玉米芯黏结剂的制备及其黏结机理研究

Research on preparation of corncob binder and its bonding mechanism

为降低膨润土用量,提高入炉球团矿品位,本文对玉米芯进行碱化处理,探究其作为有机黏结剂应用到球团生产中的可行性,并研究其黏结机理。结果表明:随着碱化剂的NaOH质量分数、碱化时间、固液比的改变,玉米芯发生不同程度的水解,最佳预处理条件下NaOH的质量分数为6%、碱化时间为4 h;2%玉米芯配加1%膨润土作为黏结剂时,生球的抗压强度达到11.5 N/P,落下强度达到10.1次/(0.5 m);玉米芯黏结剂与铁精矿粉之间由于存在配位键、氢键等吸附作用,同时玉米芯的复杂纤维空间结构可网罗大量的铁精粉颗粒,可使球团内部结构更加紧密。

In order to reduce the amount of bentonite and to increase the grade of pellets into furnace,the alkalization treatment of corncob is done,the feasibility of applying corncob into pellet production as organic binder is explored and the bonding mechanism of corncob is studied.The results show that,with such changes of alkalizer as NaOH concentration,alkalization time and solid-liquid ratio,corncob is hydrolyzed to different degrees.The optimal pretreatment conditions are NaOH concentration of 6%and alkalization time of 4 h.When 2%corncob and 1%bentonite are used as binder,the compressive strength of fresh pellets reaches 11.5 N/P,and the falling strength reaches 10.1 times/(0.5 m).There are coordination bond,hydrogen bond and other adsorption between corncob binder and iron concentrate powders.Meanwhile,the complex space structure of corncob fiber can trap a large number of iron concentrate powders,so that the internal structure of the pellets is more compact.