Recycling pyrite tailings as sustainable fine aggregate in alkali-activated slag mortars: a comparative study with cement mortars
Source abstract
Abstract
Pyrite tailings (PT), a kind of mineral processing solid waste generated from sulfuric acid production, was systematically evaluated as fine aggregate in alkali-activated slag (AAS) mortar through a comparative analysis with Portland cement (PC) mortar. The setting times, compressive strengths and autogenous shrinkage of mortars were measured, and the hydration kinetics, phase assemblage and microstructural evolution were characterised. Key findings revealed distinct responses between the two systems. The incorporation of PT sand in the PC mortar markedly delayed the setting times, reduced the compressive strengths and increased the porosity, mainly because the acidic nature of the PT sand suppressed PC hydration. Conversely, the AAS mortar exhibited superior compatibility with PT sand, mainly attributable to its inherently higher alkalinity and denser pore microstructure. The setting times were maintained within practical ranges (4.18 h and 6.14 h) and a 28-day compressive strength of 44.5 MPa was achieved. The inherent alkaline reservoir in AAS mortar effectively neutralised the acidic challenges, while residual pyrite was still detected. The results of this work demonstrate the feasibility of using PT sand in AAS mortar.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Concrete and Cement Materials Research · Recycled Aggregate Concrete Performance · Recycling and utilization of industrial and municipal waste in materials production
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Tongji University College of Civil Engineering, , Shanghai, ; Shandong Provincial Communications Planning and Design Institute Co., Ltd, Jinan, China
Shandong Provincial Communications Planning and Design Institute Co., Ltd , Jinan, ; Shandong Hi-speed Group Co. Ltd, Jinan, China; School of Qilu Transportation, Shandong University, Jinan, China
Yancheng Institute of Technology School of Civil Engineering, , Yancheng,
Shandong Provincial Communications Planning and Design Institute Co., Ltd , Jinan,
Shandong Hi-Speed Group Innovation Research Institute , Jinan,
Tongji University College of Civil Engineering, , Shanghai,
Yancheng Institute of Technology School of Materials Science and Engineering, , Yancheng,
Funding
Natural Science Foundation of Shandong Province · National Natural Science Foundation of China
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