Biogeocementation - Biologically Catalyzed reactions to improve the geotechnical properties of tailings deposits******

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The mining industry in Canada has an unmet need to improve tailings deposit performance both during mine operation and post-closure. Tailings are the byproducts that remain following the extraction and recovery of valuable minerals from mine operations. These tailings are either backfilled into mine sites, or disposed of in tailings impoundments, such as dams, raised embankments or in rivers, lakes and oceans. With no treatment it can take several hundred years to consolidate these dams, due to the poor water-releasing property of the tailings. The toxic nature of tailings means poisonous chemicals can easily diffuse into the surrounding environment, leaching acidic drainage and heavy metals to groundwater. ****The biogeocementation of tailings, using biologically catalyzed reactions to create rock-like tailings deposits, is an attractive concept because a 'cement' can be formed that is durable enough to improve the mechanical behaviour of the tailings. The current state of research in microbial biogeocementation is technically viable, but additional laboratory 'proof of concept' work is needed to attract funding from industry partners to move to pilot-scale testing.****Research will focus on how microbes responsible for producing the calcite, or 'cement', will survive in tailings dams, how effective they are at cementing the tailings, and the feasibility for utilizing these microbes at a scale seen in tailings dams around Canada. If proven viable, this technology will improve the health of both the public and the environment by reducing exposure time to toxic chemicals. In addition, the carbon footprint of mine operations will be reduced, additional water can be re-used during processing steps, and the safety and stability of tailings facilities will be increased.**