Water and the Environment
A 12-year drought in Chile has highlighted water scarcity as a major issue
Undoubtedly one of the focus areas for all businesses in Chile is water supply. In northern Chile, and in particular the Atacama (the driest desert on earth), the issue has been polemic for years. At Exponor 2019 in Antofagasta protestors stormed the conference with a sign stating ‘We will not be a sacrificial zone’, in refence to the water consumed by mining producers in the region. This was before the riots in October 2019, before the vote for the new constitution, and before Chile elected a president who has environmental concerns at the top of his agenda.
An illustration of the water intensity of certain mining processes can be seen in the extraction of lithium from brines, which can consume nearly 2 million liters of water to produce one ton of lithium. For an average family, it would take 36 years to consume 2 million liters of water. Although the numbers are striking, Rohitesh Dhawan, president and CEO of the International Council on Mining and Metals (ICMM), pointed out that when you examine the amount of water the mining industry consumes relative to other sectors, it is actually still very small. “In Chile, agriculture and livestock consumes 73% of water, drinking water is approximately 11%, industry is 6%, electricity is 4.5%, and mining consumes only 4%. Then if you look at where this 4% comes from: approximately ¼ comes from surface water, another ¼ comes from the sea, and 43% comes from underground sources,” detailed Dhawan, noting that amongst the large players in Chile which are ICMM members, approximately ¾ of the water used is typically recycled.
“One of the challenges we see is that medium-sized or junior companies do not necessarily have the funds to invest in desalination plants. A solution would be for the public and private sectors to work together and develop cost-sharing opportunities with regards to desalination and transportation.”
Claudio Lesch, President – South America, Ausenco
Central Chile has experienced a drought for the last 12 years, prompting Antofagasta Minerals (AMSA) to build a seawater desalination plant for its Los Pelambres mine in the Choapa Valley, via its INCO project, the first stage of which is due to start operation in the second half of 2022 with an output of 400 liters per second. “Our target is for raw or desalinated seawater and reused or recycled water to supply 90% of the operational water use at all our mining operations by 2025,” revealed Iván Arriagada, CEO, Antofagasta plc.
Desalination plants mean more capex for mining companies, and water scarcity also significantly drives up costs. In 2021, AMSA’s net cash cost to produce a tonne of copper was US$1.20/lb, and Arriagada acknowledged that the 2022 guidance of US$1.55/lb net cash cost was partly due to the expected impact of drought this year at Los Pelambres, in addition to declining grades at Centinela Concentrates.
Cochilco estimates that mining’s use of seawater — either used directly or desalinated — will increase by 167% by 2032, while freshwater use will decline 45%, meaning that 68% of water used by the industry will come from the ocean. The breadth of companies featured in this article also illustrates how water encompasses all aspects of the mining business, from engineering and consultancies to construction and technology providers. A multi-stakeholder approach is necessary to confront the issue of water scarcity, which represents opportunities.
“I believe that from now onwards, no mining project will be approved with fresh water, and everything will need to be done with salt water,” stated Martín Valdes, partner and head of Fund VII at Resources Capital Funds (RCF).
This sentiment was echoed by Dave Lawson, president – mining and metals at Wood, who commented that all new mines in Chile are going to use sea water of some description, “whether it is desalinated water used as potable water or non-desalinated water used in processes.”
Lawson went on to discuss some of the cost analysis considerations related to using sea water, such as the construction materials having to be different due to salt water being highly corrosive and the need to replace materials on a more frequent basis.
“We will digitalize the engineering of the INCO desalination plant and we have been training the operators. We created a simulator in which Antofagasta’s operators can increase their dexterity and skills to be ready from day one once the operations commence.”
Andrés Rojas, Automation Director – Latin America, ANDRITZ
At the moment, desalination projects are the realm of the major miners who can afford the substantial long-term investment necessary. However, a future where public/private joint ventures can guarantee water supply for a wider base would make using desalinated water viable for more stakeholders. Lawson elaborated: “If you can build a desalination plant that serves multiple consumers from various industries, costs can be shared, making more sense from an economy of scale standpoint. If the government can invest in desalination plants and use some of that water to supply cities and towns, it can offset some of the costs for smaller players in various industries.”
Tomas Fischer Ballerini, general manager of Edyce, spoke of how the Edyce-Arrigoni engineering team worked in close collaboration with Antofagasta’s engineering team to look for efficiencies regarding the steel structures of the INCO project. “It is not the first desalination project in Chile, but it is by far the biggest,” said Ballerini, noting that Chile needs more projects like this if the country wants to continue attracting mining investment.
ANDRITZ has been involved in desalination plants for mining projects by digitalization their engineering, according to Andrés Rojas, ANDRITZ’ automation director – Latin America, mentioning work the company has done in this area for BHP, Teck at QB2, and with AMSA at INCO. “Once in operation our technology makes the use of energy and water consumption more efficient, optimizing its transportation and energy costs through the incorporation of digital sensors,” said Rojas, commenting that there are many pumps pushing water that can be made more efficient with this technology and that ANDRITZ also improves water use through its solid-liquid separation equipment, both in concentrators and tailings management, to recycle the water used in these treatments.
“Because Carpi Tech has significant experience in freshwater and hydroelectric dams, where things simply cannot fail and the design has to be zero risk, we can transfer this knowledge to tailings dams in the mining sector.”
Pascual Perazzo, Business Development Manager – LATAM, Carpi Tech
Luis Soruco, general manager of Arcadis Chile, discussed the water-related engineering and consulting solutions his company offers, expanding on the issue beyond desalination plants and into the handling of water inside current operations. He commented: “Included in this is the consumption or evaporation of water in tailing dams, which is a challenge because it loses more water than any other part of the operation, therefore concentration in the tailings dam is one of the focuses for hydric efficiency in our technical analysis. Our goal is to minimize hydric use and stress through new technology and solutions.”
John Crane has been providing products for the mechanical sealing of rotating equipment for decades, but in the last three years, the company has developed more specific products that aim to conserve or reduce water usage. Carlos Ramírez, John Crane’s general manager for Chile and Peru, explained that usually a seal must have water that lubricates it to prevent wear, but today, with the implementation of diamond seal face technology, equipment can withstand extreme temperatures without the need for lubrication. “In mining, due to the complexity and harsh environments that rotating equipment are used in, generally we see very short life cycles,” said Ramírez, commenting that John Crane works with pump manufacturers such as Weir Minerals, Metso and FLSmidth to increase the uptime of their equipment through new technology, including mechanical seals, which can last up to 18 months and do not use water.
Companies that have traditionally worked outside the sector are also bringing their technologies to the mining market, such as Carpi Tech, which specializes in the waterproofing of hydraulic structures using synthetic geomembranes and geo-compounds. Pascual Perazzo, Carpi Tech’s business development manager for Latam, recalled how the company entered the mining market eight years ago working at a mine in Iran after a recommendation by tailings specialists ATC Williams: “There we made our first tailings dam with the CARPI waterproof membrane. Consequently, we have made several hydraulic structures for mining to supply water to operations.”
Image courtesy of BHP