Acid leaching technology for post-consumer gypsum purification.
| Autor: | Castro-Diaz M; Loughborough University, Loughborough, England, LE11 3TU, UK., Osmani M; Loughborough University, Loughborough, England, LE11 3TU, UK., Cavalaro S; Loughborough University, Loughborough, England, LE11 3TU, UK., Needham P; ENVA, Nottingham, England, NG4 2JT, UK., Parker B; British Gypsum, Loughborough, England, LE12 6JT, UK., Lovato T; British Gypsum, Loughborough, England, LE12 6JT, UK. |
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| Jazyk: | angličtina |
| Zdroj: | Open research Europe [Open Res Eur] 2024 May 01; Vol. 3, pp. 148. Date of Electronic Publication: 2024 May 01 (Print Publication: 2023). |
| DOI: | 10.12688/openreseurope.16583.3 |
| Abstrakt: | Background: Contaminants and water-soluble salts present in mechanically recycled gypsum from refurbishment and demolition (post-consumer) plasterboard waste limit its use as a secondary raw material in plasterboard manufacturing. This research addresses this limitation, developing a novel acid leaching purification technology combined with an improved mechanical pre-treatment for post-consumer gypsum valorization. Methods: Laboratory-scale acid leaching purification was performed with a borosilicate beaker, hot plate, and overhead stirrer. Stuccos were produced after calcination of gypsum at 150 °C for 3 hours. Samples were characterized through X-ray fluorescence, X-ray diffraction, thermal gravimetric analysis, scanning electron microscopy and particle size analysis. Results: Acid leaching at 90 °C for 1 h using a 5 wt% sulfuric acid solution was revealed to be the optimum purification conditions. Stuccos produced from purified gypsum under optimum conditions had similar initial setting times to that of a commercial stucco but with higher water demand, which could be reduced by optimizing the calcination conditions. A magnesium-rich gypsum was precipitated from the wastewater. Conclusions: Purified post-consumer gypsum with > 96 wt% chemical purity and calcium sulfate dihydrate content was produced. The research recommends acid neutralization prior filtration, use of gypsum particles < 2 mm in size, and stirring speed of 50 rpm to reduce the economic and environmental impacts of the acid leaching purification process at industrial scale. The magnesium-rich gypsum could potentially be marketed as soil fertilizer. Competing Interests: Competing interests: ENVA is a leading provider of recycling and resource recovery solutions for re-use in manufacturing and energy conversion. British Gypsum, which is part of the Saint-Gobain Group, is a leading manufacturer of plasterboard and plaster-based drylining systems and products. ENVA and British Gypsum have vested interests in the outcomes of this research and future commercialization of the gypsum purification process and purified gypsum product developed in this paper. (Copyright: © 2024 Castro-Diaz M et al.) |
| Databáze: | MEDLINE |
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