Geometallurgical Studies on Gold Ore for Enhanced Comminution and Leaching

Ghana Mining Journal Pub Date : 2019-01-01 DOI:10.4314/gm.v19i1.7

G. Ofori-Sarpong, T. Okwaisie, R. Amankwah

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引用次数: 1

Abstract

Many gold processing plants are experiencing challenges as mining pits are becoming deeper, rocks are getting harder and more complex polymetallic and refractory ores are being encountered. The variations in the characteristics of ores lead to deviations from the established parameters, and these affect gold extraction efficiency. This paper presents a study where geological characteristics of the ore types from some mining pits were used to ascertain the influence of ore blends on improving the performances of comminution and leaching circuits. To achieve this, mineralogical, comminution, gravity recoverable gold and leaching investigations were conducted on fresh and weathered ore samples and their blends. Mineralogical study showed that the main rock types associated with the mine pits were dolerite, phyllites, conglomerates and sandstone. The dominant minerals were quartz, plagioclase, with traces of pyrites. The Crushability Work Indices of the rocks were between 30 and 37 KWh/t, which are generally higher than the maximum design value of 31.9 kWh/t, and this situation will pose throughput challenges in that section. The Bond Ball Mill Work Indices of the blends tested were between 16.4 kWh/t and 9.6 kWh/t and a blend ratio of 85% fresh and 15% weathered was found to have a Bond Ball Work Index almost equal to the design value of 14 kWh/t. With gold assays of 2.5 g/t for dolerite, 2.1 g/t for phyllite, 3.7 g/t for sandstone and 3.4 g/t for conglomerate, the gravity recoverable gold was in the order of sandstone 36% > phyllite (31.5%) > dolerite (29.5%) > conglomerate (18%). The overall gold recoveries were in the sequence of conglomerate (95%), sandstone (94%), phyllite (92%) and dolerite (87%). This information could be utilised in developing a proactive plant operations strategies for an operating plant in order to ultimately manage the plant and enhance achievement of set targets. Keywords: Geometallurgy; Ore Blends; Characterisation; Communition Circuit Performance; Gold Recovery

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金矿强化粉碎浸出的地质冶金学研究

随着矿坑越来越深，岩石越来越硬，多金属和难熔矿石越来越复杂，许多黄金加工厂都面临着挑战。矿石特性的变化会导致与既定参数的偏差，从而影响提金效率。本文利用某矿区矿石类型的地质特征，探讨了混合矿石对提高粉碎浸出回路性能的影响。为了实现这一目标，对新鲜和风化的矿石样品及其混合物进行了矿物学、粉碎、重力可采金和浸出研究。矿物学研究表明，与矿坑伴生的主要岩石类型为白云岩、千层岩、砾岩和砂岩。主要矿物为石英、斜长石，微量黄铁矿。岩石的可破碎性工作指标在30 ~ 37 KWh/t之间，普遍高于最大设计值31.9 KWh/t，这将给该段的吞吐量带来挑战。试验共混物的Bond球磨功指数在16.4 ~ 9.6 kWh/t之间，当混合比为85%新鲜和15%风化时，Bond球磨功指数几乎等于14 kWh/t的设计值。含金量分别为:白云岩2.5 g/t、千层岩2.1 g/t、砂岩3.7 g/t、砾岩3.4 g/t，重可采金量顺序为砂岩36% >千层岩(31.5%)>白云岩(29.5%)>砾岩(18%)。金的总体回收率依次为砾岩(95%)、砂岩(94%)、千层岩(92%)、白云岩(87%)。这些信息可用于为正在运行的工厂制定积极主动的工厂运营战略，以便最终管理工厂并提高既定目标的实现。关键词:Geometallurgy;矿石混合;描述;通信电路性能;黄金复苏

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Ghana Mining Journal

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