Extensive potash deposits are found in the southern half of the Province of Saskatchewan. The potash ore is contained in a predominantly rock salt formation known as the Prairie Evaporites. The Prairie Evaporites deposits are bounded by limestone formations and contain the potash beds. Three potash deposits of economic importance occur in Saskatchewan: the Esterhazy, Belle Plaine and Patience Lake members. The Patience Lake member is mined at Colonsay, and the Esterhazy member at Esterhazy. At Belle Plaine all three members are mined. Each of the major potash members contains several potash beds of different thicknesses and grades. The particular beds mined at Colonsay and Esterhazy have a mining height of 11 and 8 feet, respectively.

Esterhazy utilizes shaft mining. Traditional potash shaft mining takes place underground at depths of over 1,000 meters where continuous mining machines cut out the ore face and load it onto conveyor belts. The ore is then crushed, moved to storage bins and hoisted to refineries above ground.

The underground mining operation uses a conventional room and pillar mining technique which consists of a series of equally-spaced rooms interconnected by access tunnels. The ore is mined with a continuous mining machines consisting of rotating heads studded with tungsten carbide steel bits. The continuous miners feed the ore on to an extensible belt conveyor attached to the rear of the miner. The extensible conveyors feed a number of conveyor belts which carry the ore to storage bins. From the storage bins, the ore travels by conveyor to the crushers which reduce the ore into pieces no larger than about six inches in diameter. Following crushing, the ore is transported by conveyor belt to the shaft skips. Each of the two shafts is equipped with a pair of ore-hoisting skips which operate in tandem - one skip moving up to the surface to be unloaded, while the other is on its way down to pick up more ore.

Company continues the expansion of capacity in Potash segment with the K3 shafts at Esterhazy mine. Following ramp-up, these shafts are expected to add an estimated 0.9 million tonnes to annual potash operational capacity. This will provide an infrastructure to move ore from K3 to the K1 and K2 mills. In September 2019, the first four rotor mining machine began cutting ore underground at K3. In December 2019, the second four rotor mining machine began cutting and shaft excavation was completed. A total of 1.4 million tonnes of K3 ore was transported from K3 to K2 via the overland conveyor infrastructure in 2019. As K3 production ramps up, company plans to cease underground mining at K1 and K2 by mid-2022.

The underground workings of the K1 and K2 mine are connected. Four different potash products are produced between the two mills. The four products are classified according to size or grade. These products, in descending order from largest to the smallest, are: Compacted Granular, Natural Crystal Granular, Standard, and White Muriate. Various production processes are utilized in making these products, but all start with crushing the ore into particles less than 9.5 mm. Reduced to this size, the ore separates into individual crystals of either potassium chloride or sodium chloride. The crushed ore is mixed with brine and screened. Particles which are larger than 1.7 mm are diverted to heavy media and particles smaller than 1.7 mm drop through the screen and go on to flotation.

The heavy media process produces Natural Crystal potash. In this process, the particles of potassium chloride and sodium chloride are introduced into a brine solution to which magnetite has been added. ........