Copper and silver ores
Copper ore deposits occur in several countries throughout the world and under various geological conditions. The most important are porphyry copper deposits as well as sediment-hosted stratabound copper deposits and the exhalative-sedimentary ones (massive pyrite ores). Moreover, there are other igneous copper ores of various types, generally characterized by smaller resources but sometimes of high economic value.
Polish copper ores belong to the stratabound type. The deposits are situated in areas of the Fore-Sudetic Monocline and North Sudetic Basin in the Lower Silesia and related to the Zechstein Kupferschifer formation. Minerals containing copper and other metals are mainly concentrated in the copper-bearing shales as well as underlaying sandstones and overlying dolomites. Deposits of the largest economic importance are those from the vicinities of Lubin in the Fore-Sudetic Monocline.
The copper-bearing series comprises three separate lithological layers: sandstones at the base, clay-marly or dolomitic shales and dolomitic limestones in upper part. Copper mineralization is the strongest in the black clay shales which, therefore, are named the Copper-bearing Shales. The major copper minerals of the ores include: chalcocite (Cu2S), bornite (Cu5FeS4) and chalcopyrite (CuFeS2). They are accompanied by numerous other minerals of copper, silver (including native silver), lead, zinc cobalt and nickel.
The copper deposit area extends in a belt 60 km long and 20 km wide, from Lubin in the south-east to Bytom Odrzański in the north-west. This is actually a single deposit area in which copper ores are currently exploited in the Lubin, Polkowice-Sieroszowice and Rudna mines.
Copper ore deposits in Poland are presented on the map.
In areas of the Fore-Sudetic Monocline, Żary Pericline and North Sudetic Basin prognostic resources amounted to 22.7 million tonnes of copper (5 regions with the area of 253 km2, maximum depth of 2,000 m), perspective resources amounted to 5.94 million tonnes of copper (7 regions with the area of 114 km2, maximum depth of 2,000 m) and hypothetical resources to 229.1 million tonnes - including 42.7 million tonnes to the depth of 2,000 m and 186.4 million tonnes below 2,000 m depth (11 regions with the area of 1,830 km2)(1).
In 2013 anticipated economic resources of copper ore in the areas of the Fore-Sudetic Monocline and North Sudetic Basin amounted to 1,761.96 million tonnes with metallic copper amounted to 33.78 million tonnes and silver amounted to 103.18 thousand tonnes (table 1). The resources decreased by 30.57 million tonnes in comparison with the previous year (mainly due to the output).
Anticipated economic resources of copper ore in exploited deposits in the are of the Fore-Sudetic Monocline are equal 1,446.38 million tonnes (28.37 million tonnes of metallic copper and 84.03 thousand tonnes of silver) – it accounts for about 82 % of total anticipated economic resources. Economic resources of these deposits amounted to 1,205.27 million tonnes.
In 2013, copper mining produced 30,647 thousand tonnes of copper ore (with copper content at 1.57 %) yielding 482 thousand tonnes of metallic copper and 1,393 tonnes of silver. In comparison with the year 2012, production of copper ore, recovery of silver and production of metallic copper slightly increased – by 1.5 %, 3.8 % and 0.6 % respectively.
In 2013 the KGHM Polish Copper Combine S.A. produced 565.2 thousand tonnes of electrolytic copper, 1,066 kg of gold and 7.53 tonnes of renium – both from their own and imported concentrates.
Figures below shows resources and production of copper ores and changes in resources and output of copper in Poland in the years 1989-2013.
The figure given below shows resources and output of silver in the same period.
Other metals recovered from copper ores include Ag, Au, Ni, Pb, Pt-Pd, Se, Re and sulfuric acid is a by-product. Recovery of silver is of the largest economic importance. According to the data provided by the KGHM Polish Copper Combine S.A., in 2013 the copper processing was accompanied by recovery of 1,161.1 tonnes of silver, 431.3 kg of gold, 26.71 thousand tonnes of lead, 2.76 thousand tonnes of nickel sulfides, 80.21 tonnes of selenium, 176.7 kg of Pt-Pd concentrate and sulfuric acid and copper sulfides.
Prepared by: Agnieszka Malon, Stanisław Z. Mikulski, Sławomir Oszczepalski, Marcin Tymiński
(1) S. Oszczepalski, S. Speczik, 2011 - "Rudy miedzi i srebra" in "Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31 XII 2009 r." pod red. S. Wołkowicza, T. Smakowskiego, S. Speczika. PIG-PIB Warszawa.