Innovation: Mining’s Need for Water and Waste Management

The mining industry has gone through significant changes during its history, mainly propelled by new technologies that emerged and altered the operations of thousands of companies. To respond to pressure from governments, investors and NGOs alike, the mining sector is increasingly addressing environmental, social and governance (ESG) issues as a priority matter. As these objectives to reduce waste and increase water reuse grow in importance, technology will further cement the adoption of ESG factors in the mining industry.

“When we discuss sustainability, we are talking about improvement, which is equal to innovation,” said Cristina Rodriguez, Deputy Director of Sustainability, Compañía Minera Cuzcatlán. Companies are using innovative, modern methods throughout the mining process, as these solutions help mining companies to overcome ore-processing roadblocks and drive exploration efforts while fostering a better environmental and social track record. 

One of these approaches is ore sorting, a process in which artificial intelligence (AI) and advanced instrumentation are used to isolate the best ore for further processing. This reduces the overall volume of ore sent to be processed by identifying a smaller amount of higher quality ore, which allows for smaller plants that are more energy efficient, produce fewer emissions and lower the barriers to gaining permits.

In addition, advanced technology is reducing water dependency and softening the environmental impact, for example by replacing chemicals with earth-friendly bio-based chemical agents. Many mines today are enforcing measures to capture rainwater that flows into reservoirs, too. For example, Draslovka invested US$100 million in 2022 to develop glycine leaching to help companies make their use of water more efficient, explained Claudia Marquez, Global Commercial Director, Draslovka.

Public-private projects to source water have also been proven to yield positive results, like the water treatment plant run by Minera Cuzcatlán in Oaxaca. This allows the company to source 80 percent of its water from the treatment plant while the remaining 20 percent goes to surrounding communities. The Mexican subsidiary of Fortuna Silver Mines reported that it has never used underground water for its operations at its San Jose mine in Oaxaca. Instead, the company recycles and reutilizes wastewater. 

"Waste takes up a lot of real estate, which is limited in Mexico. Being creative with waste drains and tailings is essential, ideally creating a geofill," said Jim Norine, Vice President of Minerals and Metals, Southwest USA, Ausenco

Furthermore, a key trend in the mining industry is to move from traditional slurry tailings storage toward dry tailings, as around 50 percent of the operators are moving to dry solutions. Tailings are a major issue for mines due to the problems linked to waste management and safety, explained Rodríguez. “Tailings dam failures are catastrophic, dangerous and can cost lives. Dry stack tailings are therefore driving the industry,” added Norine. Companies can transport dry tailings through a conventional conveyor belt system and stack them on a pad, similar to heap leaching. The traditional alternative of using a slurry dam and then waiting years or decades for that dam to dry up has proven to be much more complicated.

Although efforts are being made to improve water management, some decision-makers are still reluctant to invest in those solutions. "Since water is not a direct operational risk, it is often not well understood. However, water risks can shut down production or undercut a company's social license to operate," said Sarah MacKay, Water Services, ERM. Because the benefits of better water systems are only seen after many years, this adds to the lacking awareness of their value, added Rodríguez.

Adopting best ESG practices does not only benefit the environment and the communities involved, however, as companies stand to make solid financial gains. "ESG has become a standard investment requirement. I consider it good for companies, the industry and, more importantly, the environment," said Norine. 

Márquez recommended making ESG a priority for the operational strategy, adopting emerging technologies, understanding regulations, setting targets beyond compliance and involving supply chains to deliver better results. MacKay agreed and highlighted the relevance of having a clearly defined strategy and implementing it systematically.