Plants: Central Florida Phosphate Operations
The phosphate fertilizer production process includes mining phosphate rock, beneficiating (upgrading) that rock, shipping it to the chemical processing plant, processing the rock to convert the nutrients into available plant food, and then shipping the finished fertilizer products to domestic and international customers.
- Mining: mines in Florida, home to CF Industries’ phosphate operations, produce approximately 75 percent of the nation’s—and 25 percent of the world’s—phosphate rock supply. Rock deposits are generally buried from five to fifty feet below the earth’s surface. Rock is mined using large draglines, which can dig as much as 75 tons in a single load.
At CF Industries’ phosphate rock mine and beneficiation plant in Hardee County, dragline operators first remove the surface layer of “overburden,” then mine the ore body, known as “matrix.” The dragline dumps the matrix into a collecting well, where high-pressure water jets break it down into a slurry. The slurry is then pumped to the beneficiation plant.
- Beneficiating: the matrix typically contains approximately 25 percent phosphate rock, 25 percent waste clay, and 50 percent silica sand. Beneficiation separates the clay and sand from the phosphate rock, producing pebble and a finer phosphate known as “concentrate.”
- Phosphate Rock Shipping: phosphate rock is shipped by rail from the beneficiation plant to CF Industries’ chemical processing plant in Plant City, where the company uses two basic processes to chemically process the phosphate rock into dry phosphate fertilizers: phosphoric acid production and phosphate fertilizer production.
- Chemical Processing: at the Plant City chemical plant, CF Industries converts liquid sulfur, water, and air into sulfuric acid. Phosphate rock and sulfuric acid are mixed, forming phosphoric acid and gypsum. Phosphoric acid is a highly concentrated form of phosphorous and is the basis of all phosphate fertilizers. Phosphoric acid is reacted with anhydrous ammonia, brought into Florida through CF Industries’ Tampa Ammonia Terminal, in a two-step process to produce granules of Diammonium Phosphate (DAP) or Monoammonium Phosphate (MAP), the most-used phosphate fertilizer products.
- Product Distribution: DAP and MAP are shipped from the Plant City facility by rail and truck. Some of the production is shipped to the company’s Tampa Terminal and Warehouse, where it is loaded onto barges and vessels. From Tampa, the product can serve domestic or export markets.