Use of fly ash in backfill at Kidd Creek Mines

CIM Bulletin, Vol. 81, No. 909, 1988

T.R. YU and D.B. COUNTER, Kidd Creek Mines Ltd., Timmins, Ontario

In an effort to increase productivity, the use of fly ash as a binder for consolidated backfill was studied. From laboratory and underground tests for its cementitious properties and environmental effects, it was found that a portion of Portland cement could be replaced by the same amount of type "C" fly ash to produce an acceptable consolidated rockfill product for use at Kidd Creek. The environmental concerns in terms of dust control and emanation of radon gas were unfounded from measurements. The dust count was comparable to the use of Portland cement only, or with ground blast furnace slag, and the radiation readings were low, averaging one-seventh the regulation level. Since May 1984, a total of over 100 000 tonnes of fly ash has been consumed as a binder blended with Portland cement, producing over four million tonnes of consolidated rockfill. To date, the fill in the slopes has performed very satisfactorily, while yielding considerable cost savings.

Keywords: Underground mining, Fly ash, Kidd Creek Mines Ltd., Binders, Portland cement, Slopes, Backfill, Residuals, Cementing compounds, Coal residues, Radon gas.