Dysprosium (Dy) Separation from Yttrium Concentrate in Nitric Acid Solution Using Aliquat 336 Solvent

Abstract

Similarity of chemical and physical properties between rare-earth elements (REEs) and Dy is the main concern in order to get Dy with high purity, which it is necessary to do separation by extraction process. The purpose of this research is to obtain the optimum condition of operation (stirring time and rate, concentration of nitric acid, feed, and solvent) and determine the distribution constant, separation factor, and extraction efficiency of Dy using Aliquat 336. This research was conducted by varying stirring time (10, 15, 20, 30, 40 minutes), stirring rate (100, 150, 200, 250, 300 rpm), nitric acid concentration (2, 3, 4, 5, 6 N), feed concentration (25,000; 50,000; 100,000; 150,000; 200,000 ppm) and solvent concentration (10, 20, 30, 40, 50 % v/v). The optimum result is achieved when operation is carried out at stirring 100 rpm about 15 minutes in nitric acid 3 N with 100,000 ppm of feed concentration using 30% solvent concentration (v/v) which extract more Dy element than Yttrium (Y) and Godolinium (Gd). The highest distribution constant of Dy is 0.427, separation factor of Dy-Y is 6.831, separation factor of Dy-Gd is 1.799, and extraction efficiency of Dy is 31.604%.

"Individual Separation of Yttrium and Dysprosium Oxides from the Rare Earths Product obtained from Xenotime Mineral Concentrate"

“…One of these techniques is the solvent extraction technique (SX) which depends on transfer rare earth element from organic phase into aqueous phase and its stripping by acid or base. Examples of the used solvents are Cyanex 923, diisooctyldithiophosphinic acid, trialkyl phosphine oxide, CA12 and D2EHPA [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. One such attempt is to separate yttrium and dysprosium from REEs concentrate using two types of techniques: direct precipitation and solvent extraction.…”

Solvent Extraction of Yttrium from Rare Earths Concentrate Using Cyanex 272 and PC88A

“…Both sorts of solvent extraction are based on the same rule, the separation of REEs based on their relative solubility in two different immiscible liquids or the solid compound. Illustrations of the utilized solvents are Cyanex 923, bis(2,4,4-trimethylpentyl) dithiophosphinic acid, trialkyl phosphine oxide, CA12, Cyanex 527, tributylphosphate, TOA, TOPO and D2EHPA (22)(23)(24)(25)(26)(27).…”