高B_4C相含量极细碳化硼粉的制取

用碳管炉硼酐碳热还原法制得了碳化硼粉,其化学成分和杂质含量符合中国国家标准和美国国家标准对一、二级核级粉末的要求,其B_4C含量远高于按上述标准中化学成分折算的值。化学成分折算法经X射线内标法验证,证明是可靠的。两种方法获得的结果很接近。上述原始粗B_4C粉经振动球磨和酸洗后获得了成分符合技术标准的微米级B_4C细粉。实验证明:振动球磨的效率较滚动球磨高数倍甚至数十倍;振动球磨的平衡粒度和达到平衡粒度所需的时间也远低于普通球磨相应的值。

A STUDY OF SUPERFINE BORON CARBIDE POWDER WITH HIGH B_4C PHASE CONTENT

A boron carbide powder whose chemical compositions and contents of impu- rities meet the requirements of China Standard and US Standard was produced by the reduction of boric acid with carbon in a carbon tube furnace. The B4C phase content of the powder has surpassed the calculated value from the chemical composition given by the above standards. The calculated value of B_4C phase was verified by X-ray internal-standard-method. Such coarse powder was subjected to intensive vibratory milling and was acid-washed. A micron-fine powder with the chemical compositions being up to the Standard was gained. The present study- indicates that the effect of comminution in vibratory milling is several times, even dozens of times, as high as that in common ball milling. The equilibrium particle size is much smaller and the time required to reach the equilibrium particle size is also much shorter than that in common ball milling.