Technical and economic comparison of continuous and discontinuous loading in underground ore production and tunnelling
CIM Bulletin, Vol. 82, No. 924, 1989
Egon Berger, Voest-Alpine, Austria
In recent years the trend in underground metal mining has been toward ever increasing blasts (often in excess of 100 000 tonnes per blast). The Canadian mining industry has been in the forefront of these developments (VRM, LBH and cable bolting to stabilize the surrounding rock/avoid dilution).
In order to move these large tonnages, efficient loading systems have to be developed. This paper shows the technical and economic implications of various loading scenarios based on a predefined (however typical) sloping layout by: 1. discontinuous loading using scooptrams; 2. discontinuous loading using scooptrams in combination with low profile dump trucks; 3. continuous loading (based on loading performance/operating costs of the AL-60) in combination with low profile dump trucks.
The cost advantages of production concentration (loading large tonnages from one drawpoint), made possible by continuous loading as opposed to scattered mining (small tonnages), using discontinuous loading in tunnelling will be presented, based on actual results obtained in a decline development project using the AL-60 continuous loader. At a spacing of 150m between turning bays, it was found that continuous loading was outperforming discontinuous loading in approximately 80% of the overall decline development.
Fuel consumption and total cycle times are compared, and a cost assessment is presented.
Underground mining, Metal mining, Ore production, Loading, Bulk mining methods