The ore is never pure enough and must be beneficiated and purified. Some potassium is also found as brines in lakes or in sub-surface deposits. After it is mined, the potassium chloride is separated from the mixture to produce a granular fertilizer.
Potash deposits are even less evenly distributed in the earth’s crust than phosphate deposits. Only 12 countries mine potash; in 2002, six of those countries (Canada, Russia, Belarus, Germany, Israel and Jordan) produced nearly 90 percent of the world’s aggregate production of approximately 24 million tons, measured as K2O.
Canada is the source of one-third of global production. The known reserves (defined as mineral deposits of established extension that are, or could be, profitably mined under prevailing conditions of costs, market prices and technologies) of potash amount to more than 9 billion tons. More than 70 percent of this amount is located in Saskatchewan in Canada.
Potassium chloride (also referred to as muriate of potash or MOP) – containing 40-60 percent potash.
Potassium sulfate (or sulfate of potash or SOP) – containing 50 percent potash, potassium sulfate is used for plants that are particularly sensitive to chlorine, such as potatoes, fruits, vegetables and tobacco.
Sulfate of potash magnesia or potassium magnesium sulfate – for use in magnesium-deficient soils.