某核废液处理厂的火灾爆炸事故解析(Ⅰ) 核废液的沥青固化处理条件对固化产物中盐粒子的微观构造的影响

Fire and Explosion Investigation of Asphalt-sale Mixture in a Nuclear Wastes Processing Plant (Ⅰ) effect of bituminization conditions on microstructure of salt particle in the asphalt-salt mixture

设计了一套核废液的沥青固化处理模拟试验装置,对不同固化处理条件下生产的沥青固化物内的混合盐粒子的微观构造、粒径分布等进行了详细探讨。结果表明,固化处理条件的改变对固化产物中的盐粒子的大小及其粒径分布虽无明显的影响,但对其微观构造及比表面积的影响却十分明显。当核废液中含有磷酸盐并且核废液的送料速度较低时,生产的沥青固化物中的混合盐粒子的约70%是由长3-6微米,直径约1微米的针状结晶以架桥形式构成。这样的氧化剂颗粒具有很大的比表面积。

A special experimental system was designed to prepare the asphaltsalt mixture (ASM) at higher temperature imitating the real bituminization process of waste, four types of simulated ASMs, which were prepared under different bituminization conditions. The size, microstructure and specific surface area of the salt particles in each ASM have been observed experimentally. The bituminization conditions almost have no effect on the salt particles size and their diameter distribution, but have large effect on the microstructure and specific surface area of the salt particles. When the ASM prepared under low feeding rate of waste containing phosphate, most of salt particles appears as a lot of needleshaped crystals which are about 1 μm thick and 3～6 μm long to form a bridged configuration like bur of sponge, such particles have large specific surface area.