Modern Mining May 2018

COMPANIES

of the Cascade chute system, 95 % of the mate- rial runs on material at all times. This principle reduces degradation of materials by control- ling the flow of the material, and this, in turn, reduces wear and tear, noise and dust pollu- tion, spillage, excessive impact and subsequent belt damage. Says Baller: “We control material flow from the time material enters the chute to the time it leaves the chute – we make sure that it goes where we want it to go and not where it wants to go. We control direction, volume and velocity. Where the chute feeds an outgo- ing conveyor, we match up with the conveyor speed in the direction of travel and we design in such a way that minimal kinetic energy – in other words, impact – is transferred to the conveyor belt.” He makes the point that the savings on belt life alone – irrespective of the many other ben- efits – make a compelling case for the Weba Chute System. “We often come across cases where conveyor belts are literally being beaten to death by poor chute design and we are almost always able to rectify matters. In one particular application where we were called in, belts were having to be replaced every nine months or so. Now that we’ve installed our chutes, they’re lasting for several years. As a general rule of thumb, we estimate that a Weba Chute System will pay for itself within 12 to 18 months, and often much less.” The Weba chutes are noted for their durabil- ity with one installation in South Africa still performing efficiently 20 years after it was first installed. Further afield, in Wyoming in the United States, a Weba chute at one of the coun- try’s biggest coal mines has now operated for

Wherever possible – for example, when we are retrofitting to an existing plant – we will visit the site to ensure that we fully understand the physical constraints we face.” He adds that 3D scanning can streamline common surveying tasks and generate accurate 3D models from on-site conditions. Relating the history of Weba, Baller says the

Weba Chute Systems are engineered specifically for a given application requirement. The design of Weba Chute Systems has been config- ured to force a concentrated stream from the screen decks onto the conveyor.

12 years handling 6 500 t/h on an almost continuous basis. “Probably about 600 million tonnes has gone through this particular chute and it looks good for many more years of opera- tion,” says Baller. Part of the reason for Weba’s success, Baller con- tends, is its philosophy that there is no such thing as an off-the-shelf chute. “We regard every instal- lation as unique. Each application is individu- ally assessed to ascertain its particular requirements and the most appropri- ate solution is provided.

May 2018  MODERN MINING  33