Оптимизация технологии обогащения бедной технологически упорной золото-углеродсодержащей руды

Abstract

The processing of refractory gold ores is a challenging task. Refractory ores include ores that cannot be easily processed due to the fine dissemination of gold in sulphide minerals and the presence of preg-robbing carbonaceous matter. Two processes have been studied: flotation of low-grade double refractory gold ore ­using new carbon depression reagents; gravity – cleaner flotation of rougher flotation concentrate followed by pressure oxidation and the CIL treatment of POX cakes. The study is aimed to optimize the processing of low-grade (Au 0.6 g/t) refractory gold ore and achieve high process parameters. The study included the following steps: the reduction of organic carbon mass fraction (< 0.6 %) in concentrates reporting to hydrometallurgical treatment; experiments on the hydrometallurgical treatment of flotation concentrates using two process options: pressure oxidation (POX) of the initial flotation concentrate followed by the CIL treatment of POX cakes and preliminary gravity – cleaner flotation of the initial flotation followed by pressure oxidation and the CIL treatment of POX cakes. The research methodology is based on studying the influence of carbon depressant reagents on the flotation properties of organic carbon during the flotation process. When carrying out flotation experiments, the equipment of JSC Irgiredmet was used, installed at the semi-industrial testing site (laboratory mills, mechanical flotation machines and auxiliary equipment). The study is carried out in accordance with generally accepted methods of ore preparation and flotation concentration. The mass fraction of organic carbon in the flotation concentrate decreased from 2.0 to 0.5 %. It has been achieved by the use of new reagents for carbon depression (carbon depression reagents). The products of refractory gold ore flotation using new reagents for carbon depression were flotation concentrates suitable for further hydrometallurgical treatment. According to the experiments on rougher flotation concentrate pressure oxidation and subsequent POX cake cyanide leaching, the recovery of gold on the carbon adsorbent was 83.5 %. Preliminary gra­vity – cleaner flotation of the concentrate before pressure oxidation improved the loading of gold on the carbon adsorbent to 96.6 %.