Controlling sintering atmosphere to reduce the hazardous characteristics of low-energy cement produced with chromium compounds

doi:10.1016/j.jclepro.2012.12.027

CNU IR > College of Sustainable Environment and Recreation > Dept. of Environmental Resources Management > Periodical Articles > Item 310902800/27813

Please use this identifier to cite or link to this item: https://ir.cnu.edu.tw/handle/310902800/27813

Title:	Controlling sintering atmosphere to reduce the hazardous characteristics of low-energy cement produced with chromium compounds
Authors:	Chen, Ying-Liang Lai, Yi-Chieh Lin, Chien-Jung Chang, Yi-Kuo Ko, Ming-Sheng
Contributors:	環境資源管理系
Keywords:	Chromium Cement Manufacturing Sintering Atmosphere Dicalcium Silicates Leaching
Date:	2013-03
Issue Date:	2014-05-26 10:44:43 (UTC+8)
Publisher:	Elsevier Sci Ltd
Abstract:	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 gamma 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. (C) 2013 Elsevier Ltd. All rights reserved.
Relation:	Journal of Cleaner Production, v.43 n. pp.45-51
Appears in Collections:	[Dept. of Environmental Resources Management] Periodical Articles

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