Compressive Strength Characteristics of Cemented Tailings Backfill with Alkali-Activated Slag


XUE G., Yilmaz E. , SONG W., CAO S.

APPLIED SCIENCES-BASEL, vol.8, no.9, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 9
  • Publication Date: 2018
  • Doi Number: 10.3390/app8091537
  • Title of Journal : APPLIED SCIENCES-BASEL
  • Keywords: cemented tailings backfill, desulfurized ash, alkali-activated slag, uniaxial compressive strength, curing time, neural network prediction, SODIUM-SILICATE ADDITION, PASTE BACKFILL, MICROSTRUCTURAL PROPERTIES, SULPHIDIC TAILINGS, MINE BACKFILL, FURNACE SLAG, PERFORMANCE, BEHAVIOR, TEMPERATURE, GELFILL

Abstract

With the use of glauberite mineral (GM) and sodium hydroxide (SH) alkaline catalysts to stimulate slag powder's internal cementation activity and incorporate the two fine-grained solid wastes, such as quicklime (Q) and desulfurized ash (DA), a new cementitious material suitable for mine tailings was developed to replace traditional ordinary Portland cement (OPC) for reducing cement-related costs. A series of uniaxial compressive strength (UCS) tests were carried out on cemented tailings backfill (CTB) samples containing different activators. The results showed that (1) the highest UCS values of 14-day and 28-day cured CTB samples were 1.259 MPa and 2.429 MPa, respectively, and the effect of different activator types was in the order of SH > GM > DA > Q and SH > GM > Q > DA; (2) the relationship between UCS and activator dosages followed the function y = ax(3) - bx(2) + cx - d. Compared with the OPC 32.5 R cemented samples, the minimum strength growth factor was 1.45, and the maximum reached 2.03; (3) the optimal proportion of DA slag formula was 4.5% or 5.0% Q, 19% DA, 2.5% GM, and 0.7% SH. The aforesaid new cementitious materials met the mine's UCS requirements with a relatively low cost (17.04-17.20 (sic)/ton) and solved the stacking problem of solid wastes on the surface well. Ultimately, this study provides a useful reference for the development of mineral binders.