Custom engineered chute systems have significantly reduced dust levels while increasing productivity at Zimplats. Over the last two decades, Weba Chute Systems has installed 99 of its tailor-made transfer points in various applications across the mine and processing plants.
These bespoke installations span various applications including conveyor onto conveyor transfer chutes, apron feeder discharge chutes, mill feed chutes, conveyor onto bins transfer chutes, screen over and under size chutes, silo chutes, and transfer chutes at the crushing and screening stations.
The company recently secured another contract to provide ten custom-engineered transfer chutes for the expansion of an underground crusher station at Zimplats.
Ted Cruikshank, Weba Chute Systems’ project manager, explains that these chutes will handle the transportation of run-of-mine material from the ore pass to the underground crusher and from the crusher to the outgoing conveyor. He says the engineering and construction of these chutes will ensure a fit-for-purpose robust solution with the height of the chutes ranging from two to six metres.
Sharing specifics, Cruikshank said that the chutes before the crusher are designed to manage large material of up to 650mm in size from a vibrating feeder, with a maximum tonnage of 1 100tph. “Other chutes will transport the feeder’s undersize, less than 180mm in size, at 550tph, while still others will be employed in conveyor-to-conveyor applications, feeding 1 500mm wide belts with up to 1 350 tph of material and a maximum lump size of 250mm.”
The company’s unique chute design philosophy, based on the cascade system, extends the wear life of the chute through the strategic placement of dead boxes, creating a layer of ore for the moving material to flow over. Replaceable lips are incorporated on the dead boxes facilitating easy and quick swap out at the necessary intervals. Easily accessible inspection doors are also a feature which will ensure maintenance becomes an effortless process.
Cruikshank says that this design has proven particularly effective at Zimplats due to the abrasiveness of platinum ore, and the Weba chutes will continue to ensure the smooth, controlled flow of mined and crushed material, leading to less wear, damage and spillage on conveyor belts and a marked reduction in dust.
The company’s innovative design has been particularly effective in reducing dust levels. Izak Potgieter, systems manager at Weba Chute Systems, cites the example of the bunker discharge chutes.
“In this application considerable dust levels were created due to material of up to 500mm in size moving through the conventional transfer point at a rate of 600tph with no control of the material resulting in an uneven flow creating a lot of energy for dust particles to expand into the surrounding atmosphere.”
Following the replacement of the conventional transfer point with a custom engineered Weba chute dust levels were considerably reduced by about 40% and Potgieter explains that by controlling the velocity of the material it is not only possible to reduce dust generation but also to improve flow control reducing impact and wear which in turn minimises maintenance downtime.
Hilmax, the company’s local agent in Zimbabwe, will oversee the chute installations and provide spare sets of wearing lip liners for each chute to ensure optimal uptime for Zimplats.