Extraction of arsenic(III) and arsenic(V) with Cyanex 925, Cyanex 301 and their mixtures

Cyanex 925, Cyanex 301 and their mixtures were used for extraction of arsenic(III) and arsenic(V) from sulphuric acid solutions. It was found that the extraction efficiency depends on the extractant, the concentration of sulphuric acid and the diluent. The efficiency of extraction increases with an increase of sulphuric acid concentration in the aqueous feed. Cyanex 925 is better for extraction of arsenic(V), while Cyanex 301 and its mixture with Cyanex 925 are better for arsenic(III). Sulphuric acid is coextracted with these extractants. c(III) and arsenic(V) can be stripped with water from loaded Cyanex 925 in the multistage process. In the first stage, the stripping of sulphuric acid is preferred. The stripping of arsenic species with water from loaded Cyanex 301 and its mixture is ineffective.