Recovery of copper

Copper. The recovery of copper [7440-50-8] Cu, from ore leach Hquors as a stage in the hydrometallurgical route to the pure metal is one of the... 

Dissolved Minerals. The most significant source of minerals for sustainable recovery may be ocean waters which contain nearly all the known elements in some degree of solution. Production of dissolved minerals from seawater is limited to fresh water, magnesium, magnesium compounds (qv), salt, bromine, and heavy water, ie, deuterium oxide. Considerable development of techniques for recovery of copper, gold, and uranium by solution or bacterial methods has been carried out in several countries for appHcation onshore. These methods are expected to be fully transferable to the marine environment (5). The potential for extraction of dissolved materials from naturally enriched sources, such as hydrothermal vents, may be high. 

AEROPHINE 3418A promoter is widely used ia North and South America, AustraHa, Europe, and Asia for the recovery of copper, lead, and ziac sulfide minerals (see Elotatton). Advantages ia comparison to other collectors (15) are said to be improved selectivity and recoveries ia the treatment of complex ores, higher recoveries of associated precious metals, and a stable grade—recovery relationship which is particularly important to the efficient operation of automated circuits. Additionally, AEROPHINE 3418A is stable and, unlike xanthates (qv), does not form hazardous decomposition products such as carbon disulfide. It is also available blended with other collectors to enhance performance characteristics. 

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). 

Metal Extraction. As with other carboxyhc acids, neodecanoic acid can be used in the solvent extraction of metal ions from aqueous solutions. Recent appHcations include the extraction of zinc from river water for deterrnination by atomic absorption spectrophotometry (105), the coextraction of metals such as nickel, cobalt, and copper with iron (106), and the recovery of copper from ammoniacal leaching solutions (107). 

Selectivity for a single metal of a group is the basis of a solvent extraction process for the recovery of copper (qv) from low concentration ore leach solutions containing high levels of iron (qv) and other interfering metals (16). 

Fig. 1. Recovery of copper from sulfide ore. The residue from electrolytic refining is processed to recover gold, silver, and selenium. Courtesy of Kennecott...

The mud or slime is coUected from the bottom of the electrolytic ceUs and pumped to the sUver refinery, where it is processed for recovery of copper, precious metals, selenium, and, in many cases, teUurium. The anode slime contains 2—20% selenium as copper and sUver selenides, whereas gold exists as the metal and in combination with teUurium. A flow diagram is shown in Figure 8. 

Hydrometallurigcal Processes. In hydrometaHurgical processes, metal values and by-products are recovered from aqueous solution by chemical or electrolytic processes. Values are solubilized by treating waste, ore, or concentrates. Leaching of copper ores in place by rain or natural streams and the subsequent recovery of copper from mnoff mine water as impure cement copper have been practiced since Roman times. Most hydrometaHurgical treatments have been appHed to ores or overburden in which the copper was present as oxide, mixed oxide—sulfide, or native copper. PyrometaHurgical and hydrometaHurgical processes are compared in Reference 34. 

HydrometaHurgical recovery of copper from manganese sea nodules has been studied extensively, as have combined PyrometaHurgical—hydrometaHurgical processes. Advancements in hydrometaHurgy and leaching technology are described in References 35—37. 

Recovery of copper metal and alloys from copper-bearing scrap metal and smelting residues requires preparation of the scrap (e.g., removal of insulation) prior to feeding into the primary process. Electric arc furnaces using scrap as feed are also common. 

Figure 6.6 Recovery of Copper from Liquid Effluents of an Etching Plant (El-Halwagi and Manousiouthakis, 1990a. Automatic Synthesis of MassExchange Networks, Chem. Eng. Sd., 45(9), p. 2825, Copyright 1990, with kind permission from Elsevier Science Ltd., The Boulevard, Langford Lane, Kidlington 0X5 1GB, UK.)...

Recovery of Copper Powder from Wastewater in Three-Phase Inverse Fluidized-Bed Reactors... 

The recovery of copper powder from wastewater of electronic industries was investigated in three-phase inverse fluidized-bed electrode reactors(0.102m ID x 1.0m). Effects of gas and liquid velocities, current density, distance between the two electrodes and amount of fluidized particles on the recovery of copper powder were examined. The addition of a small amount of gas or fluidized particles into the reactor resulted in the decrease in the powder size of copper recovered as well as increase in the copper recovery. The value of copper recovery exhibited a maximum with increasing gas or liquid velocity, amount of fluidized particles or distance between the two electrodes but increased with increasing current density. 

