ROCK TOOLS
KPA which describes the weight percent of recycled hard material in the carbides used in Sandvik Rock Tools drill bits . “ Cemented carbide is a key component for Sandvik Rock Tools products and a well-integrated component in our circular sustainability work . Our focus has so far been on carbide recycling . Currently , Sandvik Rock Tools can recycle carbides through two processes – the Zinc Recycling Process ( PRZ ) or chemical cleaning . With the recently developed chemical cleaning process , we can now recycle carbides back to basic raw materials with the same quality and properties as virgin raw materials . This generates a > 64 % CO ? reduction and > 70 % energy consumption reduction compared to mining minerals needed to produce cemented carbide .”
Sandvik Rock Tools also works closely with its steel suppliers to make sure that they have ambitious targets and plans to reduce their climate impact . To increase steel circularity , it strives to procure steel from scrap-based suppliers .
Finally , another way to enhance productivity and service life for Rock Tools products outlined in the report is by re-sharpening drill bits through grinding . “ By regrinding the drill bits regularly , the length of their service life can increase by up to 10 times . Careful maintenance of the cemented carbide inserts in drilling tools improves almost all rock drilling parameters and ensure a more efficient and resourceful drilling experience with reduced operating cost .”
The power of PCD
Epiroc launched its Powerbit X in May 2022 , a range focused on the use of polycrystalline diamond ( PCD ) as a protective layer . “ Drill bits where the buttons are coated with diamond protect your people , your productivity and the environment . The technology is called PCD ( polycrystalline diamond ) and is used in our Powerbit X range .” Changing drill bits is a safety risk and the diamond protective layer of Powerbit X it says gives the drill bits longer service life , which means fewer changes and less exposure to danger for operators .
It adds that Powerbit X also lets users realise the full potential of remotely and automatically controlled production , so the use of these tools on autonomous drill rigs is an important focus of the new range . Part of this is realising the full potential of automation . “ Mining is going digital and new opportunities include digital drill plans and remote production where operators move from the cabin to the control room . However , you still have to change drill bits . The long replacement intervals of Powerbit X lead to fewer interruptions in your operations . You get more out of your investments in modern technology .”
And it means more sustainability : “ The extremely hard surface of Powerbit X makes it
Terelion - it ’ s not just recycling
Terelion are a major supplier of tricone drill bits for use in the drill & blast method of mining . They use a lot of steel and a lot of carbide . The tricone bits are drilled until its not economically viable to drill any further as the ROP ( rate of penetration ) falls - but the company told IM that it is what happens next that distinguishes Terelion from their competitors . About 10 % of the total weight of a tricone bit is made up of tungsten carbide and there is a lot of value in the dulled bits - often they are just wastefully thrown into landfill sites . “ Terelion engages with their customers and together with a partner , they gather the used product and separate the carbide from the steel - sending the steel to a local mill and the carbide to their recycling and manufacturing facility in Austria . There , the carbide goes through a chemical process that returns the carbide to raw powder that can be reformed into tungsten carbide teeth , and that can once again be used in the manufacture of tricone bits . It is then sent to the customer , and the circle continues . This is a “ win-win ” process : we make better use of a finite resource , which is beneficial both from a sustainability point of view , as well as from a financial perspective for both customers and Terelion .” The process saves 70 % in energy and 60 % reduced CO 2 emissions compared to the equivalent mining process . The first steps have been taken together with customers , as a major US mining company has partnered with Terelion in this important initiative , and it says many more are eager to be involved . Rotary bits aside , a major focus for Terelion is also its DTH Warrior Hammers which it describes as a game changer when it comes to DTH drilling . “ The wide range of Warrior Hammers are all designed to withstand the most difficult of drilling conditions . They are easy to assemble and disassemble , with very few tools needed . And with an optimised air cycle , we have provided a powerful hammer that lowers the total cost of your operations .”
possible to reduce the amount of CO 2 emissions per drilled metre – by up to 90 %.” The tools also mean avoiding regrinding : “ Regrinding involves a lot of logistics , and operating a grinding machine is tough work and it creates waste that needs to be taken care of . Using Powerbit X means your drill bits will last significantly longer and need no regrinding . When a Powerbit X drill bit is finally worn out it is time for recycling , not regrinding .”
Epiroc also emphasises consistency . “ Constant hole diameter is essential for efficient and even blasting . When you use a traditional drill bit , the diameter gets reduced over time , leading to smaller and smaller holes . With Powerbit X , the diamond-protected buttons keep their shape throughout the lifetime of the bit . You get holes of the same size , every time , improving your blasting quality and drilling equipment life . What is more , the rate of penetration ( ROP ) is unaffected .”
The Epiroc Powerbit X product range includes face drilling bits – 35mm , 48 mm and 51 mm – and production drill bits in sizes of 76 mm , 89 mm and 102 mm .
Talking about results from customers - Stawell Gold Mines ( SGM ) in Victoria ’ s central west faced very hard rock underground in the form of a previously unexploited flank of the ore body . They started production of this zone – known as Aurora B and situated on the east flank of the Magdala deposit – in 2019 . Specifically it is a magnetite-rich banded unit that the crew call the ‘ BIF ’ due to its visual similarity to banded iron formation .
“ We were getting maybe 7 metres or so out of a standard bit , so we ’ re very impressed with the Epiroc 76 mm Powerbit X we ’ ve been trialling – we ’ ve had five to start with – and the first one achieved 400 m , which is exceptional in this ground ,” said Mark Nellthorp , SGM Mine Superintendent . “ We ’ re a cost conscious mine , so if we can drill more metres , more effectively , and get our costs down , that ’ s the direction we want to take .”
By eliminating most of the bit changes required on a shift , the production gains have been significant . “ Basically , there ’ s less downtime from pulling rods and changing bits and realigning these in the hole ,” explained Nellthorp . “ If you can drill a hole on one pass and move on to the next one , that ’ s great . But if you have to change a bit halfway through on a 20 metre hole that would be costing – at a guess – something like 15 minutes in drill time per hole .”
There are other consequences too in terms of having to realign the drill , and SGM notes that the less movement on the drill rigs , the less wear and tear on the equipment . “ This is especially true in upholes – if the operator can ’ t get the string back exactly in the right spot , it starts putting pressure on the rods , which goes back into the drifter ,” he elaborates . “ With the Epiroc
34 International Mining | NOVEMBER / DECEMBER 2022