GROUND SUPPORT
Charette states : “ In order to provide a quick and simple solution , a small portable grouting platform was developed by Minova , to offer a very clean operation and fast mobilisation on site ; the system is based on Minova ’ s workhorse SK90 pump , which is used with portable resin tanks that allow for a full day ’ s operation without refilling . The platform tanks can be filled from larger IBCs or smaller containers and hand pumps . The system is a closed circuit which minimises exposure to chemicals during the grouting operation . As the platform system is compact , it can be used on scissor-lift trucks , to rapidly access cable anchors to be grouted .” The platform can also be located at a central location on the stope or intersection floor and via long injection hoses , the operator can easily reach the cables to be grouted .
An additional improvement of the method comprises a very quick coupling system , which facilitates the connection and disconnection of the grouting tubes within seconds to allow a very fast grouting procedure . The method is used extensively to install cable bolts in underground mines and provides a higher quality installation of cables in any ground conditions , with a dramatic reduction of cycle time compared to traditional cement grouts . An intersection can be completed under half a shift , as the cable bolts can be installed and grouted in a few hours and provide near maximum support capacity only a few minutes after grouting .
For the grouting of cable anchors in tight boreholes , Minova has also developed an injection procedure that uses small diameter injection tubes to grout various types of rock bolts and cable anchors . Such a method was recently used in underground mines in Ontario , with Double Lok ( expansion shell ) bolts in low roof situations and continuous thread bar bolts , when the use of resin cartridges did not provide the performance consistency required for the operation . The capability to use very small grouting tubes permits the utilisation of the bolts with an optimum borehole diameter . It also reduces grout wastage when used in broken ground conditions . Full training on the system was also provided to the mine .
“ Another success story in Canada is Minova ’ s UniPass system , which was developed around Minova ’ s Self Drilling Anchors™ and hollow bolts and CarboThix injection resins and can be used in OEM bolting equipment and facilitates the trend towards automated bolting . The UniPass system has been instrumental in providing a better and faster support system to several mining operations in Canada , establishing a new performance standard for mining development in conditions ranging from good to very poor ground conditions and cold to hot environments . Minova offers a range of
New Concept Mining – developments in self drilling bolting technology
With the mining industry ’ s continuous drive for improvements in safety and efficiency the concept of self-drilling and pumpable rockbolts for hard rock underground mines is gaining popularity . Whilst self-drilling rockbolts have been widely used in tunnelling and civil applications their adoption in the mining industry has been limited due to a perceived higher cost , limitations when drilling into harder and abrasive ground and the suitability of rock bolt performance to the mining industry .
In order to offer mining customer ’ s the advantages of self-drilling rockbolting systems whilst meeting the support requirements of deep and highly stressed underground mines , New Concept Mining Powered by Epiroc , has developed a range of bolting solutions for customers . The range is designed to be suitable for varying ground conditions including quasi-static , squeezing ground , seismicity and rockbursting . To complement the range of rockbolts , Potentia pumpable resins have been formulated to maximise the efficiency and consistency with which pumpable rockbolts are installed with high strength to match traditional resins used in mining . Extensive laboratory testing was conducted on the combined various rockbolt and resin systems , under static and dynamic loading conditions , prior to initiation of successful underground trials . The extension of the pumpable bolting range and launch of Potentia resins means that together with the Boltec , Epiroc is well positioned to provide customers with a high efficiency bolting system to suit their specific needs . The benefits in mining efficiency and underground safety achievable with the pumpable bolting systems is resulting in the technology being globally adopted at an increasing rate by mining operations .
injection resins , allowing the mining operator to match the speed of injection with the conditions underground ; the flexibility of application of individual formulations is another factor that allows applications spanning a wide range of temperature conditions without having to change compounds and operating procedures . Such flexibility simplifies the ground support installation leading to improved and more consistent bolting performance . CarboThix rightly has a leading reputation for pumpable anchor resins which is built on proven quality , consistency , and performance , gained from internal and external testing on important parameters , including longevity , creep analysis , dynamic performance , anchorage testing and gas analysis . Minova continues to invest and support the company ’ s flagship resins in CarboThix . The future of Minova pumpable and cartridge resins and bolting solutions will continue to track the trends of the ground support sector .”
MacLean scissor bolter milestone & battery SS5
MacLean recently shipped the first of its 30th anniversary 900 Series bolters from the company ’ s main manufacturing facility in
Collingwood , Ontario . The unit , a 975 Omnia scissor bolter , was sold to a contractor working at an underground gold mine in northwest British Columbia . The first commercialised 900 Series unit was sold in the early 1990s to a then INCO-owned mine in the Sudbury basin .
The company states : “ The MacLean Bolter is the Ground Support Engineer ’ s ultimate tool , providing the flexibility to put in any type of ground support to produce the highest quality of support cost effectively . These are the defining features of the MacLean bolting philosophy that the company ’ s 900 Series bolter design .”
“ This piece of mobile mining equipment has propelled the shift over three decades from manual to semi-mechanised bolting , with all the accompanying safety and productivity benefits that move brought about ,” notes Steve Denomme , Global Product Line Manager for Bolting at MacLean . “ Reaching this production milestone for the MacLean bolting system is significant in and of itself and , it also sets up the next chapter in MacLean ground support solutions – fully automated , robotics-integrated bolting .”
“ The importance of this product for the company and its contribution to the industry is
72 International Mining | AUGUST 2021