Hydrometallurgical technologies

The Advanced Recovery Systems, Inc. (ARS) developed the patented, ex situ DeCaF hydrometallurgical technology to decontaminate fluoride by-products and to recover recyclable metals. The technology uses a proprietary acid mixture to digest the fluoride matrix, freeing radioactive contaminants (e.g., uranium, thorium, or radium) and hazardous contaminants (e.g., lead, arsenic, or chromium). Radioactive elements are recycled or disposed. Metals are also recycled, and fluoride is recovered as a high-value salt for aluminum smelting. 

In the 1990s, BHP Minerals developed a number of hydrometallurgical technologies with the potential to improve on perceived shortcomings with PAL, to support development of the Gag Island nickel laterite project. The aims included being ... 

The pyrochemical processes are assessed worldwide as a potential alternative to hydrometallurgical technology, especially in case of the reprocessing of minor actinide-rich materials. The pyrochemical R D programme, launched at the CEA Marcoule in the late 1990s, aims to demonstrate the feasibility of an innovative grouped separation of the actinides with sufficient decontamination of fission products. The core of the... 

DEMET (2) A process for removing metal contaminants from spent FCC catalysts by a series of pyrometallurgical and hydrometallurgical procedures. These typicaly include calcination, chlorination, and sulfiding. The demetallized catalyst can be re-used. Developed by ChemCat Corporation, LA, in 1988 first operated commercially in New Jersey in 1989. Now operated by Coastal Catalyst Technology. 

Moldovan, B.J., Jiang, D.-T., Hendry, M.J. 2003. Mineralogical characterization of arsenic in uranium mine tailings precipitated from iron-rich hydrometallurgical solutions. Environmental Science and Technology, 37, 873-879. 

Solvent extraction is now a proven technology for the commercial extraction, separation, and concentration of a wide range of metals both from primary and secondary sources (see Chapter 14). In recent years, there has been a reduction in the development, production, and marketing of new commercial extractants as the overall costs of such activities increases. However, the use of established reagents in new hydrometallurgical applications continues to expand. 

Some years ago, the process, shown in Fig. 14.20, was suggested as a centrally located plant for treatment of metal-containing waste in Sweden. The operation is based on the use of a pyrometallurgical induction converter and hydrometallurgical AmMAR process technology. 

Bloch, R. Hydrometallurgical Separations by Solvent Membranes Flynn, J. E. Ed., Membrane Science and Technology, Plenum Press New York, 1970. Danesi, P. R. Sep. Sci. Technol., 1984-1985, /9(11-12), 857-894. 

The only major impediment to the development of SIRs on an industrial hydrometallurgical scale is the problem of leakage of the reagent from the resin phase into the aqueous feed solution, a problem that is more severe in the first type of SIRs than in the Levextrel resins. If this problem can be solved, a bright future is predicted for this concept in resin technology. 

R. Bloch, Hydrometallurgical Separations by Solvent Membranes, in Proceedings of Membrane Science and Technology, J.E. Flinn (ed.), Columbus Laboratories of Battelle Memorial Institute, Plenum Press, pp. 171-187 (1970). 

Because all ores contain more than one metallic element of value, it is quite possible that in the very near future, hydrometallurgical processes will be developed to extract a whole line of products which at present are being discarded with the waste material. The dwindling supply of naturally occurring ore deposits, the increased demand due to an expanding technological age, and the pressure for maintaining a clean environment will help accelerate the development of such ideal processes. 

Volume 9 is concerned with actual and potential applications of metal coordination complexes. Major developments since the 1980s in the uses of coordination compounds have occurred in catalysis and medicine. There have been important developments of coordination chemistry in the technology of dyes and optical materials, for solar energy harvesting, for hydrometallurgical extraction, and in providing MOCVD precursors for new electronic materials. As mentioned above, the last volume in the series contains the indexes. 

Shiratori T, Sonta H (1993) Application of iron oxidizing bacteria to hydrometallurgical flue dust treatment and H2S desulfurization. FEMS Microbiol Rev 11 165—174 Shoji K (1992) Studies on Thiobacillus novellus cytochrome c oxidase. Dissertation for Ph.D. degree, Tokyo Institute of Technology, Tokyo... 

Many attempts have been made to investigate the interactions occurring at solid-liquid interfaces due to their technological, hydrometallurgical, and/ or analytical implications. Although the fixation of metal cations on solvent-impregnated resins has been extensively investigated, little has been done to characterize the physicochemical interactions between the solvent and the solid support. 

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