Microwave heating is a form of high-frequency electromagnetic radiation. The heating of primary and secondary mineral raw materials in the microwave field depends primarily on their dielectric and thermal properties. The condition is the absorption of microwave radiation. Dielectric heating of materials occurs immediately after placing them in an electric high-frequency field. Knowledge of the dielectric characteristics of mineral raw materials is an important assumption for the use of electromagnetic radiation at the intensification of technological treatment methods. Most mined minerals consist of several mineral components that have different dielectric properties. Most sulphides are well heated in a microwave field. Conversely, tailings components of ores, such as quartz, are transmission materials. The study of dielectric properties involves measurements of the complex relative permittivity ε*, which consists of a real and an imaginary part. The imaginary part of permittivity “loss factor” represents the measure of dielectric losses in the material. Microwave heating of sulphide ores and concentrates such are chalcopyrite, tetrahedrite, galena depends on their chemical composition and content of impurities. The article describes the influence of dielectric properties on heating of chalcopyrite in microwave field. SEM analyses of studied samples are presented.
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Artykuł przedstawia zarys technologii SX-EW (solvent extraction-electrowinning), będącej jedną z kluczowych metod hydrometalurgicznych pozyskiwania miedzi. Omówiono jej podstawowe zalety w porównaniu z metodami klasycznej pirometalurgii. Przeanalizowano perspektywy rozwoju produkcji miedzi z SX-EW w świetle przesłanek technologicznych, ekonomicznych i środowiskowych, a także przedstawiono prognozy w tym zakresie. Wspomniano również o próbach zastosowania metod hydrometalurgicznych z użyciem różnych sposobów ługowania, podejmowanych przez jednostki badawcze w Polsce w celu poprawy efektywności odzysku metali z rud LGOM.
EN
The paper presents a short description of solvent-extraction/electrowinning process (SX-EW), as a crucial technology in hydro-metallurgical technologies for copper recovery. The major prospects for development of copper extraction by this method as an alternative for conventional smelting/refining have been discussed taking into account recent technological achievements, the bio-leaching in particular. The paper cites also a few examples of the use of leaching method, which were examined in Poland in the laboratory scale in the 1990s. However, the prospects for the method utilisation in the domestic copper industry seem to be doubtful in the near future.
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