Process for the preparation of pure MoO3 via extraction of molybdenum from sulphate solutions

摘要

The invention relates to a process for preparing pure MoO3 from molybdenum sulphide concentrates (MoS2) with a high gangue content, especially carbon-containing substances containing extractable accompanying elements such as Re, Hf, Cu and the like. In the process, a sulphuric acid-containing suspension of the raw material is reacted at elevated temperature in an atmosphere of pressurised oxygen in an autoclave in such a way that a partly reductive atmosphere is produced. In this environment, the known precipitations of MoO3 do not occur, stable sulphate solutions being produced instead which contain all of the feed content of Re, Hf, Cu and the like. Pure MoO3 and the oxides of said elements can be obtained from these solutions via suitable extraction methods.