ABSTRACT
Based on data obtained from drilling and on the analysis of samples taken from Pomorzany Mine, the author described intensity of the secondary alterations in ores (the level of oxidation of sulphide minerals including zinc, lead, and iron). The impact was shown of some geological factors (mineral composition, the depth of the ore nests, structural characteristics of rock mass) on the intensity and the pace of the secondary alterations in ores. The impact of tectonic systems on water circulation in the zone of oxidation and on the development of secondary mineralization was also discussed. Based on the analyses of chemical composition of several hundred Zn-Pb ore samples and on macroscopic analysis of selected samples, the primary origin of some of cerussite in the ores was pointed out. The content of selected elements (Cd, Ag, and As) as well in oxidised ores as in sulphide ores was presented. Finally, changes in mineral composition of ores in the region and their negative impact on ore processing were also indicated.
