Scaling the heights

Finnish mining contractor E. Hartikainen Oy has come up with an unusual breaker/carrier combination to carry out wall scaling operations at the Siilinjärvi phosphate mine in Yara Suomi, one of the world’s largest producers of mineral fertilisers. A 1,300 kg (2,860 lb) Rammer 2155 hammer is being used mounted on a 52 tonne Cat 345 CL carrier instead of the more usual carrier in the 16 to 26 tonne class. In addition, the Cat is also fitted with a lengthened boom that allows it to reach 26 m (85.3 ft). The face height at the mine is 14 m (46 ft), which means that for scaling the boom needs to be at least 1.5 times long this height.

Hartikainen has worked as a contractor at Siilinjärvi since 1979, employing some 200 people in the area, and currently carries out drilling, loading and hauling operations of apatite and waste rock at the mine’s two open-pit quarries under a long-term contract. The company’s fleet of 96 to 140 ton payload haul trucks shifted 32 million tons of rock last year alone. Excavation records will be broken again in 2015, given the high amount of surface waste rock as the mine needs to be expanded to gain access to deeper lying reserves. The ore content begins to increase at around 100 m (330 ft), from which point the proportion of waste rock gradually decreases.