GROUND SUPPORT & ROCK REINFORCEMENT
BP3 and Agilis – a new era for underground shotcrete
IM spoke to RufDiamond President , Daryl Adams and Global Product Manager – Shotcrete at MacLean Engineering , Jonathan Lavallee , about the development of the machine , from concept to reality , and why it has created such a stir already .
Q : What is the basic advantage of the system in underground mining ? JL : In initial discussions with RufDiamond we immediately saw the potential advantages of the Agilis system – being able to utilise wet shotcrete in mining or civil tunnelling without having to put in additional underground infrastructure like batch plants and slick lines . You get to keep a similar storage and infrastructure set-up as you would with dry shotcrete . With this machine you can use any pre-mixed product to produce shotcrete , concrete or grout . It ’ s not that mobile batching hasn ’ t been tried before ; basic volumetric mixing has been trialled underground in a number of projects as temporary batch plants but still with complications . Agilis produces perfect wet shotcrete using a much more robust and consistent system with the added benefit of additional quality control measures .
Q : What is a volumetric mixer and why have they proved problematic underground ? JL : A volumetric mixer ( VM ) in one way is similar to Agilis in appearance , in terms of being a large mounted holding tank , except that the VM is often open topped while Agilis is enclosed , protecting the shotcrete mixes from moisture . But inside at the back end , the VM is a segregated series of bins with cement , aggregate and any required chemicals . These are weighed and measured within that enclosed system and batched out for mixing to produce shotcrete as required . But it requires time and finesse to get a quality product . Loads are often rejected due to non-conformance , because the material is either too wet or too dry . Agilis turns this on its head and utilises proper dry to wet supersacked pre-blended mixed product produced in the patented mixing auger with a precise amount of water to give a quality shotcrete in 20 or 30 seconds . Water can be stored in a 500-gallon tank .
Q : What challenges did you face in the development ? DA : The challenges are numerous , though we have overcome them all . One of the first is to have an auger system long enough to do a proper mix . If it ’ s too long you will be non-mine compliant because of height restrictions . Once you get your upper limit figured out , then you still need to ensure the bottom end has enough ground clearance when the vehicle is being driven around the mine . You then have to have an aggressive enough style of mixing auger and process to re-dampen the water dry material to ensure an optimum mix output . The Agilis system does not use we don ’ t need separate aggregate and cement bins , and we don ’ t use gates . Overall we were able to leverage technology with a bit of ingenuity to make it work . But again , all within the typical space limitations of an underground mine . We had to look at whether the auger would have to pivot left and right or if we could articulate the base vehicle to do that . Lastly , we also learnt a lot early on about the Agilis system from a offroad unit that was mounted on a crawler Powertraxx PT15 unit , designed for surface infrastructure markets .
Q : Can you give an idea of the unit ’ s size and capacity , the steps and how you record what particular mix was used ? DA : The Agilis system carries 6 m 3 of dry pre-blended material , 500 gallons of water ( that can be heated for colder climates ) and provides 30 cubic metres of shotcrete per hour . The dry pre-mixed material is emptied from the totes into the watertight hopper and the BP3 drives to the underground location with no shotcrete production until then . You then select a pre-programmed mix design , press a button and being begin pouring . You can also load pre-stage totes onsite for continuous pour capability . Every time the Agilis mixes material all data related to the mix design is recorded , sent to a supervisor and available for printout should a project manager supervisor require information such as time , date , work location , product used , water ratio ( including any adjustments ) and strength .
Q : So where were the synergies between RufDiamond and MacLean ? DA : It ’ s been a very good match . When we started this project , we were of the mindset initially that being based in Sudbury with some many equipment companies around we would make the Agilis carrier agnostic . So anyone could put the our system on their chassis . But after meeting MacLean and having some detailed discussions , their interest in making it a joint project was clear , and they saw the same industry pain points in underground shotcrete that we were trying to solve . They put our design through its paces from a visual , application and technology point of view including trials , and from there it became a joint venture – where we now exclusively work with MacLean . Carriers may look similar from the outside but we heard from many industry levels from executives to maintainers , mechanics and operators , positive feedback on the MacLean carrier .
Q : Where is the project at today ? What has been built and tested and where ? DA : For the Agilis mixing unit itself , we at RufDiamond , partnered with a specialist supplier and fabricator called Bay-Lynx several years ago ; they are VM focussed but took our idea using pre-blended material in totes onboard even though it was initially outside their sphere . Once they saw how the system works they and their engineering team welcomed the project . Over several years we have produced a system that is ready to be combined with a MacLean carrier . We pre-sold a unit which is now in the commissioning phase . The MacLean carrier was sent from MacLean ’ s Collingwood site to the Bay-Lynx facility to be interfaced with the Agilis box mixing unit and further tested , after which the complete unit went to MacLean ’ s underground test facility on Magill Street , Lively for final commissioning then it went to the initial launch customer which is one of the large Sudbury nickel operations . JL : The Bay-Lynx and MacLean engineers have been working closely together to ensure that the carrier and back end Agilis system interfacing is seamless , and as stated the testing at our R & D ramp in Sudbury Magill really put the machine through its paces before it went to the customer . We have also built a second machine which is at Magill awaiting confirmation of our second order . The amount of interest we have been getting on the system is pretty phenomenal . These initial units are diesel but of course with MacLean ’ s expertise there is the potential to supply a BEV version as well . manufacturer and supplier of ground support & rock reinforcement systems for the mining and civil industries in Australia . With the acquisition , Normet strengthens its portfolio in dynamic ground support & rock reinforcementin underground mining and construction infrastructure projects . The parties have agreed not to disclose any financial details related to the transaction .
“ This is a strategic acquisition for Normet in the Asia-Pacific market with impact on our global ground support & rock reinforcement business .
With Garock , Australia will become Normet ’ s Global Centre for Rock Reinforcement R & D with ability to innovate in the future ,” comments Ed Santamaria , President and CEO at Normet . Garock Pty Ltd has traded under the Normet Group from 1 July 2022 .
28 International Mining | AUGUST 2022