The process of decomposition of tricalcium phosphate by phosphoric acid with partial replacement of P2O5 to sulfuric acid

Abstract

The article covers the decomposition of tricalcium phosphate with thermal phosphoric acid with a concentration of 20, 30 and 40% P2O5 with the replacement of 10, 20 and 30% P2O5 with sulfuric acid and it has been established that, regardless of the content of ammonium nitrate, magnesium sulfate or their combined presence in phosphoric acid, with an increase in the proportion of sulfuric acid, the content of both total and aqueous forms of SO3 in the acidic pulp increases. The highest results of the decomposition coefficient were obtained when phosphoric acid was evaporated to a content of 32.22-25.77% P2O5 and 5.54-9.76% SO3. The SO3 content of both total and aqueous forms in dried products increases with increasing proportion of sulfuric acid. When the proportion of sulfuric acid increases to 20%, the degree of decomposition increases to 93.45% and to 99.55% when replacing 30% P2O5 with sulfuric acid.