MechChem Africa

FLSmidth senior account manager for sub-Saharan Africa region, Ricus van Reenen, talks about the company’s range of technical, transportation and assembly options as well as optimal design and delivery solutions devised for the supply of large thickeners, while commercial manager, Terence Osborn, unveils the company’s Electra Mining focus

Finding the optimal design and delivery solution for a large thickener at a remote gold mine in the West African state of Mauritania meant considering a complex range of technical, transportation and assembly options, according to FLSmidth senior account manager, Ricus van Reenen.

FLSMIDTH thickener

The cost of transporting the components for the 50 m diameter thickener was a key factor affecting the design, says van Reenen. He highlights that transportation of components to remote sites can comprise a substantial portion of costs, and that break-bulk shipping costs are significantly higher than containerised transport.

“Given that the thickener components needed to be shipped by sea as well as by road, containers were considered the most economical mode solution,” he says. “This requires that the plate sections be cut and rolled in dimensions that can be packed into containers for shipping to site. The structural support sections, such as the I-beams, are fabricated to final stage at our facility and just bolted on site, but the plates need to then be welded by expert welders,” he explains.

While bolted thickeners are often more economical to construct, as they obviate the need for extensive on-site welding, this option cannot easily be applied to thickeners larger than 50 m in diameter.

“For these larger designs, the support structure is erected on site, followed by the welding together of the plate sections from one end to the other,” he says. “After the plate sections have been welded to the structure, the welds are sandblasted, primed and applied with a final paint coating over the welded areas.”

Van Reenen emphasises the importance of the documented assembly procedure applied when erecting these large thickeners. “When supplying a thickener, part of our engineering deliverables includes an installation methodology for the site contractor to follow, to make sure that he implements each stage correctly,” he says. He further emphasises that the forces demanded within large thickeners also makes the choice of gearbox drive much more important.

“Smaller thickeners can usually be designed with planetary gearbox drives – available from a number of OEMs,” he says. “With large drives requiring higher torque, however, we prefer to use our own ring-gear Dorr Oliver drives, which can reach much higher torque values than planetary drives.”

At Electra Mining: REFLUX Classifiers and the digital future

In pride of place on the FLSmidth Electra Mining Africa exhibition stand this year will be a 1:20 scale model of its REFLUX™ Classifier (RC) modular plant, representing – in more ways than one – the future of processing in the mining sector.

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