The intracratonic Elk Point Basin is a major sedimentary geological feature in western Canada and the northwest USA. It contains one of the world's largest stratabound potash resources. The nature of this type of deposition is largely continuous with predictable depths and thickness. It is estimated to host >5 billion tonnes of ore (Orris, 2014) and is mined at a number of locations, including Mosaic's Belle Plaine. Esterhazy and C'olonsay potash facilities. Saskatchewan potash represents almost 25% of the global potash production due to its relatively low-cost, bulk tonnage mining methods. (Orris. 2014).

The Prairie Evaporite hosts rich deposits of evaporite minerals including halite (NaCl), sylvite (KCl) and locally, carnallite. There arc a number of insoluble clay-rich zones that arc not recovered in the solution mining process. The potash deposit at Belle Plaine is uniform and laterally continuous. Solution mining methods can more easily accommodate any local variations in geological condition due to the non-selective concentrate mining process.

Three potash deposits of economic importance occur in Saskatchewan: the Esterhazy, Belle Plaine and Patience Lake Members. The Belle Plaine Potash Facility is a solution mine that recovers potash from each of the Estcrhazy, Belle Plaine and Patience Lake Members. The following is a summary of the key stratigraphic units for the Belle Plaine Potash Facility:

• Patience Lake Member: The uppermost member of the Prairie Evaporite Formation with potash production potential. Between the top of the Prairie Evaporite Formation and the top of the Patience Lake Member is a 0 to 45 ft. (0 to 14 tn) thick unit of halite with clay bands called the salt back. The sylvite-rich horizons within the Patience Lake Member arc mined using conventional underground mining techniques in the Saskatoon. Saskatchewan area and by solution mining techniques at Belle Plaine.

• Belle Plaine Member: The Belle Plaine Member underlies the Patience Lake Member and is separated from it by a zone of low grade sylvinitc. The Belle Plaine Member is mined using solution mining techniques at Belle Plaine.

• Esterhazy Member: The Esterhazy Member is separated from the Belle Plaine Member by the White Bear Marker Beds, a sequence of clay scams, low-grade sylvinitc, and halite. The Esterhazy Member is mined using conventional underground techniques at Mosaic's Esterhazy Potash Facility in southeastern Saskatchewan and by solution mining techniques at Belle Plaine.

Mosaic Belle Plaine is operated as a solution mine rather than the conventional underground mine that uses mining machines and miners to bring solid ore to the surface. In the solution mine raw ore is extracted at remote cluster sites by injecting water underground into potash deposits and recovering the saturated solution to the surface.

Similar to conventional potash mines, the by-products of Belle Plaine consist of salt (NaCl), clays (fines) and brine. Belle Plaine can, however, dispose of resaturated salts into the mine cavities as there are no underground workings.

This results in a much smaller accumulation of salts above ground in the tailings management area (TMA).

The Belle Plaine Facility utilizes an underground, solution mining process where paired wells are directionally drilled, cased, and cemented to the base of the potash beds. Solution mining techniques are used to target mining of the potash (“KCl”) bedding while minimizing mining of the halite salts (“NaCl”). Current mining practices allow for all three potash beds in the formation to be mined. During the mining process, the two wells are mined to connect with each other underground, allowing one well to become the feed well and the other well to become the return well. Water, or a weaker brine, is injected into the cavern to return a salt saturated and potash rich brine. This fluid is pumped through pipelines from the mining area and sent to the refinery complex as raw feed for further processing. The total life cycle of each cavern is approximately 25 years. Once the potash recovery is exhausted, each cavern is plugged and decommissioned in accordance with local government regulations.

The mining area capability is scheduled to ramp up to support a finished tonnage projection of 3.0 million tonnes per year and will do so until drilling is completed in the year 2066 at which point there is a ramp down in production until 2084.

The 2021 Belle Plaine LOM plan based on mineral reserves has an expected total mine life of 63 years, ending in 2084 and yielding an estimated total of 166.85 million tonnes of final product KCl.

The Belle Plaine processing plant consists of a refinery and cooling pond.

The Belle Plaine Facility processing plant receives KCl-NaCl rich brine, known as raw feed, from the mine and achieves KCl recovery through the refinery and cooling pond areas.

The refinery subjects the raw feed brine from the mining area to changing temperatures and pressures that selectively precipitates the NaCl and then the KCl out of solution in different stages of the process. Selective drop out of NaCl is achieved through two parallel lines of evaporators that heat the brine with steam, that is generated on-site through natural gas fired boilers. The heating of the raw feed brine results in water liberation, causing NaCl to concentrate in the brine and then precipitate out of solution. After the brine is conditioned in the evaporator circuit, it is pumped to the thickener area for clarification and then pumped into a crystallizer circuit for KCl recovery. The crystallizer circuit su ........