磁性灰粒在不同粒级气化灰渣中的分布特性

以气流床煤气化粗渣和细灰为原料，采用筛分和磁选的方法研究了磁性灰粒在不同粒级气化灰渣中的分布特性。结果表明：随着灰渣粒径的减小，在粗渣和细灰中，磁性灰粒的含量均呈现先升高后降低的趋势，磁性灰粒在粗渣中的含量高于细灰。粗渣中，磁性灰粒在0.5~0.25mm粒级中分布最多，该粒级神宁炉和GSP气化炉粗渣在粒度组成中的占比也最高，质量分数分别为38.42%和37.16%，各个粒级中磁性灰粒产率随粒径减小呈递增趋势；细灰中，磁性灰粒在0.074~0.045mm粒级中分布最多，而细灰粒度组成中的占比最高的却是大于0.25mm粒级，磁性灰粒产率在各个粒级都不高，呈现随粒径减小而升高的规律。气化过程中，磁铁矿会更多地富集在凝结团聚且高度玻璃化的大粒径粗渣中，粗渣和细灰中仍有相当量的含铁物相不显磁性。不同粒级煤气化灰渣中磁性灰粒的分布特性可为气化渣分级分质及高值化利用提供基础数据支撑和应用思路。

Distribution characteristics of magnetic ash particles in gasification slag of different particle sizes

The distribution characteristics of magnetic ash particles in different size fractions of gasification slag were studied by sieving and magnetic separation with entrained flow gasification coarse slag and fine ash as raw materials. Results showed that with the decrease of ash particle size, the content of magnetic ash particles in coarse slag and fine ash increased first and then decreased, and the content of magnetic ash particles in coarse slag was higher than that in fine ash. In the coarse slag, the distribution of magnetic ash particles was the most in the 0.5—0.25mm size fraction, and the proportion of the fraction in Shenning gasifier and GSP gasifier coarse slag was also the highest, which were 38.42% and 37.16%, respectively. Besides, the yield of magnetic ash particles in each size fraction increases with the decrease of particle size. In the fine ash, the distribution of magnetic ash particles was the most in the 0.074—0.045mm particle size fraction, while the proportion of fine ash particle size composition was the highest in the > 0.25mm particle size fraction, and the yield of magnetic ash particles was not high in each particle size fraction, showing a law of increasing with the decrease of particle size. During the gasification process, magnetite would be more concentrated in the large-size coarse slag that was agglomerated and highly vitrified, but there was still a considerable amount of iron-containing phase which was not magnetic. The distribution characteristics of magnetic ash particles in different size fractions of coal gasification slag could provide basic data support and application ideas for the classification and high value utilization of coal gasification slag.