The energy evolution: How filtration drives sustainable battery minerals processing

Central to this shift is the rise of battery-dependent technology, such as electric cars, phones, computers, and more. The growing adoption of these devices is rapidly increasing demand for rechargeable batteries and their input commodities - including lithium, cobalt, nickel, graphite, manganese, copper and aluminum.

“Countries around the world are looking to get rid of fossil fuels, so the demand for battery minerals nowadays will only continue to grow,” says Timo Jauhiainen, Product Manager, Polishing Filters. “We need cleaner energy in order to combat climate change and usher in a new era of sustainability.”

This rise in technology, coupled with the commitment to sustainable progress, has revealed just how important the battery minerals process really is. As the world embraces battery-driven alternatives to traditional energy sources, it’s important to remember a crucial step of the process that cannot go unnoticed. Enter: Filtration.

The filtration process lends itself to the broader narrative of sustainability, with Metso’s extensive history and offering as a solution toward a greener future. From providing new exploration and greenfield sites with state-of-the-art equipment and practices, to helping improve the efficiency of existing brownfield mining and extraction sites, plants and processes, Metso has also developed efficient and responsible processes for recycling minerals from decommissioned batteries.

Led by history and expertise

Metso has a holistic insight into the battery minerals segment, stemming from a comprehensive technological coverage of the entire value chain. Our initial filtration solutions, such as the DM filter, were originally developed through Outotec’s own technology and industry know-how. Following that success, the AC filter was introduced, based on the DM’s leading technology. This unique offering allows for a more responsible value chain from start to finish and beyond, so battery mineral processes can be not only more sustainable, but also more transparent, safe and reliable.

“We are the world’s leading company in filtration and hydrometallurgical applications, and have been for quite a while,” says Timo. “At the moment, the battery minerals industry is really booming, which means our offering in this space is more prevalent now more than ever.”

The filtration expertise continues as it is built on almost one hundred years of R&D and process knowledge and is supported by the unique Dewatering Technology Center (DTC) in Lappeenranta, Finland. The DTC plays a crucial role in Metso’s filtration solution innovations and acts as a hub for close university collaboration related to separation technology research. The commitment to continuous growth can be seen in Metso's staggering track record – over 14,000 filtration tests conducted, complemented by the global deployment of over 5,000 filters.

Where does filtration come into this?

The filtration process plays a crucial role as it secures the purity of the battery minerals. Purity is extremely important in order to get higher-grade and cleaner battery chemicals. Beyond quality enhancement, filtration's impact ripples through the plant's entire operation, as it prevents unplanned shutdowns and safeguarding equipment. This is because with cleaner liquids in the process, other equipment after the filtration such as pipelines are protected.

Another reason why polishing filters are needed in hydrometallurgical applications is the recovery of the organics from the process streams. This not only increases sustainability but also minimizes costs by enabling the reuse of valuable organic compounds.

“We’re saving money for the customer,” says Timo. “The fact that they can now recover the organic and recycle it so they can use it again is not only a bonus for them, but for the planet as well.”

Can battery minerals undergo processing without filtration? The resounding answer is no. Filtration is an indispensable component, ensuring the separation of solids from liquids, and facilitating crucial liquid separation steps. This process is instrumental in extracting organic solvent extraction compounds from process leakers.

Sustainable filtration solutions in battery minerals processing

Metso’s filtration legacy spans almost a century, boasting 15 different filter types for diverse applications. Among these innovations, the DM (Dual Media) filter and AC (Activated Carbon) filter stand out as pivotal innovations, each with a unique purpose in battery minerals processing.

Launched in 2012, the DM filter garnered global recognition, eventually prompting inquiries that began the development of the AC filter. With over 50 DM filters and 30 AC filters installed worldwide, these solutions are known for enhancing operations across multiple locations, including Turkey, Finland, Canada, and more.

In hydrometallurgical applications, DM and AC filters can be used in Solvent Extraction (SX) processes followed by electrowinning (EW), to produce metallic cathodes or crystallization for producing battery chemicals. The choice between DM and AC filters hinges on process specifics. Depending on the composition of organics and dissolution, one may prove superior. For further optimization, these filters can work together to maximize filtration efficiency.

“Simply put, activated carbon is for dissolved organics, whereas dual media filter is for physical organics compounds,” says Timo. “Both are suitable for greenfield and brownfield operations. Metso experts can determine the best combination of the filters, filter size and how many customers will need.”

