Concentration of Gold From Small Deposits in Serbia

Abstract

Tests presented in this work are conducted on samples of the Pb-Zn-Fe-Au poor mineralization from the Grabova Reka deposit, Ist Serbia. The methods are described of selective separation of auriferous minerals and accessory sulphides from complex quartz veins, small gold deposits, in Blagojev Kamen area (Grabova Reka deposit) characterized by nonunion and relatively poor gold mineralization (Au, Au+Ag, electrum, Au+Fe, Au+Pb, Au+scheelite). Gold prevailing occurs in small grains (5÷10 rarely 100 μm) contained in quartz, pyrite or in galena of pinkish shade from alloying with Bi and Cu. Electrum, a natural alloy of Au and Ag varies in grain size, but generally, electrum is found in large grains (0.5 mm on average) in the form of conglomerate where electrum is cementing cataclastic grains of pyrite (or as inclusions in pyrite and in galena) and other Pb-Zn sulphides. There are many deposits, in the mentioned region, with numerous outcrops of quartz veins with the gold rates from 10 g/t to 60 g/t or even to 120 g/t on average, somewhat lower silver, and some lead and zinc (about 1%). The analysed sample was collected by chipping in places of visible sulphide mineralization from quartz vein No. 2 in plagiogranite. The purpose of this work was to accurately establish the modes of gold or auriferous mineral occurrence, for testing its selective separation. A flow-chart is given of the mineral recovery process and the mineral balance. A characterization is given of the mineralized grains in raw material which are essential for planning the technology of processing. One of the methods used, is the heavy liquid separation analysis at the density of 13.6 g/cm 2 .