IM 2019 July 19 | Page 6

WORLD PROSPECTS VeRo Liberator comminution makes strides R eviewed by Gregor Borg from manufacturer PMS GmbH at MEI’s Physical Separation conference recently in Falmouth, UK, the innovative VeRo Liberator ® applies a mechanical high-velocity comminution principle, where numerous hammer tools rotate clockwise and anti-clockwise on three levels around a vertical shaft-inshaft (hollow shaft) system. The resulting high-frequency, high-velocity impacts cause a highly turbulent particle flow and trigger fracture nucleation and fracture propagation preferentially at and along mineral boundaries. Breakage of coarser particles occurs from the high-velocity stimulation of bulk ore particles, where the elasticity and compressibility modules control differential particle behaviour. The improved breakage behaviour results in a drastically reduced energy consumption of only 3 to 13 kWh/t and very high degrees of particle liberation in the relatively coarse fraction of the product. On an industrial scale, Anglo American has already applied two customised VeRo Liberators® in its South African platinum operations and has ordered a third which is due to be shipped. All three are specially designed to be used in industrial-scale pilot tests at their operations. Anglo refers to the approach as “shock- break technology” and has mentioned it in several investor presentation as well as showing graphics of the high-velocity comminution inside the VeRo machine. Elsewhere, Penoles and Fresnillo in Mexico have carried out advanced test-comminution of ores from several of their gold-silver-zinc-lead mines in Mexico. All of the mentioned installations have been around the 100 t/h throughput level. The 2019 MEI paper described results from test-comminution by VeRo Liberator ® of ores from Cienega mine, Durango Province, Mexico, in comparison to Cienega’s conventional comminution by SAG milling and ball milling. The results show that the VeRo Liberator ® achieves a similarly high degree of particle liberation compared to the SAG mill, but at a drastically coarser particle size. This is achieved at significantly lower energy consumption and thus energy costs and allows for more efficient dewatering of comminuted waste material and, consequently, for potentially more stable slimes dams. The mechanical high-velocity impact comminution by VeRo Liberator ® hence overcomes the notorious problems of inefficient breakage in conventional ball and SAG mills.  www.pms-handelskontor.de;  www.fresnilloplc.com; www.angloamerican.com Lihir gets 4G LTE network T 4 International Mining | JULY 2019 Private LTE technology further validates it as a dependable and scalable networking platform for the mining industry and one that enables mining houses to digitally transform. “We’ve provided Newcrest with a tailored platform that will underpin its safety and digital mining ambitions and will help improve productivity and deliver new value and efficiencies to the business,” she said. “They’ll be using it to further modernise the mine site to enable the use of current and future mining applications, including tele-remote and autonomous systems, more extensively.” The platform is completely independent from public mobile networks, according to Telstra, with Newcrest having been provided with its own dual-frequency base stations, LTE core and SIM cards, with the network’s configuration and coverage designed and implemented to meet the Lihir mine’s safety strategy and long-term mine plan. Telstra Mining Services’ solution also includes ‘HetNet’ functionality that allows the Newcrest vehicle fleet to seamlessly switch between LTE and existing Wi-Fi networks without impacting critical mining applications. Newcrest complemented the LTE technology solution by implementing new towers, data centres and redundant power systems across the site, according to Telstra. McGill added: “Newcrest and Telstra Mining Services took what has become a best-in-class preliminary deployment approach with the network. Designing it for full production but initially deploying at two sites allowed Newcrest to validate the design principles, implementation techniques and practical capabilities of LTE before scaling their investment.” Newcrest’s pragmatic approach, combined with flexibilities in the solution from Telstra Mining Services, enabled the desired outcomes and learning to be achieved within a relatively short timeframe, despite the remoteness of the Lihir operation, according to Telstra. Future phases of the project will further enhance coverage in-line with Lihir’s 20-year mine plan, and provide for expansion of coverage and capacity across the mine, processing plant, port and camp. Chris Jordaan, General Manager, Newcrest Lihir, said: “The Lihir mine extends 300 m into a volcanic crater and our workers can often be exposed to elevated temperatures. Tele-remote and autonomous mining technologies are fundamental to working the hot work areas that will become more dominant features of our operation in the future. “The Private LTE network will be a great enabler for these technologies and, coupled with the existing in-pit Wi-Fi network, we have been able to create a heterogeneous network that covers the whole mining lease.” elstra Mining Services says it has implemented Papua New Guinea’s first private 4G LTE (Long-Term Evolution) mobile network at Newcrest’s Lihir gold mine. The next generation wireless communications platform will allow for greater levels of safety, remote operation and automation, according to Telstra, which worked with Newcrest to provide design, staging, site deployment and testing of the network. Every kind of production vehicle asset, including trucks, drills, excavators, dozers, shovels and barges have now been connected and operationally proven over LTE. This process has revealed significant performance improvements in terms of reliability, speed and latency, according to Telstra. “The network has been able to resolve challenges with existing Wi- Fi connectivity and is making Newcrest’s safety and productivity systems more effective,” Telstra said, adding that fleet efficiency and real-time visibility have benefited from an 80% improvement in communications reliability on LTE-enabled assets. The gold deposit at Lihir is within the Luise Caldera, an extinct volcanic crater that is geothermally active, and is one of the largest known gold deposits in the world, according to Newcrest. Most of the ore is refractory and is treated using pressure oxidation before the gold is recovered by a conventional leach process. In the financial year ending June 30, 2018, Lihir produced 955,156 oz of gold. Since production commenced in 1997, the site has produced more than 10 Moz of the yellow metal. Dr Jeannette McGill, Head of Telstra Mining Services, said Newcrest’s decision to invest in