复掺粉煤灰吸附剂碳化固碳反应及对重金属浸出特性的影响

发布时间：2018-07-15 19:20

【摘要】：针对复掺方法提高粉煤灰矿物固碳效率和重金属析出钝化作用,采用粉煤灰掺入不同比例的消石灰和氧化铝制备了固碳吸附剂,利用三相高压反应釜模拟碳酸化固碳反应,利用热重-差热测试分析了不同配比固化剂CO_2固定量和固定效率,对碳酸化反应前后固化剂的化学成分进行了分析,揭示了复掺粉煤灰吸附剂固碳机理,对碳酸化反应前后固化剂材料中重金属浸出毒性进行了实验模拟。结果表明,粉煤灰基固化剂复掺消石灰后,增加了固化材料中CaO量,显著提高了碳酸化体系中pH值,当粉煤灰与消石灰质量比为1∶1时,碳固定效率最高,达到6.98%。当消石灰的投加量为50%时,As、Cd、Cu、Pb、Cr受到了较强的抑制效果,Ni、Zn的浸出浓度没有变化。因此,复掺消石灰、氧化铝的粉煤灰基碳固化材料可有效改善纯粉煤灰碳酸化固定CO_2的效率,并可降低粉煤灰碳酸化后重金属的浸出毒性。
[Abstract]:In order to improve the carbon fixation efficiency of fly ash minerals and the precipitation and passivation of heavy metals, the carbon sequestration agent was prepared by adding fly ash into different proportions of lime and alumina. The carbonated carbon fixation reaction was simulated by three phase high-pressure reactor, and the fixed amount and fixed effect of different ratio curing agent CO_2 were analyzed by the thermogravimetric differential heat test. The chemical composition of the curing agent before and after carbonation was analyzed and the mechanism of carbon fixation was revealed. The toxicity of heavy metal leaching in the curing agent before and after the carbonation reaction was simulated. The results showed that the CaO amount in the solidified material was increased after the flyash base curing agent was added to the cement. The pH value in carbonation system, when the mass ratio of fly ash and lime is 1: 1, the carbon fixation efficiency is the highest, when the dosage of 6.98%. is 50%, As, Cd, Cu, Pb, Cr are strongly inhibited, and the leaching concentration of Ni and Zn is not changed. Therefore, the flyash based carbon solidified material can effectively improve the pure powder. The carbonization of coal ash can improve the efficiency of CO_2 and reduce the leaching toxicity of heavy metals after carbonation of fly ash.
【作者单位】：中国矿业大学环境与测绘学院;中国矿业大学江苏省煤基CO_2捕集与地质储存重点实验室;
【基金】：国家自然科学基金资助项目(41572218,41002048) 中国矿业大学江苏省煤基CO_2捕集与地质储存重点实验室开放基金(2011KF02)
【分类号】：X773

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