Purification of Beryllium by Acetylacetone-EDTA Solvent Extraction

Abstract

A solvent extraction process for the purification of beryllium has been described previously in which ethylenediamine tetraacetic acid (EDTA) is used as a masking or sequestering agent to retain metallic impurities in an aqueous phase from which the beryllium is extractad into au organic phase (CCU) as a complex with acetylacetone (HX). Subsequent back extraction of the beryllium into nitric acid, follovved by the precipitation of beryllium hydroxide, filtering, drying, and calcination to 1000°C, has given BeO products of high purity. Approximately 1300 gm of BeO have been preparad in 23 batches. The average impurity content of these batches (based on BeO) has been very low—less than 10 ppm each of Ca, Al. and Si; less than 5 ppm each of Fe, Mg, and Cu; all other metallic impurities were below the level of detection by the spectrographic method of analysis. The maximum impurity contents for individual metallic species among all these batches were, in ppm BeO, Al-9, Ca-10, Cu-13, ^Ig-5, Fe-10, Si-11; these are considered to reflect the difficulty of keeping small batches free from contamination by dusty air and should not occur in larger operations.