A Densimetric Analysis of Flotation Concentrate from Kupferschiefer-type Copper Ore

Abstract

ABSTRACT The high mineralogical and lithological variability of polymetallic ores mined from copper and silver sedimentary deposits (SW Poland) has a strong influence on the upgrading processes and properties of the copper concentrates. This article’s subject is the analysis of the properties of industrial polymetallic flotation concentrate from copper ore showing difficult flotation upgradeability. One of the main causes of these difficulties is the transfer of organic carbon into the concentrate, which is tried to be explained in this work. A sample of industrial copper concentrate was subjected to densimetric analysis in a heavy liquid in search of the reasons for the mentioned difficulty. The separation products were balanced in terms of the content of copper, lead, silver and organic carbon as well as the mineral composition and liberation. A mineralogical analyzes of the separation products showed virtually uniform transfer of all sulfide minerals of copper, lead, iron and zinc to heavy fractions with 95–98% recovery. In the lightest fraction below 1700 g/dm3, with TOC content of 53%, approximately 0.4% of the dispersed copper carriers remained (as recovery) permanently bound mainly with organic-clay matter, which in terms of copper content was 2.6%. It was found that it is possible to separate a carbon middling from the concentrate, with a low copper content in relation to the content in the initial concentrate. Further research should be focused on finding methods to remove carbonate minerals and clay minerals from the concentrate during flotation with as the lowest losses of valuable metals as possible.