norganic feed phosphates (IFP) are inorganic salts of phosphoric acid. Inorganic feed phosphates are used to meet the phosphorus requirements for animal production: to ensure optimal growth, fertility and bone development.[1][2] Importance The importance of phosphate (PO43−) is reflected in the number of metabolic processes in which phosphorus takes part. By far the greatest amount of phosphorus is used to maintain and support the skeleton. About 80% of an animal's phosphorus is located here, co-precipitated with calcium (Ca) in the form of hydroxy-apatite complex (Ca10(PO4).6(OH)2), where it acts not only as a support system but also as a reservoir of phosphorus. In the soft tissues, phosphorus is a major component of the cells, membranes and body fluids. It also plays an important role in the energy supply. In addition phosphorus acts as a buffer, is involved in phospholipids and fatty acids transfer and in the formation of amino acids as well as DNA and RNA. Therefore, phosphorus is indispensable for animals. Production of IFPs Phosphates occur widely in nature mostly as phosphate rock or fluorapatite. There are large deposits in Russia, USA, North Africa, and China, where they are obtained mostly by open cast mining. Over 85% is used in fertiliser production, and only less than 7% in feed phosphate production. Two types of deposits exist: of volcanic and of sedimentary origin. These crude phosphates cannot be used by animals directly, but must be converted into a form which can be digested by the animal. In addition, the undesired impurities must be removed or lowered to an acceptable level. The starting point of industrial feed phosphate production is technically pure (ortho-) phosphoric acid (H3PO4), which is obtained from the apatite in a wet chemical process. Example of phosphoric acid production Wet-process phosphoric acid is prepared by adding sulfuric acid (H2SO4) to apatite or tricalcium phosphate rock resulting in the following reaction: 3 H2SO4 + Ca3(PO4)2 + 6 H2O ↔ 2 H3PO4 + 3 CaSO4•2H2O Wet-process acid has to be purified by removing fluorine and other undesirable elements to produce feed-grade phosphoric acid.