煤粉燃料球团生产中链篦机结渣物成因分析

对以煤粉为燃料的链篦机-回转窑法铁矿球团生产中链篦机预热段生成的结渣物进行了XRD、显微结构及扫描电镜能谱分析,发现其矿相组成主要是铁氧化物以及少量含镁铝固溶体。为查明链篦机结渣物形成机理,开展了温度及煤灰残碳量对结渣物形成影响的模拟焙烧试验。结果表明,焙烧物的物相中有含残碳的煤灰,其物相组成、显微结构与实际结渣物组成物相类似,证实链篦机喷煤补热燃烧过程中煤灰中的残碳可使结渣混合物体系生成含亚铁相的硅铝酸盐类低熔点化合物,是导致链篦机结渣物形成的主要原因。

Mechanism of accretion formation at preheating section of grate-kiln pellets fueled by pulverized coal

The research on properties of accretion sample taken from grate-kiln pellets process was performed by XRD,mineral composition and SEM image and EDS,and the preliminary results indicate that the mineral phase of accretion sample includes iron oxides and MgO-Al2 O3 solid solutions.The simulation experiments were carried out in order to determine the effect of roasting temperature and residual carbon content on the for-mation of accretion.The results show that the samples,which prepared and roasted with fines from preheated pellets and coal ash with residual carbon,exhibit similar mineral composition with accretion samples selected from actual grate-kiln pellet process.The formation of low melting point ferrous aluminosilicate,which pro-duced from the reaction of fines from pellets and coal ash which bearing incomplete combustion of coal,is the main factor for accretion formation