Dump copper

Table 1 gives the average metal content of the earth s cmst, ore deposits, and concentrates. With the exceptions of the recovery of magnesium from seawater and alkaU metals from brines, and the solution mining and dump or heap leaching of some copper, gold, and uranium (see Uranium and uranium compounds), most ores are processed through mills. Concentrates are the raw materials for the extraction of primary metals. 

Nonferrous Metal Production. Nonferrous metal production, which includes the leaching of copper and uranium ores with sulfuric acid, accounts for about 6% of U.S. sulfur consumption and probably about the same in other developed countries. In the case of copper, sulfuric acid is used for the extraction of the metal from deposits, mine dumps, and wastes, in which the copper contents are too low to justify concentration by conventional flotation techniques or the recovery of copper from ores containing copper carbonate and siUcate minerals that caimot be readily treated by flotation (qv) processes. The sulfuric acid required for copper leaching is usually the by-product acid produced by copper smelters (see Metallurgy, extractive Minerals RECOVERY AND PROCESSING). 

The economics of some mines frequentiy depend heavily on the revenues derived from leaching the waste to recover additional copper. This waste material, which has to be removed to uncover the ore, may be hauled to specially constmeted dumps, where the sulfides, the most common form of copper mineral, are oxidized and the leach solution can contact the waste material uniformly. Economics sometimes precludes optimization of dumps for leaching operations because of such factors as compaction, size distribution, and terrain (16). 

Many waste-rock or overburden disposal systems result ia compacted dumps having uncontrolled distribution of fines. In such dumps, solution distribution is poor and there is Htde oxygen for reaction with the sulfides. Methods for managing these dumps to maximize copper recovery have been actively pursued. 

All figures are on a dumped basis. Metal Lessing Rings are also made in stainless steel, copper, and aluminum. 

Recovery of copper from solutions generated in heap/dump leaching with sulfuric acid by cementation with iron. 

The vapour explosion which occurs when liquid copper is dumped into water has... 

A large dump of copper pyrites ore ignited after heavy rain. The thick layer (6-7 m) and absence of ventilation were contributory factors to the accelerating aerobic oxidation which finally led to ignition. 

It will be instructive to consider briefly the methodology employed in the development of solvent extraction processes that have become operational. The development of the Bluebird Mine operation for the extraction of copper from dump leaching liquors by solvent extraction and the subsequent recovery of copper as either copper sulfate or cathode copper is used as an example. The initial investigations [11] included the following ... 

In dump leaching of copper, it is not necessary to use extra stages of extraction to recover all the copper from the solution, since the raiSnate will be recycled to the dump. 

Heap (dump) acid leaching of copper sulfide ores is possible with the aid of microbial oxidation. Not all copper minerals are sulfidic, however— malachite, azurite, and chrysocolla are basic copper carbonates—and sulfuric acid heap leaching of low-grade copper carbonate ores can give solutions from which the Cu2+ ion can be separated by solvent extraction (Section 17.3) and copper metal obtained by electrowinning. 

Gokcay, C. F. Onerci, S. (1994). Recycling of copper Dotation tailings and bioremediation of copper-laden dump sites. In Emerging Technology for Bioremediation of Metals, ed. J. L. Means R. E. Hinchee, pp. 61-73. London Lewis Publishers. 

The heavy metals used in printed circuit electroless plating (copper and nickel) are in chelated form (chemically "tied-up" in an organic matrix). The plating baths are more unstable than electroplating baths, thereby resulting in more frequent "dumping". As a result, waste treatment requirements in printed circuit manufacturing operations present special problems and opportunities for membrane separation processes. 

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