Lonmin has ordered eight Weba Chutes Systems to replace existing conventional chutes which have not been performing to the standard required. The eight coarse ore silo discharge chutes will feed onto a vibrating feeder at Lonmin’s Eastern Platinum (EPL) concentrator that conveys UG2 ore with 25% chrome content.

The vibrating feeder operates at a peak of 180tph, conveying fines with a maximum lump size of 150mm and a bulk density of 1.8mm.

"The concentrator had been experiencing an unacceptable amount of blockages and spillage with the existing chutes," M&J Engineering’s Ted Cruikshank says. "Our brief was to design Weba Chute Systems that address these issues and that will consistently perform to the required specifications over the long term. Lonmin also requested access points at the back of the chutes to allow for blasting in the event of a blockage."

The Weba Chute Systems are being fabricated from 6 mm 350 WA mild steel plate lined with 25mm Hardox liners with a spile bar arrangement.

Cruikshank adds that M&J Engineering is also processing orders for an additional 12 Weba Chute Systems that will be deployed in various applications at other Lonmin sites.

Under normal operations, Weba Chute Systems can last up to 10 years in the field and many have continued to perform effectively even longer than this.

"We’re finally gaining recognition for the many unique features of the Weba Chute System concept, says Cruikshank. "The unprecedented growth we’re experiencing has confirmed our position as international market leaders in this field. The high number of retrofits we’re currently involved in points to the fact that many conventional chutes are not living up to their suppliers’ claims.

"We attribute this to a prevailing notion that chutes are little more than platework. We’ve effectively created technology that didn’t exist before and we’ve developed equipment and systems around it that address the multiple shortcomings of conventional transfer point design."

Weba Chute Systems have been primarily applied in the mining industry where materials such as copper, gold and iron ore, diamonds, coal, aggregates, cement and sand are transferred, but M&J Engineering is experiencing a steading increase in the number of enquiries from other sectors such as power generation, steelmaking, cement and food.

Locally manufactured Weba Chute Systems are designed according to the principle of conveyed material impacting on surfaces which already contain material.

"One of the most important requirements in transfer point design is to guide and control the material from the moment it enters the system until it exits the system," says Cruikshank. "This is addressed by the Weba Chute System concept that incorporates a ‘supertube’ or cascade effect that results in material running on material at all times.

"Most dust is generated when material is transferred, but using this cascade system to create a ‘super-flow’ effect, we’re able to reduce volumes of unwanted fines and associated dust. The immediate effect of this decrease in unwanted dust and noise pollution is an enhancement of working conditions impacting positively on the health of workers, which is always a major concern in this industry. Another big benefit is a decrease in abrasion of wearing parts and consequently less maintenance required."

Weba Chute Systems control the direction, flow and velocity of the calculated volume and type of material in each application, also taking into account belt width, belt speed, material sizes, shape and throughput.

"A correct and appropriate chute design is critical and it is imperative that all these factors are taken into account," says Cruikshank. "It’s not just about manufacturing a chute. We look at both current and historical data in order to fully understand exactly what each customer requires. We look at the most important factors that need to be addressed in a particular application and this, in some cases, could be as simple as reducing dust and spillage."

M&J Engineering is ISO 9000 accredited and its patented Weba Chute System design has won numerous international awards, including the Top Product awards twice in a row, the Technology 100 award and the CMA (Conveyor Manufacturer Association) award for design excellence.