Cory

Overview

PotashCorp owns and operates an underground potash mine at Cory, Saskatchewan, Canada. Production of potash from the Cory mine began in 1968.

Cory potash mine is an underground extractive operation that mines the flat lying potash beds by employing continuous miners. The mine's nameplate capacity is of 1.4 million tonnes per year.

Potash is shipped throughout North America or to ports for offshore delivery.

Potash in granular and standard forms are used as fertilizer. Industrial grade potash is used as water softener and ice melt compounds.

Location

The Cory mine is located in central Saskatchewan, Canada approx 7 km west of the city of Saskatoon.

Saskatchewan - the 'swift flowing river' in Cree language - is a landlocked Canadian prairie province and has a population of 1 million
people mostly living in the southern part of the province, a region characterized by a semi-arid steppe climate - hot summers and windy cold
winters.

The province of Saskatchewan is an important Canadian granary. Beef cattle production and forestry are other important economy  sectors. As for the mining sector Saskatchewan is a world leader in uranium and potash production.  

Only about five per cent of the potash produced in Saskatchewan is consumed in Canada.

About  two-thirds of the exports go to the U.S., where Saskatchewan potash fills approximately 70 per cent of the market demand. The province is also a major supplier to the large Pacific Rim offshore markets: China, Japan, Malaysia, Korea and Indonesia.

Geology & Mineralization

The sylvite (potash) deposits of Saskatchewan formed over 350 million years ago as a result of the final stage of evaporative concentration of
sea water in a middle Devonian sea.

This sea extended from the southern Northwest Territories southeastward through Alberta, southern Saskatchewan, and into Manitoba and North Dakota. Saskatchewan has the majority of the resulting potash deposits as this stage of evaporation was largely confined to the province.

The productive Praire Evaporite Formation comprises a series of flat-lying sedimentary deposits of interbedded sylvite (KCl), carnallite, halite beds and clay and dolomite beds.

Stratigraphy of the region is dominated by three important potash bearing beds: the upper Patience Lake member (exploited by mines employing underground and solution mining methods); the middle Belle Plaine member (solution mining); and the lower Esterhazy member (underground and solution mining).

Cory underground mining rooms are in the potash mineralized zone situated approx 15-20m below the top of the host evaporite salt, the Prairie Evaporite Formation. Depth to the top of the main mineralized zone varies between 100 m and 1,100m, averaging approx 1,020m over most of the mining and exploration area. Mine workings are protected from aquifers in overlying formations by overlying salt and potash beds.

Mining & Operation

The 1,021 meters deep Cory mine is a conventional underground mining operation whereby continuous mining machines are used to excavate the potash ore by the stress-relief mining method, with continuous conveyor belt transport of ore from the mining face to the bottom of the production shaft. 

The mine employs five two-rotor continuous mining machines. Each machine cuts a 3.3 meter by 5.5 meter profile (11 feet by 18 feet wide) and can produce 600 tonnes per hour. Once mined, the ore passes directly from the miner onto a mobile conveyor system which transports the ore to the main conveyor system, where it is transported to underground storage bins and then hoisted to the surface.

Processing

The milling process starts with crushing the ore, which then goes to thermal leach tanks where the KCl is dissolved out of the ore. The brine is clarified and pumped to crystallizers where it is cooled, precipitating white, high-purity KCl. The slurry is centrifuged to remove brine, dried and sent to the screening area.

Potash is graded for application as fertilizer or industrial products such as water softener Softouch and an ice melt; it is stored in four warehouses with a combined capacity of 179,000 tonnes. Cory's products are White Granular SGN 285; White Soluble SGN 30; WSM 0.2 Chicklets.

Cory has an annual capacity of 1.4 million tonnes KCI, and is unique among PotashCorp Potash underground operations because it produces only white muriate of potash products. In 2010 it had 430 active employees.

More than 90 percent of the product from Cory travels by Canadian National and Canadian Pacific railways to centers throughout North America for domestic sales or to ports for delivery offshore.

Environment & Community

More than half of potash sales go offshore. In China, where farmers grow  two or three crops a year, rice is the largest consumer. In Brazil, most of it is used on soybean, sugar cane and corn. In Malaysia, oil palm is the largest consumer of potash. In the US, corn is the major consumer of the agricultural grades of potash.