聚丙烯酰胺对细粒赤铁矿沉降行为的影响

Effects of Polyacrylamide on Sedimentation Behavior of Fine-grained Hematite

细粒铁精矿在浓缩过滤环节存在沉降速率慢,溢流固体悬浮物浓度高,精矿滤饼含水率高等问题。通过添加絮凝剂产生凝聚、桥连等作用使矿物颗粒形成絮团,可以促进细粒铁精矿沉降。以某赤铁矿精矿为研究对象,阴离子型、阳离子型、非离子型和两性聚丙烯酰胺为絮凝剂,通过沉降试验及赤铁矿表面ζ电位测定来考察聚丙烯酰胺对赤铁矿絮凝沉降行为的影响。结果表明:赤铁矿颗粒与絮凝药剂分子间相互作用方式主要包括静电力、氢键、范德华力、化学吸附等,而ζ电位在这一过程中是否起主要作用以及对这一过程是起促进或者弱化作用主要取决于絮凝剂使用种类、用量和矿浆pH值。试验结果为选择合适絮凝剂更好促进细粒铁精矿沉降提供了理论依据和指导。

Fine grained iron concentrate in concentrated filter link has problems of slow sedimentation rate,large overflow suspended solid value,high concentrate filter cake moisture content and so on. By adding flocculants,the mineral grains floccules based on cohesion and bridging function,which promotes the sedimentation of fine ore grain. A hematite concentrate were as research object,the anionic,cationic,nonionic and amphoteric polyacrylamide as the flocculating agents,through the sedimentation test and Zeta potential measurement to examine the effects of polyacrylamide on flocculation and sedimentation behavior of fine-grained hematite. Test results show that,the interactions between ore grain and flocculation drug molecules include electrostatic force and hydrogen bond,Van Der Waals force,chemical adsorption,and Zeta potential plays a main role in this process or not and promotes or weakens this process which mainly depends on the type,the dosage of flocculants and p H value of the slurry. It provides theoretical basis and guidance for adding flocculants to select appropriate flocculant to promote the settlement of fine iron concentrate.