IRON REMOVAL FROM PHOSPHORIC ACID BY A PRECIPITATION PROCESS
Dr. A.K. Ismail
Central Metallurgical R & D Institute
Tuesday, March 17, 1998, 3:30 pm.
Ben Bandy Conference Room
Center for Applied Energy Research
Fertilizer grade phosphoric acid of 50% P2O3 concentration should contain <1.5% fe2o3, otherwise the p2o3 water solubility of the fertilizers prepared from high iron acids will be low. high iron egyptian phosphate concentrates from the two localities were leached with sulphuric acid and recycled phosphoric acid to produce eventually 50% p2o3 phosphoric acid with 4% and 2.7% fe2o3, respectively. these high iron contents were reduced to the industrially accepted limit of 1.5% fe2o3 by precipitation with potassium sulphate. the different factors affecting the efficiency of the precipitation process, e.g., temperature, time, k7o:fe2o3 stoichiometric ratio were systematically studied and the optimum conditions were achieved. clarification of the prepared phosphoric acids from iron-containing sludges was also investigated at different temperatures and durations.