Optimization of a leaching process for copper-bearing materials by means of biotechnologically produced leaching agents such as acetic acid, citric acid ammonium and (poly) glutamic acid


Research output: ThesisMaster's Thesis

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The ore deposit of the European copper shale (kupferschiefer) is large sediment-hosted copper deposits with a high content of base metals, precious metals and PGM. The Copper shale ore possesses a large content of carbonate rocks up to 75% that hinders traditional bioleaching with acidophilic microorganisms. Therefore heterotrophic microorganisms were examined with respect to metals leaching at neutral pH to avoid carbonates dissolution. In the present thesis optimization of the leaching process was investigated employing heterotrophic microorganisms to produce leaching agents as citric acid, acetic acid, ammonium and poly-γ-glutamic acid by Kombucha-culture, Yarrowia lipolytica, Sporosarcina ureae and Bacillus licheniformis respectively. Copper shale ore samples come that from Mansfeld mining waste dump (Germany), Sangerhausen mine (Germany) and Rudna mine (Poland) were leached with biologically produced leaching agents. Chemical analyses of ore samples demonstrate leaching kinetic and efficiency reaching copper yield up to 45.1%. Based on experiments planning technique and obtained results the response surface models were built in order to optimize the impute parameters such as temperature, pH and pulp density in order to increase copper yield. Eventually, mineralogical analyses indicate copper minerals dissolution ratio of bornite, covellite, chalcocite and chalcopyrite giving an overview of on their ability to be leached at applied conditions. The results showed the dissolution of all copper sulfides that proof process feasibility.
Translated title of the contributionOptimierung der Laugung von kupferhaltigen Materialien mit biotechnologisch produzierten Laugungsagenzien wie Essigsäure, Zitronensäure, Ammonium und (Poly)-Glutaminsäure
Original languageEnglish
  • Moser, Peter, Supervisor (internal)
Award date7 Apr 2017
Publication statusPublished - 2017

Bibliographical note

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  • leaching process
  • copper-bearing

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