While the modern world simply cannot function without mining and industrial operations, environmental rehabilitation is an essential and sustainable response to the man-made destruction of the natural habitat that is a consequence of these activities. Environmental restoration is an important consideration for Multotec, a leading mineral processing equipment manufacturer. The company recently undertook several environmental clean-up projects that have yielded positive outcomes, and the results have demonstrated the potential for Multotec's advanced mineral processing equipment to be harnessed in the field of environmental rehabilitation.

Faan Bornman, Technology Manager at Multotec, explains that the company had been approached by a number of clients – both local and international – to see whether it could provide solutions to specific environmental issues.

Initially, Multotec was contacted by a company based in Spain that specialises in crushing and milling accident-damaged cars that have been written off. This client required a solution that would separate the metal and plastic parts of vehicles in order to recycle the metal.

“We conducted test work using spirals, equipment usually used in mineral processing, to establish if we could separate the materials and we were successful. Apart from being able to distinguish the plastic from the metal, we took it a step further and used magnetic separation to extract the iron out of the samples,” says Bornman.

“Secondly, a South African electronic recycling company, DESCO Electronic Recyclers also approached us as they required PC components to be recycled. An important element of this process is to separate the metals from the plastics and non-valuable waste. Bornman states that Multotec ran the samples over spirals to gravity separate the components. “We once again managed to separate the metals – copper and iron – from the silica particles, microplastics and fibres. We had some challenges, as the materials were very fine, but were successful and produced a report for this client, highlighting how their business could be enhanced through this process,” he adds. 

Enrico Airaga, Technical Director at DESCO Electronic Recyclers adds that by attempting to separate the unwanted plastics from the metals, the material is upgraded into a much better quality. This enhances the product and also the profitability of the fraction.

Bornman states that Multotec also concluded test work on contaminated gravel as an operation was experiencing process problems due to the presence of plastic in the gravel. The plastic would find its way into the mining process and ended up, along with the gravel, in the processing plant where it would cause blockages. A method was needed to separate the plastics from the gravel. “We used a regular cyclone and also tested a stacker cyclone, where a vacuum is created in the overflow, which would separate the plastic from the gravel. With this scenario, we were also successful in that we were able to extract the plastic through the overflow, which is the top part of the cyclone where fine and light particles accumulate.” 

Similarly, Multotec also conducted test work to remove sand and earth from a manure sample. The manure was then further used to generate energy, says Bornman.

Bornman mentioned that while these were once-off projects, they proved that Multotec could use its existing mineral processing equipment for environmental rehabilitation work, which is an area that the company is eager to explore.

Finetuning the process

“Even though these are different applications, we managed to show that our mineral processing equipment is suitable and can be used for environmental clean-up work. Perhaps the process can be finetuned even further in the future, as we get deeper into what is needed for environmental clean-ups,” he says.

“Cyclone, spiral and magnetic separators were used to get the results from the test work, but we could potentially look at designing a plant through a design house that could be installed at a recycling centre. The possibilities are endless.”

Multotec, could potentially address customer challenges that are specific to different regions and industries. Through the test work that it undertakes, Multotec gains valuable experience that allows it to refine its processes and solutions, ensuring continuous improvement and enhanced effectiveness in addressing customer challenges, Bornman says.

“While we have not commercialised our environmental clean-up processes, this is an area where we could potentially make a significant contribution. This forms part of our drive to enhance the performance and efficiency of our products to maximise the separation of valuable materials from non-valuables, thus addressing many customers’ primary challenges,” Bornman concludes.

Multotec’s test work services are available to assist the general mineral processing market globally, tertiary institutions, its customers, and is also open to non-customers.