Study On Separation Of Boron Isotopes

This article is devoted to the separation of boron isotopes by the method of chemical isotope exchange distillation between BF3 and the complex anisole?BF3. Taking into account the higher separation factor, the lower rate of breakdown of anisole, the lower toxicity and operation under room temperature and atmospheric pressure, complex compounds of BF3 with anisole is superior to the other. The process of enriching boron isotopes was improved, designed and calculated. The process flow chart was composed of recombiner, exchange column, decomposer, purification tower and drying tower. Two towers in series was used to deduce the height because the process required hundreds of theoretical plates. The reason of decomposition of anisole was discussed in the article. And two routs of donor decomposition define the measures required to prevent this process. one was the anisole dehumidification up to the water concentration of ～0.003%-0.005%. The other was reduction of temperature in the zone of high BF3 concentration and reduction of BF3 concentration in anisole in the high-temperature zone. Moreover, anisole should be purified from products of decomposition in purification tower. The relationship between separation factor and reaction equilibrium constant was analyzed. The article gave an expression for the temperature dependence of separation factor in the An?BF3-BF3 system. The mathematical model of the steady-state separation of boron isotopes was built and was solved by a Fortran program. Rules of separation of boron isotopes were gained. The influence of temperature and reflux ratio on the process of separation was analyzed and some valuable conclusions were obtained. The process of separation of boron isotopes was solved on the basis of the model and the influence of temperature and reflux ratio on the result of separation was analyzed. The experiment on anisole dehumidification was carried out. And the results showed that the way of drying anisole by dry nitrogen is proved feasible.