天然有机高分子粘结剂在铁矿造块中的粘结性能

Effect of Natural organic Polymers on Iron Ore Agglomeration

进行了添加原淀粉、变性淀粉、羧甲基纤维素和腐植酸的磁铁精矿压团实验 ,探讨了粘结剂分子量、主链结构、极性基的种类、数量及受热活性等结构参数对其粘结性能的影响。结果表明 ,腐植酸主链结构为刚性结构 ,且分子中带有受热可发生交联反应的活性基团 ,其干团块和热态团块具有良好的机械强度 ,但它的分子量小 ,湿团块强度较差 ;淀粉和纤维素类粘结剂的主链为低能键 ,热稳定性较差 ,其分子中引入亲水、亲固羧甲基 ,可改善粘结剂的粘结力和内聚力 。

Natural organic polymers, such as raw starch, sodium humate, dextrin, carboxylmethyl starch and carboxylmethyl cellulose, were used as binders for iron ore agglomeration. The effects of their molecular weight, functional group and bond structure etc. on their adhesive property were investigated. The results showed that the molecular of sodium humate has rigid structure and active groups which cause cross linking reaction by heating them.Its dry and hot briguettes have good mechanical strength. However,its green briguettes have poor mechanical strength due to their low molecular weight.Since the main chains of starch and cellulose are low energy bonds,their thermal stability is poor.In these binders,the carboxylmethyl starches exhibit a good adhesive property because functional group -COOH can not only react with the Fe 3+ on the surface of iron ore, but also improve their mechanical properties.