Study on removing Mo from tungstate solution using coprecipitation adsorption method based on novel Mo sulphidation process

A coprecipitation–adsorption method based on a novel Mo sulphidation process is proposed for deep removal of molybdenum from tungstate solutions. First, a new sulphur source, P2S5, is used to provide HS− for the Mo sulphidation process. The MoO42− can be thoroughly converted into MoS42− while tungsten still exists as WO42−. Next, in the sodium tungstate solution, 99·4% of MoS42− is removed with precipitated ‘nascent’ CuS under 6 h reaction at 30°C when the molar ratio Cu/Mo is 3. Similarly, in a commercial (NH4)2WO4 solution, by controlling the molar ratio Cu/Mo at 6, 98·4% of MoS42− is removed after 1 h at 30°C. Subsequently, phosphorus introduced during Mo sulphidation is removed using the magnesium ammonium phosphate method allowing the ammonium paratungstate to reach the GB 10116-88 APT-0 standard. On propose une methode de co-precipitation et adsorption basee sur un nouveau procede de sulfuration du Mo pour l’enlevement en profondeur du molybdene de solutions de tungstate. Premierement, on utilise un...