TY - JOUR

T1 - Simultaneous Extraction of Valuable Metals from Iron-Containing Residues by Selective Chlorination and Evaporation

AU - Steinlechner, Stefan

AU - Witt, Kerrin

N1 - Publisher Copyright: © 2023, The Author(s).

PY - 2023/12

Y1 - 2023/12

N2 - In different nonferrous metal producing industry sectors the impurity element iron has to be removed from the process solution. Examples for the arising residues are jarosite or goethite precipitates from nickel or zinc production but also red mud from aluminum production. Regardless of environmental concerns, the material is landfilled in almost any case, although valuables such as indium, silver, nickel, or zinc are present in considerable amounts. Within the presented research a low carbon dioxide emitting multi-metal recovery from such iron containing residues by means of a selective chlorination extraction has been fundamentally evaluated by experiments but also by comprehensive thermodynamic calculations. The paper summarizes the thermodynamic fundamental concept exploited to separate the dominating iron matrix from the valuable elements and shows verification experiments in a lab size of several grams. Through thermodynamic calculations and small-scale experiments with pure metal oxides and sulfates, it has been proven that the metal chlorides AlCl3∙6H2O, FeCl3∙6H2O, and MgCl2∙6H2O are viable and effective reactants for chlorination. In trials with actual industrial iron precipitation residues from the zinc industry, especially the use of MgCl2∙6H2O and FeCl3∙6H2O lead to high extraction rates for the investigated valuable metals Ag, Au, Bi, Cu, In, Pb, Sn, and Zn.

AB - In different nonferrous metal producing industry sectors the impurity element iron has to be removed from the process solution. Examples for the arising residues are jarosite or goethite precipitates from nickel or zinc production but also red mud from aluminum production. Regardless of environmental concerns, the material is landfilled in almost any case, although valuables such as indium, silver, nickel, or zinc are present in considerable amounts. Within the presented research a low carbon dioxide emitting multi-metal recovery from such iron containing residues by means of a selective chlorination extraction has been fundamentally evaluated by experiments but also by comprehensive thermodynamic calculations. The paper summarizes the thermodynamic fundamental concept exploited to separate the dominating iron matrix from the valuable elements and shows verification experiments in a lab size of several grams. Through thermodynamic calculations and small-scale experiments with pure metal oxides and sulfates, it has been proven that the metal chlorides AlCl3∙6H2O, FeCl3∙6H2O, and MgCl2∙6H2O are viable and effective reactants for chlorination. In trials with actual industrial iron precipitation residues from the zinc industry, especially the use of MgCl2∙6H2O and FeCl3∙6H2O lead to high extraction rates for the investigated valuable metals Ag, Au, Bi, Cu, In, Pb, Sn, and Zn.

KW - Selective chlorination

KW - Jarosite

KW - Goethite

KW - Iron precipitate

KW - Residue recycling

KW - Metal recovery

UR - http://www.scopus.com/inward/record.url?scp=85176394984&partnerID=8YFLogxK

U2 - 10.1007/s42461-023-00872-5

DO - 10.1007/s42461-023-00872-5

M3 - Article

AN - SCOPUS:85176394984

VL - 40.2023

SP - 2023

EP - 2036

JO - Mining, Metallurgy and Exploration

JF - Mining, Metallurgy and Exploration

SN - 2524-3462

IS - 6

ER -