Christian Schorr-Golsong details a ‘quantum jump’ in wire rope life for drum and friction winders
The lifespan of wire rope in mine winding is critically important, not just due to the high cost of materials but more importantly, the downtime in production during a failure or changeover. Investing in durable solutions has saved mines in Australia and elsewhere around the world millions of pounds.
Casar has long been an innovator in wire rope technology and was the first manufacturer to produce eight-strand wire ropes when six-strand was the norm and later was a leader in developing plastic-filled wire ropes, compacting and swaging.
The addition of plastic impregnation to the wire rope, in constructions such as the eight-strand Turboplast product, was highly innovative at the time and provided several benefits previously not available in wire rope technology. The plastic core provided a cushion between the outer strands and the inner core of the wire rope.
It also aided in retaining the lubrication in the core and providing a structural stability not available previously. These factors along with specialised wire requirements and computer-aided design enabled the special mining ropes to achieve an extremely long service life.
Western Mining Corporation (now BHP Billiton) at Olympic Dam in South Australia had previously used a number of traditional triangular strand ropes from various manufacturers but still struggled to achieve an acceptable rope life. The costly downtime during rope change-outs was a major interruption to production. Casar suggested Turboplast in a world-first for Casar in the critical mine winding application. The outright purchase price of the Turboplast was in excess of the ropes the company had been using but the promise of extended rope life and less costly downtime was worth the extra investment. The ropes performed exceptionally well, achieving a service life of nearly five times the previous ropes. BHP Billiton is still using Casar ropes at Olympic Dam to this day.
After this success, Mt Isa Mines and other mines were next on the agenda. The installation achieved a then world record number of cycles for a double drum winder, which was in excess of 5.5 times that achieved by previous ropes. Mt Isa has just removed the second set of ropes with another world record, achieving a further 25% rope life.
Casar is a leader in winder rope applications in Australia for metalliferous mines and boasts installations at all major metalliferous mines. All mines have excellent results in regards to cycles achieved, thus justifying the higher purchase price of these premium wire ropes. Add to this the need for less maintenance and the reduction in the number of rope changes required and the mine is still well and truly in front.
The rope change alone on a set of ropes can take up to 40 hours and if two or three rope changes can be eliminated this is a significant saving in terms of extra production (up to 120 extra hours) but each application is investigated on its merits and all operational factors are weighed up before a certain rope construction is chosen.
Experts from Casar also assist the mine with a maintenance programme that is suited to each individual rope installation and encompasses NDT inspections and rope life monitoring. However, the maintenance required is far less than the traditional rope constructions previously used so critical maintenance personnel are freed up for other duties on the mine site.
Casar has expanded its experience with underground mines in Australia into other markets. It has about 25 installations in South Africa and further installations in Sweden, Russia, Canada and other countries.
Roger Smith, senior consultant, Casar High Tech Mining Ropes, states “We are continuing to innovate. The next generation of mine winder ropes feature Kevlar cores and under laboratory conditions have achieved phenomenal results.”
Smith adds: “The new Turbolite hybrid ropes have the potential to conservatively achieve cycles in excess of three times the current generation of Turboplast and Starplast ropes and also have the added benefit of considerable weight reduction, which could lead to higher payloads and increased production.”