The majority of fertilizer grade potash is processed using flotation processing. A second method, crystallization, is used mainly to produce Industrial and specialty-grade (white) potash.
In both methods, impurities are removed from the potash ore, and the size of granules can be changed, but the final product is the same naturally-occurring mineral as was originally mined.
In floatation processing, potash ore is crushed and placed in a solution. Through a combination of sieving, centrifuging and floating, the impurities are removed, leaving behind the valuable components of potash. Excess moisture is then removed and the material is sent to a compaction plant to create the desired granule size of the final potash product.
The crystallization process involves heating the solution to dissolve potash, which is then sent through a series of crystallizers, which precipitates high-purity Industrial potash.
Most grades of potash undergo a special treatment to protect them during shipping. Reagents are applied to minimize dust and prevent caking during dispatch to storage and/or during railcar loading.