The latest member of Atlas Copco’s blasthole PV-310 rotary drill rig range – the Pit Viper 311 – has recently completed a six month field test at a copper mine in the southwestern region of the United States. The result: full marks on all counts.
The prototype PV-311 went into service at the mine with the focus on cooperation between mine personnel and Atlas Copco engineers to test modifications that would help increase productivity and efficiency.
The PV-311 drilled 255 mm (10 5/8 in) and 317 mm (12¼ in) diameter holes – the largest hole this rig can drill – on benches 15 m high. The 255 mm holes were drilled to a depth of 17 m with 2 m of subdrill, while the 317 mm holes were drilled to a depth of 20 m with 3 m of subdrill.
Five different drill patterns were used depending on the location of the test in the pit. The rig typically completed 35 to 40 holes amounting to 365 meters drilled in a 12 hour shift. The average availability was 90–95%. The rock encountered in the mine is typical of most copper applications, not homogeneous and with a compressive strength around 250–300 Mpa.
Atlas Copco Secoroc Tricone/DTH bits were used with each bit lasting 2.5–3 days. The prototype rig was subsequently purchased by the mine.
Maureen Bohac, Product Manager, Large Blasthole Drills, at Atlas Copco says: “The PV-311 had no trouble managing rough conditions while consistently hitting its targeted depth and maximizing the quality of the hole drilled.
“One of the contributing factors was that the PV-311 is designed so that the bits are changed above the rig’s deck, even while single-pass drilling a 20 meter deep hole.
This enabled the operators to focus on making and breaking the pipe connections each time.
“In addition, this prototype included our optional hydraulic clutch, which is designed to reduce fuel consumption during non-drilling operations and this had a big impact. Another factor that influenced fuel efficiency was the autodrill functionality of the rig’s RCS rig control system.”
Fuel efficiency was approximately 20 per cent better than other rigs on the site. On top of this, the PV-311’s quiet and comfortable cab proved to be especially appreciated by the operators.
“The new cab on the PV-310 series is one of the things operators are most excited about,” continues Bohac. “The cab has a fully adjustable and elevated chair with joystick and cab controls and an excellent view with larger windows and mirrors, well placed so the operator can see what’s going on at ground level and in front of the rig.”
The PV-311 is now production drilling at mines on three continents in applications including copper, coal and iron.
Epiroc operated under the trademark “Atlas Copco” prior to January 1, 2018.