Engineering & Mining Journal

APR 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 62 of 91

UNDERGROUND MINING APRIL 2018 • E&MJ 61 will unlock immense value considering that one shaft that was mined 20 years ago still has 7,000 hectares of fines with yields of between 12 g/mt. However, these pan- els cannot be reached safely using manual methods. Importantly, our technology can also be used to clean the back ends, where as much as 30% of daily production ends up in the PGM industry due to poor blast- ing practices. A local PGM mine is current- ly only cleaning a maximum of 80 m 2 per day using a crew comprising 30 people, as opposed to the required 200 m 2 per day at yields of typically 4.5 g/mt, according to mining production figures." CMTI Group's machines are currently being operated from the gulley as part of the first phase of the development pro- gram. The second phase will entail op- erating the ULPs from the surface and eventually off-site. This supports the drive by the South African mining industry to remove workers from potentially harmful working environments, while substituting low-skilled employment prospects with skilled jobs that are safer and secure. The intention is to also replace tradi- tional underground mining jobs with higher paid positions in factories as mines grad- ually deploy more local innovation — a strategy that is endorsed by Dr. Paul Jour- dan, a resource-development strategist and staunch proponent of the urgent mechani- zation of South African mining. This narra- tive was also again given significant weight at the ruling party's national conference in December, where Minister of Trade & In- dustry Rob Davis emphasized the need for all economic sectors to embrace advanced technologies to boost South Africa's com- petitiveness on the global stage. Drilling 2 Panels in a Shift CMTI Group's MT100 has a maximum height of 420 mm and a battery life of sev- en hours, and can be equipped with any two attachments, such as a sweeper, scraper and dozer with an 850-kg dozing capacity. Powered by a trailing cable, the MT1000 features a rock-breaker for non-explosive mining and a patented multidrill attach- ment, which allows four holes to be drilled quickly and accurately at the correct angles. Both machines feature a multitrack concept. Four tracks are individually driv- en and are able to swing around a center point for the platforms to negate vertical obstacles as high as 400 mm. The tracks on the MT1000 are also steerable and, at Burnstone, the machine aligns itself with the rock face, while driv- ing parallel to it, and then drills a 46-mm diameter hole. It indexes the breaker to the hole's position and inserts it, before imparting lateral force to the rock. Using the technology, two panels are be- ing drilled in a single shift, and Burger said CMTI Group will improve on this stellar per- formance early this year. This is in stark con- trast to the extended periods it currently takes up to five rock-drill operators to drill a 30-m panel using traditional mining methods. Slamming the Brakes on Substandard Testing Locally developed technologies are providing underground and surface mines with a safer, as well as more reliable and efficient means of testing the braking systems of their mechanized produc- tion and transportation equipment. CMTI Managing Director Dr. Danie Burger said the company is using its experience developing mining systems to design integrated brake-testing technologies. "They are based on the suggestions of a workgroup, compris- ing all mining houses and OEMs in the South African mining industry," Burger said. "Steered by Anglo Platinum's De Wet Strydom, the workgroup was tasked with assisting in the design of a solution that would address the many challenges facing both underground and surface-mining operations." For example, dynamic testing, used in underground mining environments, can cause unnecessary damage to trackless mo- bile mining (TMM) machines and only inspects the efficacy of the service-brake, as opposed to the entire system, including the park and emergency brakes, as well as accumulators. The technology is also not suited to testing tractor-trailer combinations due to the risk of "jack-knifing" the vehicles. He also noted the important findings of extensive studies undertaken by the Mine Health and Safety Council have shown that the technology can be up to 200% inaccurate when vehi - cles are tested at speeds of less than 12 km/h as is also men - tioned in SANS 1589. Burger added, "Mine personnel also do not realize that a 35% measurement reading on the service brakes of a vehicle on a decline with a gradient of 20% means that the vehicle has failed the test and is, therefore, non-compliant. It remains a se- rious concern that machines with brake efficiency levels of only 15% are being returned to service, despite the severe risk that they pose in already complex working environments." While causes of accidents, injuries and fatalities may vary, transport-related incidences remain one of the three main rea- sons for mine injuries in underground mining environments, ac- cording to the South African Chamber of Mines. This includes the use of TMM machines, which are a critical component of the mechanization of South Africa's underground op- erations to ensure a safer working environment, in addition to their long-term sustainability by replacing outdated mining methods. CMTI Group's pull-brake tester for underground vehicles is semistatic to avoid damaging the brake system and is a safe means of testing the service, neutral and park/emergency brakes. In addition, all tests are undertaken with a 10% over- load to facilitate the trending of brake degradation, while wear data is recorded and measured against the OEM's standards. All tests are photographed and a comprehensive report, in- cluding a time and date stamp, is generated for every test and can be used for legal purposes. All TMMs are pre-loaded into the system, streamlining the testing process by allowing the operator to merely select the relevant model and enter the plant number, while an email noti- fication is automatically sent directly to the relevant mine repre- sentatives in the event of a failure. CMTI Group's technology meets the stringent requirements of the Mine Health & Safety Act. The new regulations for the static testing of TMMs were implemented in February 2015 and are undertaken according to the SANS/ISO1589 standard. The semistatic pull-brake tester avoids damaging the brake system and is a safe means of testing the surface, neutral and park/emerging brakes. (Continued on p. 63)

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