Sylvinite is a sedimentary rock made of a mechanical mixture of the minerals sylvite (KCl, or potassium chloride) and halite (NaCl, or sodium chloride).Weiss N.L., SME Mineral Processing Handbook 1985, Page 22-2 Sylvinite is the most important source for the production of potash in North America, Russia and the UK. Most Canadian operations mine sylvinite with proportions of approximately 31% KCl and 66% NaCl with the balance being insoluble clays, anhydrite and in some locations carnallite. Other deposits of sylvinite are located in Belarus, Brazil, France, Germany, Kazakhstan, Slovakia and Spain.

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