六硝基六氮杂异伍兹烷的粒度控制生产工艺

六硝基六氮杂异伍兹烷(CL-20)的粒度和形貌对其感度、安全性以及填药密度有重要的影响。研究通过控制和优化重结晶工艺条件,分别探索超声辅助重结晶法和反溶剂法中不同因素以及搅拌器类型对CL-20晶体粒度的影响。在超声辅助重结晶法中,考察了超声连续震动和间歇震动频率以及不同超声频率(20~40 kHz)对生产小粒经产品的影响;在反溶剂法中,以乙酸乙酯和三氯甲烷为良溶剂和不良溶剂,考察了三氯甲烷滴加速度(20、50、100 mL·h^-1)、三氯甲烷与乙酸乙酯滴加量比例(1∶1、1∶2、1∶3),重结晶时间(24、48、72 h)以及重结晶温度(30、40、50℃)对大粒径产品的影响。通过设计正交试验,确定了最优条件;在对搅拌器对产品影响的研究中,选择了四直叶开启涡轮式、六直叶涡轮式和双层分散盘三种搅拌器类型以及相应的多种转速对产品的粒度和形貌的影响。结果表明,间歇超声辅助重结晶可显著减小晶体粒度,采用频率40 kHz,每震动30 min,停5 min的超声方式,可以获得平均粒度为14μm的CL-20颗粒;反溶剂法控制粒径的研究中,结晶时间72 h、结晶温度30℃、三氯甲烷滴加速度为20 mL·h^-1、滴加量为150 mL时,可获得大粒径的CL-20产品(平均粒度为140μm);采用双层分散盘制备的CL-20晶体外形为类球形,表面光滑均匀,粒径在40~100μm之间可控。对比四直叶开启涡轮式和六直叶涡轮式搅拌器制备的晶体,采用双层分散盘制得的产品撞击感度和摩擦感度较低,撞击感度特性落高值和摩擦感度爆炸概率分别为23.5 cm和44%。

Production Process to Control Particle Size of Hexanitrohexaazaisowurtzitane

It was proved that the sensitivity,safety and density of explosive compound were extremely affected by its morphology and particle size.The influence factor of hexanitrohexaazaisowurtzitane(CL-20)particle size was studied in the recrystallization process with the ultrasonic-assisted recrystallization method,the anti-solvent method and the optimization of agitator type,respectively.The effects of continuous and intermittent ultrasonic with different ultrasonic frequencies(20-40 kHz)were also investigated in order to obtain the small particle size product.In the recrystallization process with anti-solvent method,ethyl acetate and chloroform were applied as solvent and anti-solvent respectively.The dropping acceleration of chloroform(20,50,100 mL·h^-1),the ratio chloroform and ethyl acetate(1∶1,1∶2,1∶3),the recrystallization time(24,48,72 h)and temperature(30,40,50℃)were optimized by orthogonal experiments.In addition,three types of agitator including four straight-blade open turbine,six straight-blade turbine and double-layer dispersing discs were performed in the CL-20 product morphology study together with their stirring speed effect.It was concluded that the assistance of intermittent ultrasonic could considerably reduce CL-20 crystal size.Particle size of 14μm CL-20 could be obtained by ultrasonic assistant method while the frequency was controlled at 40 kHz with every 30 minutes vibration after 5 minutes stop.Moreover,L9(34)orthogonal experiments were designed and particle size of 140μm CL-20 could be achieved when the crystallization time,temperature,the chloroform dropping rate,and the dropping amount was 72 h,30℃,20 mL·h^-1 and 150 mL,respectively.Furthermore,three kinds of agitators were employed in the recrystallization process which obviously effected CL-20 morphology and particle size.A controllable particle size between 40-100μm CL-20 crystals with spherical shape,a smooth and uniform surface were prepared with the double-layer dispersion disc.Comparing with the four straight blades open turbine type and the six straight blades turbine type agitator,it is proved that the product with desired impact sensitivity and friction sensitivity could be prepared by the double-layer dispersion disc method,which characteristic drop height and the explosion probability were 23.5 cm and 44%,respectively.