Our Dual Media (DM) filter is a cost efficient, reliable and proven filter for high-capacity and polishing applications. Originally launched in 2012 by Outotec, this filter was developed in-house utilizing our unique and extensive industry knowledge. This filter plays a pivotal role in processes that entail the separation of physical organic compounds from process streams. It operates with the dual-media principle, making it an integral component within our solvent extraction and electrowinning (SX-EW) technology or as a stand-alone solution.

At its core, the DM filter is a pressure vessel encompassing two distinct filtration media: anthracite and garnet. The filtration process is top-down, allowing the process leaker to permeate both media. The anthracite layer removes organic compounds from the process stream, while the garnet media works to eliminate solid compounds, thus justifying its "dual media" namesake. Notably, with the anthracite layer facilitating the recovery of organics, this allows operations to recycle these vital compounds back into the process.

The DM filter also comes in 10 different sizes to suit differing production. Ranging from DM 1000 to DM 5200, this polishing filtration unit is applicable to increase product quality for all operations. Already with over 50 installations, the DM filter continues to be utilized on a global scale.

By combine coalescing and adsorption filtration, this drastically reduces entrained organic and particulate concentrations to a few parts per million. In doing so, it boosts production capacities and elevates the quality of battery chemical and cathode products.

Initially based on customer needs and the hydrometallurgy team requests for polishing SX plants, the universal success of this filter has sparked further product development. This has resulted in our latest innovation, the AC filter. In collaboration with customers, further development is steadily ongoing, as Metso aims to continuously improve customer processes.

Activated Carbon filter

Launched in 2022, the AC filter emerged as a response to an emerging demand. Fueled by customer inquiries and the insights of Metso's hydrometallurgical department, the AC filter bridged a crucial gap in filtration capabilities. Its conception was propelled by the necessity for a specialized filter that excelled at eliminating dissolved organics, a challenge that conventional filters struggled to address.

Mechanically, the AC filter is very similar to the DM filter, but in this case, there is only one filter media inside the filter - and that is activated carbon. Following a top-to-bottom feeding process, the filter goes through the activated carbon media and the activated carbon removes organic compounds from the process stream. This process is more efficient for dissolved organics, since they can be adsorped into the activated carbon, thus yielding purer liquor.

The AC filter is based on nearly a century of experience and strengthens the Metso filtration portfolio even further with its cost effective and modular design, increasing recovery and recycling of valuable process chemicals. This filter also optimizes backwashing using filtered process liquid. This minimizes water usage while simultaneously reducing energy consumption due to its low pumping pressure, adding a layer of sustainability to its efficiency.

The AC filter becomes an ideal choice when the solution is already free from suspended solids and when a very clean solution filtrate is needed. It is also used for raffinates, when a very clean solution is needed to follow SX steps to ensure that the remaining solvents and reagents from previous extraction step do not pass to the following step.

Driving the sustainable energy transition

Metso supports circular economy and responds to the growing battery minerals demand by supplying sustainable solutions for filtration in battery minerals.

Evidently, both the DM filter and AC filter embody Metso's dedication to minimizing environmental impact. Their low operating pressure translates to reduced energy consumption and lower operational costs, fostering a greener approach to filtration. These filters have also been designed to utilize filtered product. Process liquid is a filtrate, so by utilizing this as a backwash liquid, water is no longer needed for washing the filter.

“The rise of technology and the obligation to minimize our environmental footprint continue to be the catalyst for this growing demand,” says Timo. “Batteries for electrical vehicles and other types of equipment are most commonly using batteries as a source of power. This will continue.”

The efficiency of these filters can lead up to a remarkable 15% decrease in energy usage, attributed to prolonged cycle times and low operational pressure. Furthermore, they minimize water consumption by a staggering 90%, utilizing filtrate for filter backwash operations. The absence of moving parts in these filters also translates to less maintenance, as their unique media cleaning system ensures extended media lifespans.

Both filters are a part of Metso’s Planet Positive portfolio. Planet Positive is our all-encompassing approach to sustainability, which covers the environmental, social and financial aspects. Our Planet Positive offering has a central role in our sustainability agenda and 1.5 °C journey as it represents the key means of improving the resource efficiency of our customers’ operations.

Metso’s filtration offering for battery minerals optimize our commitment to sustainability, as they seamlessly integrate operational efficiency with environmentally responsible practices. As the mining industry marches towards a more responsible future, these filters stand as beacons of innovation and conscious resource management. That’s why, together, we are the partner for positive change.