Effect of natural pozzolans as mineral admixture on the performance of cemented-paste backfill of sulphide-rich tailings.
This paper presents the effect of the natural pozzolans as mineral additives on the short- and long-term strength and stability performance of cemented paste backfill (CPB) samples. Prior to their use in CPB studies, the natural pozzolans - the volcanic tuffs (Akkus Trass [AT] and Fatsa Trass [FT]) and pumice (KP) - were tested for their pozzolanic characteristics. These tests revealed that the pozzolanic activity of the natural pozzolans is closely inter-related with their content of reactive silica and, accordingly, KP has the highest pozzolanic activity. The addition, or increasing the amount, of natural pozzolans in the binder phase resulted in a slower rate of strength development of CPB samples. The deterioration in stability of CPB samples prepared from Portland cement (PC) alone (i.e. a strength loss of 24.6%) occurred following 56 days. The replacement of PC with FT and AT led to even higher losses in strength. However, the addition of KP (up to 30 wt%) mitigated, to a certain extent, long-term strength and stability problems with the losses in strength of CPB samples consistently lower than 20%. It can be inferred that the performance of the natural pozzolans as a mineral additive in CPB is dependent intimately on their pozzolanic characteristics.
Department of Mining Engineering, Faculty of Engineering, Karadeniz Technical University, 61080 Trabzon, Turkey. bercikdi@ktu.edu.tr
Bayram
B
Ercikdi
Ferdi
F
Cihangir
Ayhan
A
Kesimal
Haci
H
Deveci
Ibrahim
I
Alp
D002484:Cementation / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007220:Industrial Waste; D008903:Minerals / Q000737:chemistry*; D008906:Mining; D012037:Refuse Disposal / Q000379:methods*; D017640:Silicates / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry*; D018707:Volcanic Eruptions
D007220:Industrial Waste; D008903:Minerals; D017640:Silicates; D013440:Sulfides; C005144:pumice