More than 80% of the phosphate produced worldwide is used to produce fertilizers and animal feed supplements. It is necessary to explain that the concentration of P2O5 in phosphate rocks that suitable for chemical fertilizer production should be at least 28%. The concentration of this substance in high quality rocks is 30% or more. Along with P2O5 percentage, high-quality rocks should have a possible acceptance of calcium carbonate (about 5) and less than 4% of Iron and aluminum oxide.
In addition to Phosphorus for fertilizers and food supplements’ production usage, this vital element has applications in food preservatives, in metallurgy, water treatment, in ceramics, detergents, cosmetics, anti-corrosion materials, drugs, insecticides and fungicides.
In this article, we have discussed 3 important applications of phosphate rock.
Phosphate rock’s usage in animal feed supplements production
In order to ensure the supply of phosphorus required by animals and their growth through in term of weight gain, farmers use phosphate food supplements in animal feed. The use of these supplements is critical to the continued industrial production of livestock. The importance of these phosphorus supplements comes from facilitating the metabolic processes in which they play a vital role.
Animal food supplements are non-mineral salts which these salts can be produced by phosphoric acid that is comes from a wet chemical process of rock phosphate (apatite).
The phosphorus in these supplements helps to stabilize and shape the animal’s skeleton and can use these bone structures as a source of phosphorus storage needed in the body’s metabolism (for phosphorus absence periods). Phosphorus stored in bones usually are combinations of calcium-containing hydroxyapatites. Calcium can play a facilitating role in the absorption of substances into the bone. Phosphorus compounds also plays a vital role in the formation of soft tissues.
These compounds also help in the formation of cells, fluids and membranes in soft tissues.
In addition, phosphorus compounds are essential as a dietary supplement for energy supply and as transporters of fatty acids and phospholipids to form amino acids and parts of RNA and DNA.
Phosphate applied in metallurgy
In metallurgy, phosphate can be used to coat metals, especially steel. There are three types of Phosphate coating: manganese phosphate, iron phosphate and zinc phosphate.
The aim of coating with manganese is to prevent corrosion and lubrication, and can be done by immersion. Coating with iron phosphate is the basis of secondary coating and can be applied by immersion and spraying. Zinc phosphate coatings are used to create corrosion resistance, to keep the lubricant holding layer, as well as for paint or second coatings, and can be applied by immersion or spray. Another advantage of this method is that it can be applied on galvanized steel.
Among the three types mentioned above, manganese phosphate coating is very important for the protection of metals due to its high resistance to abrasion. This type is used before painting metals and to increase the hardness of the metal against corrosion.
The manganese phosphate coating forms a crystalline layer on the metal surface that attracts lubricants to the metal surface. Therefore, coating metals with manganese phosphate creates corrosion resistance in the metal and also for lubrication use. Manganese phosphate provides good and continuous protection for the metal surface, especially metals that are subject to abrasion, such as car parts. This is why manganese phosphate have an advantage over zinc phosphate. The same advantage necessitates the use of phosphate manganese coatings for power transfer parts, such as washers, brakes, bolts, other magnet cores, and other items for their smoothest movement.
Phosphate applied in water purification
The use of phosphate in water treatment is done for several reasons, the first is for adjusting the amount of Iron and manganese in the water, the second is to prevent the creation of sediment and removal of existing sediments, the third is to prevent the corrosion of the equipment and fourth to keep the cl amount of the water, constant.
Naturally in the water, manganese and Iron exist as divalent. When water is exposed to air, divalent manganese & Iron are oxidized to form trivalent iron and manganese, colored and soluble in the water. The entry of chlorine into water produces oxides of iron and manganese that are normally insoluble in the water. This causes colored water (iron produces red water and manganese, black water) and residual on industrial equipment and kitchen appliances.
For that using 2 to 4 ppm of a polyphosphate (polyphosphate) such as sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STP), tetrasodium pyrophosphate (TSPP) before chlorine injection, forms a colorless phosphate compound of heavy metals and removes insoluble matters. This reduces the hardness of the water and controls the copper and lead in it. In addition to removing iron, manganese and heavy metals, polyphosphate injection both prevents the deposition of water on transmission pipes and equipment and also removes existing sediments. This protects the equipment and prevents water from corrosion and leaving residual.