双溶剂法硼包覆工艺及其工艺参数研究

A Study for Coating Boron Particles with Two-Solvent Method and its Process Parameters

关键词:  双溶剂法  硼  包覆  正交试验  工艺参数 

Key words:  Two-solvent method  Boron  Coating  Orthogonal experiment  Process parameters

摘要:

针对重结晶法硼包覆工艺的不足,采用了双溶剂法对硼颗粒进行包覆。应用pH法对包覆效果进行验证。设计正交实验研究了超声波混合时间、蒸发温度和搅拌速度这三种因素对双溶剂法包覆效果的影响。试验结果表明:双溶剂法的包覆效果要优于重结晶法；超声波混合时间的最优水平为10min,使用超声波混合可以有效地提高双溶剂法包覆效果；蒸发温度的最优水平为350℃,提高蒸发温度有利于促进包覆效果,但温度越高时,提高温度对包覆效果的促进作用将减弱；搅拌速度的最优水平为200r/min,一定的搅拌速度可以维持硼在溶液中的均匀分散,有利于硼颗粒的包覆,但搅拌速度过快又会使已经包覆在硼颗粒表面的LiF在剪切力的作用下重新从硼表面脱落,降低了包覆效果。 

Abstract:

Because of the shortcoming of recrystallization method, a new way named two-solvent method for coating boron particles was proposed. The PH-method was used to verify boron coating effect. The effects of ultrasonic mixing time, evaporation temperature and stirring speed on coating effect were studied through orthogonal experiment. The results show that two-solvent method is superior to recrystallization method for coating boron particles. The optimal value of ultrasonic mixing time is 10min. Using ultrasonic mixing can improve coating effect effectively. The optimal value of evaporation temperature is 350℃. Increasing evaporation temperature is beneficial to improving coating effect, but the promotion effect decreases with increasing evaporation temperature. The optimal value of stirring speed is 200r/min.If the stirring speed is too slow, it cannot maintain the uniform dispersion of boron particles in the solution which goes against the coating effect. Meanwhile, if the stirring speed is too high, the coating agent on the boron particles will exfoliate because of shear stress. 