What needs is the mining industry facing today?
According to Reuters, the world’s top mining companies have been recently warned that assets will be stranded and investors will walk away unless they deal with water scarcity in key mining regions such as Africa, Australia and Latin America.
The Mining industry is considered to be the 4th largest industrial user of water during daily operational activity. Water is essential during every stage of the mining process, and the bulk of the assets of major mining companies are in water-stressed regions mostly in the southern hemisphere. Anglo American, for example, are striving to use as little water as possible, and have so far limited water consumption by using 65% recycled water with the goal of reaching 95% over the next decade (Reuters).
- Gold production is expected to hit a fresh record in 2019 - experts predict that 2019 will mark the fastest pace of growth in 3 years for gold mining (primarily produced in China, Australia, Russia, the US & Canada).
- Copper production is expected to double by 2035 - copper is incorporated in electrical equipment & electric vehicles production (primarily produced in Chile, China & Australia).
- Increased opportunities for lithium recovery - Portable electronics & electric vehicles run on Lithium-Ion batteries (primarily produced in Chile, Argentina & Australia).
- Other critical commodities are facing shortages - Such as cobalt (primarily produced in the Democratic Republic of Congo), chromium and nickel (primarily produced in China, Australia & the US).
Mining activity, which historically has been driven by cyclical supply and demand, is directly related to commodity prices. Mining companies are consequently seeking alternative solutions to provide for their water needs - be it desalination, water reuse or other advance treatment technologies.
Lastly, new mining projects have gradually given way to resource recovery projects, where lithium and other metals are recovered from the surface in the form of soft coal or coal waste. As a result, a momentous ramp-up is expected in the widespread introduction of water treatment involving membrane technologies to the global mining sector.
Tough mining - the challenges:
As mentioned above, water scarcity and extensive water needs pose a major headache for the mining sector. In addition to that, challenges in the form of tougher regulatory restraints due to increasing environmental awareness, are becoming more and more evident.In the US alone, environmental regulations stated in the Clean Water Act, Clean Air Act, National Environmental Policy Act and numerous others apply to mining activities, while the more recent Liability Act was used by the US Environmental Protection Agency (EPA) to address active mining operations. Mining companies, especially in the US, can expect an ever-increasing level of scrutiny and control over their operations, bringing more and more of them to be increasingly conscious of the environmental impact of their activities.
When surface ground water interacts with the solid waste of metal mining, processing and beneficiation, acid mine drainage is created, which is likely one of the most severe environmental problem of the mining industry. When water interacts in an oxidizing environment with the sulfide minerals typical of most metal mines, sulfuric acid is created. Metals are then dissolved in the resulting acidic water and create acid mine drainage - which can contaminate drinking water and affect aquatic and plant life if met with surface or ground waters.
Permitted sulphate discharge levels have therefore been tightened in recent years. Mining companies are put under increasing pressure to recycle chemical reagents used in beneficiation, to seal waste piles so they are less exposed to the water necessary for acid formation, and reduce the chances that tailings ponds will leak into surrounding soil and groundwater. The market for clarifiers and suspended solids removal solutions is hence expected to grow accordingly.
These regulatory restrictions, which are becoming more and more stringent due to the rise in environmental and public health concerns, bring quite a few mining companies to invest heavily in water infrastructure and management systems in order to reuse water, improve metal recovery and treat effluents prior to discharge. The not so bright side of the heavy regulation is that a considerable number of mining companies still refrain from building a long-term plan in order to address their water needs. That being said, disposal of water is considered a last resort, and wastewater minimization is promoted as a more efficient and regulation-friendly option.
Every drop counts - Water spent and applications:
- To produce 1 kg of copper, 100 liters of water are required
- Processed water and wastewater are reused in the following processes: conveyance and dust control, cooling, drilling, wash-water, remediation, separation and leaching, power generation and land reclamation
What’s in the crystal ball - Market forecast:
Capital expenditure by region:
In 2018, water spent was accounted for over 15% of total mining expenses, and is expected to continue growing in the following years (source: GWI).
Capital expenditure by application:
Wastewater treatment represents a marginally higher proportion of expenditure than water, reflecting the global trend towards harsher wastewater discharge regulations (source: GWI).
Capital expenditure by technology (source - GWI):
So what are the water treatment solutions for mining?
As the scope of the mining industry grows, quarried substances demand is on the rise and environmental regulation is tightening, the need for more efficient and economical water treatment is evident and more pressing than ever before.
- Water recycling - Depending on quality, it is estimated that over 90% of mining wastewater could be reused by applying advanced treatment technologies such as RO.
- Water technologies - Zero Liquid Discharge solutions can meet the most stringent regulations, minimize the environmental impact.
- Modular water treatment solutions can dramatically simplify installation, reduce civil works and local site risks, leading to reduced erection costs.
- Water reuse combined with proper water management procedures, might enable mines to save up to 40% of their daily freshwater intake.
Seawater and brackish water reverse osmosis (SWRO & BWRO), thermal desalination and solutions for reuse of mines effluents, are ideally suited for the mining sector in terms of their operational, regulatory and economical needs. Advanced industrial water treatment solutions to address Acid Mine Drainage and Tailing Ponds challenges, take a comprehensive, integrated, end-to-end approach in order to address the unique requirements of the mining sector, and are essential for maintaining growth while securing efficiency, sustainability & cost-effectiveness.
- Frost & Sullivan, Membranes and mine water - waste or revenue stream (2016)
- The National Academies Press, The industrial green game: implications for environmental design and management (1997)
- Reuters, Water scarcity tops list of word miners’ worries (2017)
- Mining.com, Global gold production (2019)