铜渣尾矿团粒过程黏结剂筛选及黏结机理

Binder Selection and Bonding Mechanism in Pelletization Process of Copper Slag Flotation Tailings

为减少铜渣尾矿资源化利用过程的粉尘和烟气,以铜渣尾矿为原料,以羧甲基纤维素钠(CMC)、膨润土、水玻璃单独或复配为黏结剂制备铜渣球团,通过落下强度、抗压强度和生球爆裂温度考察黏结剂的成球效果,借助扫描电镜、红外光谱和Zeta电位测试分析球团内部微观形貌、吸附特征和表面电位变化。结果表明:3种黏结剂均可实现铜渣尾矿的团粒化黏结;黏结剂单独使用时,CMC配量应大于0.20%,膨润土配量应大于2.0%,水玻璃配量应大于2.5%;CMC与膨润土或水玻璃复配,CMC配量0.1%时,膨润土配量应大于2.0%,水玻璃配量应大于2.5%;CMC配量为0.15%时,膨润土配量应大于1.5%,水玻璃配量应大于2.0%。添加黏结剂后,球团内部结构更加紧凑,空间结构更加牢固;铜渣尾矿颗粒表面Zeta电位降低,亲水性提高,促进了颗粒间的吸附作用进而提高球团质量。

Copper slag flotation tailings were taken as raw materials,and carboxymethylcellulose(CMC),bentonite,sodium silicate alone or the mixture were taken as binders to prepare copper slag pellet for reducing dust and flue gas generated during utilization of copper slag tailings.The effect of binder on balling was explored in terms of the drop numbers,compressive strength and cracking temperature of green ball,and microscopic morphology,adsorption characteristics and surface potential changes were also analyzed by scanning electron microscopy,infrared spectroscopy and Zeta potential detection.Results show that all three binders can be useful in agglomeration of copper slag tailings.When used alone,CMC,bentonite and sodium silicate are required to be added at an amount more than 0.20%,2.0%and 2.5%,respectively.In case of CMC used in combination with bentonite or sodium silicate,bentonite or sodium silicate should be added at an amount of more than 2.0%and more than 2.5%,respectively,with the addition of CMC is at an amount of 0.1%;while with the addition of CMC at an amount of 0.15%,the addition of bentonite or sodium silicate should be more than 1.5%and more than 2.0%,respectively.With the addition of binder,the prepared pellet has more compacted structure and stronger spatial structure.It is found that copper slag tailings particles have a lower value of zeta potential,and an improved hydrophilicity,which can promote interparticle adsorption,and thus improves pellet quality.