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Management, treatment, and reuse of water for the mining sector in Latin America

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Water is a fundamental component of mining applications. It is essential for both the mineral extraction and cleaning process and for the needs of the personnel who operate the facility. Treatment of the wastewater from these operations is also necessary to prevent detrimental environmental impacts and to enable reuse in the mining process.

The mining industry needs a constant and reliable source of clean water to keep the business going. Tighter regulations, increasing water scarcity and rising raw material prices strongly influence the mining market and drive the development of new technologies and solutions. The current trend is to reduce water extraction and use unconventional sources in mining operations. This reality is leading mining companies to boost their investment in cutting-edge water treatment technologies to improve their use standards.

Mining operations are often located in difficult-to-access places and areas with extreme weather conditions. Water resources are not usually located close at hand and if they are, there is competition from industrial, agricultural or domestic consumers. For these reasons, unconventional water alternatives are emerging as essential aids to enable the mining industry to continue its activity. Desalination of seawater or brackish feedwater is a feasible alternative to obtain the required quality and quantity of process water for ore extraction and processing to obtain the value-added metals. High-quality water is also needed for the essential services of the mining camp in terms of water for personal, hygiene and sanitary use.

The mining industry has contributed enormously to the world economy. However, the waste it generates represents a challenge.

According to Chilean government sources, the mining industry will require fifteen new desalination plants by 2028 and the use of seawater will almost equal that of continental water within a decade. On the basis of a report drawn up by the Chilean Copper Commission (Comisión Chilena del Cobre – Cochilco), the Project Management Department of the Ministry of Mining of Chile estimates that adding the fifteen new initiatives to the current projects for supply and use of both desalinated and natural seawater, the copper mining industry will consume nearly the same quantity of seawater as it will freshwater within a decade. Specifically, this means that 53% of the water resources used in mining will come from continental water and 47% from the sea by 2031.

Desalination is a feasible alternative to obtain process water for ore extraction and processing to obtain the value-added metals

The Antofagasta Region will lead the country in desalination by around 2031 with the capacity to supply 66% of the water required by the copper-mining industry. It will be followed by Atacama, Tarapacá and Coquimbo with 16%, 14% and 4% respectively of their water needs supplied from the sea, according to the Government of Chile.

The use of water to obtain metals from ore entails contamination of the process water by minerals and other solids. Contaminated mine water is generated when rock containing mineral sulphides is exposed to water and oxygen, producing acids and high concentrations of metals and sulphates in the water. This results in contaminated water that requires treatment to be reused or returned to the environment while complying with the country's environmental protection-related regulations.

Mining effluents can be generated by the following factors:

  • Sluicing and flushing water.
  • Acids from the extraction process.
  • Leaching, flocculation and concentration water.
  • Effluents from refining and gas scrubbers.
  • Rain or groundwater that filters into the mine’s deposits causing oxidation, hydrolysis, flushing, etc. giving rise to highly-polluted wastewater.
Published in SWM Bimonthly 9 - September 2021
SWM Bimonthly 9

Both from the environmental and operational points of view, the ideal situation would be to eradicate the use of natural freshwater from mining altogether, and especially from the separation and transport of ore, minerals and waste, while avoiding pollution of external water sources and reusing mining wastewater safely as far as possible. The goal is to develop more sustainable and profitable mining operations by making water reuse more efficient while recycling mining waste.

The overall cost of treating metal-contaminated wastewater depends on the process employed and the local conditions. As a general rule technical feasibility, profitability and the simplicity of the plant are the key factors when selecting the most suitable treatment method.

There is no doubt that efficient management and reuse of water in mining entails cost savings, enhanced performance and a better image for the mining industry.

The future of water in mining

The global mining industry continues to grow by increasing production, improving operational efficiency and optimizing costs. It is estimated that positive investment trends in the mining water and wastewater sector will continue to improve treatment methods, enhance resource recovery and increase desalination capacity in the next few years.

In June 2021, Almar Water Solutions doubled its commitment in Latin America with the acquisition of 50% of Aguas y Riles S.A.

This dynamic behavior of the mining industry is driving the demand for solutions for water and wastewater from mines. For this reason, developed regions will focus on advanced water and wastewater treatment technologies with closed-loop systems, highly-efficient resource recovery mechanisms and higher sustainability standards in the use of water.

Moreover, automation, sensor technology and control devices are already providing smarter practices in the water-management field for mining systems by providing real-time information on the use of mine water. Inefficient water circuits, potential problems and waste from leaks and other losses can be identified by water management simulation applications. This critical information helps mines to improve their water use efficiency. Application of new smart technologies will be one of the fastest-growing fields in the short and medium term.

Water scarcity forces mining companies to consider the use of water exchange or desalination, recovery and reuse technologiesmi

Only companies capable of ensuring long-term sustainability by strengthening their research, development and innovation will achieve a comprehensive competitive advantage in the mining industry in years to come.

An ally of the sector

Almar Water Solutions is a leading company in the fields of water infrastructure development and provision of operation and maintenance services. Our commitment to Latin America and to meeting the water-related needs of industry have led us to invest in and develop a regional platform in partnership with two organizations with special expertise in the area: Osmoflo SpA and Aguas y Riles S.A.

Almar Water Solutions acquired Osmoflo SpA, a Chilean water treatment company, in 2019. We expanded our portfolio of third-party operation and maintenance services with this acquisition, enabling us to provide turnkey solutions to our clients and to add new references in desalination, purification, potabilization and water for industrial uses to our portfolio. These include the Antucoya reverse osmosis desalination plant, the Centinela brackish water desalination plant and the Aritia and Novaustral wastewater treatment plants. We have been awarded new contracts such as the Mantos Blancos processing plant and the Salares Norte desalination and wastewater treatment plant after the merger.

Antucoya Mining desalination project in Antofagasta, Chile

Recently, in June 2021, Almar Water Solutions doubled its commitment in Latin America with the acquisition of 50% of Aguas y Riles S.A., a Chilean company founded in 2001 that provides the following services, among others: operation and maintenance (O&M) for industrial clients, dedicated investment transactions, design and construction of water treatment plants, industrial liquid waste management and specialized services for water treatment and purification plants. Our common goal is to grow hand in hand sharing our material resources, experience and technology in the water sector.

Almar Water Solutions thus continues to work to improve the water-related processes and management in Latin America in close collaboration with outstanding qualified experts. In particular, the Almar group develops new systems for the mining industry, a sector that demands ever-increasing quantities of clean, high-quality water to carry on its activity without neglecting sustainability and environmental protection.

Salares Norte desalination and wastewater treatment project in Antofagasta, Chile