Study On The Analysis Technology Of Boron Isotope Separation

At present,the chemical exchange distillation is the most stable and steady method to separate the boron isotope by using anisole as donor.To find a fast and real-time method to determine the key factors inside of the system is important because there was high requirement for the instability of the device about the process of chemical exchange distillation.This article has studied on the determination of boron isotope ratio,composition ratio and the impurities and water in anisole in the process of the separation of boron isotope,and the method of online determination of boron isotope ratio by infrared spectroscopy was mainly studied.Based on the difference of the two special infrared absorption bands of BF₃,?₃and 2?₃,the isotope ratio between ¹⁰BF₃ and ¹¹BF₃ was discussed.The feasibility of this method and instability of results were proved.The peak areas ratio determined by IR method was corrected with the determination results of inductively coupled plasma mass spectrometry,and the corresponding correction factors were calculated;Gaussian,Lorentzian and Voigt profiles were used to fitting the curves of?₃ and2?₃ bands of IR spectrums,respectively.The multimodal fitting at the same time was realized with the help of the software 1stOpt.The results showed that the Voigt lineshape is more specifically suited to the fitting of?₃ band and Gaussian lineshape is more suited to the fitting of 2?₃ band.By using the partial least square?PLS?method to analize and predict the spectrum data.The results proved that the two methods have higher stability and reliability than the method of integral area directly,and PLS method is the faster and more convenient one;Here,the isotpe ratio of boron in BF₃ utilized the 2?₃ band was determined.The method of online measurement is used to investigate the isotope ratio changes in the system in real-time.In this way,the changes of isotope ratio in system could be investigated by real-time,and give supervision in production;The relationship of composition ratio density and temperature were investigeatd,meanwhile the related empirical formula for the precise determination was calculated.Density of BF₃-anisole comple sampling from the separation part and complex part of the chemical exchange distillation device were determined online by using tuning fork densitometer.The composition ratio was masured online after this densitometer was fixed on both sides of the bottoms of separation and complex part of the chemical exchange distillation device;The main by-products in anisole,including phenol,p-cresol and p-Methylanisole,was determined by gas chromatography external standard method to get the accurate content.An online determination system of water content in anisole was designed to measure the trace amount of water in anisole,and the operation parameters for anisole drying technology was optimized by this system.