Ageing Chilean mines push water, energy consumption levels higher

Water and energy consumption across Chile's mining industry grew last year as several facilities are facing declining grades and deeper pits, following decades of mineral extraction.

Water consumption in the copper industry grew 6.4% last year from 2015 to 59.3m3/s, while energy consumption increased 1.4% to 168,572TJ, Chilean copper commission Cochilco said in a report.

Chile's copper industry produced 5.6Mt of copper last year, and is facing several constraints largely related to the ageing deposits. Several mines, like Codelco's Chuquicamata and El Teniente mines, have been mined for over 100 years, while other major facilities, like BHP's Escondida and Antofagasta Minerals' Los Pelambres (pictured), have been operating for 26 and 18 years, respectively.

However, in the case of water consumption, the industry has been adapting its processes to use recirculated water, reducing its overall water footprint. Recirculated water accounted for 74.3% of the industry's water consumption last year.

The industry has also seen an increased used in seawater usage to 2.45m3/s in 2016, growing 7.5% from the previous year, the report said.

Chile's mining industry accounts for just 3% of the national water consumption. In the case of energy consumption the industry currently accounts for 12% of all of the country's energy consumption, according to Cochilco.

Of the 168,572TJ consumed by the industry last year, more than half (88,315TJ) was electric consumption, while fuel consumption totaled 80,256TJ.

Cochilco highlighted the importance of greater integration between sustainable water and energy consumption across the industry; recirculation, combined with watershed management, could provide a solution to the scarcity observed in the highly vulnerable watersheds located in arid environments.

The agency also highlighted the need for major facilities to share use of key infrastructure, such as pipelines and desalination plants, in order to take full advantage of the use of desalinated water, which would reduce energy consumption and funding needs.

In recent years the industry has seen the creation of joint ventures to lower the capex of future projects, through the combination of assets and merger of key infrastructure. Some examples are Teck-Goldcorp's NuevaUnión project and Goldcorp-Barrick Gold's Cerro Casale project.