Fineness Effect on Pozzolanic Activity of Cu-Ni Slag in Cemented Tailing Backfill

This paper presents the experimental results of the fineness effect on the pozzolanic activity of Cu-Ni slag in cemented tailing backfill. Cement paste and cemented tailing backfill samples that without or contain Cu-Ni slag with various grinding times were made and cured at 20°C for 7, 28, and 150 days. Mechanical test and microstructural analyses are performed. In general, the pozzolanic activity of Cu-Ni slag increases with the fineness of particle size. The strength of cemented tailing backfill samples decreased with the addition of Cu-Ni slag. It was found that the pozzolanic activity of Cu-Ni slag used in this study is relatively low. According to the fineness, the Cu-Ni slag will make the cemented tailing backfill samples looser or denser. For the sample containing ground Cu-Ni slag ground for 30 min to 50 min, the sample becomes dense gradually as the particle size of Cu-Ni slag becomes finer.