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.