NARROW VEIN & LOW PROFILE MINING
the direction of vertical drilling to the vein deposit , according to MM .
These narrow machine dimensions have , in the past , caused problems with stability during tramming and drilling , but MM has solved these issues using a central , oscillated vertical main pivot that changes the tyre load distribution and increases stability during travel on uneven roads and headings . At the same time , the drilling process requires high stiffness of the carrier as can be achieved by using a rigid chassis , with Mine Master implementing a “ state-of-the-art solution ” to convert the flexible , oscillated carrier to a rigid module .
An Australia first
Earlier this year , a Sandvik DD212 customised drill rig designed to deal with narrow-vein mining started up at Silver Lake Resources ’ Rothsay gold mine in Western Australia .
The single-boom , electro-hydraulic drill for mining development and production was the first to arrive in Australia and was a welcome addition to the mine ’ s fleet , Silver Lake said in April .
Rothsay is within the Warriedar Greenstone gold belt of the Yalgoo Goldfield in the Southern Murchison Region of Western Australia . The current project plan would see mineralised ore extracted from narrow sub-vertical structures , according to contractor Redpath , aligning well with the compact dimensions of the new rig .
The Sandvik DD212 is an upgrade of the Sandvik DD210 development drill rig , delivering an up to 20 % reduction in boom positioning time per face and a circa-15 % improvement in drill penetration rate based on factory tests . Its 3 % improved pull-out ratio , meanwhile , can result in an up to 10 cm greater advance per face when compared with similar equipment , Sandvik says .
Among the new features are a drilling control system , the THC562 , which provides torque control and reaming hole selection . This enables the DD212 to provide increased drilling performance , while reducing the wear on both the rock drill and rock tools .
The SB20i intelligent boom is used for accurate hole electronic positioning , which enables precise and fast navigation of drill feed and tool , with automatic parallelism and instrumentation for hole angle measurements , Sandvik says . The boom offers a large face drill coverage from 6-25 sq . m thanks to the 1 m boom extension and the two narrow-vein type rotation actuators .
The development drill has an extended , 12 ft ( 3.7 m ) TF feed rod , which optimises the advance / round , while its RDX5 rock drill provides a fast drilling cycle time and low operating costs .
The specific compact and versatile CFX telescopic feed , meanwhile , can retract from 12 ft to 6 ft ( 1.8 m ), enhancing multi-purpose operation in small tunnel sizes of 2.5 m x 2.5 m to 3.5 m x 3.5 m – similar dimensions to the narrow vein operations at Rothsay .
Battery-electric options
Aramine ’ s compact and robust mining equipment has found its way into many narrowvein mines across the world , with its LHDs , drill rigs and mining trucks renowned , the company says , for their high productivity , reliability , comfort and safety .
Its offering has , in recent years , expanded to electric-powered and battery-powered machines on top of its existing diesel-powered fleet , with the battery-powered segment growing in demand as mines look for flexible and ‘ green ’ machines to add to their fleets .
What began with its miniLoader L140B – a 1.3 t payload LHD powered by a lithium-ironphosphate battery – has since expanded to
The Sandvik DD212 is an upgrade of the Sandvik DD210 development drill rig , delivering an up to 20 % reduction in boom positioning time per face and a circa-15 % improvement in drill penetration rate based on factory tests
include the miniDumper T500B , a 3-5 t payload battery-powered equivalent of Aramine ’ s existing T500D diesel-powered truck suitable for development and production in small section and narrow-vein mines . The company also confirmed recently that a DM901HBE battery drill rig will join the offering at the end of the year .
Yet , all the talk ahead of the upcoming MINExpo event in Las Vegas , USA , is about the battery-powered L350B , a 3-5 t payload LHD based off the diesel-powered L350D .
Those familiar with the diesel-powered L350D will be pleased to hear the frame and systems of the L350B will be the same as the diesel version , “ except that the diesel version with a diesel engine drives a hydrostatic motor where the battery version has the batteries drive an electric
Aramine ’ s battery-powered L350B is a 3-5 t payload LHD based off the existing diesel-powered L350D
54 International Mining | JULY 2021