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 2011 anticipated economic resources of copper ore amounted to 1,810.44 million tonnes with metallic copper amounted to 34.87 million tonnes and silver amounted to 107.37 thousand tonnes (table 1). Anticipated economic resources of copper ore increased by 57.56 million tonnes in comparison with the previous year. Anticipated economic resources of copper ore in exploited deposits are equal 1,494.85 million tonnes (29.45 million tonnes of metallic copper and 88.22 thousand tonnes os silver).
In 2011, copper mining gave 22,985 thousand tonnes of copper ore yielding 459 thousand tonnes of metallic copper and 1,635 tonnes of silver. In comparison with the year 2010, production of copper ore and recovery of silver increased (by 2 % and 33 % respectively).
Figures given below shows resources and production of copper ores and changes in resources and output of copper in Poland in the years 1989-2011.
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 and Re. Recovery of silver is here of the largest economic importance. According to the data provided by the KGHM Polish Copper Combine S.A., in 2011 the copper processing was accompanied by recovery of 1,259.6 tonnes of silver, 510.1 kg of gold and 30.0 thousand tonnes of lead.
Prepared by: Agnieszka Malon, Stanisław Z. Mikulski, Sławomir Oszczepalski, Marcin Tymiński
(1) S. Oszczepalski, S. Speczik, 2011 - "Rudy miedzi i srebra" w "Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31 XII 2009 r." pod red. S. Wołkowicza, T. Smakowskiego, S. Speczika. PIG-PIB Warszawa.