PROCESS FOR THE REMOVAL OF CADMIUM FROM CRUDE PHOSPHORIC ACID OBTAINED BY DECOMPOSITION OF PHOSPHATIC ORES BY MEANS OF SULFURIC ACID

摘要

The invention is concerned with a process of removing cadmium from acid, especially P2O5-containing solutions by liquid/liquid extraction with the aid of alkyl amine salts that are dissolved in an inert, organic solvent. The cadmium ions are removed from the acid, aqueous phase and are enriched in the organic phase. The cadmium-containing organic phase, subsequently, is re-extracted with an aqueous salt solution, with the cadmium ions migrating from the organic phase into the aqueous phase. The process is particularly suitable for extracting cadmium from concentrated, highly acid aqueous solutions.