Production of high purity molybdenum compounds from a Cu-Mo acid-washed liquor using solvent extraction--Part 1: Laboratory studies

摘要

Solvent extraction, using Alamine 304-1 for loading (extraction) and ammonia for stripping, was used for selectively recovering molybdenum from acid wash liquor produced by a Mo processing plant. The results showed that the extraction could be completed in 3 stages, using Alamine 304-1 as the extractant (10 percent , v/v in Anysol 150 diluent), with almost all the Mo(VI) recovered from an acidic sulfate wash liquor, containing 10-15 g/L Mo(Vi), 10g/L Cu(II) and 2g/L Fe(III), using an O/A volumetric ratio of 3:2. Using ammonia (12.5 percent , w/v), at an O/A ratio of 5:1, all the Mo(Vl) from an Alamine liquor containing 17.5 g/L Mo could be removed in one strip, yielding a solution with 87.0 g/L Mo(VI). High purity (>99.9 percent ) MoO_3 and CaMoO_4 were produced from this pure liquor via an intermediate hydrate precipitate (MoO_3 centre dot H_2O). The study also showed that understanding the stability and speciation of various soluble and solid Mo species are essential for the development of an efficient recovery process.