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Updated: Jul 23, 2025
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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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Repurposing carbonate-based waste for producing an innovative binder: optimization and characterization
Ahmed S Elshimy1, Aref A Abadel2, Hussam Alghamdi2
1Faculty of Earth Science, Beni-Suef University, Beni Suef, 62511, Egypt.
Summary
This study demonstrates the effective recycling of dolomite waste (DW) into a new cementitious material using alkali activators. Sodium silicate (Na2SiO3) proved superior to sodium hydroxide (NaOH), yielding a high compressive strength of 34 MPa.
Area of Science:
- Materials Science
- Green Chemistry
- Civil Engineering
Background:
- Dolomite waste (DW) presents a significant disposal challenge.
- Developing sustainable construction materials is crucial for environmental protection.
Purpose of the Study:
- To investigate the feasibility of utilizing dolomite waste (DW) as a precursor for alkali-activated cementitious materials.
- To evaluate the influence of different alkali activators (NaOH and Na2SiO3) on material properties.
Main Methods:
- Dolomite waste was ground into a fine powder.
- The powder was mixed with alkali activators (NaOH or Na2SiO3) at varying concentrations.
- The resulting mixtures were cured at room temperature and their compressive strengths were measured over time.
Main Results:
- Activation with NaOH resulted in low compressive strengths (<11 MPa) due to gaylussite formation.
- Activation with Na2SiO3 significantly enhanced compressive strength, reaching 34 MPa at 90 days with a silica modulus of 1.5.
- Optimal performance was achieved with Na2SiO3, attributed to the formation of calcium silicate hydrate (CSH).
Conclusions:
- Dolomite waste can be successfully recycled into a novel alkali-activated cementitious material.
- Sodium silicate is an effective activator for DW, producing high-strength materials.
- This approach offers a sustainable and cost-effective method for waste valorization in construction.
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