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Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
Published on: February 21, 2017
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A preliminary study of aeolian sand-cement-modified gasification slag-paste backfill: Fluidity, microstructure, and
Jie Xin1, Lang Liu2, Longhua Xu3
1Energy School, Xi'an University of Science and Technology, Xi'an 710054, China; Research Center for Functional Backfill Technology in Mine, Xi'an 710054, China.
The Science of the Total Environment
|March 26, 2022
Summary
This study introduces aeolian sand-cement-modified gasification slag-paste backfill (ACGPB) for low-cost green mining. ACGPB effectively utilizes hazardous solid waste while meeting mechanical and environmental standards.
Area of Science:
- Materials Science
- Mining Engineering
- Environmental Science
Background:
- Hazardous solid wastes, such as gasification slag, pose disposal challenges.
- Low-cost and environmentally friendly backfill mining methods are crucial for sustainable resource extraction.
Purpose of the Study:
- To propose and investigate a novel aeolian sand-cement-modified gasification slag-paste backfill (ACGPB) model.
- To evaluate the performance of ACGPB in terms of rheology, mechanical properties, and heavy metal stabilization.
- To understand the microstructural mechanisms influencing ACGPB performance.
Main Methods:
- Rheological tests (slump, yield stress, apparent viscosity, thixotropy) using the Herschel-Bulkley model.
- Mechanical property assessment through uniaxial compressive strength tests at 3 and 28 days.
- Leaching toxicity tests for heavy metals.
- Microstructural analysis using FTIR, TG-DTG, SEM, and hydration heat measurements.
Main Results:
- ACGPB slurry rheology follows the Herschel-Bulkley model.
- Sodium sulfate (Na2SO4) and calcium oxide (CaO) as activators influenced slurry properties differently.
- Most ACGPB recipes met mechanical requirements (3 d ≥ 0.5 MPa, 28 d ≥ 1.0 MPa) and national standards for heavy metal leaching.
- Activators enhanced the stabilization/solidification of heavy metal ions.
Conclusions:
- ACGPB offers a viable solution for the safe disposal and resource utilization of hazardous solid wastes.
- The choice and dosage of activators significantly impact ACGPB performance.
- This research provides a novel approach for sustainable solid waste management in mining.
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