Mine tailings by David Dodge
Guest blogger José Luis Gutiérrez-Gutiérrez shares his experience of working in the mining industry in the Canadian arctic. He explores an interesting alternative to storing mine waste in natural or man-made containment ponds that has had success in an Arizona mine. Read Part One of this story.
And now for the conclusion of this story. Remember where we left off
? I was telling you about how metal mining companies can turn their toxic waste into a revenue stream through a practice called “upcycling”.
Here’s a quick recap. Upcycling is the practice of taking something that is disposable and transforming it into something of greater use and value. Upcycling is an emerging, small, disaggregated industry that is full of innovation and is growing fast. It is upgrading a waste item to something better that can be used or sold for a profit.
For example, plastic debris floating needlessly in three oceans could become gasoline, diesel, kerosene, or light crude oil. Waste cooking oil will turn into biodiesel, and mine tailings will produce autoclaved aerated concrete (AAC) building materials such as blocks, and roof and wall panels.There are no barriers to upcycling that cannot eventually be solved for it to become a widely used practice in mining. A change in industry attitudes, initial investment as part of a company’s sustainability strategy, government incentives, and closer collaboration between industry and communities are all part of a recipe for successful upcycling.
In the future, the intention of mining companies to make a profit and to make life better for metal users (i.e., everyone) , will be a harmonic intention that is integrated or combined in nature. This is another way to say, create a win-win situation. There will be no need to sacrifice a lake to achieve the goals of making a lot of money.
With a harmonic, integrated, holistic approach, and an upcycling mentality, cooperation between industry and government could see regulatory loopholes to pollute Canada’s lakes with toxic waste, like Schedule 2 of the Metal Mining Effluent Regulations
, replaced with valued conservation solutions.
Communities that are directly and simultaneously affected and benefited by a mining operation could join with government to invest in the conservation of any water body proposed for use as a tailings pond. They could do this by funding the construction on the mine’s site of a tailings detoxifying plant and another facility called a “tailings-to-Autoclaved Aerated Concrete (AAC)” plant. I’ll get to AAC in a moment…
Mining companies generally like to focus on mining rather than new initiatives, so what would their interest be to collaborate or support building these or other value-added plants on their property? You will see below. But first, let’s talk cement.
Among all the environmentally hazardous materials in the world, cement is somewhere in the top among the most destructive. Every tonne of cement manufactured causes the direct emission of 0.8 tonnes of CO2.Mining can combine cement and unwanted, abundant mining tailings to make concrete, particularly autoclaved aerated concrete. Already the Phelps Dodge Casa Grande, Arizona Copper mine tailings were used in AAC products with some limitations because the silica content was not ideal.This would reduce the amount of cement required to make concrete, and it would re-purpose tailings. Because tailings use displaces cement use, it also reduces the need for cement production from non-renewable resources.
Cooperation from the cement industry to promote the use of mine tailings as aggregate in AAC could also save lakes from becoming tailings ponds, and other water bodies from contamination, resulting in fewer disturbances on the environment, employment for more people, and the manufacturing of a useful product – all while reducing our collective carbon footprint.
Because I’m still translating from mining reality, these ideas sound expensive, not proven; they’re tree-hugging and pipe-smoking hippie talk. From the mining mindset, the push for implementing alternative disposal solutions to submerging tailings in water bodies needs a solid base on an economic reason.
That is when human reality kicks into mining gear.
The money fueling the lake conservation, and the cleanup and upcycling operations will not come from donors and donations, instead it will come from investors who are attracted to the idea of making a return on their investment and helping to conserve the lakes and other water bodies in the mine claim.
The investor behind the tailings detoxifying plant, which is a necessary piece of this puzzle, gets a return on investment through the recovery of the trace metals contained in the tailings.
The investor behind the tailings-to-AAC plant makes money from multiple revenue streams;
1. Selling the AAC products to the market;2. Selling all the conservation attributes that a conserved lake/water body has to offer, including recreation, eco-brokerage, ecologically-friendly aquaculture, and agriculture;
CO2 emission reduction derived from replacing tonnes of cement with mine tailings in the AAC production. Selling the carbon savings from the AAC products to offset the carbon footprint of the mining project and of the cement company.3. There are some limitations as to where the type of tailings upcycling described above can be implemented, and material transportation costs, tailings detoxification and metal recovery profitability, concrete quality and other factors have to be examined. Notwithstanding, it is this sort of technological innovation to reduce, reuse and upcycle waste that separates stakeholders’ and key employees’ mindset from environmental compliance to business value.
Who knows, in the near futurer we may be reading headlines about a federal or provincial decision to give a harmonic, eco-effective, integrated, holistic mining project the green light, saying that avoiding environmental damage more than balances wealth, community prosperity and job creation.