ABSTRACT
Freeport McMoRan Copper & Gold is running one of the biggest and most difficult mining operations in the world. Located at about 4000 m above sea level in a remote mountain region of Irian Jaja, the mine requires always new and advanced equipment tailored to handle the steadily growing material masses of the operation. Mining of ore was started by Freeport at 16,000 t/d to reach now 250,000 t/d. Based on a ratio of 3.1 between overburden and pay mineral, this means a huge volume of overburden to be handled per day, with simultaneous increase of the hauling distances and higher lifts for the burden. In 1997 Freeport decided therefore to install an In – Pit Crushing System for the overburden handling. Comprehensive tasks were specified for the system. It had to be designed for a max. handling rate of 12,000 t/h, while the spreader was requested to fill up a lake situated 400 m below the upper dump crest. The development of the complete system took nearly one year and is described in this paper. Special emphasis was given to the design of both the crusher and the spreader. The crusher is presently the largest semi-mobile gyratory unit in the world and the semi-mobile design of the spreader is unique. Both plants are relocated using the same transport crawler.
