Continuous ion exchange technology

Minerals processing equipment supplier Multotec Process Equipment has secured its first two projects for the continuous ion exchange technology it offers and is achieving notable progress in both, Multotec senior process engineer Carien Spagnuolo tells Mining Weekly.

It is used to treat mine water for reuse and to recover valuable elements that may be in the water.  Clean TeQ’s technology is based on the foundation of conventional ion exchange technology, which is then enhanced to be more effective. This constitutes two principles – continuous movement of resin when treating waters, and moving the resin counter-current to the flow of the solution.

For its first reference project, Multotec installed and is commissioning an effluent treatment plant for the treatment of wastewater at an antimony roaster in Oman, in the Middle East, for an undisclosed client.

This project began in February last year, and cold commissioning was completed in July, with hot commissioning expected in September.

This project illustrates the ability of Clean TeQ’s technology to treat “difficult waters” at high water recovery, and it is being used in conjunction with conventional technologies in certain applications, notes Spagnuolo. She explains that difficult waters are typically those that have very high scaling elements, such as acid mine drainage water, scrubber blowdowns or run-of-mine water.

“For this project, our technology is combined with conventional precipitation and reverse osmosis technology – the combination provides the high water recovery, exceeding 90%, but without our technology, it would not be possible.”

The second project, also for an undisclosed client, in the Democratic Republic of Congo, entails uranium recovery from a processing stream at a cobalt operation. The DRC project began in December last year and the technology is projected for delivery in September. The project is Multotec’s pioneer project for the continuous ion exchange technology in Africa. ,” acclaims Spagnuolo.

The client’s initial preference was to use conventional ion exchange technology, but opted for the Multotec’s version because it operates with much smaller resin volumes. Spagnuolo informs that metal recovery resin is very expensive, and any savings in the amount required in this operation translates into big cost savings.

For this project, the majority of the technology’s components will be manufactured in South Africa, with the design of the technology undertaken by Clean TeQ, in Australia.

Both projects were executed following extensive testwork. Spagnuolo emphasises that conducting testwork prevents any challenges when executing projects. Testwork also allows for technology designs to be executed correctly to each client’s water specifications and to mimic the process of the technology at lab-scale, which allows for ease of scale-up. 

Thorough Testing

For the Middle East project, testwork proved that the technology would achieve a very high water recovery when treating the project’s difficult water. Multotec conducted laboratory-scale testwork at its facilities, in South Africa, simulating the entire project, which generated the information required to design the technology. For the DRC project, an extensive range of testwork was undertaken in Australia to guide the design.

Such testwork is not new to Multotec, as the company has been actively undertaking testwork for various clients to show the flexibility of its technology for different types of waters following its partnership with Clean TeQ, informs Spagnuolo.

These reference projects form part of Multotec and Clean TeQ’s efforts to change the way in which mining companies and industries perceive water and water management – instead of seeing water treatment as a grudge purchase, water should be perceived as a carrier of value, that can be reused.

Multotec’s focus on the environmental impact of mining and industrial activities was enhanced by its partnership with Clean TeQ, as the company’s technology provides solutions for water sustainability in the mining sector.

The continuous ion exchange technology is very sustainable because it produces less waste, owing to its high water recovery, says Spagnuolo. Water can be then be reused – reducing mines’ reliance on external water sources.