Simplot Phosphate Don Plant, Idaho

Next to the site of the former FMC plant in Pocatello is the Don Plant, a large functioning phosphate plant operated by Simplot, with a growing black gypstack behind it. The plant has been operating since 1944, when it was the first fertilizer production facility built by the J.R. Simplot company. Much larger now, it produces more than a million tons a year of phosphate fertilizers, feed phosphates, and industrial products, and employs around 350 people. The Don Plant consumes around 400,000 tons of sulfur annually (which comes by rail), to generate sulfuric acid. The sulfuric acid is mixed with phosphate ore to become phosphoric acid, which is then mixed with ammonia to produce ammonium phosphate, the basic form of fertilizer, and source for more complex fertilizer and phosphate products.