Promoting sustainable use of water
Water is an essential resource for the mining industry. In minerals and metals processing water is used from seas, rivers, lakes and even groundwater. The level of water consumed is case-specific and varies greatly depending on factors such as climate, water quality, geology, ore mineralogy, mine management and practices, and the commodity being processed. However, water is a scarce resource in many parts of the world where the industry operates. Also decreasing ore grades mean that it is becoming necessary to extract higher volumes of ore to generate the same amount of refined product. In general, the lower the ore grade, the more water-intensive the processes to extract the ore will be.
We are trying to reduce the impacts of mining on local communities. Minerals and metals processing requires approximately 4 cubic meters of water per ton of ore. In theory, it is possible to decrease freshwater intake to 0,2 cubic meters of water per ton of ore. However, this means that the remaining 3,8 cubic meters of water required, must come from recycled process water.
The socio-political impacts of water use have also created pressure to use water more efficiently in the mining industry. Achieving a social license to operate is critical for mining companies. Also, laws and environmental permits which restrict the use of water are tightening.
New generation water management solutions
New water management and tailings solutions decrease the overall usage of process water and enable the use of different water sources. In addition to freshwater, surface water or groundwater, new solutions can use salt water or even urban wastewater. Outotec develops technologies that enable the recycling of water, as we believe that it is the solution for sustainable water usage in the future.
We are developing solutions that enable totally closed water circles. It means that the only amount of freshwater which is withdrawn to the process is water that replaces water which is evaporated to the sky and withdrawn through products.
New water management solutions recycle the process water before it enters the tailings ponds, increasing water recovery and hence decreasing the need for freshwater intake. However, the shortening of the water recycling process has some side effects regarding the quality of water.
SERENE project funded by EIT RawMaterials is a new IIoT-based water management system that helps the mining industry monitor the entire mine site’s water balance in real-time. The system also provides the industry with the possibility to create short-term forecasts for the site’s water volumes and water quality in different production and environmental conditions. It has been developed as a response to the common water management challenges in the mining industry. Such challenges are pressure to increase water recycling, fulfil environmental regulations and decrease effluent generation, minimise production losses and avoid product quality problems due to poor and fluctuating water quality.
The mining industry uses massive amounts of water for minerals processing and therefore water scarcity and management of vast water volumes constitute risks for the companies. One source of risk is that the mining industry’s water cycle interconnects with the general hydrologic water cycle. Due to this connection rain, surface runoff, evaporation, infiltration and seepage all have a big, unpredictable and often seasonal impact on the site’s water volumes and qualities. For example, tailings areas and water ponds are of special interest as they are a huge and changing resource of contaminated water and interact greatly with the environment. Another challenge is that mining operations drastically change sites’ topographical and hydrological conditions in the end. Mineralogy and therefore water chemistry differ by site and by time. Consequently, the entire site’s water balance management should be considered as a continuous process that deserves to be followed and updated throughout the whole mine life cycle.
Real-time visibility and forecasting capability help the mining industry reduce water-related economic and environmental risks. It enables them to use mine site’s water resources optimally, as a valuable raw material. Comprehensive, real-time visibility to water resources helps the industry improve process water recycling and identify water recycling impacts on production performance. Consequently, we can help the mining industry respond to investor, authority and socio-political pressure that forces the industry to ensure sustainable, acceptable mining.
SERENE project consortium:
- Outotec Oy, Finland (Lead partner)
- Aalto University, Finland
- Balder Consulting, Sweden
- Fundación Tecnalia Research & Innovation, Spain
- GreenDelta, Germany
- Langis, Finland
- Mondo Minerals B.V. Branch Finland, Finland
- Tecnalia Ventures, S.L., Sociedad Unipersonal, Spain
- Technical Research Centre of Finland Ltd. (VTT), Finland