ROCK TOOLS ROCK TOOLS
ROCK TOOLS process , so stopping all work to change bits , even if you have auto pulling , for safety still means stopping all work while refilling or changing bits with a human presence , which means high operating costs , so the longer the interval for these changes , the more savings for the mine .”
Robit ’ s Director Global Sales , Jorge Leal adds : “ Until drill rig manufacturers invent an automatic way to change the drill bits , there will be a need for more resistant drill bits so they can keep running the machines without interruption . Depending on ground conditions , a drill bit can drill between 50-80 m before it needs to be taken out to be re-sharpened . A drill rig can drill 250-300 m in a shift ( depending on many variables ) so it is not productive to take out those bits . That is why for example Robit has diamond coated button bits to provide the solution to drill with ease that amount of metres , and even more .”
Brunner & Lay Marketing Director , Shane Jimison commented : “ The autonomous drills either underground or surface will produce better results on drill string life and efficiency . These drills can be set up based on the current environment with the proper settings and the end result will allow for life improvements along with better production numbers for the mining operations . This will eliminate setting changes , poor drilling habits and many other factors that not only reduce the life of the drill string but overall efficiency .”
Rockmore unveils Retrac
In new product developments , Rockmore recently introduced a new drill bit design specifically used in tunnelling applications . Reaming type bits in underground drilling and blasting operations are used to enlarge selected existing blast holes to bigger diameters for effective blasting and rock fragmentation . This is typically performed in tunnelling , mining , and underground construction drilling operations . The larger reamed holes are not loaded with blasting agents and therefore allow the rock formation to implode during the explosion phase . The empty voids in these reamed holes promote better rock fragmentation and more efficient blasting patterns .
After blast holes are drilled in the drift or tunnel face with hole diameters ranging from 43-51 mm , certain holes in the pattern are enlarged with a typical reaming bit to 76-102 mm , depending on the blast and rock formation requirements . Standard reaming bits feature face designs with dome or narrow nose fronts and are intended to effectively enlarge a predrilled hole . When they are retrieved out of the hole , however , at the end of the target hole depth , they often seize up due to the loose rock debris inside the hole formation .
Rockmore engineers addressed the challenge of retrieving these style bits by developing a new model that features retrac style cutting fins in the rear section to promote better retraction out of the hole . The fins effectively push out any rock chips trapped behind the bit when the drill string is pulled from the blast hole resulting in more efficient reaming operations in underground drilling operations . The particular model shown in the attached image is designed to ream from 41 mm to 102 mm holes and configured with a R32 thread connection to the tunnelling rod .
The new Arrow drilling system from Brunner & Lay it says was developed to enhance the ability of modern , high powered rock drills in both surface and underground applications to produce more precise holes
drill string failures extending service life . Brunner & Lay is now offering a variety of straight hole drilling tools in the form of guide rods , guide / pilot tubes , and shoulder driven drill tubes to meet a wide array of applications . Utilisation of this system along with the proper bit design for the rock type can produce significant improvements in the operation ’ s bottom line .”
Fewer drilled holes means an optimised drilling pattern with increased burden and spacing , less possibility of drill string jamming , improved safety with better blast control and reduced consumption of explosives , which makes up for 40-50 % of the total cost of drilling and blasting .
Drill tubes are more rigid than conventional drill strings of extension or MF drill rods . It is this increased rigidity that ensures far less hole deviation and a more cost-effective drill and blast cycle . Additional rigidity provided by pilot / guide and drill tubes enable thick layers of overburden and broken rock to be drilled through without appreciable hole deviation . Tubes also limit the potential for jamming while retracting the drill string through overburden .
Jimison told IM that customers that have used the system have experienced less hole deviation when compared to traditional systems in both underground long-hole applications and top-hammer surface use .
Rockmore Retrac bit designed to ream from 41 mm to 102 mm holes and configured with a R32 thread connection to the tunnelling rod
Brunner & Lay points the Arrow
The new Arrow drilling system from Brunner & Lay it says was developed to enhance the ability of modern , high powered rock drills in both surface and underground applications to produce more precise holes necessary for production in the modern mine & quarry site . Jimison comments : “ Blast holes that are straighter improve several aspects of the drill / blast operation with overall time savings having most impact to the operational bottom line . Straight holes improve drilling by providing less bending stress on the drill string and reduced hole deviation to improve the service life of the string . They typically require less energy to produce the holes , thus saving on fuel and wear-andtear on the drill itself . Straight holes improve blasting operations by reducing fly-rock , back-break and deliver intended fragmentation to reduce the need for secondary drilling and breaking .” The system is currently available for its T38 , T45 , T51 and B60 applications .
The company adds : “ Straight holes mean easier and faster drilling and charging . Less bending stress throughout the drill string yields less fatigue induced
Sandvik digitalisation & Guide Adapters
Back in June 2020 , Sandvik Rock Tools launched what it says is an entirely new digital solution : My Rock Tools – Analyze . It is a mobile application designed to help customers improve their rock tool performance through analysing failure and discard reasons .
The new solution is an application specifically designed to conduct failure and discard analysis and provide advice and guidance in a customer report – all remotely . The aim is to determine the root cause of the failure or discard reason of the rock tool , prevent it from happening again and to help improve future performance .
“ Sandvik Rock Tools ’ suite of digital solutions serves our customers in a number of ways , and we are now very happy to be able to add My Rock Tools Analyze in order to offer easy-to-use remote support for failure and discard analysis . With it , customers can ultimately increase productivity and profitability by using the analysis results to improve their drilling operations ” says Charles Macfadyen , Digital Solutions , Rock Tools Division , Sandvik Mining and Rock Technology .
The application is very easy to use : customers receive
52 International Mining | NOVEMBER / DECEMBER 2020