Hydrothermal Manufacture of Zeolitic Lightweight Aggregates from Clay and Marine Plastic Litter
Mixed plastic fraction (MPF) from marine litter was investigated as a pore-forming agent in formulations with kaolin and a rejected Mg-clay (rich in smectite and sepiolite) to obtain innovative zeolitic lightweight aggregates. Round granules of ~10 mm in diameter were shaped and fired at 600 ºC (mix...
| Autores: | , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/715788 |
| Acesso em linha: | http://hdl.handle.net/10486/715788 https://dx.doi.org/10.3390/app14177674 |
| Access Level: | acceso abierto |
| Palavra-chave: | Hydrothermal treatment zeolitic construction materials lightweight aggregates marine plastic litter clay Geología |
| Resumo: | Mixed plastic fraction (MPF) from marine litter was investigated as a pore-forming agent in formulations with kaolin and a rejected Mg-clay (rich in smectite and sepiolite) to obtain innovative zeolitic lightweight aggregates. Round granules of ~10 mm in diameter were shaped and fired at 600 ºC (mixtures of kaolin with 0, 5, 10, and 20 wt.% MPF) and 900 ºC (mixtures of rejected Mgclay: kaolin (1:0, 2:1, 1:2; 0:1) with 10 wt.% MPF). The fired specimens were hydrothermally treated in a 3M NaOH solution at 150 ºC for 24 h. Mixtures containing 20 wt.% MPF led to specimen crumbling, while those with 5 and, especially, 10 wt.% MPF favored a significant crystallization of zeolites and feldspathoids (50–80%), highlighting cancrinite, nepheline, zeolite A, and analcime. The resulting materials were lightweight (1.5–1.8 g/cm3) and their crushing strength increased substantially with the hydrothermal treatment, from 0.04–0.5 MPa to 2.3–5.5 MPa after zeolitization. High content of rejected Mg-clay in the mixture (>67%) negatively affected the zeolitization and the properties of the final aggregate, while 33 wt.% was adequate, increasing slightly the crushing strength (3.4 vs. 3.1 MPa). These findings contribute to plastic waste circularity and sustainability/technological progress in materials production |
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