Polymetallic sulphide ores

Tailings and slimes dams represent the waste product after crushing, grinding and processing of the ore. Deposition can be in a dry form or hydraulically emplaced in the impoundment. Traditionally these dams are a major source of potential problems from escape of contaminants into the environment. For example a polymetallic sulphide ore can generate elevated anions, cations and metals together with chemical reagents from the process. 

The polymetallic sulphide deposit at Rudny Altay comprises a number of nearly vertical ore bodies at depths of 450-500 m in a tuff-slate formation. The tuff-slate is covered by dense Mesozoic-Cenozoic clays 40-50 m thick. The lithogeochemical survey does not yield clear anomalies. But the CHIM results for lead delineate satisfactorily the position of the ore bodies and their approximate projection to the surface (Fig. 2-22). 

By 1990, after a lot of study, it was concluded that a better way of treating the polymetallic sulphides was not in prospect. We were also forced to conclude tliat the gap of lost values was widening and was more likely to get still wider as the mineralogical complexity of the ores processed became worse. Strategically, the industry might be able, for a time, to select, and find, further deposits with easy mineidogy but with the demand for metals increasing this could be no more than a short term palliative. 

N.A. Warner, Towards Polymetallic Sulphide Smelting , Complex Sulphides. Processing of Ores. Concentrates and By-products. A.D. Zunkel et al., Eds., TMS-AIME, Warrendale, PA, U.S.A., 1985, 847-865. 

This type contains a variety of ores, including(a) gold-pyrite ores, (b) gold-copper ores, (c) gold-polymetallic ores and (d) gold oxide ore, usually upper zone of sulphide zones. The pyrite content of the ore varies from 3% to 90%. Other common waste minerals are quartz, aluminosilicates, dolomite etc. 

Such bacteria multiply in very aidic solutions (pH < 4.5). Their greatest amoxmt (on average 10 -10 cell-g" ) are discovered in water of copper sulphide and sulphide-polymetallic ore. The source of energy for them are oxidizing processes of not only protoxide metals in water solutions but also almost all reduced forms of sulphur. Bacteria Leptospira ferrooxidans are also capable of oxidizing protoxide iron with getting energy. These bacteria are close in a number of properties to Thiobacillus ferrooxidans, but as opposed to them do not oxidize sulphur. 

It was concluded that none of the known smelting routes could be adapted to smelt zinc rich sulphide feed with a high slag fall and that, therefore, they would not be suitable for raising the recoveries of value from polymetallic ores. 

It is shown that the Velikanov model [6] of polyfunctional conductor (PEC) is a good approximation for the properties of the LVl film. The electrochemistry of PEC had attracted considerable attention in the 1970s with regard to the practical problem of electrochemical processing of chalcogenide (sulphide) compounds, the components of natural polymetallic ores. 

PolyMet Mining Corp. (PolyMet) is advancing the development of the NorthMet Project. The NorthMet deposit is located in northern Minnesota, adjacent to the historic Iron Range. The deposit was discovered in the 1960 s and consists of a large, magmatic, disseminated sulphide, polymetallic deposit with values in Cu, Ni, Co, Zn, Au, Ag and Platinum Group Metals (PGM). The shallow, tabular orebody may be mined by open-pit methods with minimal pre-strip and a low waste ore strip ratio. 

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