Not Your Grandfather’s Mine

The five ways in which technology and innovation are making mining more sustainable

 

When asked to picture a mine, many Canadians imagine a deep pit filled with noisy trucks belching diesel fumes and dust into the air. The miners they picture may be older men with dirty faces and scruffy beards, working in dark, cramped conditions with hand-held tools. Each day, this image becomes further from the truth. As the Mining Association of Nova Scotia says, it’s “not your grandfather's mining industry” anymore.

Modern mines use a range of technologies, including machine learning, supercomputers, automation, monitoring sensors and artificial intelligence, to reduce the environmental footprint of mining. By tapping into renewable energy sources and reducing, reusing and recycling water onsite, companies are creating climate-smart mines to produce the minerals and metals needed for a low-carbon future.

Mines built in Canada and Canadian companies operating overseas are governed by stringent environmental regulations and driven by social awareness to build each new mine better, safer and cleaner than the last. Here are five ways in which mining is becoming more sustainable.

No. 1 – New sources of water

Water is a precious and finite resource. Each year, mines use hundreds of millions of litres of water to process and extract ore, create facilities to store tailings and waste rock, cool and wash machinery, and suppress dust. Often, mines in water-stressed countries and regions are competing with agriculture for scarce water supplies.

As a result, mining companies are looking beyond fresh, drinkable water to alternate water sources that may not be suitable for agriculture or human consumption but are fit for industrial purposes. They are also coming up with clever ways to reduce, reuse and recycle water onsite.

Acting on the suggestion of a community leader, international mining company Freeport-McMoRan built a wastewater treatment plant to treat 85 percent of the municipal sewage produced in Peru’s second-largest city, Arequipa. About half of the treated water is used for mining operations and the rest is released into the Rio Chili to be accessed by farmers around Arequipa. To learn more about this project, read Canadian International Resources and Development Institute's case study.

No. 2 – Climate-smart mines

The environmental footprint of a mine is measured primarily by the amount of greenhouse gas released and the amount of water and fossil fuel consumed. The deeper the mine, the more energy is required. Mines need energy for blasting, hauling, crushing, ventilation and processing, and the dominant energy sources for mines in Canada are diesel fuel and electricity.

Borden electric underground mining vehicle

Converting diesel trucks and equipment to run on battery power dramatically diminishes the footprint of a mining operation as it reduces emissions and the need to run large ventilation systems that remove emissions from and pump breathable air into underground mines.

Canadian gold mining company Goldcorp is building Canada's first fully electric underground mine at its Borden Lake project near Chapleau, in Ontario. Over the border in Quebec, Nouveau Monde Graphite is hoping to be the first to build an all-electric, open-pit mine with a carbon-neutral footprint at its Matawinie project, where construction is planned to start in the middle of 2020.

 

 

No. 3 – Deliberate digging

Each scoop of rock removed from the earth at a mining operation contains a small amount of valuable ore and a lot of waste rock. A substantial portion of the energy, water and effort on a mine site is used to move, process and store this waste rock.

To make mining operations more efficient, innovative technologies are being used to identify what is ore and what is waste rock. These technologies include custom underground robots that locate and select mining ore and devices that scan the rock in transit between the mine and the processing plant to literally “separate the wheat from the chaff”.

Canadian mining company Teck Resources partnered with another Canadian company, MineSense, to trial a bucket-mounted shovel sensor at the Highland Valley Copper mine in British Columbia. The sensors are mounted on the shovel bucket and use X-rays to tell the difference between waste rock and valuable ore. The load is then either sent to the mill for processing or handled as waste rock. To learn more about this technology, read the Teck article.

No. 4 – Clever mine waste disposal

The quality of the water leaving a mine site is an environmental and social concern, particularly for local communities and ecosystems. Mines in developed countries like Canada must adhere to strict regulations when returning water to the environment and prevent the unplanned release of potentially contaminated process water.

Process water is used to store ground rock—the rock “leftovers” resulting from the process of separating valuable minerals from the rock where they were contained. When combined, they form a slurry. This slurry is stored in a natural or engineered structure called a tailings facility. Major tailings failures, along with a desire to use fewer resources and reduce the water footprint of a mine, is driving the mining industry in Canada and globally to come up with better ways to store tailings.

Canadian gold mining company Goldcorp is developing a tailings management system that does not require a water cover. EcoTails™ mixes filtered tailings with waste rock to produce a thick slurry that is stable enough to be formed into dry tailings “pyramids”, using significantly less fresh water and reducing the overall environmental footprint of the mine. To learn more about this system, read Goldcorp's blog post.

Photo credit: Jose Luis Valverde Ortiz, Water Management Superintendent, Freeport McMoRan.
 

No. 5 – High-tech rehabilitation

Mining companies have an obligation to rehabilitate areas disturbed by their extraction activities. While mine site remediation practices have advanced beyond repairing the landscape, measuring and restoring the rich biodiversity of a site after a disturbance can be challenging.

Photo credit: Centre for Biodiversity Genomics

Some mining operations are harnessing the power of genomics—a combination of biology, genetics and computer science that provides an in-depth look at the DNA of all living things—to monitor and restore biodiversity during site restoration.

Canadian mining company New Gold Inc. recently collaborated with researchers from the University of Guelph, in Ontario, to explore the potential of genomic tools for site rehabilitation at their New Afton copper-gold mine in central British Columbia. Using simple traps, the biodiversity of a rehabilitated site and a nearby control site is measured by sending a “bug soup” of captured insects and spiders to the laboratory for next-generation DNA sequencing. The resulting snapshots of the creepy-crawlies can then be compared and used to guide restoration efforts. To learn more about this genomic tool, read CIM Magazine's article.

Mining is an evolving sector that uses innovation and technology to create sustainable operations that provide the minerals and metals needed to build a low-carbon future. The path is long, but the image of “your grandfather’s mine” is fading into history.