Manufacture of simple superphosphate from Tahoua rock phosphate

In this work, we used the rock phosphate Tahoua sample. It underwent several processing steps before obtaining the raw phosphate powder. However it presents a weak solubility and this weakness is due to the presence of metal oxides in the phosphate. Indeed, rock phosphate is the raw material of the fertilizer industry and it is rarely used directly as is, because of its low assimilability by plants. To solve this problem, we have transformed merchantable phosphate into phosphate fertilizers directly and easily assimilated. The objective of this work is to manufacture a simple superphosphate fertilizer (SSP) and study its solubility in perchloric acid and water. We manufactured a simple superphosphate based on crushed and ground Tahoua merchant phosphate. The studied granulometries are: (inferior to 63µm; 63µm; 100µm; 160µm). The attack was made with sulfuric acid (H2SO4) with a variation of temperatures (40°C; 60°C and 80°C) in order to determine the effects of the granulometrys and temperatures. The results obtained for granulometries (inferior to 63µm; 63µm; 100µm; 160µm) with ripening times (5th day, 12 days) and at these different temperatures are respectively 40°C (15.79%; 14.77%; 17.35%; 15.93%); 60°C (18.58% ; 8.32%; 8.32%; 12.67%); 80°C (16.40%; 19.73%; 16.54%; 21.56%) in the perchloric acid solution and 40°C (5.74%; 8.32%; 8.32%; 12.67%); 60°C (7.64%; 8.32%; 8.73%; 7.91%); 80°C (11.86%; 12.67%; 11.04%; 6.55%) in water These results allowed us to conclude that Tahoua rock phosphate is suitable for the manufacture of simple superphosphate fertilizer at 80°C (total P2O5 equals 21.54%) and at 60°C (and a soluble P2O5 equal to 12.87%) for a particle size of 160µm.