Synthesis of Mg–Zn–Nd Master Alloy in Metallothermic Reduction of Neodymium from Fluoride–Chloride Melt

Abstract

In the presented article, a differential thermal analysis was carried out and the temperatures of thermal effects were established that arise during the reduction of neodymium from a technological salt mixture KCl–NaCl–CaCl2–NdF3 with a magnesium–zinc alloy. The results of experimental studies on the reduction of neodymium from a fluoride–chloride melt in a shaft electric furnace at temperatures of 550, 600, 650, 700 °C are presented. In order to increase the degree of extraction of neodymium into the Mg–Zn–Nd master alloy, the study of the influence of technological parameters on the degree of extraction of neodymium was carried out. It was experimentally proven that when zinc is added to a reducing agent (magnesium), the degree of extraction of neodymium into the master alloy is 99.5–99.7%. The structure of the obtained master alloy samples, characterized by a uniform distribution of ternary intermetallic compounds (Mg3,4NdZn7) in the volume of a double magnesium–zinc eutectic, was studied by optical and electron microscopy.

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

“…Despite the method of bauxite processing, RM contains a high number of valuable components, especially rare earth elements (REEs) that are widely used in high-tech materials production [12][13][14]. REEs do not dissolve during bauxite alkali leaching and concentrate in the solid residue with an enrichment factor of about two [15,16].…”