INNOVATION July-August 2013

Opposite: When exposed to carbon dioxide and water through natural weathering over time, the mineral olivine starts to absorb CO 2 .

countries with high environmental standards or those experiencing severe climate shifts. Norway has had a carbon tax since the 1990s, which now stands at over $70 a tonne (compared to BC’s $30 per tonne). The result has led to Norwegian carbon capture technology directing emissions underground. Australia, a country hard hit by climate change, has followed with emission permits purchased by industry. “They have really been decimated by climate change between droughts, flood, and fires. They are feeling the effect more than we are in Canada,” says Dipple. The UBC research focused on two areas when it began. Both Hitch and Dipple started their investigations with different and independent views, but combined their efforts as their research progressed. Hitch’s team looked at carbon sequestering in terms of mine operations. “Mine waste management is a big part of mine economics,” observes Hitch. “The concept of using one industrial waste product to capture another and furthermore realizing a carbon tax saving just seemed like good business sense. It was also environmentally satisfying for the mining industry.” From Problem to Potential Hitch focused on olivine, a greenish rock, with the requisite magnesium silicate chemistry. When exposed to carbon dioxide and water through natural weathering over time, olivine starts to absorb the CO 2 , forming magnesium carbonate (MgCO 3 ) or the mineral magnesite with silica (sand) and water as byproducts. The reaction is also exothermic and waste heat can be recovered for other uses. In its mineral form, CO 2 is at its most stable, fixed in place for hundreds of thousands of years. Both MgCO 3 and the silica are saleable by-products with MgCO 3 used in common form in the food, drug, and other industries where a white filler powder is required. MgCO 3 can also be used in making cement, so a downstream consideration is the possibility of turning a problem gas, when sequestered in mineral form, into building materials for use in eco-construction.

“The really cool thing is that there is nothing toxic or negative about this process,” he says. “We will have mining in BC for a long time and it only makes sense to develop synergies where we can create wealth and prosperity, while at the same time, doing something meaningful to curb emissions.” By marketing and selling sequestered CO 2 products, says Hitch, an additional revenue stream for a mine is possible, as well as the potential to trade or sell excess carbon credits. Under BC’s proposed carbon cap- and-trade framework, any excess credits can be sold on the open market. These combined revenues could all become positive benefits for an operating mine and extend mine life, or help to support the financial cost of mining lower grades of ore that might not be otherwise financially viable. “One day we might even find ourselves mining for sequestration materials, and the metals that were once of interest would just be a by-product,” Hitch suggests. Hitch and his team use high temperature and pressure autoclaves to speed up the natural reaction. “I am in the industrial process right now,” he says. The mine tailings his team is working on are from a BC project site. Prior to entering the autoclave, the tailings are ground to different

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