Modern Mining April 2021

Efficient control of dust and material spills in underground conveyor systems sion and subsequent belt damage.”

Dust is a major problem associated with conveyor systems, particularly those in confined underground mining conditions, where miners have prolonged exposure to the hazards of dust particles. Apart from the negative effects of dust on a miner’s health – like irritation to the eyes, skin and respiratory tracts, as well as serious lung diseases – some types of dust can also form an explosive mixture with air, which is extremely dangerous. ScrapeTec has developed advanced solutions for conveyor systems – AirScrape, TailScrape and SpeedScrape products – which encompass the latest technology, to prevent dust formation, reduce material spill, enable thorough belt-cleaning and minimise the risk of explosion at critical sections along the conveyor route and at transfer points, explains Ken Mouritzen, MD, BLT WORLD, specialist in bulk handling systems. “BLT WORLD specialists work closely with mine engineers and the ScrapeTec team to alleviate problems associated with dust generation, material spills and contamination at the transfer points of underground conveyor systems. The team also offers solutions to misalignment, abra-

ScrapeTec’s contact-free AirScrape con- veyor belt skirting system hovers freely above the conveyor belt, preventing skirt friction and belt damage, thus extending service life of the conveyor system. The AirScrape system – which encompasses inward facing, hardened-steel diagonal blades - operates according to a new prin- ciple where it hovers 1-2 mm, on the left and right side above the conveyor belt. The blades deflect larger particles inwards, while using the air-flow of the conveyor belt and conveyed material to create an inward suction, forcing any dust and fine particles back into the product flow. Through these diagonally fitted plates and the speed of the running belt, air is drawn from the out- side inwards. As a result, neither the dust nor material can escape. Conventional skirting is pressed against a conveyor belt to keep dust and material in the middle of the belt, but after a period, wear of the skirting and belt can be so severe, that material and dust escapes. Material spillage at transfer points needs to be removed and regular maintenance and housekeeping of belt skirting and transfer points is necessary.

Mine conveyor with AirScrape.

production in late 2022 or early 2023. “We are pleased to continue our strate- gic partnership with Sandfire Resources. We have worked with Sandfire in the past and are very grateful to be selected again for their flagship Motheo project. Our proven proprietary and sustainable technologies will support Sandfire with achieving their inter- national growth and diversification strategy,” says Kai Rönnberg, vice president, Minerals Sales, Asia Pacific at Metso Outotec.  Wi th the AirScrape dust-free and contact-free, side sealing system for belt conveyors, there is no skirt contact and therefore no belt wear or damage. Motor power requirements are reduced as there is no belt-skirt friction and because there is continuous skirting with no gaps, product loss is minimal. Experience shows that even seven years after installation and with continuous use in harsh underground mining condi- tions, the AirScrape system shows little sign of wear. Operational costs are also reduced because there is no need for spill- age collection, regular maintenance, or replacement parts. 

Metso Outotec to supply processing tech to copper-silver project in Botswana Metso Outotec has signed a contract to deliver all of the main process technologies for Sandfire Resources’ flagship Motheo copper-silver concentrator in Botswana. The order value of approximately €17-million was booked in the Minerals segment’s Q1/2021 orders received. in the future. Metso Outotec will deliver all key minerals processing equipment includ- ing gyratory and pebble crushers, apron feeders, semi-autogenous (SAG) mill and the associated reline machine, TankCell flotation cells, Vertimill fine grinding mill, high rate thickeners, and a pressure filter. Additionally, spare parts and supervisory services will be supplied to support commissioning and plant ramp up. Delivery will take place during 2021 and 2022, and the plant is expected to start The 3,2 mi l l ion tonnes per annum greenfield plant will be built in the Kalahari copper belt in Botswana, with the potential to expand to 5,2 million tonnes per annum

April 2021  MODERN MINING  39