Recovery of Molybdenum and Rhenium Using Selective Precipitation Method from Molybdenite Roasting Dust in Alkali Leaching Solution

Abstract

A study has been conducted for the separate recovery of molybdenum and rhenium from alkali leaching solution of molybdenite roasting dust by a selective precipitation method. Two kinds of synthetic alkali leaching solutions were employed and more than 85% of molybdenum was recovered as a precipitate in the experimental conditions of 243.15 K, pH 2.2, 200 rpm of agitation speed, 7,200 s of reaction time, and 1.5 of equivalence ratio between NH₄OH and NaOH for NaOH leaching solution. Regarding NH₄OH leaching solution, the optimal conditions for the formation of molybdenum precipitate were found to be 243.15 K, pH 2.5, 100 rpm of agitation speed, and 18,000 s of reaction time. The precipitation efficiency of molybdenum was higher than 99% in these conditions and molybdenum was observed to be precipitated as ammonium molybdate. Contrary to the precipitating behavior of molybdenum, rhenium was precipitated very little in the given conditions, which suggested a possibility for the selective recovery of molybdenum and rhenium.