Little known outside Florida, phosphate mining has been a major contributor to the regional economy since the 1930s, accounting for 75 percent of phosphate used in the United States, mostly in fertilizer.
Two large companies, Mosaic Fertilizer and CF Industry Holdings, operate most of the open pit phosphate mines in Hardee and Polk Counties. At the mines, cranes dig a mixture of phosphate, sand and clay that is generally below 15 to 30 feet of topsoil and sand. The material is dumped into a nearby pit and blasted with high pressure water to create a slurry that is pumped through pipes to a plant for final separation of the phosphate. The leftover clay-water mixture is dumped into other pits that become ponds. Today, the ponds dot the landscape. The sand is used to help fill the pits after mining.
