低放稀土渣中氡析出的估算与测定
时间:2018-04-11 22:45 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：由于我国广袤的地理环境，造就了我国丰富的稀土资源。我国的稀土储量约占世界总储量的23%，并且稀土资源是不可再生资源，因此稀土在一定程度上具有战略意义。由于稀土资源伴生着大量放射性核素，其中就包括放射性元素氡，所以在对稀土资源的开发利用中，对环境和人类可能造成放射性危害。稀土冶炼主要废物为各种废渣，包括酸溶渣、中和渣等。因此，对于废渣中氡的测量与监管具有非常重要的意义。 酸溶渣、中和渣是工业稀土冶炼中最常见的废渣，本文将通过各种模型来对废渣中氡进行测量。制造两种模型分别为薄膜、圆柱。在一定体积的密闭空间里，对废渣中氡的析出予以监测。按照不同监测时间，绘出氡随时间变化的曲线。同时又比较两种不同模型在相同条件下的氡的析出率。20989 实验结果表明，酸溶渣中氡的放射性含量要高于中和渣，而且酸溶渣在一定空间内达到氡的平衡的时间要高于中和渣。稀土渣后处理需将稀土渣放置一段时间，再妥善处理，否则将会造成放射性污染，对周围水体、环境、乃至人员造成放射性伤害。 毕业论文关键字：稀土渣 后处理 氡析出率 酸溶渣 中和渣 Estimation and determination of low-level radioactive radon emanation of rare earth slag School of Environmental and Biological Engineering, Radiation Protection and Environmental Engineering Major Instructor：Lu, Jiaqi Abstract:Because of the vast geographical environment, creating a country rich in rare earth resources. China's rare earth reserves account for about 23 percent of the world's total reserves, and rare earth resources are non-renewable resources, rare earth strategic significance to a certain extent. Due to a large number of rare earth resources associated radionuclides, including radioactive radon, so the exploitation of rare earth resources in the environment and humans may cause radiological hazards. The main waste for a variety of rare earth smelting waste, including acid-soluble slag, slag neutralization. Therefore, the waste radon measurement and regulation has a very important significance. Acid-soluble residue, and in rare earth smelting slag is the most common industrial waste residue, this article will be measured through a variety of waste radon model. Manufacture two models were thin, cylindrical. Confined in a volume of space, waste of precipitation radon be monitored. According to different monitoring time, radon plotted versus time curve. While comparing two different models of radon exhalation rate under the same conditions. Experimental results show that the content of acid-soluble radioactive radon slag and slag to be higher than that, and the acid-soluble residue in a certain space of time to reach equilibrium than in radon and slag. Rare earth rare earth slag slag processing need to place for some time, and then properly handled, otherwise it will result in the radioactive contamination of the surrounding water, the environment, and even personnel injury caused by radioactivity. 目录 1 绪论 5 1.1 我国稀土工业的概况 5 1.1.1 什么是稀土元素 6 1.1.2 我国稀土矿的分布及类型 6 1.1.3 我国稀土工业的发展状况 6 1.2 稀土工业中的放射性废物及氡的危害 6 1.2.1 放射性对公众的危害 7 1.2.2 稀土材料在冶炼过程中主要采用的工艺流程 7 1.2.3 稀土的放射性主要转移到各种废渣中 8 1.2.4 放射性元素氡的危害 9 2 实验设计及分析验证 10 2.1 设计实验的内容、目的、步骤 10 2.1.1 实验所用材料、仪器 11 (责任编辑：qin) |