HOISTS AND WINDERS
Weir Minerals ’ alternative vertical transport system
IM recently caught up with Ralph van Rijswick , Chief Engineer Venlo Technology Group at Weir Minerals . While most of this article is about traditional winder-based mine hoisting , Weir argues that hydraulic ore hoisting has the potential to revolutionise vertical transport systems in the mining industry . Weir Minerals has designed a system that harnesses its GEHO ® positive displacement ( PD ) pumps – a proven technology with the high pressure and flow assurance and stability requirements needed for this application . Its GEHO ® hydraulic ore hoisting system is an innovative solution that has the benefit of being a continuous process that ’ s basically scalable to any required capacity .
Weir Minerals recently built and validated its GEHO ® hydraulic ore hoisting system using an industrial scale prototype at its Venlo Technology Hub in the Netherlands . The success of this project means that the technology is now considered ready for the next step of scale up and field qualification in actual mining operations .
Rijswick : “ The most obvious opportunities to implement this technology are in greenfield projects because the capital investment associated with creating a new , large diameter shaft with the required hoisting infrastructure would be significantly higher that an hydraulic ore hoisting system . Moreover , factoring in hydraulic ore hoisting as the preferred vertical transportation method at the early stages of the mine plan will ensure its integrated with up and downstream processing requirements . For instance , as more continuous mining methods are being developed and implemented in hard rock mining applications , the material comes off the face at a smaller size and , as a result , requires less processing in order to be pumped .”
If , on the other hand , drill and blast is used , the ROM PSD ranges from very fine sand size ( 63-125 um ) to cobble ( 63- 250 mm ) or even boulder size (> 250 mm ) material . Therefore , sub-surface size reduction would likely be required to make the ROM suitable for hydraulic ore hoisting .
Rijswick adds : “ Moreover , as technologies like ore sorting improved and are more widely embraced , the efficiency of the hydraulic ore hoisting system will also be improved further enhanced because it won ’ t be required to transport as much non-valuable ore . In other words , there are quite a few synergies between hydraulic ore hoisting and new and emerging technologies that are likely to make mining more efficient , sustainable and cost effective .”
There are more variables when it comes to brownfield projects , which means that determining whether hydraulic ore hoisting is the ideal solution will need to be done on a case-by-case basis . “ For instance , if an open pit mine is transitioning to an underground operation , there is obviously going to be significant mine development and sinking new shafts is likely to be significantly more CAPEX intensive than implementing a hydraulic ore hoisting system . On the other hand , if an underground operation is expanding to mine a nearby reef and the existing infrastructure is suitable , then hydraulic ore hoisting might not be the ideal solution .”
Unlike traditional vertical transportation methods , hydraulic ore hoisting isn ’ t an intermittent process , nor is it limited both in terms of
Weir hydraulic ore hoisting loop
depth (< 100 m ) and tonnages (< 200 t / h ) like trucking . With traditional vertical transportation methods , as an operation goes deeper underground , the distance the material needs to be transported increases and , as a result , capacity is reduced .
“ While truck haulage offers a relatively low CAPEX solution , fuel and labour costs are a significant OPEX burden and , in a 24 / 7 production environment , it ’ s difficult to scale up . And , in terms of sustainability , it ’ s an extremely carbon intensive solution . Moreover , from a safety perspective , manned haul trucks pose a significant considerable risk , accounting for roughly 50 percent of all mining fatalities .”
Rijswick says that skip hoisting systems run up against limitations related to the size of the shaft and skip , as well as the hoisting systems ’ cable diameter and the capacity of its winding motors . This means that – like truck haulage and unlike hydraulic ore hoisting – it also can ’ t be easily scaled up . “ In contrast , scaling up hydraulic ore hoisting systems can be achieved by increasing the size of the pressure exchange chambers for the required flow rate and operating multiple PD pumps in parallel to provide the required flow rate of driving fluid .”
GEHO ® PD pumps are capable of producing high enough discharge pressures to achieve the lift capacity required for this application ; this , in concert with the market ’ s acknowledgement of their unrivalled reliability and stability , means they are the integral piece of equipment in the hydraulic ore hoisting system .
However , Weir Minerals says its all-of-mine capabilities and Integrated Solutions approach – whereby it looks at the process holistically rather than focusing too narrowly on each individual piece of equipment in the flowsheet – means it has the upstream and downstream capabilities to ensure the overall process operates optimally . “ Our Trio ® comminution equipment could be utilised in the underground primary and secondary crushing applications to achieve the required PSD , while the slurry can be dewatered with Cavex ® hydrocyclones and / or Enduron ® dewatering screens when it reaches the surface . Weir Minerals portfolio of products , global service and support network and trained personnel ensure it is ideally placed to deliver and provide on-going support for miners interested in exploring hydraulic ore hoisting as an alternative vertical transportation system .”
force of up to 450 kN in the cable running directly onto the drum jacket in the first winding layer .
The shaft is fitted with auxiliary equipment to ensure the hoisting of buckets in the shaft and to fulfil the functions deriving from the sinking technology and the construction of the shaft , ie a three-floor working platform that at the same time serves as a tensioning frame for the guide and hoisting cables , and a two-floor platform for the cementing of the shaft suspended on two suspension ropes . In the shaft hoists , excavation buckets with a capacity of 4 m 3 and 5 m 3 and a lifting capacity of 6.4 t or 10 t respectively were used as the primary excavation vessels . Openbottomed buckets with a capacity of 2.3 m 3 and 2.5 m 3 have been used as material buckets ( designed to lower concrete and loose materials ).
The GG-1 shaft is currently in a transition period , following completion of the shaft sinking and prior to its outfitting with target equipment and final facilities of the shaft yard . The GG-1 shaft is of significant importance for the development of KGHM . It provides key support for the process of opening new areas of the copper deposit and extending the operation of the Polkowice-Sieroszowice and Rudna mines - at Rudna , MWM Elektro also upgraded a Koepe type
36 International Mining | AUGUST 2023