Engineering & Mining Journal

OCT 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 46 of 91

CONVEYOR ENGINEERING OCTOBER 2018 • E&MJ 45 clogging as no stopping time difference between the two sections, and capital ex- penses were optimized by eliminating the drives and substation at the intermediate transfer point. More recently, RBL-REI has just been awarded a new contract to supply two belt conveyors for the coal extraction in an underground mine based in Soma coal basin, owned by the Turkish energy company Polyak Eyneez. For this appli- cation, RBL-REI will design a system to convey raw coal from 650 meters under- ground to the prep plant on the surface. This will be a first and an engineering feat for Turkey as it will be fitted with a total drive power of 9,000 kW and high resistant belts ST6600. RBL-REI ex- pects this system to be commissioned in the second quarter of 2019. Takraf Technology Selected for Iron Ore Ops In September, Rio Tinto initiated a ma- jor sustaining capital project to replace the original stackers at its Paraburdoo iron ore mine in Western Australia. Enclosed Conveyors Put Safety First Whether they are operating underground or on the floor of a processing plant, conveyors are vital to automating an operation. But they still require human interaction to operate effectively, so there will always be safety concerns whenever human contact is required with equipment. A conveyor's level of safety begins with how it is designed, explained Andrew Parker, vice president, CDM Systems Inc. "Covering moving parts and preventing access to materials that often move at high speeds are important starting points," Parker said. "The more you can minimize human contact with a con- veyor or prevent things like boot laces or shirt sleeves from get- ting caught up in a shaft rotating at 2,000 rpm, the better your chances of having a safe operation." Belt conveyors are some of the most common conveyors in use today, but they bring a litany of safety concerns that are inherent in their design: • Exposed idlers located approximately every four feet along a run, which means an extensive number of maintenance points as well; • There is the potential for spillage or dusting from the move- ment of the exposed materials; • If materials become wedged under a roller or between two points on a belt conveyor, the belt can be cut, creating an unsafe operating situation; and • Material jams can generate friction and heat that can ignite flammable materials. All conveyors require a certain amount of expected main- tenance. Protecting maintenance crews is especially important and it's important to adhere regulations and guidelines. "Wheth- er it's a 70-lb weight limit for removable pieces, requiring a tool to gain access to moving parts, or eliminating any gap larger than 0.5 in. between exposed shafts and rotating equipment, those regulations and guidelines are not always enough when the human factor is taken into consideration," Parker said. One should never assume that maintenance workers will follow safety guidelines when servicing equipment, Parker explained. Any conveyor can be shipped and assembled with guarding in place, but maintenance workers, possibly in an ef- fort to work faster or more efficiently, often take shortcuts that leave guards loose or completely removed. On a belt conveyor, that safety risk exists every 4 ft for the entire run. One solution to ensuring optimal safety while enhancing efficiency, productivity and profitability lies in the adoption of an en-masse conveyor, such as a chain conveyor, screw convey- or, or bucket elevator, that features an enclosed or sealed de- sign. These types of systems move materials more safely and eliminate concerns about dusting and airborne material. Enclosed conveyors also reduce the potential for injury by allowing only two access points to moving parts at the front and back of the con- veyor run. This means easier maintenance and relief for techni- cians who are used to handling heavy guards and access panels. En-masse conveyors in particular can carry more material in less space compared to other conveyor technologies, with mini- mal material degradation. This addresses the profitability issue by increasing efficiency, and because it moves material in an en- closed steel casing, the en-masse design is a viable option that results in fewer injuries, less dust, fewer aspiration problems, and less potential contamination of the material. With millions of dollars and people's lives at stake, ensuring the safest possible environment for employees should be the top priority for any industrial manufacturing operation. "It's simply the right thing to do," Parker said. "Fortunately, it doesn't have to come at the expense of attaining and maintaining profitabil- ity. With any conveyor system, it's important to identify safety challenges before they result in an injury, worker's compensation claim, or worse. Doing so requires a thorough understanding of a variety of material handling demands, which underlines the importance of partnering with an experienced equipment manu- facturer before deciding on any conveying solution." Proper guarding and enclosed conveyors prevent fugitive emissions and safety mishaps.

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