Within the European Union (EU27) the two most important gold producers are Finland and Sweden, covering more than two thirds of the European market. Due to the high gold prize mining companies are looking to extract more of the metal by improving recovery. We have done textural analysis on three gold-bearing deposits to better understand how the gold-textures seen in drill cores might affect the processing of different gold-ore types. In the Nautanen IOCG deposit, gold deportment is different whether gold is associated with pyrite or magnetite, and this must be considered when optimising the future mine and process planning. In the VMS-type Kristineberg deposit, the gold is associated with pyrite, sphalerite, and galena. Low gold recoveries from flotation could be explained by the occurrence of gold-inclusions in the pyrite. In the epigenetic Svartliden lode gold deposit, the gold is rather coarse-grained and associated with arsenopyrite-löllingite, and silicates. The relatively large grain size of gold can result in incomplete breakdown of the largest gold grains in the cyanide leaching process. To properly understand gold deportment in ores and to be able to improve mine planning and predict metal recoveries a comprehensive textural analysis of gold in drill core-samples is essential.
Godkänd; 2013; 20130819 (bark)