改性膨润土降低高比例硫酸渣球团黏结剂消耗  

Reduction consumption of binder by modified bentonite in high proportion sulfuric acid slag pellets

作　　者：刘嘉琦 夏羽 康有成 郑浩然 夏子豪 张子悦 LIU Jiaqi;XIA Yu;KANG Youcheng;ZHENG Haoran;XIA Zihao;ZHANG Ziyue(School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243032,Anhui,China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243032

出　　处：《中国冶金》2024年第11期107-116,共10页China Metallurgy

基　　金：安徽省自然科学基金杰青资助项目(2208085 J19);安徽省研究生创新创业实践项目(2023cxcy sj071)。

摘　　要：为解决高比例硫酸渣球团黏结剂用量高、球团质量差的难题,开展了低品质钙基膨润土提质改性研究,以降低黏结剂用量、提高硫酸渣比例。在钙基膨润土基础上添加1.5%有机黏结剂OA(高分子有机聚合物)后,采用高压挤压的有机插层改性方式得到改性膨润土。结果表明,以黏结剂用量1.2%为基准,混合矿硫酸渣比例均为50%时,使用改性膨润土较使用未改性钙基膨润土制备的球团性能显著提高,其中生球落下强度由1.2次(0.5 m)提高至4.8次(0.5 m),焙烧球强度由1095 N/P提高至2721 N/P。改性膨润土的晶体层间距由钙基膨润土的d_(1)(001)=1.5297 nm降低至d_(4)(001)=1.1906 nm,说明有机改性效果充分,Si—O—Si、MgAl—OH、H—O—H、COO—和NH_(4)^(+)的特征峰得到增强,提高了原料的持水能力和球团的塑性变形性能,最大毛细水质量分数由未改性时的23.8%增加至27.0%。此外,改性膨润土中的有机组分受热挥发,在膨润土晶层间形成孔道,有利于氧气向球团内部及矿粒表面扩散并充分氧化固结,使球团内部结构更加紧密,从而提高了球团强度。研究可为低品质膨润土的提质改性和高比例硫酸渣球团的工业化应用提供理论指导和实践依据。To solve the problem of high binder dosage and poor quality of pellets with a high proportion of sulfuric acid slag pellets,research on the quality improvement and modification of low-quality calcium-based bentonite was carried out to reduce the binder dosage and increase the proportion of sulfuric acid slag.After adding 1.5%organic binder OA based on calcium-based bentonite,the modified bentonite was obtained by a high-pressure extrusion of organic interlayer modification.The results show that with the binder dosage of 1.2%as the basis,the proportion of mixed ore sulfate slag is 50%,the properties of pellets prepared with modified bentonite are significantly improved compared with those prepared with unmodified calcium bentonite,including the raw ball drop strength increases from 1.2 times(0.5 m)to 4.8 times(0.5 m),and the baked ball strength increases from 1095 N/P to 2721 N/P.The crystal layer spacing of the modified bentonite is reduced from d_(1)(001)=1.5297 nm to d_(4)(001)=1.1906 nm for calcium-based bentonite,indicating that the organic modification effect is sufficient.The characteristic peaks of Si—O—Si,MgAl—OH,H—O—H,COO—,and NH_(4)^(+) are enhanced,which improves the water-holding capacity of raw material and the plastic deformation performance of the pellet,and the maximum capillary water increases from 23.8%to 27.0%.In addition,the organic components in the modified bentonite are volatilized by heat,forming pores between the bentonite crystal layers,which is conducive to diffusing of oxygen to the interior of pellet and the surface of mineral grains and fully oxidizing and solidifying,so that the internal structure of the pellet is more compact,which improves the strength of the pellet.The result can provide theoretical guidance and practical basis for the upgrading and modifying of low-quality bentonite and the industrial application of high-ratio sulfuric acid slag pellets.

关 键 词：硫酸渣 氧化球团 黏结剂 膨润土 有机插层改性 

分 类 号：TF046.6[冶金工程—冶金物理化学]