of the evaporating pond.
