Use of Concrete in Mining at the Jeffrey Mine
TH E Jeffrey mine of Canadian Johns-Manville Co. Ltd. is located at the town of Asbestos, in the Eastern Townships, about 85 miles east of Montreal. Asbestos ore is mined from a large open pit and by block caving from underground. The underground mine has been producing l 2,000 tons per day. The orebody consists of asbestos veinlets in a fractured and serpentinized peridotite. Hardness and structural strength of the rock vary from soft shear zones at one extreme to a small amount of hard granitic inclusions at the other. In general the ore is weak and deteriorates on exposure to air, so that it is difficult to maintain underground openings. Permanent workings are lined with concrete and temporary ones are driven minimum size and supported with steel sets or rock bolts as required.
Keywords:
Air, asbestos, celite, concrete, Underground Placer, victaulic, Concrete, Cost, Costs, Drifts, Mine, Mines, Pipe, Underground
