Intensification of magnetic separation and leaching of Cu-ores by microwave radiation

The microwave radiation is used intensification of magnetic separation and leaching of Cu-ores. The thermic decomposition as a result of interaction between microwave radiation and sulphidic minerals makes possible the magnetic separation of weakly magnetic chalcopyrite and tetrahedrite. In case of magnetic separation of chalcopyrite ore it is possible to obtain the Cu- recovery in 62.53%. The volatile substances (Hg and Sb) releasing at thermic decomposition of tetrahedrite are adsorbed on the surface of active coal. The subsequent magnetic separation of tetrahedrite from the active coal has showed the decrease of the content of Sb from 14.3% to the value 0.8% and Hg from 0.8% to the value 0.1%. The influence of microwave energy on the extraction of components from the chalcopyrite concentrate into the leach was investigated and has been showed that its leaching in microwave oven with ferric chloride agent becomes more effective; the temperature of the leaching suspension was 90 degreesC. The leaching of tetrahedrite was realized in leaching solution Na2S (300 g/l) and effect of microwave radiation is evident: after 15 min was observed the 4-manifold arising of As recovery. The positive influence of microwave radiation was also noticed at extraction of Ag from tetrahedrite: the 9-manifold arising of Ag recovery was determined. (C) 2002 Elsevier Science B.V. All rights reserved.