In-line removal of impurities by ion exchange during a recrystallization step in the phosphoric acid production process

摘要

During the production of phosphoric acid by the HemiDiHydrate process, calcium sulfate dihydrate (DH, gypsum) is formed as a byproduct, which is mainly disposed. Some impurities from the feedstock, like lanthanides and some heavy metals, mainly end up in the gypsum.