Water is a crucial component in oil sands mining, essential for separating extra-heavy crude oil, also known as bitumen, from the mixture of sand, clay, and water that makes up the oil sands. Additionally, water is used in hydrogen production, where steam reacts with natural gas to generate hydrogen. This hydrogen is then utilised in upgrading processes, turning bitumen into higher-quality synthetic crude oil (SCO), enhancing its market value.
Oil sands mining operations require extensive water use due to the arid conditions of the deposits. Large amounts of water are necessary to create a slurry that is transportable and can be separated by gravity. The typical ratio of oil sands to water is around 1-to-1 (or 50% water in the slurry), with a standard operation consuming about nine barrels of water for every barrel of bitumen produced, as reported by Oil Sands Magazine. This indicates that for every barrel of bitumen extracted, a significant water footprint is left behind. Although much of this water is recycled to reduce waste, the volume required presents ongoing environmental and operational challenges.
Tailings ponds, also known as tailings storage facilities, are crucial for managing water in oil sands operations. These ponds hold the by-products of the extraction process, which are typically about 50% water. As the mixture sits in the ponds, the heavier solids gradually settle to the bottom, leaving cleaner, clearer water at the surface. This reclaimed water can then be reused in the mining process, making the operation more efficient and sustainable.
This cycle is essential for reducing the demand for fresh water and minimising environmental impact. The reclaimed water is mostly pure, with around 99% being water and only a small amount of fine solids and trace hydrocarbons. However, these tiny particles can make water treatment and recycling more challenging. To ensure the water remains clean and the operation runs smoothly, advanced technologies and strategies are needed to handle these impurities effectively.
Challenges of Tailings Pond Management for Oil Sand Mining
Tailings ponds can fill rapidly, particularly when the production of tailings exceeds the rate of water reclamation and reuse. The location of the mining operations can further complicate matters, as regions with heavy rainfall and rapid snowmelt can contribute additional water to the ponds, increasing the likelihood of overflows and resulting in potential environmental contamination.
When these ponds reach capacity, careful management is crucial to prevent overflow and environmental contamination, which can lead to regulatory, environmental, and public relations problems. The long-term environmental impacts of these ponds, such as potential leaks and failures, are ongoing concerns. Continuous monitoring and innovative water management practices are essential to ensure sustainability in oil sands mining.
Poor water management can have significant consequences if not properly addressed. For example, in 2022, a mine in Montana experienced severe disruptions due to a catastrophic flood. Unusually warm weather caused rapid melting of snow and ice, and intense rainfall over a single weekend worsened the situation. The resulting damage required extensive repair and recovery efforts to restore full operations. The mine had to suspend its activities in the aftermath, leading to significant revenue losses for several months.
Similarly, a Canadian Gold Mine experienced snowfall levels 150% to 400% above the norm, with the ensuing freshets overwhelming the mine’s infrastructure. This forced a temporary shutdown of operations for four and a half weeks, costing the company millions in lost revenue. Over the three-month snowmelt period, the Gold Mine reported a substantial financial impact, with losses totaling $9.5 million CAD, dramatically shifting its EBITDA from a profit of $8.72 million CAD to a loss of $941,000 CAD.
These instances highlight the importance of effective water management strategies and the challenges associated with managing water and tailings storage facilities.
Beyond Oil Sands Mining
These concerns extend beyond oil sands mining. The extraction of critical minerals, such as lithium—essential for electric vehicle batteries and solar panels—is particularly water-intensive. This is notably true in the ‘lithium triangle’ region, which includes parts of Chile, Argentina, and Bolivia, where over half of the world’s lithium supply is found beneath vast salt flats. Here, lithium-rich brine is extracted and deposited in large surface pools, where the water evaporates, leaving behind lithium carbonate. However, reports from Chile and Argentina have raised alarms about the contamination of essential freshwater sources used for drinking, livestock, and agriculture with harmful by-products from these lithium operations.
If not managed carefully, this could lead to serious environmental and social challenges. Contamination risks not only harm local ecosystems but also affect the health and livelihoods of communities that rely on these water resources. This underscores the urgent need for the mining industry to adopt and enhance sustainable water management practices. Efficient water use and minimising waste are crucial for reducing environmental impacts and ensuring the long-term sustainability of mining activities.
Minetek’s Water Evaporation Solutions
Minetek Water has been at the forefront of delivering innovative water management solutions to the mining industry for nearly four decades. Our water evaporation technologies are among the most comprehensive and economical globally to mitigate the risks linked to excess water and comply with environmental regulations.
Minetek’s Water Evaporators are designed to handle a wide range of water qualities, providing a sustainable water management solution. These units can process solids up to 4.0mm in diameter and accommodate water with pH levels ranging from 1.8 to over 14. The system operates by pumping water at high pressure through specially designed nozzles, which atomize the water into fine droplets. These droplets then evaporate into the atmosphere, while the remaining solids, salts, heavy metals, and contaminants fall back into the water source. With over 500 systems installed worldwide, our technology is trusted across various industries for effective wastewater management.
Our evaporation technology is versatile and works efficiently in a variety of climates, from tropical regions like Brazil and Southeast Asia to colder areas such as Canada and Northern Europe. It’s built to handle seasonal changes in water influx and can operate continuously, 24/7.
Minetek’s Environment Management System (EMS) offers real-time monitoring and response to environmental changes. Using a wireless remote PLC, this system can automatically adjust to various environmental factors like sunlight, wind speed, humidity, and temperature. The EMS optimises operations for maximum efficiency, enabling clients to manage their water resources responsibly and adapt effectively to changing conditions.
Conclusion
The challenges associated with water management in oil sands mining are complex, necessitating innovative solutions to reduce environmental impacts and promote sustainable operations. Technologies such as Minetek’s Water Evaporation Solutions provide promising methods to address these challenges by improving water use efficiency and meeting strict environmental regulations.
With the increasing demand for resources like oil and critical minerals, the mining industry should adopt sustainable practices to maintain its growth and contribute to environmental preservation.