Effects of current density(I) on the recovery of copper in the reactor can be seen in Fig. 5. As can be seen, the value of R increased gradually with increasing ciurent density, since the mass transfer rate of copper ion is proportional to the current density. Effects of amount of fluidized particles on the recovery of copper can be seen in Fig. 6. Note that the addition of a small amount of fluidized particles (W=1.0wt.%) to the reactor could increase the copper recovery up to 10 25%. It has been mderstood that the contacting of fluidized solid particles with the cathode plate could clean the siuface as well as decrease the diffusion layer of copper ion, which results in the increases of reaction rate and current efficiency, thus, the recovery of copper could be increased. 

Fig. 4. Effects of Ug on the recovery of copper in inverse fluidized bed electrode reactors(W= f.Owt.%, I=3.5A/dm UL=0.001m/s, Lac=...

Fig. 5. Effects of I on the recovery of copper in inverse fluidized bed reactors(W=1.0wt.%, Lac= 0.015m, UL=0.001cm/s, Ucj=0.001m/s).

However, when the amount of added particles increased(W=2.0 or 3.0wt.%), the effective surface area of cathode plate decreased due to the considerable increase of solid holdup between the two electrodes, thus, the amount of copper recovery decreased. In this experimental conditions, the distance between the two electrodes(LAc) also influenced the recovery of copper, as can be seen in Fig. 7. In this figure, the value of R was maximum when the distance(LAc) was 1.5cm, in all the cases studied. 

Fig. 6. Effects of amount of fluidized solid particles on the recovery of copper in an inverse fluidized bed electrode reactor(LAc=0.015m, Ug= 0.001m/s,UL=0.001m/s).

By-product of copper ores By-product reserves of copper ores are those contained in ores that are or would be mined mainly for the copper content. Molybdenum recovery occurs as a by-product or secondary product during processing of the ore for the recovery of copper. 

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

Recovery of Copper from Printed Circuit Board Etchant... 

Mahdi C, Oualid H, Fatiha A, Christian P (2010) Study on ultrasonically assisted emulsification and recovery of copper(II) from wastewater using an emulsion liquid membrane process. Ultrason Sonochem 17(2) 318-325... 

Figure 5 A simplified flowsheet and materials balance for the recovery of copper from oxidic and transition ores by heap leaching, solvent extraction and electrowinning.

Kyuchoukov, G. Mihaylov, Y. A novel method for recovery of copper from hydrochloric acid solutions. Hydrometallurgy 1991, 27, 361-369. 

Kyuchoukov, G. Mishonov, I. A new extractant mixture for recovery of copper from hydrochloric etching solution. Solvent Extr. Ion Exch. 1993, 11, 555-567. 

Kumar, V. Jana, R. K. Pandey, B. D. Jha, D. Nayak, A. K. Bagchi, D. Akerkar, D. D. Recovery of copper, nickel and cobalt from ammoniacal leach liquors obtained by direct ammonia leaching of sea nodules. Trans. Indian Inst. Met. 1987, 40, 64-70. 

Bulatovic, S., and Newman, D., The recovery of Copper/Nickel and PGM from Strathcona Plant, Report of Investigation LR3958, 1984. 

A recent and extremely important development lies in the application of the technique of liquid extraction to metallurgical processes. The successful development of methods for the purification of uranium fuel and for the recovery of spent fuel elements in the nuclear power industry by extraction methods, mainly based on packed, including pulsed, columns as discussed in Section 13.5 has led to their application to other metallurgical processes. Of these, the recovery of copper from acid leach liquors and subsequent electro-winning from these liquors is the most extensive, although further applications to nickel and other metals are being developed. In many of these processes, some form of chemical complex is formed between the solute and the solvent so that the kinetics of the process become important. The extraction operation may be either a physical operation, as discussed previously, or a chemical operation. Chemical operations have been classified by Hanson(1) as follows ... 

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 the optimization of the solvent extraction process for the recovery of copper using LIX 64N, Robinson [77] described the eost funetion in terms of the sum of the operating and capital costs. The operating eosts were taken as resulting from losses of eopper and solvent ... 

Tunley, T. H. Birch, C. P. The recovery of copper from sulphate leach liquors by liquid ion exchange with LIX64N, National Institute of Metallurgy, Johannesburg, South Africa, Report No. 140904. 

Another reported example with two metals in solution is the recovery of copper and zinc from brass mill flue dust [11]. The material contains very little iron. The solid material is leached with sulfuric acid to produce a weak acid... 

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