Process for the reduction of the heavy metal content in raw phosphate.

摘要

1. A process for treating crude phosphate by an acid lowering the heavy metal content, especially the content of cadmium compounds, wherein a) an acid is added to the crude phosphate in the presence of Ca-ions up to a pH value of 0.2 to 3 whereby the Ca-ions are formed from the crude phosphate by acid treatment and/or additional Ca-ions are added and a weight ratio of the crude phosphate to the acid containing Ca-ions of 0.3 to 3.0:1 is adjusted, and b) the crude phosphate having a lowered heavy metal content is separated from the acid containing the Ca-ions and that of heavy metals.