The keys to achieving successful mine closure

The closure phase of a mine must be prepared from the start of planning to contribute to an industry committed to caring for the environment and the wellbeing of people. 

In Chile, Barrick Gold's Pascua and Codelco's Ventanas copper smelter are in the closure stage, while BHP's Cerro Colorado is following a closure program while evaluating the opportunity to extend the operation. 

To find out more about the keys to a successful process, BNamericas talks to Troy Dunow, director and global head of mine closure at UK consulting firm Turner & Townsend, who has participated in the planning and management of the closure of mines belonging to diamond producer De Beers and to BHP's legacy assets team, among others.

BNamericas: What are the main aspects to make a good mine closure plan?

Dunow: Start planning for mine closure even before starting to build it. Then this has to be updated, but if you wait until the end, you don't really know what you have until you get there. In addition, it's important to work on it from the beginning under current environmental and social standards that have more challenges than five or 10 years ago.

BNamericas: What kind of challenges?

Dunow: Now we have more accurate regulations around communities, social and environmental aspects. Mining companies are required to do more and take more actions for stakeholder engagement, with more communication with the communities to understand what they really want in the end. So that when the mining company walks away and gives the land back, the community can use it for whatever they need. It's no longer simply leaving a big hole in the ground. In this sense, we may have more innovations.

BNamericas: In terms of innovation, what are the biggest concerns of miners? 

Dunow: The biggest trends involve operational and management improvements, as well as greater community involvement to make sure they get what they want.

BNamericas: How has Latin American mining performed in terms of mine closures?

Dunow: From what I understand, not many mines have closed in Latin America, but there are some in the process of closing. Generally speaking, no one in the world is doing very well in this regard. It's been 10 or 15 years since people started taking it seriously. So, things are trying to catch up.

BNamericas: What are the main trends in mine closure planning?

Dunow: Everything that has to do with decarbonization, through electrification using renewable energies. In Canada we're seeing people putting up solar panels and wind farms. We did work in Washington in the US where for the operation of a water treatment plant a small dam was built on the river that feeds the plant to avoid the use of wires. To have your own little service minimizes the impact on the environment.

BNamericas: Is there any example in the world that you consider a good closure plan?

Dunow: There are many successful closure plans and a lot of them are still in progress or monitoring activities for contamination issues. The plan to close a mine in Utah, for example, involves making it a study area for the universities to see how best to close the mine. It hasn’t been converted yet as it hasn't closed, but it's part of the plan when it does. 

There are also methods in which the property is made available to communities for recreation, leaving parts that are maybe dirtier for industrial areas, or water treatment facilities that are big enough to also supply the communities. The mindset now is how can we make this better than before?

BNamericas: What are the differences between a closure plan for a copper operation and that of gold or lithium?

Dunow: The closure plan is related to the contamination caused by the materials used in the mining process. This changes the way things should be managed. For example, in gold you need an acid-generator material and acidic water, and those things get into the aquifer or surface water, and it can cause a lot of problems. But in a diamond mine, you don't have those pollution problems. It really depends on the process used and the byproduct. 

BNamericas: Given the increase in mining production to meet the growing demands of the global energy transition, will the requirements for mine closures also increase?

Dunow: The transition requires a joint effort between the mining company, the community and the government, as there's a big possibility of mature countries taking advantage of less mature countries like in Africa, where they just care about getting money. But they don't do it responsibly and there's a big possibility of hurting the environment. But if we keep the environmental aspect at the top of our minds, and a key driver, then we'll be able to manage its impacts.

BNamericas: How much does mine closure planning factor into investors' decisions?

Dunow: I think it's a mix. There are investors who are only looking for a return on their investment, but others want to do it responsibly. People are starting to look at how other companies address environmental issues to avoid getting in trouble for something they did 50 years ago. That is why we see interest in advancing technologies, ESG, etc.

BNamericas: What do you think of the guidelines provided by global mining entities such as the International Council on Mining and Metals (ICMM) or the Copper Mark?

Dunow: They have the right vision and have independent consultants in most of the major mining companies and government agencies. The ICMM presented a tailings [management] standard, after the disaster in Brazil for example.

[Editor’s note: In 2019, a Vale tailings dam collapsed in the city of Brumadinho, releasing a wave of waste and mud that destroyed homes and businesses and left around 300 people dead.] 

The others are also trying to push the mining industry in the right direction. I would like to see governments seeking those accreditations from mining companies before allowing them to carry out a project.

BNamericas: About tailings management, what are the most relevant practices to avoid impacting the environment, and is the option of reusing tailings to obtain other minerals a growing trend?

Dunow: It's great to reuse tailings to find other uses, or anything else to get rid of the risk. It's also about monitoring and maintaining the facilities, not abandoning them, although permanent monitoring is very expensive. This is an issue that is being discussed a lot and at the end of the year there will be a conference in Australia that will largely revolve around tailings management. There are many people working on how we can improve this aspect.

BNamericas: Will the geopolitical tension generated by the strategies of countries such as the US, Canada, Japan or Australia to secure their mineral supply chains for the global energy transition continue to grow?

Dunow: Geopolitical issues will continue because battery manufacturers will continue to try to get supply from mining companies and supply will not meet demand. We know that 10 years is the average from a mine being identified and construction beginning, but there are even longer times. This puts pressure on mining companies to obtain material as soon as possible, and on governments and communities to grant permits, because there's not enough time.

BNamericas: Permitting is one of the main risks of mining in Chile, as well as in other countries. How can an agile system with exact priorities be created?

Dunow: In 2019 we did a survey with SRK and one of the questions was whether governments are prepared and whether they have enough people to grant permits. About 80% of people said that the government doesn't have the right people. To make it faster, you need people who understand mining in the government, because the permit shouldn't just be what the government wants, but also what the community wants. It needs to be a joint effort. If we want permitting to be successful and faster, the people who are going to grant them must have the right knowledge and not be a simple bureaucrat who stamps a piece of paper.