Application and Modification of Phosphate-Bearing Rock in Myanmar as a Potential Mineral Fertilizer

Phosphate rock is the basic material used in all phosphorus fertilizer production. In Myanmar, phosphate rocks are found in Shan State, Mon State, Kayah State and Mandalay Division. In this work, phosphate minerals as phosphorite samples were collected from Thabeikyin area in Mandalay Division. The phosphorite mineral consists of 8.59 % of P2O5 which is modified by wet screening and hydroseparation method to upgrade the phosphate content. Phosphate fertilizers; phosphoric acid, normal and triple superphosphate were prepared from upgraded phosphate powder (14.56 % P2O5) by using concentrated sulphuric acid, H2SO4. Analyses of the prepared phosphate fertilizers were carried out by using conventional and modern instrumental techniques. The prepared phosphoric acid was found to contain 8.74% of P2O5, and the content of primary and secondary nutrients of superphosphates were 15.42% of P2O5, 8.65% of Ca, 11.78 % of S and 7.3 % of K2O in normal superphosphate and 18.94 % P2O5, 8.32 % of Ca and 3.5 % of S in triple superphosphate. The prepared fertilizers were used as mineral inorganic fertilizers in the growth and yield of two selected crops; maize and eggplant on neutral clay soil. Field studies show that the prepared phosphate fertilizers were able to produce a higher percentage yield of vegetables 1981.94 kg/ha for maize and 32291 kg/ha for eggplant than to the control soil. Comparative study of all fertilizers treatment was made and found that after the harvesting stage, triple superphosphate fertilizer treated soil has higher nutrients contents compared to the original control soil. From the field work investigations, it was observed that prepared phosphate fertilizers promote plant growth, aggregate soil particles, improve physical conditions of soil and also enhance the yield of the crops