Underground disposal of retorted oil shale.
Earnest-HW; Rajaram-V; Kauppila-TA
Proceedings of the 10th Oil Shale Symposium April 21-22, 1977, Golden, Colorado. Reubens JB, ed. Golden, CO: Colorado School of Mines Press, 1977 Jul; :213-222
Methods for underground disposal of retorted oil shale from a gas combustion retorting process have been investigated under contract no. J0265052 for the U.S. Bureau of Mines. These methods include transport and stowing by hydraulic, mechanical, and pneumatic means for a deep mine in the Piceance Creek Basin of northwestern Colorado. Mechanical transport and stowing, using conveyors, was determined to be the most promising system, based on a ranking analysis which included subjective and objective technical analysis, and capital and operating costs. The various backfilling methods were studied as an integral part of two mining methods: chamber and pillar, and sublevel stoping. Excessive water and energy requirements, poor pillar support characteristics of the backfill, and high costs were the principal reasons for rejecting hydraulic transport and stowing. Excessive energy requirements, severe dust problems, and high costs resulted in the rejection of the pneumatic transport and stowing methods. The surface and underground environmental effects of the various methods were considered in all evaluations. Underground disposal of retorted shale may reduce the amount of material placed on the surface by as much as 85 percent. Resource recovery may be increased up to 16 percent when backfilling provides supplementary pillar support and the opportunity to reduce the size of rib pillars. Preliminary operating cost estimates for underground disposal ranged from $0.3101 per ton, for conveyor transport and stowing, to $1.1855 per ton for pneumatic transport and stowing. Operating costs for total surface disposal are estimated to be $0.2438 per ton.
OP; Conference/Symposia Proceedings
OP 5-78; Contract-J0265052
Proceedings of the 10th Oil Shale Symposium April 21-22, 1977, Golden, Colorado
The Cleveland-Cliffs Iron Company, Rifle, Colorado