Alkalinity neutralization and structure upgrade of bauxite residue waste via synergistic pyrolysis with biomass
| Autor: | Chuxuan Li, Shengguo Xue, Jingju Zhou, Feng Zhu, Jun Jiang, Lu Tang |
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| Rok vydání: | 2020 |
| Předmět: |
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Environmental Engineering Municipal solid waste Alkalinity 02 engineering and technology 010501 environmental sciences engineering.material 01 natural sciences Residue (chemistry) Biochar Aluminum Oxide Environmental Chemistry Biomass 0105 earth and related environmental sciences General Environmental Science Chemistry Carbonization Water General Medicine 021001 nanoscience & nanotechnology Pulp and paper industry Bauxite engineering Leaching (metallurgy) 0210 nano-technology Pyrolysis |
| Zdroj: | Journal of Environmental Sciences. 93:41-47 |
| ISSN: | 1001-0742 |
| Popis: | Bauxite residues, a large volume solid waste, are in urgent need of effective disposal and management. Especially, strategies to alleviate the high alkalinity of bauxite residue remain a big challenge. Here, we developed a synergistic pyrolysis to neutralize the alkalinity of bauxite residue and upgrade the structure of biomass simultaneously. By cooperating the catalytic feature from bauxite residue, rice straw, a cellulose-enriched biomass, could prefer to produce acidic components under a hypothermal pyrolysis temperature (below 250 °C) and partial oxygen-contained atmosphere as evidenced by the synchronous TGA-FTIR analysis. In return, these in-situ produced acidic components neutralized the bauxite residue profoundly (pH decreased from 11.5 to 7.2) to obtain a neutral product with long-term water leaching stability. Also, a higher pyrolysis temperature led to neutral biochar-based products with well-defined carbonization characteristics. Thus, the biomass-driven pyrolysis strategy provides a potential to dispose the alkalinity issue of bauxite residue and further opportunities for the sustainable reuse and continuing management of bauxite residue. |
| Databáze: | OpenAIRE |
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