Phosphoric acid process with high circulation rates

摘要

Phosphoric acid is prepared from phosphate rock and sulfuric acid by using a reaction train comprising a dissolving slurry and a crystallization slurry maintained at different sulfate levels. Both inter and intra vessel circulation are used at high rates to minimize reagent concentration gradients and temperature gradients and provide a suitable crystallization environment. Preferably, the intra vessel circulation is substantially in plug flow, as through a draft tube.