Source: IMC Global Press Release
With an annual capacity of over ten million short tons, IMC Kalium is among the world's leading and lowest-cost producers of potash. With 1997 net sales and gross margins of $617.4 million and $237.7 million, respectively, the business unit represents 14% of global capacity.
IMC Kalium's potash products were sold in more than 20 countries during 1997. China was the business unit's largest export customer, and offshore sales accounted for 18% of Kalium's shipments during the year. Shipments to U.S. agriculture and industrial users totaled 55% and 13%, respectively. Canadian agriculture and industrial uses accounted for 4% of total shipments.
IMC Kalium operates five mines in Canada and three mines in the U.S. IMC Kalium describes its Belle Plaine, Saskatchewan Canada, solution process mine as "the world's lowest-cost potash mine." It produces a high purity white muriate of potash primarily for industrial markets.
To recover the potash, the Belle Plaine mine uses an Ellicott® B-490 electric powered bucketwheel dredge which has performed reliably for years.
The solution containing dissolved potash is pumped to a refinery where sodium chloride, a by-product of this process, is separated from the potash through the use of computer-controlled evaporation and crystallization techniques.
Concurrently, solution is pumped into a 130-acre cooling pond where additional crystallization occurs and the resulting product is recovered via the Ellicott® floating dredge. Refined potash is de-watered, dried and sized.
The Product – IMC Kalium makes many different potash products, some of them through patented processes. It all starts with crushing the ore which splits into individual particles of potash and salt each less than 3/8 inch in diameter. The crushed ore is then mixed with brine, a salty solution, and pumped through 10-mesh screens, which are about the size of household window screens. Larger particles diverted by the screen go to Heavy Media. Smaller particles drop through and go to Flotation. In a state of the art computerized central control room, fluctuations in the surface operations are continually monitored to ensure quality products.
Heavy Media — In this process, the unseparated larger particles of potash and salt are mixed with brine and magnetite. The specific gravity of this heavy media solution is such that potash will float to the surface and the salts and impurities will sink to the bottom. The floating potash, or coarse size particles, are then washed, de-brined and dried. Some particles, called middlings, are not separated in the heavy media process. They are re-crushed, screened, and directed to flotation.
Flotation — First, insoluble materials and brine are removed from these small particles of ore in a process called desliming. Next, the ore is conditioned with chemical reagents that coat the potash particles. Then it is mixed with brine. This slurry is pumped into flotation tanks and air is injected into the mixture. The coated particles of potash cling to air bubbles and rise to the surface producing the Standard and Special Standard grades. The potash is skimmed off, de-brined and dried. The unaffected salts remain, sinking to the bottom.
Crystallization — Fines, or potash dust, are recovered in dust collectors and in the scavenger flotation process. The fines are dissolved in heated brine and re-crystallized by cooling in three stages, producing larger, purer crystals of potash (White Muriate). These crystals are de-brined and dried. White Muriate can be refined to 99.9 percent pure Refined KCL through re-crystallization. Refined KCl is high in purity and is used in the chemical industry.
Compacting — Granular grade potash is made by the high-pressure compaction of dry Standard and Special Standard sizes into potash flakes which are crushed and screened to size.
One More Step — Most grades undergo a special treatment to protect them during shipping. If a product is too dry, it will tend to get dusty. If too damp, it will tend to cake. To prevent dusting or caking, the product is sprayed with a mixture of oil and amine before loading. White Muriate is only treated with amine; Refined KCl does not need treatment.
Excerpted from an IMC Global Press Release and IMC Kalium's internet homepage