What is a Gyp Stack?
The Redwater plant produces phosphate nutrient products used by farmers to increase yields and condition soils for growing grain, corn and other food crops. Approximately 620,000 tonnes of our phosphate products are distributed throughout Western Canada and the Pacific Northwest annually. One of the main raw materials we use is phosphate rock, currently mined in Ontario, and shipped by rail to our Redwater plant. The phosphate rock is mixed with sulfuric acid to dissolve the phosphorous. The reaction produces phosphoric acid and solid calcium sulfate, commonly known as “phosphogypsum”. The phosphoric acid is used in fertilizer production; the phosphogypsum is a by-product and must be stored. For every metric ton of phosphate rock used in the process, approximately one and a half metric tons of phosphogypsum is produced. In 2002, this amounted to 1.7 million tonnes of phosphogypsum produced. This by-product is mixed with water to form a slurry and pumped into a phosphogypsum pond as a “