In recent years, the surface miner fleet of the Fortescue Metals Group (FMG), one of Australia’s largest iron ore producers, has grown to a total of 43 machines, with 28 Wirtgen 4200 SM and 15 Wirtgen 2500 SM, which ensure the selective, economical extraction of high-quality iron ore in the Pilbara region. “The Wirtgen Surface Miners enable us to separate the ore from the excavated material. The majority of the ore stock could not have been extracted using conventional means, making the surface miners decisively important to our success,” explains Cody Faryna, FMG Surface Mining Manager Christmas Creek mine site.

The Wirtgen Surface Miners cut, crush and load the material in a single step, thus providing enormous potential savings. For example, they lower production costs by some 40 per cent per ton of iron ore, and the investment costs are around 50 per cent lower than for conventional mining methods.

Synergy effects increase cost-effectiveness and machine availability

The good partnership between FMG and Wirtgen forms the basis for a constant continuing development of the technologies. In the 4200 SM, FMG and Wirtgen have developed a surface miner that is even more powerful and ideally adapted to the mining conditions for iron ore, and which has been successfully proven since 2009. “Support for our machines is a continuous development strategy between Wirtgen and Fortescue. In order to maintain a constant product volume, we have to concentrate on a highly reliable fleet. And Wirtgen plays a major role in the development and improvement of all components,” says Faryna, discussing the challenges involved.

A Wirtgen 4200 SM produces up to 3800 tons of iron ore per hour, depending on the hardness. The cutting depth is up to 650 mm in hard rock and the cutting width 4200 mm.

Innovations in cutting technology pay off

Everyday practical experience is used in the ongoing development of the surface miners – especially in cutting technology, one of Wirtgen’s core competencies. With the HT15 quick-change toolholder system, the innovation leader has developed a unique device which simplifies the process of changing toolholders and shortens it by 60 per cent. Together with the new WPI (Wirtgen Pick Inspection) tool wear detection system, which ensures maximum use of the cutting tool capacity, the latest innovations have led to significant production increases at FMG.

Expanding proven service structures with new concepts

Especially in mining, where the machines are in use every day, 24 hours a day, machine availability is a central factor for success. In addition to surface mining technology, Wirtgen also presents itself as a reliable partner with a comprehensive service offering. The service products are the result of an intensive collaboration between the main Wirtgen plant in Germany and its subsidiary Wirtgen Australia in Perth. The regular communication with and physical proximity to the customer ensure fast reaction times. New demands, process changes or machine developments can thus be quickly implemented – both directly on site in the mine and in the plant, as Hedley Quick, FMG Superintendent Surface Miners Cloudbreak mine site, confirms: “Wirtgen incorporates our ideas and practical experience into the further development of the machines. What is more, they offer a service that meets our very high demands and requirements. It is unique in the mine. Wirtgen takes care of everything we need.”
In the middle of 2012, a general overhaul of the surface miners in Perth was added as a new product in the Wirtgen Group’s service program. With the strategic change to a proactive maintenance system, both partners are setting the course for the future, as the growing surface miner fleet means increased maintenance. The general overhaul sets the pace for an optimized and far-sighted maintenance strategy.

With inhomogeneous materials, the Wirtgen 4200 SM extracts the iron ore using the windrowing method. This makes the material quality easier to determine and differentiate.