The challenge of minimizing water usage in the mining process

As water experts warn of a serious global water shortage resulting from climate change, sustainable water management is critical. Mining companies are on the front line of water security risks. The mining industry uses water for a variety of purposes, including mineral processing, dust suppression, slurry transport and storage, extraction processes, and site usage. In most mining operations, operators extract water from groundwater, streams, rivers, lakes, or through commercial water service suppliers. To make things even more challenging, some mining sites are located in areas where water is already scarce.

The business is well aware of the need for more sustainable use of water and many companies cooperate with suppliers to find new efficient technologies. While the expected details and efficiencies vary greatly depending on the technicalities of the industry process, the complexity of the design, and the geographic location, there are a few areas that have a great impact when it comes to optimizing water management. Screening is one of them.

Managing high-moisture screening

Many mining sites are located in regions with humidity or periods of intense rainfall. High-moisture screening is often a big challenge and it easily results in blinding, if water is not added in the process. However, when adding water is not an option, the need for a solution that provides efficient dry-screening of high-moisture ore, becomes crucial.

Metso Outotec has been investigating this area for many years and pushed the limits of the “impossible screening” of difficult screening step by step. The target is to eliminate the need for water, and to improve screening efficiency and safety. This cuts a plant’s total water consumption and eliminates the need for tailings dams. The elimination of process water eventually results in lower processing costs due to the removal of tailings handling and enables mines to become more competitive and profitable.

Next generation in screening

Metso Outotec started doing a series of laboratory testing in 2008, which eventually resulted in the development of an elliptical motion screen with high G-force. The technology has been running with high availability, reliability, and performance at a customer’s site for many years and it has been optimized with the help of valuable feedback from the customer. 

5-6G operation combined with elliptical motion and flexible rubber screening media reduces pegging and blinding with high-moisture ore and allows higher capacity compared to linear or circular motion. With this technology, it’s possible to use of the same screen sizes as with traditional screens.

With screens proven to offer 15-30% increased throughput at 90% efficiency in dry screening high moisture applications, we have introduced a real game changer that could benefit the entire industry. Mining companies will be able to further push the limits of what is possible to screen in a dry process and hence eliminate the need for water and reduce the total water consumption in the process.