Dump leaching, copper ores

The factors that determine the choice lof solvent for a given ore are dependent on the nature of the mineralization and association of the metal values with the unwanted bulk of the ore. Since in the process of dissolution of the desired metal, other metals are also simultaneously going into solution, the minimization of the unwanted side reactions becomes very important in the final choice of a solvent. It must be remembered that the concentration of the recoverable metal in the ore very seldom exceeds 1% and in most cases is only a fraction of 1%. In the dump leaching of copper waste dumps, an average value of 0.30% is... 

Type 1 would be rhe leaching of a fractured ore body near the surface nhove the natural water table in the surrounding area. This would apply to mined out regions of old mines such as a bluck-caved portion of a copper mine, or regions which have been fractured by hydrofracturing or by the use of explosives. The chemistry and physical requirements wonld be essentially the same as in dump leaching. 

Table 9.2-1 presents the copper production by major copper producers in the western United States for the year 1978. The tonnage pi uc by dump leaching and the leaching of oxide ores was 18% of mial year tonnage. An estimated two-thirds of this, or approximately 12% of die total, nu be attributed to dump leaching of low-grade predominantly suuide-waste materials. 

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