TY - THES

T1 - Evaluation of extraction routes for sulphide concentrates from processing of complex skarn ores located in the Erzgebirge region

AU - Mongoljiibuu, Shine-Od

N1 - no embargo

PY - 2022

Y1 - 2022

N2 - The subject of this work is the processing of a hydrometallurgical approach for the extraction of economically significant metals from a sulphide concentrate, focusing predominantly on zinc. The sulphide concentrate had been produced from sulphide flotation in the Tellerhäuser pilot plant which was set up to process a tin skarn ore from the Erzgebirge region. The combination of different hydrometallurgical processes is a promising way to obtain metals, some of which are low in concentration and indispensable for modern life, in an ecologically and economically sustainable way. In the case of zinc, the currently used process consisting of roasting, leaching and electrolysis have environmental disadvantages due to the emission of toxic gases. For this reason, the acidic direct leaching of the sulphide concentrate was investigated in this study, as this approach eliminates the roasting stage, which produces sulphur dioxide. The feed material and the leaching residues of the different fractions were characterised using different analytical techniques such as X-ray diffraction, X-ray fluorescence, ICP-OES as well as scanning electron microscopy using the MLA Suite software. In the leaching experiments, sulphuric acid was used in combination with the oxidant hydrogen peroxide. The oxidant was used to improve the extraction rates of the target elements. The influence of central parameters on the extraction of zinc and other valuable metals was investigated. The following parameters were considered over a period of 96 hours each: Temperature (24-60 ºC), hydrogen peroxide concentration (1 %, 3 %, 5 %), sulphuric acid concentration (0.3 M, 0.5 M, 1.0 M, 1.5 M) and particle size (-50 µm, +50-80 µm, bulk material). In this context, the extraction of indium was also observed. In the course of the work, different batch reactors and different analytical methods were used to determine the metal extraction. The results showed that with a solution consisting of 1.5 M H2SO4 and 5 % H2O2 at 40 °C and using an S/L ratio of 1:10 and the finest material, 98 % of the zinc can be extracted. Overall, a high acid concentration is also advantageous for high zinc extraction. Based on the results of the experiments as well as previous studies, the classical economic feasibility was evaluated by calculating the NPV and IRR of such a plant for the extraction of zinc and indium.

AB - The subject of this work is the processing of a hydrometallurgical approach for the extraction of economically significant metals from a sulphide concentrate, focusing predominantly on zinc. The sulphide concentrate had been produced from sulphide flotation in the Tellerhäuser pilot plant which was set up to process a tin skarn ore from the Erzgebirge region. The combination of different hydrometallurgical processes is a promising way to obtain metals, some of which are low in concentration and indispensable for modern life, in an ecologically and economically sustainable way. In the case of zinc, the currently used process consisting of roasting, leaching and electrolysis have environmental disadvantages due to the emission of toxic gases. For this reason, the acidic direct leaching of the sulphide concentrate was investigated in this study, as this approach eliminates the roasting stage, which produces sulphur dioxide. The feed material and the leaching residues of the different fractions were characterised using different analytical techniques such as X-ray diffraction, X-ray fluorescence, ICP-OES as well as scanning electron microscopy using the MLA Suite software. In the leaching experiments, sulphuric acid was used in combination with the oxidant hydrogen peroxide. The oxidant was used to improve the extraction rates of the target elements. The influence of central parameters on the extraction of zinc and other valuable metals was investigated. The following parameters were considered over a period of 96 hours each: Temperature (24-60 ºC), hydrogen peroxide concentration (1 %, 3 %, 5 %), sulphuric acid concentration (0.3 M, 0.5 M, 1.0 M, 1.5 M) and particle size (-50 µm, +50-80 µm, bulk material). In this context, the extraction of indium was also observed. In the course of the work, different batch reactors and different analytical methods were used to determine the metal extraction. The results showed that with a solution consisting of 1.5 M H2SO4 and 5 % H2O2 at 40 °C and using an S/L ratio of 1:10 and the finest material, 98 % of the zinc can be extracted. Overall, a high acid concentration is also advantageous for high zinc extraction. Based on the results of the experiments as well as previous studies, the classical economic feasibility was evaluated by calculating the NPV and IRR of such a plant for the extraction of zinc and indium.

KW - sulphide concentrate

KW - zinc

KW - Tellerhäuser pilot plant

KW - direct leaching

KW - hydrogen peroxide

KW - sulphuric acid

KW - Sulfidkonzentrat

KW - Zink

KW - Tellerhäuser Pilotanlage

KW - Direktlaugung

KW - Wasserstoffperoxid

KW - Schwefelsäure

M3 - Master's Thesis

ER -