Minerals (Category A)
Potash is the common name given to a group of potassium-bearing minerals such as potassium chlorite and various mined and manufactured salts containing the element potassium. The term potash arose from the traditional practice of producing potassium carbonate, needed for making soap, by the leaching of wood ashes in large iron pots. The ash-like crystalline residue remaining in the large iron pots was called ‘‘pot ash’’. While there are a number of such minerals, only those that are water-soluble are of significant commercial interest. The most common commercial product is potassium chloride (‘‘KCl’’), also known as muriate of potash (‘‘MoP’’) or sylvite, a naturally occurring pink mineral.
According to the IFA, in 2010, approximately 90% of the world’s potash production was used as agricultural fertilizer. Plants deficient in potassium are less resistant to pests and disease, and have poor size, shape, colour, taste and shelf life. Most virgin soils contain adequate potassium to allow farmers to produce average crops. The agricultural cycle of growing and harvesting crops depletes the soil of potassium, nitrogen and phosphate, which need to be replenished in consistent ratios if the soil is to remain fertile. This explains the historical agricultural practice of leaving land fallow for a number of years in order to replenish itself, however, this practise is becoming less practical in today’s world of scarce agricultural land.
Fertilizers replace the nutrients that crops remove from the soil, thereby sustaining or enhancing the yield of crops. Farmers determine the types, quantities and proportions of fertilizer to apply depending on the crop, soil quality, weather conditions, regional farming practices and fertilizer and crop prices. The functions potassium performs cannot be carried out by other nutrients and potash has no commercially viable substitute as a potassium fertilizer source. Besides agriculture, the remainder of potash consumption consists of the manufacture of potassium bearing chemicals, detergents, ceramics, pharmaceuticals, water conditioner and de-icing salt.