Wire rope specialist Casar has set a new world record at Northparkes copper and gold mine, with the Turboplast M used for the work establishing a new milestone after 652 239 completed working cycles, attaining a service life of 46 months and moving more than 22-million tons rock and, subsequently, being retired.
The Northparkes copper and gold mine is located in a rural area of the state of New South Wales, around 450 km to the west of Sydney and, at the end of 2013, China-based company China Molybdenum took over 80% of the shares of the Rio Tinto Group company, while the remaining 20% are still owned by the Japanese Sumitomo Group.
Casar explains that when underground mining began in 1997, the triangular strand ropes that were used reached a service life of around 100 000 working cycles. The rotation- free 19 7 hoist ropes that were subsequently used only had a very short service life and the first set of Casar ropes was introduced in 2000.
The company adds that this set increased the service life to 245 000 cycles and only had to be discarded, owing to mechanical damage caused by rockfall.
“The following change to a competitor caused nothing but problems for Northparkes and left them with a short rope service life, which is why the company went back to Casar. Since going back to Casar, three additional sets of Casar ropes have been used, and with each set it was possible to increase the service life further,” Casar comments.
The company explains that it was with the fourth set that it managed to increase its own world record of 485 300 cycles on a friction winch, which the company had set using the third set, to an incredible 652 239 cycles.
The company notes that its performance ought to be rated even higher, as important parameters, such as speed, payload, acceleration and utilisation were increased over time, while maintenance measures were reduced.
“Normally, all this would rather lead to a reduced service life. However, with an intensive examination of the discarded ropes and a comprehensive study of the relevant damage mechanisms, the rope experts from Casar managed to continuously develop the rope for Northparkes, successfully managing to prevent the rope reaching discard maturity prematurely,” Casar highlights.
Further, the company points out that when the rope was changed in January this year, again a Casar Turboplast M was installed to confirm its world-record performance.
Casar adds that in the long term, the company hopes to exceed this record again significantly, aiming for a service life of 800 000 cycles. This should be achieved by using Turboplast MF for the sixth set of Casar ropes, which are optimally adapted to the requirements and circumstances on a friction winder.
“The now discarded world-record rope has been transported back to Germany for intensive examination by Casar. This is the only way to guarantee a continuous improvement of our product and to come a bit closer to our goal. “The relevant managers at Northparkes will also be present during the rope examination,” Casar says.
Casar details that the rope was discarded according to plan in mid-January last year under the supervision of experienced high-tech mining ropes expert Roger Smith in the service of Casar, and mining ropes sales engineer Alexander Fäh.
The hoisting machine is a ground-mounted friction winder with a motor power of 3 MW, which transports a maximum payload of 16.5 t at a speed of 15.3 m/s from a depth of 590 m to the top. Four hoist ropes with a diameter of 32 mm and a length of 750 m are used, two ropes right-hand Lang’s lay and two ropes left-hand Lang’s lay.