High Efficiency Electro-Refining for Direct Capture of Saleable Metals
DOE Phase I Contract DE-FG02-05ER84320
Electrowinning is an important process used in the mining and refining of many valuable metals. Conventional electrowinning technologies are economically practical only at high metal concentrations, greater than 1000 mg/L. As a result, a large amount of metal value is lost as toxic waste that must be treated for proper discharge. There are also large aqueous sources laden with valuable heavy metals that are too dilute to be economically utilized as a resource.
Development of a high-efficiency electro-refining system for direct recovery of economically valuable metals from a variety of aqueous sources will be conducted during Phase I and Phase II. The core of this system is a unique electrolytic technology that allows control over key operating parameters that determine the electrowinning selectivity for individual metals. The new technology is reagentless, simple in design and process flow, low cost, mobile, and enables economic metal recovery and separation to very low concentrations, less than 1 mg/L.
During Phase I this unique electrolytic technology will be developed into a flow-through electrowinning system. Operating parameters and performance specifications will be determined for efficient recovery and selectivity of a number of target heavy metals. Electrolytic cell design and materials will be tested and evaluated for performance and longevity. This information will be used to design a pilot-scale flow-through electro-refining system to be constructed and demonstrated during Phase II.
Successful development of the proposed high-efficiency electro-refining system will allow selective recovery of metals from liquid streams down to very low concentrations. This will provide more complete utilization of available metal resources and greatly reduce toxic metal discharge and treatment costs. The primary targeted end-users of the proposed technology are the mining, refining, metal finishing, semiconductor/electronics, and environmental remediation industries.