Hydrometallurgical processing of molybdenum middlings from Shatyrkul-Zhaysan cluster ore

Abstract

This research investigates the hydrometallurgical processing of molybdenum middlings extracted from copper-molybdenum ore at the Shatyrkul-Zhaysan cluster in Kazakhstan. Molybdenum intermediate product obtained after selective flotation of the copper-molybdenum concentrate was used, with 0.07% yield, 22.23% molybdenum content, and 74.91% extraction. Mineralogical analysis shows molybdenite and chalcopyrite as the main minerals. Experiments study atmospheric leaching with nitric acid in single-stage and two-stage countercurrent modes to optimize molybdenum extraction and reduce acid consumption. The optimal conditions obtained were: 300 g/L nitric acid, 100 g/L sulfuric acid, 90?C temperature, and 2 hours leaching time in single stage leaching, giving 98.8% molybdenum extraction. Two-stage leaching under optimized conditions allows obtaining 94.3% molybdenum extraction in solutions with lower residual acidity (0.89 g-eq/L) and redox potential (550 mV) without reducing valuable component extractions. Molybdenum extraction reaches 94.3% in the subsequent solvent extraction stage from two-stage leaching solutions. The final product, calcium molybdate containing 46.83% molybdenum, meets commercial grade specifications. This research demonstrates an effective process for the hydrometallurgical production of commercial calcium molybdenite from copper-molybdenum ore, with high molybdenum recovery, reduced acid consumption through two-stage leaching, and minimal hazardous discharges.