【作者】 杨艳梅；

【导师】 肖红卫；

【作者基本信息】 昆明理工大学 ， 化学工程， 2008， 硕士

【摘要】 随着精细磷化工的不断发展,作为新的基础原料酸一多聚磷酸其纯度受到了广泛关注,因为纯度直接决定产品用途。元素砷是衡量磷酸纯度的重要指标之一,也是最难除去的杂质之一,因此如何降低多聚磷酸中的砷含量以达到低砷(≤10ppm)磷酸的要求是目前研究的热点也是难点。本论文便是根据这种需求,同时鉴于目前国内还未见这方面的报道,对多聚磷酸脱砷工艺进行探讨。论文首先通过各种磷酸脱砷工艺路线的比较,结合多聚磷酸的特点以及砷可能脱除的形式,确定了多聚磷酸脱砷的工艺方法一卤化物法,这是一种新的无需过滤及后处理的方法;同时考察了脱砷剂的选择、反应温度、反应时间、搅拌速率以及脱砷剂用量等因素对脱砷效果的影响;通过正交实验获得了最佳的工艺条件:1.以卤化氢气体为脱砷剂的最佳工艺条件:反应温度:150℃;反应时间:60min;搅拌速率:250 rpm;脱砷剂用量为多聚磷酸质量的0.8%。2.以氢卤酸为脱砷剂的最佳工艺条件:反应温度:135℃;反应时间:5min;搅拌速率:250 rpm;脱砷剂用量为多聚磷.酸质量的1.5%。通过前面两种脱砷剂处理后的多聚磷酸中的砷含量分别为:3.9ppm和2.8ppm,都达到了低砷酸的要求,产品回收率可达98%以上。在此基础上研究了如何拓宽此工艺方法的应用范围。另外,从热力学的角度对多聚磷酸脱砷反应机理作了初步探讨,对今后的研究工作有一定的指导意义。更多还原

【Abstract】 Developing of the fine phosphorus chemical industry, the purity of polyphosphoric acid as a new , basis, raw material has been concerned widly, because the end use depends on its degree of purification . The element arsenic is not only one of important indicators on studying the degree of purification of phosphoric acid, but also one of the impurities that remove difficultly, thus how to reduce the content of arsenic of polyphosphoric acid to achieve the requirement of low arsenic (≤10ppm) phosphoric acid is a hot and difficult research currently . This paper is related to arsenic removal process of polyphosohoric acid , which is based on mentioned demand earlier, and in the light of no reports in this regard at present .In this paper, compared with various kinds of arsenic removal process of phosphoric acid, considered the characteristic of polyphosphoric acid, and the form of arsenic removal possible, at last define the arsenic removal process of polyphosphoric acid-halide process, this is a new process without filtration and treatment method; Inspect some factors, which contained how to choice arsenic removal substance, reaction temperature, reaction time, stirring rate as well as the amount of arsenic removal substance and so on, they effect arsenic removal simultaneously; Obtain the best conditions by orthogonal experiment.When hydrogen-halogenated is arsenic removal substance, the optimum conditions are reaction temperature: 150℃, reaction time: 60min, stirring rate: 250rpm and the amount of arsenic removal substance: 0.8%(w%).When Hydrohalogenic acid is arsenic removal substance, the optimum conditions are reaction temperature: 135℃, reaction time: 5min, stirring rate: 250rpm and the amount of arsenic removal substance: 1.5%(w%).The content of arsenic in polyphosphoric acid are 3.9ppm and 2.8ppm by the front arsenic removal process respectively, which have been reached a low arsenic trioxide requirements, the recovery rate is more than 98%. On the basis of this, study the process of how to broaden the scope of the application.Furthermore , discuss the reaction mechanism of arsenic removal of polyphosphoric acid from the perspective of thermodynamics preliminarily . This paper will have certain guiding sense to the future work.更多还原