Case Studies:
40 Workdays Saved for the Largest Infrastructure Project in Norway
In 2016, one of the service tunnels connecting the Follo Line project to the existing railroad in the Oslo Port had to go under the access tunnel for the port’s underground oil depot. The access tunnel was equipped with pipes used for transfer of oil coming by ships into the depot as well as to the trains transporting it for processing. Due to the importance of the equipment in the access tunnel there were very strict limitations for vibrations.
JARNOLTOWEK QUARRY CONTINUES TO OPERATE WITH LIMITED IMPACT TO ITS NEIGHBORS
Jarnoltowek is small quarry in the south of Poland, with houses in close proximity (<500 m).
Annual production is 150,000 tons per year. Typical blast parameters are hole length from 10 to 13 m, hole diameter 89 mm, burden 2.3 m and spacing 2.3 m. Charge weight vary from 35 to 55 kg.
The local legislation order to measure the vibrations on the ground in front of the structure as well as inside the structure on the basement’s ground level.
Explosive Volume reduced by 9% in LKAB, Svappavaara Mine
Using E*STAR electronic detonators with optimized timing focused on rock properties and blast conditions allowed to increase stemming length which meant saving of 9 % of bulk emulsion per hole. Using E*STAR electronic detonators had also other benefits like improved initiation control, possibility to choose direction of blast movement and objective ore and waste separation.
Quarry Fragmentation improves by 15% while secondary breakage is reduced by 67%
Geology variation throughout the quarry made it difficult to keep consistent fragmentation. Most of the time the muckpile contained boulders that required intense secondary breaking by a hydraulic hammer. Subsequently, the blasts were creating uneven faces that were influencing safety on bench; making it harder for blast planning to keep the patterns uniform as needed for the desired final fragmentation.
Reduction of Ground Vibrations by 14% with Blast Size increase by 300%
Nonelectric blasts were generating unpredictable vibrations with a big value spread. When blasting operations get closer, vibrations get higher, and the spread gets bigger. Typical blast parameters are: hole lengths from 15 to 20 m, hole diameters 92 mm, burden 3.3 m and spacing 2.9 m. Charge weight might be a maximum of 27 kg per deck. The request was for the lowest vibration inside the caves – close to stalagmite.
Mill throughput improved by 46 % with reduction of critical size particles by 11 %
After several trials with different powder factors, the Phu Kham Mine decided to use our services and tailor the timing of their blasts using E*STAR detonators to bring the intended results.