Fragmentation tests using electronic detonators exceeded all expectations.
DRILL & BLAST
HOW FOUR BECAME ONE
T
o many in the quarrying industry in Victoria and South Australia, the Impact Drill & Blast brand is a familiar name, as is NorthStar Blasting in the Northern Territory, Caruana Blasting in central and northern Queensland and Sequel Drill & Blast in southeast Queensland. These four successful, family-owned, businesses all began providing drilling and blasting services to the quarrying, mining and construction industries in the 1980s and 1990s. Fast forward to April 2019 when the four became one – Impact Drill & Blast. This is a story of four successful familyowned drill and blast companies, each with more than 30 years of knowledge and experience, being brought together under one name to provide a fleet of drills, explosives delivery trucks and blast crews anywhere in Australia. This means the days of having to deal with multiple contractors for drill and blast are over. Impact Drill & Blast provides a fully integrated service that is safe, professional and adds value. Impact has a modern fleet of more than 40 drills, four mobile processing units (MPU) with trailers, a capacity of 21 tonnes of emulsion/ammonium nitrate blends, and two ANFO MPUs. Since the amalgamation, the new company has embarked on a program of change to provide value to its customers through the introduction of technology in all areas of the business: survey, blast pattern design, drilling, and initiation of explosives. Impact recently took delivery of its first GPS drill from Sandvik, which, coupled with the 3D drone surveying and 3D blast pattern design software means there is no need to do a traditional pattern mark-up. For Impact’s customers, this saves time and increases their productivity. The coming months will see Impact commission its new emulsion plant in the Northern Territory to service the “top end” of Australia. Impact’s national operations manager Robert Payne said it is “the only emulsion plant in the Northern Territory and being centrally located will provide quarry and mining customers across the top end with a locally produced product and no risk of being cut off from supply during the wet season”. Impact has formed strategic partnerships with companies that are leaders in their fields
Impact recently took delivery of its first GPS drill rig – the Sandvik DXi900 – which promises ‘no more dots on the ground’.
to access the best technology. One of these partnerships is with Davey Bickford ENAEX (DBE), a leader in the development and manufacture of electronic detonators. DBE has worked closely with Impact and its customers to deliver exceptional blasting outcomes. One of Impact’s quarry customers west of Brisbane required an increase in fines material, reduction in oversize and improvement in its crusher throughput. The quarry has challenging geological conditions of jointed basalt intersected with soft strata bands, which in the past had not favoured the creation of fines. While the introduction of Impact’s RedStar emulsion had given much better results than ANFO, with more fines and less oversize, Impact and DBE believed there was still improvements that could be made using electronic detonators. Impact designed a staggered blast pattern of 102mm holes loaded with RedStar 60/40 emulsion blend. The DBE engineers worked with Impact’s shotfirer to design an initiation sequence using interactive timing which would use the energy in each hole to work together to create more fines while meeting the environmental requirements for the blast. The outcome of the blast exceeded the customers’ expectations and continues to this day. The introduction of electronic detonators with the RedStar emulsion reduced oversize to less than two per cent and increased fines significantly to improve crusher throughput by more than 100 tonnes per day. The improved
fragmentation also led to the removal of a secondary crusher. Another advantage of the change to electronic detonators was reduced back-break and pre-conditioning of the pit walls, improving safety for everyone in the pit. In July 2020, Impact commenced drill and blast operations at a central Queensland quarry. The customer wanted suitable material for road base, with additional fines. The customer usually provides the drill and blast parameters but Payne put forward a proposal for Impact to do the drill and blast design. “The customer was sceptical because our designed powder factor was 18 per cent lower than their previous designs,” he said. However, 20 tonnes of RedStar emulsion was loaded in one day and fired using electronic detonators as the initiation system. The customer said it was the best blast they have seen at the quarry. Impact’s customers are continuing to report reduced downstream costs and improved plant productivity, due to better blasting outcomes. Safety is the key foundation of the Impact Drill & Blast operations. The move to DBE electronic detonators was as much to do with safety and security of the blast crew and the community as it was for blast outcome. Since March 2020, all blasting in Queensland has used electronic detonators and Impact has committed to using electronics for 100 per cent of its blasting activity by the end of 2020. • Source: Impact Drill & Blast
Quarry August 2020 41
