| 摘要 |
Enclosed herein is a process for extracting and concentrating rhodium metal from its ores or from secondary sources which comprises electrolysis of an aqueous solution of halide ions at a selected pH so as to generate a reactive species and causing metallic rhodium or a rhodium-containing mixture to remain in intimate contact with said solution. Rhodium is dissolved by the solution and is obtained in a concentrated form by either subsequent redeposition on the cathode of the cell or by removal of the electrolyte solution as it becomes enriched in ionic rhodium species. Rhodium is conveniently separated from the cathode of the cell or the electrolyte and purified using techniques known to those skilled in the art. The use of extreme reaction conditions, and the need for on-site storage of certain dangerous chemicals are avoided. As a result, health and environmental risks are diminshed, and plant equipment undergoes less corrosion than a prior art. According to the present invention, extraction and concentration of rhodium proceeds at a reasonably fast rate using comparatively milder conditions than those in prior art. The starting materials required are safer to store and handle than methods of prior art, and greater economy is realized from increased control of the reactive species. Since the concentration of reactive species is controlled to near its equilibrium level for a given solution temperature, the use of an excess of reagents is avoided, and fume scrubber requirements are proportionately reduced. Rhodium metal concentrates are obtained.
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