Kupferschiefer Ore Research Articles

Evaluation of Long-Term Post Process Inactivation of Bioleaching Microorganisms

The H2020 BioMOre project (www.biomore.info, Grant Agreement #642456) tests the feasibility of in-situ bioleaching of copper in deep subsurface deposits in the Rudna Mine, Poland. Copper is leached using biologically produced ferric iron solution, which is recycled back to the in-situ reactor after re-oxidation by iron-oxidizing bacteria (IOB). From a post operational point of view, it is important that the biological processes applied during the operation can be controlled and terminated. Our goal was to determine the possibility to use natural saline mine water for the inactivation of introduced IOB remaining in the in-situ reactor after completion of the leaching process of the Kupferschiefer ore. Aerobic and anaerobic microcosms containing acid-leached (pH 2) sandstone or black shale from the Kupferschiefer in the Rudna mine were further leached with the effluent from an iron-oxidizing bioreactor, at a temperature of 30°C, for 10 days, to simulate in-situ leaching. After the removal of the iron solution, residing IOB were inactivated by filling the microcosms with saline water (65 g L-1 Cl-) originating from the mine. The saline water completely inactivated the IOB and the naturally occurring saline water of the mine can be used for long-term post process inactivation of bioleaching microorganisms.

Effect of glutamic acid on copper sorption onto kaolinite - Batch experiments and surface complexation modeling

High carbonate content of the European Kupferschiefer ore deposits is a challenge for acid copper leaching (pH ≤ 2). Therefore investigating the mobility behavior of Cu(II) under conditions related to an alternative, neutrophil biohydrometallurgical Cu(II) leaching approach is of interest. As glutamic acid (Glu) might be present as a component in the growth media, we studied its effects on the adsorption of Cu(II) onto kaolinite. The binary and ternary batch sorption measurements of Cu(II) and Glu onto kaolinite were performed in the presence of 10 mM NaClO4 as background electrolyte and at a pH range from 4 to 9. Sorption experiments were modeled by the charge-distribution multi-site ion complexation (CD-MUSIC) model by using single sorption site (≡SOH) and monodentate surface complexation reactions. Glu sorption on kaolinite is weak (<10%) and independent of pH. Furthermore, Glu slightly enhances the Cu(II) sorption at low pH but strongly hinders (up to 50%) the sorption at higher pH and therewith enhances copper mobility. The results of isotherms show that Cu(II)-Glu sorption onto kaolinite mimics the Freundlich model. The proposed CD-MUSIC model provides a close fit to the experimental data and predicts the sorption of Cu(II), Cu(II)-Glu and Glu onto kaolinite as well as the effect of Glu on Cu(II) mobility.

Mobility and transport of copper(II) influenced by the microbial siderophore DFOB: Column experiment and modelling

Acid Cu leaching from the European Kupferschiefer ore deposits is a challenge e.g. due to its high carbonate content. In this study, we investigated the transport behaviour of Cu under conditions related to a biohydrometallurgical leaching approach using neutrophil microorganisms in neutral to slightly alkaline solutions. We studied the effect of the microbial siderophore desferrioxamineB (DFOB) as a model leaching organic ligand on Cu mobility in column experiments with kaolinite. The results revealed that DFOB strongly enhances Cu mobility. The breakthrough of Cu occurs considerably earlier in the presence of DFOB than in the absence of the organic ligand. Furthermore, complete elution of Cu was observed at 5 pore volume exchanges faster compared to elution with deionized water. The established geochemical transport model shows good agreement with the experimental data and suggests a maximum efficiency at a Cu to DFOB molar ratio of 1:1. In addition, results of modelling revealed that in the absence of the ligand, a pH increase from 6.5 to 8.5 significantly retarded Cu breakthrough, whereas in the presence of DFOB, Cu breakthrough curves were nearly insensitive to pH changes and close to the breakthrough curve of a non-reactive tracer.

World production and possible recovery of cobalt from the Kupferschiefer stratiform copper ore

Cobalt is recognized as a strategic metal and also E-tech element, which is crucial for worlds development. An increasing demand for cobalt forces for searching of new resources that could be explored in European countries. There are many examples of cobalt recoveries, mostly from laterite and sulphide deposits. However, the accurate choice of the technology depends on many factors. The Kupferschiefer stratiform copper ore located in Poland is the biggest deposit of cobalt in Europe. Although KGHM Polska Miedz S.A. recovers many precious metals from this ore, cobalt is not recovered yet. This metal occurs as an accompanying element, mostly in the form of cobaltite (CaAsS), with the average content of 50–80 g/Mg. In this paper a possible recovery of cobalt from the Kupferschiefer ore, with the use of hydrometallurgical methods, was investigated.

