FILTRATION & THICKENING
commitment to environmental sustainability and operational safety. Our DELKOR High- Density Thickener is particularly suited to such applications where high water recovery is required. Through efficient and reliable water and tailings management solutions, we are able to assist our clients in meeting their goals while contributing to safer and more sustainable mining practices,” states Andres Costa, Managing Director of TAKRAF Chile and Peru.
TAKRAF Group CEO Thomas Jabs added:“ This project award reaffirms TAKRAF Group’ s DELKOR brand as a global front runner and expert in dewatering solutions. Our DELKOR Thickener technology, together with other DELKOR dewatering technologies, play a crucial role in enabling operations to recover and recycle water, reduce their tailings footprint, and enhance process efficiency. These solutions not only address the challenges of water scarcity in regions like Chile but also contribute to safer and more responsible operations.”
Metso on high rate to high density
IM also caught up with Metso’ s Simon Courtenay – Product Manager for Thickeners, initially to discuss market trends in customer strategies regarding tailings and thickener selection. He stated:“ It is definitely the case that the tailings community in mining favours filtered tailings for small to medium scale projects when there is a requirement for either maximum water recovery or dry disposal. But for the very large throughput copper tailings projects, thickened tailings is the predominant method of treatment, with the volume
Metso’ s High Compression Thickener( HCT) is a market leading technology for slurry thickening, based on proven successful innovations developed over decades
46 considered challenging to process through filters.”
Interestingly, Courtenay also feels there has also been a change in how paste tailings are designated:“ What we’ ve seen is a shift towards the high compression point on the curve rather than say classic paste rheology. I think people want that higher density compared to a high-rate thickener and there’ s several cases now, particularly in Chile, where high rate thickeners have been installed and operational expectations have shifted, so some of those customers are now focusing on a higher density for tailings disposal in new expansion projects.”
He adds:“ For new projects there is a goal to increase the output and the performance from larger high compression thickeners, and this influences the direction of our product development. There are some key principles of Metso High Compression Thickener technology including even dispersion of flocculated solids into the thickener through the Reactorwell™ to create a consistent bed. Additionally, looking at the geometry of the tank such as the floor slope and its ability to assist with the transport of solids towards the centre, plus the sidewall height for compaction. The rake requires sufficient drive torque to rake the thickened material, together with the correct design of rake mechanism to minimise solids bridging. So, there are a number of factors that we’ ve been focusing on to create a complete solution.”
Courtenay said decisions are driven by two factors either separately or together and these are regulatory requirements or simply water recovery.“ The regulatory requirements may be a function of the permitted volume of the existing tailings dam facility as the storage capacity will influence their mine life. In Chile, for example you have scarcity of water as well leading to a high focus on recovering as much tailings water as possible. In South America, many projects handle over 100,000 t / d of tailings, typically opting for several large, high-compression thickeners.” What about the operational risks of having fewer large-diameter thickeners if one goes offline?“ Today, 50-60 m high-compression thickeners are well established. While there are inherent risks in ensuring each unit performs reliably to meet targets, some customers view fewer units as reducing operational complexity. Managing many smaller units requires evenly distributing the feed, maintaining consistent particle size and slurry conditions, and coordinating underflow collection into a common system, which can increase operational risk. Very large capacity projects need to be thought about from an equipment design and operation risk point of view, but also from the overall plant operation and production point of view.”
What about constructability and modularity?“ The overall supply plan is a big part of the whole project. Additionally, we are looking ahead at key component relationships to provide more support for access and consider options available from a range of key suppliers. We’ ve been working with the suppliers in China for around 20 years. Now we’ ve got strong capabilities also in other regions, as well as new alternatives we are exploring. Additionally, we are looking ahead with key components in relationships to support our product development. Drive units for example currently range up to 14.5MNm with new designs up to 20MNm. Bolted tanks are another area that can benefit construction speed, but the suitability of this construction depends on a combination of the thickener size and type, the slurry SG and the seismic zone, so the selection needs to be verified for each case.”
Another Metso strength is in test work – it has extensive testing facilities as well as pilot rigs.“ In all our cases we try to back up our proposal with test results and test work. We believe this gives us a strong position to understand the best solution. Plus, our additional services can bring additional benefits over the longer term, throughout the thickener lifecycle. The market is highly competitive, and we are seeing many Chinese OEM activities in the Chinese market itself but also in markets like southeast Asia and Africa. But it is mainly in thickeners up to around 50 m diameter – once you get above that size, we see the Chinese mining companies are selecting Western options as a better guarantee of performance and quality. For example, in 2023 we announced a package of equipment supply to Zijin Mining’ s Julong copper mine in Tibet that included five High Rate Thickeners- two of which were for tailings and are 100 m in diameter.”
IM also spoke to Metso Product Director, Thickening Services, Andrew McIntosh about the aftermarket. How do mining customers squeeze more out of what they already have, and what are the different options for companies with a thickener that was installed 20 or even 30 years ago?“ The first thing to note is that technology has developed vastly in the past 20 years. Then over the time that the thickener has been
International Mining | OCTOBER 2025