Integrated mine tailings management by combining environmental desulphurization and cemented paste backfill: Application to mine Doyon, Quebec, Canada

Abstract

Achieving optimal wastes management and site remediation is one of the main challenges facing the mining industry around the world. This paper describes how environmental desulphurization and cemented paste backfill technology (CPB) could be combined in the particular case of the Doyon mine, a gold mine operation located in the Abitibi region, Quebec, Canada, to improve its sulphide tailings management. The environmental desulphurization process was first optimized using laboratory flotation tests and an on-line mobile flotation bank. Assessment of the acid generation potential of the separated fractions (sulphide concentrate and low sulphide tailings) was performed to demonstrate that low sulphide tailings were non-acid generating. The sulphide concentrate was then used to produce various CPB mixtures. The binder used with the reactive tailings was the one presently used at the mine: a combination of 30% Portland cement and 70% blast furnace slag, representing 5% of the total dry tailings weight. The cured CPB samples were submitted to uniaxial compressive strength tests and leachability tests. The results obtained from this study demonstrate that for the Doyon mine case, environmental desulphurization could produce non-acid generating low sulphide tailings and a sulphide concentrate. The sulphide concentrate could be used to produce a cemented paste backfill with adequate strength while improving its environmental behaviour in the CPB.