论文部分内容阅读
用波特兰水泥来固化和稳固含铅废料的应用已十多年,然而其中的化学过程及机理并未完全为人所知。在该领域中,对硝酸铅的研究取得可喜的进展,但铅的其它化合物,特别是常见于废料堆中的化合物还没有受到应有的重视,本文研究多种不同含量水平的铅化合物来揭示铅-水泥系统的化学作用和机理。实验中制作一个拟绝热热量计来测量铅-水泥浆体的早期水化过程。用不同的石灰水溶液来模拟水泥孔溶液,并测定其中的可溶铅含量。结果表明:由于铅化合物中阴离子的不同,根据在石灰水溶液中的溶解度和形成难溶钙盐的程度,铅化合物可分为三类。而以水解理论的溶解度不能作为铅化合物分类的标准。并且,可溶铅的多少随石灰浓度或铅-石灰比的变化而变化。本文提出了其缓凝机理及实际应用的预测模型。
The use of Portland cement to cure and stabilize lead-containing waste has been used for more than a decade, but the chemical processes and mechanisms are not fully known. In this field, there has been gratifying progress in the study of lead nitrate. However, other compounds of lead, especially compounds commonly found in waste heaps, have not received due attention. This article examines various levels of lead compounds to reveal Lead-cement system chemistry and mechanism. A pseudoadiabatic calorimeter was made in the experiment to measure the early hydration process of the lead-cement paste. Different lime aqueous solutions were used to simulate the cement pore solution and the soluble lead content was determined. The results show that lead compounds can be classified into three types depending on the solubility of anions in lead compounds and the degree of formation of insoluble calcium salts in aqueous lime solutions. However, the solubility of the theory of hydrolysis cannot be used as a standard for classifying lead compounds. Also, the amount of soluble lead varies with lime concentration or lead-lime ratio. This paper proposes its retardation mechanism and its application model.