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 relates to a process for removing cadmium from acidic, in particular P2O5-containing solutions by liquid-liquid extraction with the aid of alkylamine salts which are dissolved in an inert organic solvent. The cadmium ions are removed from the acidic aqueous phase and enriched in the organic phase. The cadmium-containing organic phase is then re-extracted with an aqueous salt solution, the cadmium ions migrating from the organic phase into the aqueous phase. The process is particularly suitable for the extraction of cadmium from concentrated strongly acidic aqueous solutions.