Phosphate is a kind or rocks which contains high amounts of phosphate bearing minerals. The phosphate content or grade of PRis conventionally expressed as phosphorus pentoxide (P2O5). In some low-grade commercial deposits, this may be as low as 4 percent. In the phosphate industry, the phosphate content of the rock is usually expressed as tricalcium phosphate and traditionally referred to as bone phosphate of lime (P2O5 × 2.1853 = BPL). The latter term is reminiscent of the time when bones were the principal source of phosphate in the fertilizer industry. Manufacturers of phosphoric acid
and P fertilizers normally stipulate a minimum content of 28 percent P2O5, and most marketed grades of PR contain more than 30 percent P2O5 (65 percent BPL).
Phosphate & Fertilizers Industry
Phosphate Rocks can be used either as raw materials in the industrial manufacture of fertilizers or as Primary sources for direct application in agriculture. The fertilizer industry consumes about 90 percent of world Phosphate Rock production, fertilizer producers obtain phosphorus only from phosphate rock there are no substitute sources, also used for industrial purposes and for the production of animal feed supplements and food products. Phosphate rocks also used as primary material to produce Phosphoric acid.