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Fraser Alexander Tailings has partnered with Multotec to develop a globally unique tailings deposition solution for the global mining industry that optimises cost savings, productivity and site safety, and reduces environmental impact presenting a truly viable alternative to traditional methods.
Fraser Alexander Tailings has already deployed 12 of these revolutionary new track mounted self-propelled cyclone units (SPCU’s) into the field at a tailings dam in Stilfontein and has placed an order for a further 12 units with Multotec for a tailings dam in Brakpan.
“These new units are very site specific,” Aidan Götz, operations director at Fraser Alexander Tailings, says. “They have been developed to address the particular issues associated with high tonnage tailings dams. For example, we have deployed the first units at a tailings dam with a tonnage of around 1.8mn tonnes per month.
Tailings deposition methods affect how the tailings deposit and settle within the impoundment. Up until now, when cyclones have been harnessed in tailings deposition, this has typically been approached using a multi-deposition point method, where the cyclones operate in banks. A typical challenge associated with this method, however, is moving the numerous cyclones around the site. Cyclone deposition can also take place via a single deposition point, where a cluster of cyclones is deployed on a certain spot, operating in such a manner to uniformly produce the geotechnical specifications required by the engineer.
The challenge with this method is that the massive cyclone cluster still needs to be moved around the site. These challenges prompted us to investigate the possibility of building an SPCU to overcome the mobility question, suitable for large tailings dams where the cyclone multi-deposition point method would be extremely complex. Having already developed a track mounted hydraulic mining gun, the solution was right in front of us.”
Talking about, and specifying, mining technology
At that time Fraser Alexander Tailings had initiated a Full Tailings Dam Cyclone study and Multotec was one of the companies contributing to the study. Fraser Alexander started talking to the Multotec team about the possibility of co-developing a track mounted cyclone unit. Fraser Alexander later officially appointed Multotec to put together a set of cyclones to produce the required geotechnical specifications from certain tailings, and then to design and manufacture a cluster cyclone assembly to be mounted onto a diesel/electrical self-propelled track chassis as developed by Fraser Alexander.
“We needed Multotec’s input to work out how to combine their cyclone technology onto the unit we had conceptualised,” he says. “The resulting prototype was put to work in an exacting field trial for about nine months and the result actually exceeded our expectations. Although the original unit is still evolving in terms of minor modifications, Multotec gave us a well designed cyclone assembly that clearly exemplifies the company’s immense experience in this arena. Multotec’s portion of the unit has been accomplished with the utmost professionalism — we got exactly what we wanted. Multotec’s approach aligns perfectly with our company value of continuous innovation and we were impressed by their willingness to walk alongside us and their ability to make adjustments along the way in order to produce a really impressive end product.”
Götz says there is a definite trend in the local mining industry that is seeing clients move to the larger, “super-tailings” dams. Up until now, many mines have run tailings strategies on multiple structures — that is, limiting the size of their tailings dams — but these multiple structures have both cost and environmental implications.
“The introduction of the SPCU opens up an exciting new alternative to companies producing high tonnages of tailings,” he says. “In addition to the cost benefits associated with building bigger tailings dams, the remotely controlled SPCU helps to create a safer environment for operational personnel, while having a single point of deposition makes for a far better geotechnical output compared with a multi-stage approach at this level of tonnage. We are currently showcasing the SPCU to clients and are finding that there is a definite appetite out there for this pioneering alternative.”
Multotec’s Ian du Plessis comments that the productivity levels of the new SPCU are quite remarkable — with a single SPCU with four 420 mm cyclones capable of achieving the same output as 16 conventional 250 mm cyclones.
“We are very excited about the part we have played in the development of this unit, proving that we are able to partner with clients to meet their unique requirements and at the same time come up with technological innovations that will benefit the entire industry,” he says.
IMAGE: Fraser Alexander Tailings, Multotec/PIC 01
CAPTION: The track mounted self-propelled cyclone unit
IMAGE: Fraser Alexander Tailings, Multotec/PIC 02
CAPTION: The remotely controlled self-propelled cyclone unit in action
IMAGE: Fraser Alexander Tailings, Multotec/PIC 03
CAPTION: The self-propelled cyclone unit offers a globally unique tailings deposition solution
IMAGE: Fraser Alexander Tailings, Multotec/PIC 04
CAPTION: The track mounted self-propelled cyclone unit optimises cost savings and productivity