Metallurgical and Materials Transactions B

, Volume 47, Issue 5, pp 2889–2903

Thermodynamics Behavior of Germanium During Equilibrium Reactions between FeOx-CaO-SiO2-MgO Slag and Molten Copper

  • M. A. H. Shuva
  • M. A. Rhamdhani
  • G. A. Brooks
  • S. Masood
  • M. A. Reuter
Article

DOI: 10.1007/s11663-016-0759-x

Cite this article as:
Shuva, M.A.H., Rhamdhani, M.A., Brooks, G.A. et al. Metall and Materi Trans B (2016) 47: 2889. doi:10.1007/s11663-016-0759-x

Abstract

The distribution ratio of germanium (Ge), \( L_{\text{Ge}}^{s/m} \) during equilibrium reactions between magnesia-saturated FeOx-CaO-SiO2 (FCS) slag and molten copper has been measured under oxygen partial pressures from 10−10 to 10−7 atm and at temperatures 1473 to 1623 K (1200 to 1350 °C). It was observed that the Ge distribution ratio increases with increasing oxygen partial pressure, and with decreasing temperature. It was also observed that the distribution ratio is strongly dependent on slag basicity. The distribution ratio was observed to increase with increasing optical basicity. At fixed CaO concentration in the slag, the distribution ratio was found to increase with increasing Fe/SiO2 ratio, tending to a plateau at \( L_{\text{Ge}}^{s/m} \) = 0.8. This behavior is consistent with the assessment of ionic bond fraction carried out in this study, and suggested the acidic nature of germanium oxide (GeO2) in the slag system studied. The characterisation results of the quenched slag suggested that Ge is present in the FeOx-CaO-SiO2-MgO slag predominantly as GeO2. At 1573 K (1300 °C) and \( p_{{{\text{O}}_{2} }} \) = 10−8 atm, the activity coefficient of GeO2 in the slag was calculated to be in the range of 0.24 to 1.50. The results from the current study suggested that less-basic slag, high operating temperature, and low oxygen partial pressure promote a low Ge distribution ratio. These conditions are desired for maximizing Ge recovery, for example, during pyrometallurgical processing of Ge-containing e-waste through secondary copper smelting. Overall, the thermodynamics data generated from this study can be used for process modeling purposes for improving recovery of Ge in primary and secondary copper smelting processes.

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2016

Authors and Affiliations

  • M. A. H. Shuva
    • 1
    • 2
  • M. A. Rhamdhani
    • 1
    • 2
  • G. A. Brooks
    • 1
    • 2
  • S. Masood
    • 1
    • 2
  • M. A. Reuter
    • 3
  1. 1.Department of Mechanical and Product Design EngineeringSwinburne University of TechnologyMelbourneAustralia
  2. 2.Wealth from Waste Research ClusterMelbourneAustralia
  3. 3.Helmholtz Institute Freiberg for Resource TechnologyFreibergGermany

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