Controlling sintering atmosphere to reduce the hazardous characteristics of low-energy cement produced with chromium compounds
| Autor: | Ming Sheng Ko, Ying Liang Chen, Yi-Chieh Lai, Yi Kuo Chang, Chien Jung Lin |
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| Rok vydání: | 2013 |
| Předmět: |
inorganic chemicals
Cement Materials science Chromium Compounds Chromate conversion coating Renewable Energy Sustainability and the Environment Strategy and Management Reducing atmosphere Metallurgy technology industry and agriculture chemistry.chemical_element Industrial and Manufacturing Engineering Chromium chemistry.chemical_compound chemistry Oxidizing agent otorhinolaryngologic diseases Leaching (metallurgy) Hexavalent chromium General Environmental Science |
| Zdroj: | Journal of Cleaner Production. 43:45-51 |
| ISSN: | 0959-6526 |
| DOI: | 10.1016/j.jclepro.2012.12.027 |
| Popis: | Chromium is a common element present in cement clinkers, and its toxicity is highly related to the oxidation states. It is known that hexavalent chromium, Cr(VI), is much more toxic than other oxidation states, and is easily formed after a high-temperature burning process. This paper describes the influence of sintering atmosphere on phase transformation of dicalcium silicates (Ca2SiO4, C2S) and chromium oxidation states in the production of a low-energy cement, and examines the chromium leachability of the resulting clinkers. The results show that C2S can be synthesized under both oxidizing and reducing atmospheres, and the presence of chromium including Cr(III) and Cr(VI) was effective in inhibiting C2S from transforming to the nonhydraulic γ phase. While the reducing atmosphere relatively increased the level of chromium evaporation, it prevented most of the residual chromium being Cr(VI) and reduced chromium leaching, and this therefore makes the resulting clinkers more environmentally-friendly. |
| Databáze: | OpenAIRE |
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