Solvent extraction and recovery of beryllium from hydrochloric acid solution with naphthenic acid

Abstract

Beryllium is an essential metal for strategic purposes but remains an under-explored element. The separation of beryllium and aluminium and the purification of beryllium hydroxide from a multi-component solution has always been a challenging task in the beryllium industry and offers great research potential in academic fields. In this research, a solvent extraction method was used to purify and recover beryllium from trace impurities. A systematic investigation of the extraction process revealed that under optimal conditions, 98.66% of the beryllium was extracted in a three-stage countercurrent extraction using naphthenic acid (NA) as the extractant. The aluminium, iron and other trace impurities in the organic phase can be scrubbed with 1 mol/L HCl, then 99.27% of the beryllium was stripped with 5 mol/L NaOH by two-stage stripping. Be(OH)2 with a purity of 99.67% was recovered from the stripped beryllium solution by hydrolysis precipitation method. Furthermore, FT-IR analysis and slope analysis demonstrate the mechanism of beryllium extraction with naphthenic acid accompanied by cation exchange. The influence of temperature on the beryllium extraction was investigated and the thermodynamic parameters and the equilibrium constant of the extraction reaction were calculated. Accordingly, a process flowsheet for the separation of beryllium from multiple impurities using naphthenic acid was developed. This process is believed to offer the advantages of high efficiency, recyclability, and a favorable beryllium-aluminium separation effect; presenting a promising new approach to beryllium recovery.