The Research On Rehenium Richment By Solvent Extraction

Rehenium is a kind of rare metal with little content in nature, and it has not been found the single rhenium mineral so far, mainly scattered in molybdenite and bornite. Rehenium and its alloys have a common application prospects in the petrochemical, aerospace, metallurgy, defense and other industries because of its unique physical and chemical properties with high melting point, high boiling point, high density, excellent ductility, formability, catalytic activity and so on, so it is in short supply in the market.Extraction technologies were adopted in this paper, aiming at solving the problem of the separation and enrichment of rehenium in the production process of Blazers Molybdenum, and the optimized experiment conditions obtained could providing an improved method of the recovery of the materials including rehenium.The concentrations of Re and Mo were analyzed based on a thiourea spectrophotometry method and potassium thiocyanate spectrophotometry method, respectively. The extraction of Re and Mo by acetone, butanone and Tri-butyl phosphate dilution in the kerosene was studied, investigating the influence on the extraction efficiency of the factors, such as the volume added of the solvent, the acidity-alkalinity of the feed, the extraction time to approach the equilibrium, extraction stages, etc. The extraction performance of three kind of solvent were estimated.When utilizing the acetone as the extraction solvent, with the optimization extraction conditions : the alkalinity of the feed solution adjusted to 4 mol/L sodium hydroxide, the ratio of A/O set as 1:2, the extraction efficiency by single extraction of Re and Mo after contacting time for 5 minutes at the ambient temperature were 99.52% and 7.5%, respectively; a three-stages solvent extraction process is found to separate Re with the A/O ratio equal to 2:1, and the extraction rate of Re and Mo is obtained at 99.67%, 7.55%,respectively; when using the methyl ethyl ketone as the extractant, accompanying with the A/O ratio chosen as 1:5 and the p H value adjusted to 6, the the extraction efficiency by single extraction of Re and Mo after contacting for 5 minutes at the ambient temperature were 95.84% and 4.81%, respectively; a three-stages solvent extraction process is found to separate Re with the A/O ratio equal to 1:1, and the extraction rate of Re and Mo is obtained at 98.61%, 5.44%,respectively; the Infrared Spectroscopy analysis of the loaded organic phase where the characteristic absorption peak of carbonyl group migrated compared to the original organic solvent indicated that the active group of the ketones was carbonyl. When adopting the Tri-butyl phosphate diluted in the kerosene as the extracting agent, the p H value should be adjusted to 2.0 in the first step, the extraction efficiency by single extraction of Mo were 99.81% with the A/O ratio 1:2, contacting for 15 minutes and the ambient temperature, at the same time, the little amount of Re was extracted, the extract liquor A obtained; then the p H value of the raffinate was adjusted to-0.5, the extraction efficiency by single extraction of Re were 99.70% with the A/O ratio 1:1, the other conditions kept the same as the Mo extraction, the extract liquor B obtained; for the stripping of Mo from the extract liquor A, the optimization conditions were as follows: adopting the ammonia with the mass concentration of 20% as the stripping agent, p H=9, the A/O ratio 2:3, contacting time for 5 min, at the ambient temperature, with the above conditions the stripping efficiency of approximate 99.8% could be obtained; the stripping stages being four with the A/O ratio 1:10, and 99.88% of Mo could be stripped; for the stripping of Re from the extract liquor B, the optimization conditions were as follows: adopting the ammonia with the mass concentration of 20% as the stripping agent, p H=5, the A/O ratio 1:5, contacting time for 5 min, at the ambient temperature, the stripping efficiency of approximate 99.8% could be obtained with the above conditions;the stripping stages being two with the A/O ratio 1:10, 99.89% of Re would be stripped. When taking the tri-butyl phosphate as the extraction solvent, the products prepared were identified as ammomium dodecamolybdate and ammonium perrhenate by XRD spectrum analysis, XRF spectrum analysis and SEM, and the content of Mo and Re were 58.185% and 68.66%, respectively.Therefore, the tri-butyl phosphate was estimated to have a better extraction performance.