Influence of Carbonate Solubilisation on Copper Leaching from Kupferschiefer with Organic Acids

The European Kupferschiefer deposits offer potential for regional resources of base metals such as copper. Because of its chemical and mineralogical complexity the Kupferschiefer ore is still investigated regarding sustainable exploiting strategies such as (bio)leaching with organic acids. The current study examines different processing parameters investigating types of organic acids at pH 4 and 7 in order to reveal the influence of carbonate decomposition onto copper leaching performance. Obtained results show superior leaching performance of organic acids at neutral to alkaline pH range.

An Integrated Process for Innovative Extraction of Metals from Kupferschiefer Mine Dumps, Germany

AbstractDumps in the Central German Mansfeld mining district have been investigated by a multi‐disciplinary research team to develop a holistic concept for the recovery of base and trace metals from low‐grade Kupferschiefer ore. Geochemical and mineralogical data from representative sampling indicate that the low‐grade Kupferschiefer dumps contain significant amounts of Cu (0.6 %) and Ag (up to 800 ppm), besides exploitable grades of Pb and Zn. Additionally to flotation and hydrometallurgy, first shake flask bioleaching experiments on otherwise untreated Kupferschiefer ore yield Cu recovery rates of up to 95 %. A total of 900 t Cu and 5 t Ag contained in black copper can thus be produced from the pilot dump of 100 000 m3 low‐grade Kupferschiefer ore. Additionally, large volumes of limestone waste, separated from the dumps by sensor‐based sorting, can be utilized as aggregate in the construction industry.

Origin of the Kupferschiefer polymetallic mineralization in Poland

The Kupferschiefer ore series, between the Lower Permian (Rotliegendes) terrestrial redbeds/volcanics and the Upper Permian (Zechstein) marine sequence, is developed as dark-grey organic matter-rich and metal sulphide-containing deposits (reduced zone) and as red-stained organic matter-depleted and iron oxide-bearing sediments (oxidized zone = Rote Faule). The transition zone from oxidized to reduced rocks occurs both vertically and horizontally. This zone is characterized by sparsely disseminated remnant copper sulphides within hematite-bearing sediments, replacements of copper sulphides by iron oxides and covellite, and oxide pseudomorphs after framboidal pyrite. These textural features and copper sulphide replacements after pyrite in reduced sediments imply that the main oxide/sulphide mineralization postdated formation of an early-diagenetic pyrite. Hematite-dominated sediments locally contain enrichments of gold and PGE. The Kupferschiefer mineralization resulted from upward and laterally flowing fluids which oxidized originally pyritiferous organic matter-rich sediments to form hematitic Rote Faule areas, and which emplaced base and noble metals into reduced sediments. It is argued that long-lived and large-scale lateral fluid flow caused the cross-cutting relationships, expansion of the hematitic alteration front, redistribution of noble metals at the outer parts of oxidized areas, and the location of copper orebodies directly above and around oxidized and gold-bearing areas. The Rote Faule may be a guide to favourable areas for both the Cu-Ag and new Au-Pt-Pd Kupferschiefer-type deposits.

Clay mineralogy, crystallinity, and K-Ar ages of illites within the Polish Zechstein Basin; implications for the age of Kupferschiefer mineralization

Sir: We are pleased to respond to J. Nawrocki’s comment. It gives us an additional opportunity to articulate our ideas on the significance of the K-Ar ages of illites with respect to Kupferschiefer ore genesis (Bechtel et al., 1999). Nawrocki perhaps has overstated our intent by writing that we used paleomagnetic data to verify our indirect method for measuring the age of the Kupferschiefer mineralization event. The ages in question were estimated ages of diagenetic illite in both the abstract and in the main body of the paper. In the closing sentence of the abstract, we wrote that our results suggest that the formation of diagenetic illite was induced by the mineralizing event. We did not claim verification of the indirect dating method, and in the concluding statement that Nawrocki specifically criticized, we claimed only that the ages we inferred are, within limits of error, in agreement with the ages from paleomagnetic data (Jowett et al., 1987a). We did not (could not) claim agreement with Nawrocki’s then unpublished data that the pole position of …

