Immobilization of Co(Ⅱ) Ions in Cement Pastes and Their Effects on the Hydration Characteristics
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2011年第1期
论文作者：Eisa Hekal Essam Kishar Wafaa Hegazi Maha Mohamed
文章页码：74 - 80
摘 要：The immobilization of Co（Ⅱ） in various cement matrices was investigated by using the solidification/stabilization（S/S） technique.The different cement pastes used in this study were ordinary Portland cement in absence and presence of water reducing-and water repelling-admixtures as well as blended cement with kaolin.Two ratios of Co（Ⅱ） were used（0.5% and 1.0% by weight of the solid binder）.The hydration characteristics of the used cement pastes were tested via the determination of the combined water content,phase composition and compressive strength at different time intervals up to 180 d.The degree of immobilization of the added heavy metal ions was evaluated by determining the leached ion concentration after time intervals extended up to 180 d.The leachability experiments were carried out by using two modes:the static and the semi-dynamic leaching processes.It was noticed that the concentration of the leached Co2+ ions in the static mode of leachability was lower than the solubility of its hydroxide in all the investigated cement pastes.
Eisa Hekal1，Essam Kishar2，Wafaa Hegazi2，Maha Mohamed2
1. Chemistry Department,Faculty of Science,Ain Shams University2. Chemistry Department,Women s College for Arts,Science and Education,Ain Shams University
摘 要：The immobilization of Co（Ⅱ） in various cement matrices was investigated by using the solidification/stabilization（S/S） technique.The different cement pastes used in this study were ordinary Portland cement in absence and presence of water reducing-and water repelling-admixtures as well as blended cement with kaolin.Two ratios of Co（Ⅱ） were used（0.5% and 1.0% by weight of the solid binder）.The hydration characteristics of the used cement pastes were tested via the determination of the combined water content,phase composition and compressive strength at different time intervals up to 180 d.The degree of immobilization of the added heavy metal ions was evaluated by determining the leached ion concentration after time intervals extended up to 180 d.The leachability experiments were carried out by using two modes:the static and the semi-dynamic leaching processes.It was noticed that the concentration of the leached Co2+ ions in the static mode of leachability was lower than the solubility of its hydroxide in all the investigated cement pastes.
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