Effect of Low Temperature on Backfill Quality in Permafrost Condition


Backfilling in mines that operate at low temperatures is a unique challenge. As temperature decreases, the hydration of cement is inhibited and therefore the strength of the backfill is compromised. For underground mines requiring cemented backfill, freezing temperatures must be addressed. Reduced strength of backfill not only impacts the safety of the mining environment, it potentially adds to the dilution of the adjacently mined ore. Concrete technology has a well developed history of dealing with freezing conditions and has been adapted for use with cemented mine backfill. This paper reviews the strategies that have been used to deal with mine backfill in permafrost conditions. Various strategies for backfilling in permafrost mines were reviewed and an experimental study was conducted. It was found that the temperature impact on hydration can have a significant impact on backfill strength and that there are opportunities to improve this for cold temperature placement.