铝尾矿泥浆中微米级细颗粒自然沉降规律研究

Study on Natural Settlement Law of Micron Fine Particles in Aluminum Tailing Slime

平果铝厂中铝矿泥浆中小于75μm的微米级细颗粒含量超过90%,研究微米级颗粒粒径组成规律是研究尾矿泥浆颗粒迁移规律的关键点之一。传统土工试验测量中测试小于75μm细颗粒粒径的方法如密度计法、移液管法受人为操作因素影响较大,故拟采用激光粒度仪的动态光散射原理测量,结合深度变化与颗粒特征粒径的相关性规律,分析微米级矿泥颗粒随深度变化的拟合关系。结果表明:矿泥沉降过程中分为3个区域:表层、过渡层及沉降团聚层,随着矿泥颗粒浓度的上升,减少了带负电荷的胶体粒子的生成,使矿泥下部的颗粒迅速团聚,形成团聚层。此结论为进一步研究矿泥颗粒迁移规律提供了一定的理论依据。

The content of micron fine particles smaller than 75μm in the alumina slurry of the Pingguo Aluminum factory is more than 90%.It is one of the key points to study the particle migration law of tailings slurry to study the composition law of micron particle size.Traditional geotechnical test measurement method to test the fine particle size is less than 75μm as the densimeter method,pipette method is greatly influenced by artificial operation factors,therefore,the proposed principle of dynamic light scattering measurement of laser granulometry,combined with the depth change with the characteristics of particles size correlation rule,analysis micron grade the fitting relationship of slime particle with depth change.The results show that slime settling process is divided into three regions:surface layer,transition layer,and sedimentation reunion layer,with the rise of slime particle concentration,the formation of colloidal particles with a negative charge are reduced,which makes the particles in the lower slime quickly agglomerate and form the agglomerate layer.This conclusion provides a theoretical basis for further study on the migration law of slime particles.