Extraction of yttrium

Abstract

The demand for yttrium and other rare metals in many branches of technology, as well as in the chemical industry, is growing every year. The Republic of Kazakhstan possesses raw material sources of rare earths of the yttrium group. The improvement of technologies for the extraction and processing of rare earths is necessary to meet the needs of the industry for its own raw materials and, therefore, for the development of high-tech industries. To extract yttrium, an extraction method was used in this work. Organic reagents and their mixtures with low-melting organic compounds were tested as extractants. According to the results of the study, a mixture of D2EHPA-HCA(di-(2-ethylhexyl) phosphoric acid and higher carboxylic acids) was chosen as an effective extractant providing the quantitative extraction of yttrium. The extraction patterns of yttrium extraction by this extractant were studied depending on various factors (рН, Vw:Vorg, Сex, CMe, t°C). The yttrium content after extraction was determined in the aqueous phase by the photometric method with the arsenazo I reagent. The content in the organic phase was determined by calculation. In an acidic environment, the yttrium recovery rate was 97,45%. In this case, the optimal conditions for the extraction were as follows: pH = 3.0, the volumetric ratio of the aqueous and organic phases 1:10, the concentration of D2EHPA in the extractant 10%, the initial concentration of yttrium CMe = 10-4M, the temperature of the extraction 40-60°C. The results obtained show the efficiency of yttrium extraction from solutions obtained after dissolving yttrium-containing ores with the extractant D2EHPA-HCA.