By the end of 1988, Falconbridge Ltd. will know whether or not copper/nickel ore reserves in the Craig orebody, north of Sudbury, will be sufficient to justify driving a new shaft to provide a means of hoisting ore from the orebody.
Diamond drilling from underground drifts, driven from the nearby Onaping mine shaft, toward the Craig orebody on the 2,000-, 3,000- and 4,000-ft levels, should indicate by year-end whether or not there are 20 million tons of mineable mineralization in the deposit, Onaping mine engineer John Vary told The Northern Miner on a visit last week.
If there are more than 20 million tons in the Craig orebody, a shaft will be justified. If not, then the orebody will be accessed by an internal ramp and ore will be trammed to the 4,200-ft Onaping shaft and hoisted there.
The company has already let a 4,000-ft raise bore contract to mine contractor Patrick Harrison Co. in North Bay for the Craig orebody. This project involves driving two, 2,000-ft ventilation raises, 10 ft in diameter — one from the 4,000-ft level to the 2,000-ft level and one from the 2,000-ft level to surface.
When completed, two years from now, it is expected to be the longest raise bore project of this diameter in Canada.
Falconbridge expects to mine about 70,000 tons from the Craig orebody this year. But the company plans to eventually mine one million tons annually from the orebody.
About 400,000 tons of ore and 200,000 tons of waste rock are expected to be hoisted up the Onaping shaft this year.
About 150,000 tons of copper/ nickel ore are mined per year from three highly mechanized cut-and- fill stopes in the No 2 zone in the Onaping mine. These stopes are located below the existing Onaping shaft. Access is provided by an internal ramp.
There is an internal shaft, from the 4,200-ft level to the 5,800-ft level, but it would cost an estimated $1 million to recondition and it is too small to hoist a significant amount of ore, Vary says.
An additional 150,000 tons per year are mined from captive cut- and-fill stopes in the No 3 zone.
Ore production from the Onaping shaft accounts for about 15% of Falconbridge’s total output in the Sudbury area. But by 1990, the company intends to increase that to 35% by developing highly mechanized stopes in the Craig orebody.
Be the first to comment on "Falconbridge considers shaft for Craig orebody"