While the mining industry plots its course toward a more sustainable future, companies are finding that increased circularity throughout an entire value chain is crucial to achieving success in this endeavor. Two recent announcements illustrate examples of the strategies mine operators, OEMs and other business partners are employing to meet their ESG goals.
For example, cemented carbide is a key component in high-quality drill bits, and an important ingredient in carbide insert fabrication is tungsten, one of the rarest materials on Earth. Texas, USA-based Terelion says that through its Circularity program, it is now possible to recycle cemented carbide inserts back to virgin material – pure tungsten – which can then be used in manufacturing new cemented carbide inserts. Terelion highlighted Rio Tinto Kennecott’s recent decision to join the program.
At Kennecott’s Bingham Canyon mine, used carbide bit inserts are collected on-site and shipped to a facility where the inserts are separated from the steel. The inserts are then sent to a plant in Austria where they are processed into powder, and then made into new tungsten carbide inserts.
Terelion said the Circularity program for tungsten carbide drill bits at Rio Tinto Kennecott is estimated to reduce CO2 emissions associated with carbide drill bit manufacturing by 64%. Energy consumption will be reduced by 70% compared with sourcing tungsten via conventional mining methods, according to the company.
Earlier this year, Epiroc and SSAB announced a further expansion of their partnership to secure fossil-free steel for use in the production of Epiroc’s mining equipment. Since then, the two companies have expanded their collaboration into exploring possibilities to use fossil-free steel when manufacturing spare parts and components with additive technology.
The initial step in the process has been to create a prototype of a hydraulic block for a mining rock drill using additive technology with conventional steel powder. Traditional manufacturing with milling and drilling requires this type of part to be plugged and sealed after production. When using additive manufacturing, six potential points of leakage can be eliminated. It is also possible to improve hydraulic oil flow since sharp edges can be avoided when the channels are printed in the part.
While traditional manufacturing uses a block of steel weighing approximately 50 kg (110 lb), the optimized design for additive manufacturing uses 7.5 kg of steel for producing this part. This reduces the amount of material needed for production with 85% in this case, which leads to more efficient use of raw materials. The weight of the end-product is also significantly lower: In traditional manufacturing the part weighs 15 kg after manufacturing; the optimized design together with additive manufacturing makes the part weigh 6.6 kg after production. This reduces the weight by 55%.
As rock drills are positioned far out on the feed of the drill rig, their weight has a substantial impact and new technology opens the possibility to create stronger components without affecting the balance of the machine. Reduced weight on the feed could also improve the lifetime of other components due to the reduction of stress and load, according to Epiroc.
With the prototype successfully produced with additive manufacturing, the next step in the process is to experiment with fossil-free steel powder.