MissionZero: to 2030 and beyond

To meet the 2-degree scenario set out in the Paris Climate Agreement, global GHG emissions need to be reduced by 24% by 2050. While mining is not currently the biggest industrial contributor of GHGs, it does account for 4-7% of global emissions and, if this is left unchecked, these numbers will quickly rise.  

Demand for metals is predicted to grow sharply over the next 30 years. Large quantities of copper, nickel and cobalt are needed to produce wind turbines and electric vehicles. Without these technologies, it will be impossible to meet the green energy targets set by governments. 
 

But as demand for metals increases, the average grade of deposits is falling. And, with several world-class copper operations approaching the end of their economic lives, the mining industry needs to look closely at the efficiency and sustainability of its processes. 

Time for action

Across society, awareness of climate change and its potential impacts is growing. 

This, coupled with the safety and environmental risks that tailings dam failures have highlighted recently, have kickstarted conversations around responsible mining practices. The desire for greater transparency and traceability in metal supply chains is now of key importance to investors and consumers.

“Social license to operate is one of the biggest risks that miners face,” emphasises Manfred Schaffer, FLSmidth’s President of Mining. “That’s why the time is right to explore what the mining industry can do to help fight climate change. We believe a big part of the solution will come from technology.”

There are two areas of the mining process that are particularly energy intensive: the first being mineral processing. 

According to the Coalition for Eco-Efficient Comminution, comminution accounts for 2.7% of all electrical energy consumed globally. Emissions produced in this area fall mainly under the scope 2 category – those incurred through power consumption.

The second area is mobile equipment driven by diesel engines which produce scope 1 emissions – those produced by mining operations. GHGs from these two areas combined account for around 1% of global emissions, with the other 3-6% contributed by fugitive emissions at coal mining operations.

“When it comes to CO2, we have two ambitions,” Schaffer says. “One is to eliminate all diesel-driven equipment. For those mines where it is appropriate, we have in-pit crushing and conveying systems. Then we need to find alternative technologies for milling and grinding and reduce the amount of fine grinding required through alternative flowsheets.”  

Part of the challenge that we and other vendors face is convincing mines of the business case around the switch to new technologies. Many require a significant capital investment which can be off putting at first. 

However, the benefits stretch far beyond saving a few dollars on energy or water. 
In some regions, water is so scarce that the mining industry is competing with local communities for access to supplies. 

Morgan Stanley states that social unrest related to the use of limited water resources is already constraining copper production rates and, in recent years, has hampered the construction of a number of new copper mines, including Tia Maria in Peru, Buenavista in Mexico, and Los Bronces and Los Pelambres in Chile. 

Given the level of social importance, it is irresponsible not to conserve that water as much as possible once it is on site.  

For many companies, carbon taxes are reason enough to look at alternative technologies; currently around 70 countries or regions apply some form of carbon price, but many groups, including the International Council on Mining & Metals (ICMM), are supporting the introduction of a globally applied carbon price in the near future. 

Schaffer agrees: “If we can find solutions to mine and process metals in a more sustainable way, that will help improve the bottom line as well as the top. There’s a good business case behind reducing emissions.” 

Ways with water

While climate change mitigation and reducing GHG emissions are a major concern for the mining industry, miners must also adapt their operations and business models to deal with the impacts of climate change. 

Water conservation is our biggest focus for MissionZero, and the company has been working with the ICMM to accelerate innovation in this field. 

“We have a two-step approach,” explains Schaffer. “The first is to dewater tailings on a large scale, so that we have dry stack tailings and 100% recyclable water. That is our vision up to 2030. 

“We can do that now at smaller capacities, but we are talking about mining operations producing over 100,000 tonnes per day of tailings. We need to prove the technology at full scale and that will take a few years.” 

Looking ahead, we are also developing solutions that will allow water to be eliminated from mineral processing altogether. Currently, water is required as a carrier in milling and grinding and is crucial in flotation. 

“Removing water altogether will require techniques such as solvent extraction and dry processing,” Schaffer adds. “But that’s not part of our 2030 vision; that’s the 2050 vision.”

From 2030 to 2050

When it comes to dry processing, we have already taken the first steps. We have learnt many lessons from our history in cement, an industry that uses dry processes exclusively.
 
“We’re looking into alternative milling and grinding technologies from the cement business,” says Schaffer, pointing to high pressure grinding rolls as an example of fruit already borne from this synergy. 

Rapid Oxidative Leaching (ROL) technology could also feature in a waterless flowsheet. This uses a mechano-chemical process to leach low-grade sulphide ores quickly, under low temperature and pressure conditions. 

ROL reduces the need for fine grinding, making it safer and less energy intensive than other leaching methods. It is also capable of removing arsenic from copper concentrates.
The issue of land usage is another interesting point. One which has the potential to completely transform concentrators.

“Dry tailings will help us reduce mine footprints,” Schaffer explains. “But we’re also talking about new concepts where processing plants could be made semi-mobile or taken completely underground. From the surface, you wouldn’t even see the mine.”

Changing hearts and minds

Schaffer stresses that the success of these concepts links strongly to timing. 

Ten years ago, no one would have listened to such ideas. However, mining companies are now more open to considering new concepts.

“We’re seeing lots of interest, particularly in the elimination of wet tailings,” he says. “I believe that by 2030, dewatering and dry-stack tailings will be an industry standard.

“Going forward, in terms of comminution, we will see milling and grinding processes which are less energy intensive. 

“But the industry won’t switch to waterless processing anytime soon. Ten years in mining just isn’t enough to develop and prove the technologies. 

“The ambition to recycle all water by 2030; that’s doable.” 

Of course, it is difficult for a technology company to address such huge challenges alone. 

“We need to work together as an industry,” urges Schaffer. “If there’s alignment between mine suppliers and operators on what the future should look like, that will make adoption and acceptance of technologies much faster.

“We just need to find the right partners.”



Carly Leonida is Editor of The Intelligent Miner website.