Conveyors, Transfers, Chutes, Dust Control & Environment

Queensland magnesia plant opts for fully enclosed belt

3D model layout of the system. These images (supplied by Wave International) show the versatility of the system including the turns, lifts and declines. Approximately 300m of endless Sicon conveyor belting safely conveys 50t/ph of caustic calcined magnesia from plant to silos. The conveyor is shown in blue.

With conventional belt and pneumatic conveyors failing to perform at its Rockhampton plant, Sibelco QMAG needed a solution. With a compact plant, tight turns, close residential proximity and hygroscopic white powders, it was a challenging brief.

Sibelco QMAG’s Rockhampton facility in Queensland is involved in the mining, beneficiation and production of deadburned, electrofused and calcined magnesia products.

To produce this range of magnesia products, raw magnesite is fed into furnaces where it is heated by natural gas to 1,000°C to produce magnesia (MgO) or caustic calcined magnesium oxide (CCM) products. Further upgrading of the calcined magnesia is completed prior to the production of high-grade deadburned magnesia (DBM), and electrofused (EFM) products.

After failing with various traditional conveyor and pneumatic conveying systems, Paul Wilson, manager engineering services for Sibelco QMAG, had decided to contact ContiTech Australia to discuss its Sicon conveyor.

Any solution would require extremely tight routing. Furthermore a flexible position for three loading and three discharge points was also necessary due to the configuration and footprint of the plant’s relatively small transporting circuit which is quite close to populated areas.

Sicon is an extremely versatile enclosed conveyor belt system, produced by ContiTech in Germany. The belt is a closed, endless conveyor belt suitable for all types of bulk material. “Because of its high flexibility, the conveying route can be designed with radii of less than a metre, eliminating the need for transfer points at corners and curves. Inclinations up to 35° are possible,” explained ContiTech Australia’s application engineer Joern Gehl.

“The belt opens up only at loading and discharge areas and is also closed on the return trip. Therefore even sensitive material remains protected and pollution can be avoided.

“Several feeding and discharge areas can be installed along the conveying track and the belt can be used as a two-way conveyor system, loaded in both directions, and can run through several paths back and forward. The belt is lightweight and flexible, is self-centring between guide and support rollers and is also self-cleaning.”

Based on initial studies about the routing, Gehl submitted a proposal for the design and installation of a Sicon belt and its associated mechanical components.

After some assessments Sibelco QMAG decided to commence the project and awarded the order. Other than the conveyor structure and installation of the roller sets, ContiTech supplied all of the conveyor hardware for the system including roller sets, pulleys, drives, splicing equipment and commissioning technicians.

Detailed structural engineering and design for the system was jointly provided by Wave International, Brisbane.

In the process, the main loading point onto the new Sicon conveyor is from a sidewall conveyor which lifts the material to approx 40m above ground.

The material is then conveyed through the existing plant to the outside of the building, on top of the first silo. Here there is an intermediate discharge station where the material can either be fed into silo 1 or can re-feed itself and carry the material onto the top of silo 2 where the final discharge occurs.

From there the belt runs empty back to silo 1 where a bucket elevator allows the material to be taken out of the silo again from the bottom, lifted on top of the silo and fed back into the Sicon conveyor.

This then carries the material back in the building, passing the main loading station and discharges the material into a screw conveyor for further processing. The caustic calcined magnesia is transported @ 50 t/ph @ 1.3m/sec and has a bulk density of 0.8 t/m3. The entire Sicon belt length is 310m of which 225m is actually transporting material.

“Results since the first trials in December 2014 have been very good so far,” Wilson said.

“Even though it’s a relatively short travelling distance, the intricacies associated with this CCM material and challenges with our plant location requirements proved too difficult for the conventional conveying systems we tried. But the Sicon system is performing beautifully — we’ve had virtually no issues or problems at all.”

Joern Gehl said it had been some time since a Sicon system had been installed in Australia.

“The first Sicon-S1000 conveyor ever was installed in 1988 at a Swedish cement producer’s site. This conveyor system is still transporting sand and limestone for cement production. Today there are more than 140 Sicon installed systems worldwide, predominantly in Europe and USA.

“We have installed half a dozen or so systems in Australia and New Zealand — it’s a niche market really. Given the complexity of the conveyor system and process flexibility required by Sibelco this ContiTech Sicon conveyor belt was considered the only solution to satisfy all requirements demanded.

“Our very good working relationship with Mark Stonham and his clever team from Wave International resulted in a seamless design and engineering contribution which further added to the project’s success for Paul and his company.”

Sibelco was founded in 1872 with its main focus on mining quartz sand for Belgium’s glass producers. Nowadays the multinational firm processes a broad range of non-metallic industrial minerals at its 228 production sites in 41 countries and employs around 11,000 people. It supplies products to the glass, mining, agriculture, construction and manufacturing industries.

The company acquired QMAG in Rockhampton, QLD, in 2012, and formed Sibelco QMAG.

Contact: Joern Gehl, email: joern.gehl@cbg.contitech.net.au

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