Working with geological complexity at Quintette Coal Limited's Mesa open pit

CIM Bulletin, Vol. 81, No. 917, 1988

G.P. GORMLEY,Quintette Coal Limited,Tumbler Ridge, British Columbia

Future open pit metallurgical coal mines in western Canada will be developed in complex geological environments. The success of these operations will be influenced by the mine operators' ability to prepare accurate mine plans and to predict and, subsequently, to control both out-of-seam dilution and coal recovery. Quintette Coal Limited has been mining its tightly folded and severely faulted Mesa deposit at annual rates of up to 9 Mt of raw coal, since October 1982. Ongoing development drilling combined with continuous utilization of blast hole information, has been required to achieve an acceptable geological data base for short range mine planning. Thrust faulting has been a primary geological cause of difficulty in selectively mining waste and coal, which has resulted in higher than expected dilution in plant feed. The same geological phenomenon has also increased reserves by 6.3% and allowed for expanded mine plans to include a lower thrust plate, ultimately doubling the mines original reserve base. This paper illustrates the geology of the Mesa deposit and the type of work involved in its interpretation.

Keywords: Quintette Coal Limited, Coal, Geology, Open pit mining, Out-of-seam dilution, Computer applications.