Fusion of phosphate by-products and glass waste for preparation of alkali-activated binders
Landfilling of mine and industrial waste streams leads to environmental and economic issues. Sustainable management methods through valorization in manufacturing green construction materials are a current research interest. Here, a promising process for recycling mine tailings, such as phosphate slu...
| Autores: | , , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2022 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/283961 |
| Acesso em linha: | http://hdl.handle.net/10261/283961 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Mine tailings valorization Glass waste Phosphate sludge Alkaline fusion Alkali-activated materials NMR |
| Resumo: | Landfilling of mine and industrial waste streams leads to environmental and economic issues. Sustainable management methods through valorization in manufacturing green construction materials are a current research interest. Here, a promising process for recycling mine tailings, such as phosphate sludge, is proposed. A mixture of phosphate sludge, kaolin clay (Al source), and glass waste (Si source) was prepared. Three fluxing agents were tested at 1000 °C (NaOH, NaCO, NaSO). NaCO was selected as the most cost-effective. The precursors were alkaline activated with NaOH solution (2, 6, and 8 M). At 28 days of curing (20 h room temperature + 6 h 85 °C + room temperature), the best compressive strength (of more than 45 MPa) was obtained with 8 M NaOH. The reaction products, characterized by XRD, FTIR, SEM, and MAS NMR, show that the main reaction products is a gel N–A–S–H/(N,C)–A–S–H together with some unreacted crystalline phases formed during the fusion. |
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