SIDEBAR 5-2 Blue Sky Ideas for Research on Environmental Issues
• Economical recovery of metallic constituents from acid rock drainage releases, including methods of recovering iron sulfides in a form that could be used as a soil acidifier in agriculture. Technologies that could turn costly waste-treatment projects into economically viable production activities would have significant benefits in terms of resource conservation and waste minimization, in addition to the clear economic benefit of creating a secure and dedicated funding source for the remediation of acid rock drainage releases problems.
• Sealing of pit walls to prevent the oxidation of sulfides and the formation of acidic pit lakes. Open-pit mine walls at or above the water level of a pit lake can continue to oxidize and adversely affect the quality of pit water if they contain unbuffered sulfide minerals. Significant technical barriers must be overcome to devise a cost-effective way to seal these rock faces and prevent their long-term oxidation.
• Sealing of in-situ mineralized zones to prevent the inflow of groundwater and allow in-situ leaching and complete recovery of solutions without continuous pumping to maintain a cone of depression. The migration of metal-rich leaching solutions beyond the mineralized zone of an in-situ orebody and into the surrounding aquifer is currently controlled by continuous pumping of the groundwater to create and maintain a cone of depression around the operation. The cost of this dewatering activity, as well as the use of the water resource, could be eliminated if the mineralized zone could be sealed in place. Better control of the leaching solution would also provide a significant environmental benefit.
• Remote sensing of groundwater quality throughout the operating life of a mine and during the closure and postclosure periods. Groundwater-monitoring programs at mine sites can involve large numbers of wells, require thousands of samples and analyses, and last for decades. Techniques for direct, down-hole measurements and data logging could significantly reduce the cost and human resources requirements of monitoring.
• Effective, inexpensive technology for removing low concentrations of contaminants (e.g., selenium, arsenic) from high-flow volumes of water. The cost-effective recovery of low concentrations of potentially toxic large flows would have significant economic and environmental benefits.
• Techniques for rapidly developing soils on mine wastes, heaps, and tailings. The direct vegetation of mine wastes, without a soil cover or amendments designed to create a suitable growth medium, may foster some plant growth but can result in the establishment of a monoculture that cannot support complex ecosystems. Research should be conducted to develop cost-effective techniques for creating soil that can support a diverse plant community directly from mine waste.