High Efficiency Metal Recovery from Dilute Streams and Mine Drainage

Benefits:

• Profitable extraction of precious metals from aqueous streams
  
• Low operating costs
  
• Selective metal removal from mixed streams
  
• Highly pure metals recovered at very low concentrtions (<5 ppm)
• Modular, scalable to meet application requirements

Some people consider cleaning up the drainage at mine sites a hazardous, expensive, regulatory necessity. Some people consider cleaning up the drainage at mine sites a hazardous, expensive, regulatory driven necessity. Eltron looks at it as an opportunity to recover precious metals, remediate the site and generate revenue.

Traditional metal extraction and refining from aqueous streams is dominated by heap-leach, flotation, chemical reduction and in situ extraction methods. These treatment methods incur costs, but they don't create revenue. Electrowinning, another option, typically requires that metal solution concentrations are greater than 1,000 mg/L to be profitable, leaving behind significant amounts of wasted, environmentally detrimental resources.

The Solution
Eltron is turning clean-up into a profitable exercise with its innovative, turn-key electrolytic system for recovering saleable metals and metal-based products from dilute aqueous streams, leaching solutions and AMD. This electrowinning technology captures metals directly from low-concentration (<500 mg/L) leaching, refining and mine drainage streams.

While optimized for copper removal, the system is capable of selectively removing a broad spectrum of metals from mixed streams. It enables cost effective recovery of higher-purity precious metals, coinage metals and heavy metals, as well as toxic metals such as lead, cadmium and arsenic.

The steadily increasing demand for copper is driving the price up and making places such as the Berkeley Mine pit in Butte, Montana an ideal example for demonstrating the value of Eltron’s electrowinner. The water in the Berkeley Mine pit contains about 52 million pounds of copper and 165 million pounds of zinc at its current liquid volume, but at low concentration (172 mg/L Cu and 550 mg/L Zn, pH 2.8 H2SO4).

Eltron’s electrowinner will recover copper in high purity and at low cost, turning the mile-wide, 900-feet deep environmental headache into a new source for this highly prized metal. 

The Benefits
Eltron’s electrowinning technology helps reduce capital and operating expenses, lowering overall waste treatment costs. It also provides an economically profitable means for recovering saleable metals from aqueous streams that are otherwise considered waste or an environmental liability.

Eltron’s electrowinner is a green technology; no chemical reagents are required in the process. And, it’s the only electrowinning AMD treatment technology that combines a flow-through system with remote and unattended operation. When configured as a multi-stage system, it will provide single-pass flow through treatment of AMD.

The low power requirements of the system allow for off-the-grid operation (using wind, solar, hydro-electric power) which minimizes operating costs.

It’s estimated that there are 500,000 mine sites in need of AMD treatment. Whether they are remote or in populated areas, these mines represent a source of groundwater contamination and health hazards. With Eltron’s electrowinning technology, these sites can be turned from an environmental disaster into a profitable resource.