Evaluation of problematic indigenous phosphate deposits for phosphoric acid manufacture

Abstract

To examine the possible utilization of indigenous phosphate reserves, bench scale studies were under-taken to assess their suitability for phosphoric acid manufacture. It was found out that in spite of few problems, the Silicious phosphate reserves of 2–3 million tons could be utilized for phosphoric acid manufacture, because low sulphuric acid consumption 2.52 ton acid/ton P2O5 and better P2O5 recovery yield (94.71) was achieved. The dolomitic phosphate reserves of 4–5 million tons (having 5–6% MgO) remained problematic, giving low P2O5 recovery yield (89.25) and higher sulphuric acid consumption 4.08 tons acid/ton P2O5. Product acid from the dolomitic reserves upon concentration became paste like at 36–38% P2O5 and therefore, these indigenous dolomitic phosphate reserves could not be utilized for the production of phosphoric acid.