Formation of Sulfide-Calcite Veinlets in the Kupferschiefer Cu-Ag Deposits in Poland by Natural Hydrofracturing During Basin Subsidence

Calcite and copper-(iron) sulfide veinlets in the Kupferschiefer ore deposits in southwestern Poland display many characteristics of antitaxial veinlets, including trails of wall-rock shards from wall to wall. Cross-cutting relationships demonstrate a change from sulfate to sulfide chemical stability and an evolution of stress orientation during ore-formation. Bedding-plane sulfate veinlets and later bedding-plane sulfide veinlets are superseded by vertical sulfide veinlets, suggesting tectonic extension during ore-formation. Thin bedding-plane calcite-(sulfide) veinlets record a return to pre-ore stress conditions after ore formation ceased. The vertical veinlets are thin and lens-shaped, typically 1-3 mm thick, 30-35 cm high, and 50-70 cm long, with orientations similar to Kimmerian-age (Triassic-Jurassic) directions. Sulfide replacement lenses cut across and are cut by vertical veinlets, suggesting contemporaneous formation after lithification. A mid-Triassic paleomagnetic age and cross-cutting Alpine-...

A Mid‐Triassic paleomagnetic age of the Kupferschiefer mineralization in Poland, based on a revised apparent polar wander path for Europe and Russia

Extensive mineralization occurs in southwest Poland as zoned blankets of Cu‐Ag‐(Pb‐Zn) sulphides in the Kupferschiefer and Zechstein Limestone across the base of the Late Permian Zechstein restricted marine sequence, and in the Weissliegendes sandstone at the top of the Early Permian Rotliegendes continental volcanic and siliciclastic sequence. The Rote Fäule (RF) zone, an oxidized, hematitic equivalent of the normally pyritic basal Zechstein, directly underlies the copper ore and is part of the metal zoning. Although the origin has generally been considered to be syngenetic, geologic controls of the RF‐ore systems in Poland suggest a late diagenetic origin by converting metalliferous brines migrating through the Rotliegendes clastic redbeds up along basement highs, oxidizing the pyritic Kupferschiefer to form the RF, and precipitating base and precious metals on the reduced side of this oxidation‐reduction front. A paleomagnetic study of the ore zone in five mines in Poland, the RF zone in three mines, and of the barren pyritic basal Zechstein from outcrops and quarries in Poland, Germany, and England was undertaken to determine the absolute age of the mineralization. In the barren pyritic rocks and the copper sulphide ore, thermal demagnetization and vector subtraction revealed an unstable low‐temperature first‐remanence component (76.9°N, 12.2°E; A63 = 1.6°), parallel to the ambient field, and a second, higher temperature component (82.6°N, 145.9°E; A63 = 1.9°), which could be Miocene (10–20 Ma) or, less likely, Cretaceous (110 Ma) or Jurassic (180 Ma). This second component is erased at 350°–400°C and is thought to be carried by a product of weathering after Alpine age uplift and erosion. No primary magnetization could be isolated in the copper or pyritic zones. The RF hematite, however, contained a very stable third, reversed component (49.0°N, 157.2°E; A63 = 2.2°) which was revealed typically between 500° and 620°C, and is considered to represent a secondary chemical remanent magnetization acquired during the mineralizing process. In order to date the isolated magnetic components, Carboniferous to Neogene apparent polar wander (APW) paths for Europe and Russia were constructed using paleopole catalogs. Mean paleopoles every 10 Ma from 350 to 0 Ma, with A63 circles of confidence, were calculated as running averages using overlapping 20‐ and 30‐Ma time intervals. The RF pole, corresponding to the third remanence component, coincides extremely well with a Middle Triassic age of 240 Ma on the 20‐Ma APW path and a Late Triassic age of 230 Ma on the 30‐Ma APW path. Statistical analysis yields upper and lower age limits of 250 and 220 Ma. This Triassic paleomagnetic age supports the proposed late diagenetic origin of the Kupferschiefer ore deposits, and suggests that the RF‐ore systems were formed immediately after Triassic continental rifting associated with the opening of the Tethys ocean to the south—a likely source of the thermal anomaly necessary to initiate adequate convective velocities within the Rotliegendes clastic basins.