全尾砂絮凝沉降中APAM单耗对不同粒级颗粒絮凝作用规律及机理研究

Study on the Flocculation Law and Mechanism of APAM Unit Consumption to Different Particle Size in the Flocculation and Sedimentation of Tailings

某铜矿添加不同单耗的阴离子型聚丙烯酰胺(APAM)进行全尾砂絮凝沉降试验,使用Winner 2000激光粒度仪分析全尾砂粒径变化规律,并借助扫描电子显微镜(SEM)观察絮凝沉降过程中某一时间尾砂样品的微观形貌特征,以探究不同絮凝剂单耗对3种不同粒径范围内的颗粒作用影响规律及机理分析。研究表明:当添加APAM单耗较低时,少部分游离在砂浆中的"细"颗粒(尾砂粒径范围在0.1~9.703μm)与絮凝剂高分子链产生吸附桥连作用,此时沉降效果不佳;随着单耗逐渐增加,有足够的絮凝剂高分子链能与游离的"细"颗粒尾砂产生吸附桥连作用,并且"网捕"不能与高分子链产生吸附作用的"粗"颗粒(尾砂粒径大于36.851μm),加速液面沉降;当单耗增加到一定量时,絮凝剂高分子链对原本吸附效果不佳的颗粒(尾砂粒径为9.703~36.851μm)产生了影响。

In a copper mine,APAM with different unit consumption was added to carry out the flocculation and sedimentation test of the full tailings.The particle size change rule of the full tailings was analyzed by the winer 2000 laser particle size analyzer,and the micro morphology characteristics of the tailings samples at a certain time in the process of flocculation and sedimentation were observed by means of scanning electron microscope(SEM),so as to explore the influence rule and mechanism analysis of different unit consumption of flocculant on the particles with three different particle sizes.The results showed that when the unit consumption of APAM was low,a small amount of fine particles free in mortar(tailings particle size of 0.1~9.703μm)had an adsorption bridging effect with flocculant polymer chain,and the settlement effect was not good at this time.As the unit consumption increasing gradually,there were enough flocculant polymer chain to produce adsorption bridging effect with free fine particles tailings,and to accelerate the surface settlement by catching the coarse particles(tailings particle size larger than 36.851μm)that can’t produce adsorption with the polymer chains.When the unit consumption increased to a certain amount,the flocculant polymer chain had an impact on the particles(tailings particle size of 9.703~36.851μm)with poor adsorption effect.