酸洗比色法在直链烷基苯生产质量控制中的应用

APPLICATION OF THE ACID-WASHED COLORIMETRY MEASUREMENT ON LINEAR ALKYL BENZENE (LAB) QUALITY CONTROL

对于首次应用于大亚湾中微子物理实验的液体闪烁介质——直链烷基苯(LAB)的工业化生产,其最重要的质量控制指标为光衰减长度,这通常需要在实验室里利用专门仪器进行测量分析。经过对比研究,在LAB工业化生产流程的基础上,建立了相应的测试方法——酸洗比色分析方法,即使直链烷基苯和98.4%的发烟硫酸反应,在波长403 nm处测定其透光率。研究表明:酸洗比色测量值与光衰减长度测量值之间存在着密切相关性,相关系数达到0.9806。利用酸洗比色测定方法可以对生产流程中的LAB进行实时、有效的在线质量监控,且快捷、准确。

Linear Alkyl Benzene（LAB） was widely used as an intermediate to produce the detergents in petrochemical industry. It was selected as an excellent solvent for the Gadolinium-loaded Liquid Scintillator in the Daya Bay reactor neutrino experiment, because of its attractive properties such as appreciable optical yield, high content of protons（13%）, security flash point（130℃）, and environmental friendly. According to some characteristics of LAB mass production from the LAB plant of Jinling petro-chemical, its light attenuation length had only 5-6 m. So that it is necessary to improve the current producing technique, and promote its quality in order to meet the requirement of the Daya Bay experiment successfully. An acid-washed colorimetry method was set up, which was directly used on LAB production procedure, to compare with the results of the attenuation length of some measured LAB samples from our laboratory. It was found that the results of the acid-washed colorimetry measurement corresponded well with the attenuation length of these samples. Therefore, the acid-washed colorimetry method, which is fast and accurate for the on-site measurement, can be used on LAB quality control directly during its producing process, and also would be beneficial to further applications for the LAB producing technique promotion.