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%.
