Synthesis of high-purity precipitated calcium carbonate during the process of recovery of elemental sulphur from gypsum waste
Copyright © 2015 Elsevier Ltd. All rights reserved.
| Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 46(2015) vom: 16. Dez., Seite 619-27 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Calcium sulphide Gypsum waste Indirect carbonation Precipitated calcium carbonate Valorisation Industrial Waste Sulfur 70FD1KFU70 mehr... |
| Zusammenfassung: | Copyright © 2015 Elsevier Ltd. All rights reserved. We recently showed that the production of elemental sulphur and calcium carbonate (CaCO3) from gypsum waste by thermally reducing the waste into calcium sulphide (CaS) followed by its direct aqueous carbonation yielded low-grade carbonate products (i.e. <90 mass% as CaCO3). In this study, we used the insight gained from our previous work and developed an indirect aqueous CaS carbonation process for the production of high-grade CaCO3 (i.e. >99 mass% as CaCO3) or precipitated calcium carbonate (PCC). The process used an acid gas (H2S) to improve the aqueous dissolution of CaS, which is otherwise poorly soluble. The carbonate product was primarily calcite (99.5%) with traces of quartz (0.5%). Calcite was the only CaCO3 polymorph obtained; no vaterite or aragonite was detected. The product was made up of micron-size particles, which were further characterised by XRD, TGA, SEM, BET and true density. Results showed that about 0.37 ton of high-grade PCC can be produced from 1.0 ton of gypsum waste, and generates about 0.19 ton of residue, a reduction of 80% from original waste gypsum mass to mass of residue that needs to be discarded off. The use of gypsum waste as primary material in replacement of mined limestone for the production of PPC could alleviate waste disposal problems, along with converting significant volumes of waste materials into marketable commodities |
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| Beschreibung: | Date Completed 16.08.2016 Date Revised 10.11.2015 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2015.08.023 |