Article first published in Mineria Chilena, June 2024. Reprinted with permission.

The industry understands the world needs an increased supply of critical minerals for the decarbonization of the energy system. These minerals include copper, lithium and nickel, among others.

In this context, the mining industry faces numerous challenges in both mineral processing and tailings management, such as water scarcity, limited deposition areas and stricter safety and environmental regulations. The use of sustainable practices is crucial to minimize environmental impact and protect communities.

Addressing these challenges involves prioritizing responsible and safe tailings storage. Proper design, construction, management and compliance with both national and international standards are crucial to mitigating risk. New technologies, such as advanced monitoring and dewatering, are improving stability and sustainability by reducing the volume of water in tailings, making them easier to manage.

Under this scenario, Anglo American is developing Hydraulic Dewatered Stacking (HDS) technology for tailings management, inspired by coarse particle flotation (CPR), at its El Soldado copper mine in Chile.

Ausenco is collaborating with Anglo American on this exciting new technology.

Greater Innovation

CPR technology produces sand with low fine material content as a by-product. Anglo American identified this by-product as a key input for the development of HDS technology where the sands are used as a filter medium and water collection system within the tailings storage facility for whole and fine tailings, maximizing water recovery and accelerating tailings consolidation time.

Anglo American's patented HDS technology, which is being promoted in collaboration with Ausenco, has achieved water recoveries of over 80% to date without the utilization of filter and paste technologies. These initial results from the pilot plant at El Soldado have been very promising, highlighting the effectiveness of this technology.

"The high levels of water recovery, and the speed with which it is achieved, make HDS technology very competitive in terms of cost and water recovery efficiency compared to filter and paste technologies," says Claudio Román, Principal Geotechnical Engineer at Ausenco.

The expert explains that today, the industry is driving the development of new innovations for processing, transporting and tailings deposition making them more efficient, safer, and with less cost and greater recovery of water.

Finding the better way

"At Ausenco, we are using the multidisciplinary knowledge of our expert teams to advance and explore this new technology. We are looking for the best way to optimize it, as well as to replicate it in other operations," says Sergio Lagos, Principal Process Engineer at Ausenco.

Lagos appreciates that Anglo American has included Ausenco among the companies it invited to support them with this new technology and determine its applicability. "Our strength is that we are a holistic company, we have extensive experience in all phases of a project - from mine to port. And in the case of tailings, we cover processing, transportation and deposition," he says.

Claudio Román emphasizes that behind this technology there is a lot of geotechnical and hydraulic development and analysis in order to scale it to higher capacities. This work also includes determining how to generate sands in mining operations where there is no CPF, and the quality required for this type of technology.

At Ausenco, we pride ourselves on being at the forefront of providing the industry with efficient, safe, responsible and stable designs that challenge conventional tailings management practices. Our experts are committed to delivering these solutions through innovation and we have a strong commitment to environmental practices that ultimately help our clients manage their tailings more effectively, protecting people and communities, and the planet.