Status : Verified
| Personal Name | Cayanan, John Carlo D. |
|---|---|
| Resource Title | Utilization of nickel mine tailings for the preparation of geopolymer binder with supplementary cementitious material and hydroxides |
| Date Issued | 11 November 2025 |
| Abstract | The global accumulation of mine tailings, particularly those generated from nickel mining operations, poses substantial environmental hazards due to the presence of leachable heavy metals (HMs). Among the emerging remediation techniques, stabilization/solidification via geopolymerization offers a promising circular strategy by transforming hazardous waste into valuable construction materials while immobilizing toxic contaminants. This study investigates the potential of nickel mine tailings (NMT) as a precursor for geopolymeric binders, in combination with supplementary cementitious materials (SCMs) including ground granulated blast furnace slag (GGBFS), coal fly ash (CFA), and limestone powder (LP), incorporated at 75 wt%, 50 wt%, and 25 wt% ratios. Sodium hydroxide (NaOH) and calcium hydroxide (Ca(OH)₂) were used to initiate geopolymerization. The result showed that near absence of aluminosilicates in nickel mine tailing presents inadequacy of the material as standalone precursor for preparation of geopolymer. Hence, the addition of supplementary materials as sources of alumina and silica demonstrated favorable engineering properties. Highest 28-day compressive strength of 20.05 MPa was achieved in sample containing 75wt% GGBFS via Ca(OH)2 activation, attributed from C-A-S-H and C-S-H formation, while comparable strength of 14.32 MPa was attained in sample activated by NaOH. Optimized mix ratio for CFA-based sample of 75wt% CFA, NaOH-activated yielded a 28-day compressive strength of 13.01 MPa. These strengths fall within the acceptable range for load-bearing mortar application as per ASTM standards. Samples have also demonstrated HM immobilization rates, as high as 99.9859%, 99.9995%, and 99.9380% for Ni, Mn, and Cr, respectively. In addition, NaOH-based activation presented more resistance to HM remobilization and acid attack due to strong alkalinity and ability to synthesized to denser matrices. This study implies the potential of NMT-based geopolymer |
| Degree Course | Master of Science in Environmental Engineering |
| Language | English |
| Keyword | Heavy metal immobilization; Mine tailing valorization; Geopolymerization; Nickel mine tailings |
| Material Type | Thesis/Dissertation |
Preliminary Pages
3.05 Mb
Category : P - Author wishes to publish the work personally.
Access Permission : Limited Access