Relationship between Mineralogy and Gold Recovery in Palaeoplacer Tarkwaian Conglomerate, Ghana

Abstract

This paper focused on mineralogy and gold extraction from three Palaeoplacer gold pits at Tarkwa in Ghana. The rocks investigated were generally composed mainly of quartz, minor chlorite, sericite and plagioclase with traces of epidote. Ore minerals were mainly pyrite, magnetite, pyrrhotite, chalcopyrite and hematite. The percentage of gold recovered ranged from 89.64 % to 99.21 %. Lime consumption for virtually all ranged from 1.0 to 1.5 kg/t except for partially weathered rocks from Pit 3 which recorded 5.30 kg/t. Cyanide consumption was moderate and ranged from 0.01 to 0.10 kg/t. Gold recovery in the Tarkwaian ore was related to sulphide mineralogy factor involving pyrrhotite (Po) and pyrite (Py), and platy mineralogy factor comprising of chlorite (Chl) and sericite (Ser) as follows:                                                                                                                                                                          

This equation should be developed to predict recovery from known modal composition of the palaeoplacer ores.