Potash Characteristics

When customers are deciding what type of potash to buy, traditionally, they are concerned about four specific things: the potassium chloride (KCl) content reported as potassium oxide (K2O) value, sodium chloride content, size, and colour.?

Potassium Oxide (K2O) Value?

The K content of KCl fertilizer is frequently expressed on the basis of its K2O value. Canpotex potash, that is primary used in agriculture as a fertilizer, guarantees a minimum 60% K2O. Our Industrial and Agricultural white grades guarantee a minimum 62% K2O. Ultimately, the higher the K2O percentage, the higher purity-grade of potash.

The K part of potash provides the agronomic benefit for the plant.?

Sodium Chloride (NaCl) Content

The amount of sodium chloride (otherwise known as common table salt) varies in potash. Sodium chloride is the largest quantity impurity present in potash.?

Canpotex's Industrial potash grades are purer than its Agricultural grades, because we guarantee a maximum NaCl level in those grades for our customers.


The size of potash particle is important for agricultural customers, especially when potash will be bulk blended (primarily with nitrogen and phosphate). For the Industrial grades, smaller particles are often preferred because they are dissolved faster for use in chemical manufacturing.?

Size is also important when the potash will be distributed using mechanical measures, such as specific farm equipment used to spread the potash.

SGN and UI are recognized sizing measurements:

  • SGN (Size Guide Number) refers to the calculated diameter of the mean particle size. The higher the SGN, the larger the mean diameter of the product.
  • UI (Uniformity Index) refers to the unit of measure that indicates the consistency of particle sizing. This is primarily important in granular grades. The higher the UI, the more uniform the product.


The colour of potash varies (from white to dark red) based on its iron content. Typically, potash that contains more iron will be more reddish in colour. Our potash grades that range from light pink to dark red in colour, do so because of the different levels of iron oxide naturally occurring in the potash ore.?

White-coloured potash is a result of the potash being mined and further processed in a specific way, which removes the iron oxide.?

Overall, the colour of potash has no agronomic significance. Whether red or white, Canpotex potash is an excellent source of potassium chloride—a vital crop nutrient. Visible variation in colour between our potash is expected, which is natural and typical of Canpotex potash.