2020 at Outokumpu ’ s Kemi chromite mine for a | |||
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trial period with contract miner Tapojärvi , equipped with a Minova pumpable resin system , and is back now in Örebro to be used as a R & D development machine . In addition two batterypowered Boltec E Battery machines are operating at Agnico Eagle ’ s Kittilä .
Looking at the performance of pumpable resin systems on non-battery Boltec units , when leading mining company Vale started the development required to transition the Voisey ’ s Bay mine in Canada from an open pit to an underground operation , operators found they were jamming up at the bolting phase of the drill-blast cycle . As a result , overall cycle times at the nickel-copper mine in northern Labrador were slower than expected and the production timeline was under threat . If Voisey ’ s Bay was to begin producing underground by mid-year 2021 , as projected , something had to change . “ Our biggest issue was assuring that the bolt actually adhered properly in the hole ,” said Voisey ’ s Bay Construction Manager Will Menheere . “ We ’ d
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Getman ’ s ProShot™ Concrete Sprayer North American trial
Getman Corporation says it has received positive feedback this summer around performance and productivity in its initial North American trial of its new ProShot™ Concrete Sprayer .
Operators during early trials gave the ProShot strong reviews overall . Reports show that nozzle operators appreciate the speed at which the ProShot can lay up consistent layers of concrete , with productivity increased by 26 %. It says shotcrete personnel appreciate the advanced safety protocols built into the ‘ revolutionary ’ Getman design . With the boom mounted on the centreline of the chassis , the machine can park in the middle of the drift , with equal room on both sides of the chassis for safe egress . “ Operators appreciate both the superior visibility provided by the spacious , air-conditioned , centre mounted cab and the process information screens . Two are located in front and one in the back of the unit . These screens display pumping speed , component status , dosing rates , and volumes .” With six pre-sets available for varying dosage percentages , visible selection is instantly available to the operator ( changed on the remote ).
Mine management also shared feedback on operator performance and efficiency . " Nozzle operators with limited spray experience immediately adapted to the ProShot because of the intuitive controls , applying uniform and consistent concrete support in minimal time . The efficiency and improved output of the ProShot during the trial ’ s performance allowed them to quickly catch up on their concrete schedule ." Current options on the ProShot include a LiDAR scanner and a removable tablet for measuring sprayed layer thickness . Pre- and post-spray scans are instantly overlayed by the software and result in a colour-coded image revealing sprayed layer thickness . These images are used to generate reports that may then be transferred to a flash drive or transmitted via WiFi .
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shoot resin cartridges in the holes , install the bolt , spin it around , mix the resin and let it sit . But we were finding , on a number of occasions , that the resin would creep into fractures in the rock , and the bolt would pull out right away .”
The Epiroc rig has two resin tanks of 200 litre capacity for the pumpable resin system ; a cabin optimised for operator safety , comfort and visibility ; and a mesh handling boom for mechanical handling of mesh . The bolting unit itself has a signature indexing cradle design for accurate and fast bolting plus a BUT 45 boom which is strong and stiff for stable and fast positioning .
To avoid the delays associated with having to
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redo bolts as development proceeded , not to mention the dangers of unreliable rock reinforcement , Vale needed a new solution . The company was already using Epiroc ’ s Boltec M drill rig for bolting , but opted to use a different resin and delivery system that would work better in fractured rock – pumpable resin [ Minova ’ s CarboThix ], designed to be fast-setting and viscous enough to hold the bolt in place within seconds , but runny enough to be pumped easily . In early 2020 , Voisey ’ s Bay decided to give the resin and injection system a try , the |
Canada to do so . Once the rock reinforcement rigs had been altered to apply the new solution , the improvement was almost instantaneous says Vale . “ We are seeing a significant reduction in the cycle time ,” said Menheere . “ Plus , the selfanchoring bolts used with the system , though more expensive than traditional bolts , can be installed faster and with better quality results , so overall costs are lower .”
Safety has also improved in both the near and long-term , adds Vale Geotechnical Engineer Brad King . The Boltec rig keeps the bolting team away from the face and out of harm ’ s way , while the quality of the installation is expected to reduce the need to rehabilitate the reinforcement over the 15-year life of the mine . A bonus is that the bolting operators get more satisfaction , because they don ’ t have to keep redoing their work . “ The pumpable resin ’ s magic lies in the chemical reaction that takes place by mixing two substances together before they are injected into the hole . The mixing can leave behind a residue , but by flushing the mixing elements with biodegradable grease , the solution can be used repeatedly in a closed system that avoids any spillage .”
The Boltec rigs at Voisey ’ s Bay are flexible
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Epiroc recently imported its first Boltec M Battery rig to Canada |
first mine in |
enough to install multiple bolt types including |
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