Hydrometallurgical recovery of high-tech metals from a complex sulfidic flue dust with focus on the separation of rhenium and molybdenum by solvent extraction


Hydrometallurgical recovery of high-tech metals from a complex sulfidic flue dust with focus on the separation of rhenium and molybdenum by solvent extraction

Helbig, T.; Haseneder, R.; Werner, A.; Kelly, N.; Scharf, C.

“Theisenschlamm”, a flue dust of the former copper shale processing in Germany, comprises high amounts of zinc and lead as well as a variety of low concentrated high-tech metals, such as rhenium, molybdenum, cobalt and germanium. A hydrometallurgical process route was investigated to recover the valuable metals with focus on rhenium and molybdenum. However, very low concentrations of some target elements (1 – 15 mg/L) had to be considered. The process includes an innovative combination of membrane filtration and solvent extraction. With the first processing step 95% molybdenum were extracted from the pregnant leach solution in a continuous mixer settler set-up with the extractant Cyanex 272. High selectivity over rhenium was obtained, with a coextraction of only 0.3%. Continuous membrane nanofiltration technology achieved a selective separation and enrichment of 97.3% zinc, 98.5% iron(III), 97.0% copper, 98.3% aluminium and 99.1% cobalt over rhenium (7.2%) and germanium (7.7%). From the permeate solution 98.4% germanium were separated from rhenium (0.1%) by a continuous reverse osmosis membrane process. Extraction of 99.9% rhenium was obtained by continuous solvent extraction with Alamine 336. Considerations for the selective enrichment of very low concentrated target elements by solvent extraction are discussed in detail. Moreover, potential solvent extraction processes are suggested for further processing of the cobalt, germanium, zinc and copper containing membrane process streams.

  • Contribution to proceedings
    Hi-Tech Metals '18, 22.-23.11.2018, Cape Town, South Africa
  • Lecture (Conference)
    Hi-Tech Metals '18, 22.-23.11.2018, Cape Town, South Africa

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Publ.-Id: 28506