The basic product of the Legnica copper smelter/refinery, located in the Lower Silesia region of Poland, is electrolytic copper in the form of cathodes weighing 100 kg and round billets of 150-300 mm in diameter and 300-2500 mm in length. The quality of the cathodes is guaranteed by the internationally-recognised HML brand. The cathodes have been listed under this brand since 1990 on the London Metal Exchange as "A" grade, i.e. of the highest quality. The byproducts arising during production are nearly all put to economic use with benefits for the environment.
Currently, the Legnica copper smelter/refinery produces annually 100 thousand tonnes of high quality electrolytic copper in the form of cathodes and 15-20 thousand tonnes in the form of billets.
The Legnica copper smelter/refinery was established in 1951 as the Legnica Metallurgical Plant. On 24th December 1953, copper from ore, from the so-called Old Copper Belt, was extracted for the first time. On 19th March 1959, the Legnica Metallurgical Plant was transformed into the Legnica copper smelter/refinery, with an annual production capacity of 12.5 thousand tonnes of electrolytic copper. The discovery of the new copper ore deposit and the construction of the Lubin and Polkowice mines led to the expansion of the facility and the increase of its production capacity in 1960 to 60 thousand tonnes annually. In July 1970, the Legnica copper smelter/refinery became part of the Copper Mining and Smelting Industrial Complex (KGHM). Since then, the facility has been steadily modernised, adapted to technological change and global production standards, especially in respect of environmental protection.
Production in the Legnica copper smelter/refinery is based on the technology of copper concentrate smelting in shaft furnaces.
The main stages of the process are:
- Preparation of the input material for smelting - preparation of concentrate briquettes with 15-20% content of copper, slag and coke;
- Smelting - as a result copper matte is obtained, being a sulphide alloy , mainly copper and iron sulphides;
- Converting, i.e. processing copper matte in a converter furnace (oxidisation of sulphides) to obtain converter blister copper with 98.5% Cu content;
- Fire refining in anode furnace to remove impurities and cast copper anodes;
- Electrorefining, during which anode copper is dissolved in electrolyte and copper is recollected on cathodes.
Copper cathode, with 99.99% Cu content, is the final product, which is then either sold or processed to obtain other products at the Cedynia wire rod rolling mill. The anode slimes remaining after electrorefining are are further processed to recover silver, gold and platinum group metals.