硫化砷的催化氧化研究

【作者】 施孟华；

【导师】 汤德元；

【作者基本信息】 贵州大学 ， 化学工艺， 2009， 硕士

【摘要】 在各种重金属污染中,砷的污染最为严重,含砷废渣对环境十分有害。大多数除砷过程都会产生硫化砷渣。长期以来含砷废物大多采用囤积贮存的方法处理,随着高浓度含砷废物越积越多,对其无害化处理成为亟待解决的问题。目前国内外处理含砷废渣和污泥时常用的固化处理技术。这种处理方式不仅增加企业负担,而且造成资源的极大浪费。随着科技的发展,砷的市场需求不断增加,含砷废物的处理从“固砷”逐渐转变到开发新技术、新工艺以提高砷资源的利用率,变废为宝。目前国内外对硫化砷渣处理工艺很多,大体上分为火法和湿法两种。本文采用碱浸空气氧化法,以对苯二酚作为催化剂,空气中氧气作为氧化剂,对来自贵州某公司氟硅酸脱砷后的硫化砷渣进行氧化研究。考察了氧化时间、氧化温度、催化剂使用量各种因素对该过程的影响,并对各影响因素做正交试验,进行极差分析,得到各因素对指标影响大小的主次关系为:氧化反应时间＞催化剂用量＞氧化反应温度。通过方差分析得到氧化反应时间对实验结果的影响最为显著,同时各因素之间又相互交叉影响。故分别以硫的氧化回收率和砷的氧化率为指标来做单因素实验,最终综合分析得到最优的工艺条件如下:反应时间:8h;反应温度:45℃;催化剂使用量:0.4g/l。此时硫的氧化回收率为:61.44%;砷的氧化率为:57.36%。更多还原

【Abstract】 Arsenic residue which is one kind of the heavy-metal contamination is more harmful to the environment. Arsenic sulfide slag would be produced in most processes of arsenic removal. Arsenic residue treated by accumulation of storage in a long period of time would accumulated gradually.So it is an urgent problem to deal with arsenic residue.At present, the way of solidification processing technology is usually used to deal with the arsenic residue or sludge. It not only increase the burden on enterprises but also cause the greatest waste of resources. With the development of the technology and increased market demand for arsenic, new technologies and new techniques will be developed to improve the utilization of arsenic resources.Currently, the treatment processes to arsenic sulfide slag is divided into Fire-process and Wet-process. Air oxidation to arsenic sulfide slag dipping in alkaline environment is chosen in this article, in which hydroquinone as catalyst and oxygen from air as oxidants. Arsenic sulfide slag deprived from fluosilicic acid as raw materials comes from Guizhou Wengfu. Impacting on that process,oxidation time, oxidation temperature and use of catalyst are studied by orthogonal test and range analysis.The result is that oxidation time and oxidation temperature and use of catalyst are followed by decreasing.So the oxidation time impacts on the indicators seriously among those factors.And they are affecting each other.Recovery of sulphur and oxidation rate of arsenic are being targets for single factor experiment.The Optimal process conditions is that reaction time is 8 hours and its temperature is 45℃and 0.4g/l of catalyst should be used.The recovery of sulphur is 61.44% and oxidation rate of arsenic is 57.36%.更多还原