DEVELOPMENT OF TECHNOLOGICAL PRINCIPLES FOR OBTAINING PURE MOLYBDENUM TRIOXIDE FROM MOLYBDENUM CONCENTRATES

Abstract

Under industrial conditions, high-purity molybdenum trioxide is obtained by hydrometallurgical or evaporation methods. The technological process of evaporation is not preferable for large production volumes, as it is costly due to energy consumption and the need for complex equipment. This paper describes a technology for producing high-purity molybdenum trioxide from molybdenite concentrate. After oxidative roasting, the molybdenite concentrate was washed with a solution of HCl + NH4Cl, which allowed the molybdenum trioxide to be purified of undesirable metal impurities, reducing their content to <0.1%, and also reducing the content of copper and iron impurities by 90% and 60%, respectively. Following this purification stage, the molybdenum trioxide was dissolved in an ammonia solution. For further purification of the obtained ammonium molybdate solution from impurities, an alcohol solution of lumogallion was used as a complexing agent. Mixtures of Fe, Cu, Co, and Ni with lumogallion form stable complexes, which were removed with activated carbon, then, high-purity ammonium paramolybdate crystals were obtained by crystallisation from an ammonium molybdate solution followed by thermal decomposition to obtain high-purity molybdenum trioxide.

Additional extraction of molybdenum from the mother liquor was also carried out using Purolite A-100 Mo ion exchange resin, and it can be said that Purolite A-100 Mo resin provides high sorption efficiency (90-95%).

Based on the results of chemical and X-ray phase analysis, optimal regimes were determined for various stages of the process.