Papers by Keyword: Kupferschiefer

Abstract: “Deep in situ biomining”, widely considered to be a potentially environmentally-benign and cost effective biotechnology for extracting and recovering base metals from deep-buried base metal deposits, is being developed within the EU Horizon 2020 project “BioMOre”. Data are presented from non-aerated column experiments in which a saline, calcareous copper-rich ore (kupferschiefer) was subjected to a three-stage eaching protocol: (i) with water, to remove soluble salts; (ii) with sulfuric acid, to remove calcareous minerals and other acid-soluble salts; (iii) indirect bioleaching with a microbiologically-generated ferric iron lixiviant. Sequential leaching with water and acid removed ~85% of the chloride prior to bio-processing, while ~13% of the copper present in the ore was leached using sulfuric acid, and a further 39 - 59% by the lixiviant.

Abstract: Pregnant leach solutions (PLS) resulting from bioleaching of copper concentrate from Kupferschiefer are characterized by low pH values and high concentrations of mainly ferric iron, copper, zinc and sulfate, as well as significant amounts of nickel and cobalt. In order to recover the valuable metals for further processing, a novel technique that promotes selective metal recovery and sulfate removal from acidic liquors, described in this study, is proposed.

Abstract: Indigenous microorganisms isolated from organic-rich copper-bearing black shale from the Fore-Sudetic Monocline were able to transform naturally occurring metalloporphyrins in laboratory cultures. It was also demonstrated that these bacteria can utilize synthetic metalloporphyrins as the sole energy and carbon source. The first step in metalloporphyrin biotransformation was identified as the highly effective bioaccumulation of these compounds in bacterial cells. The ability of both living and dead cells to biosorb metalloporphyrins was also confirmed. Besides contributing to the important biogeochemical role of these microorganisms in the environment, their biotransformation activities are of potential use in the bioremediation of copper tailings as well as in the recovery of metals from organic-rich black shale ore, which is not possible using traditional hydrometallurgical procedures.