粒级组成对尾砂絮凝沉降性能的影响

采用人工调配尾砂粒级组成进行静态絮凝沉降试验的方法,定量分析了尾砂粒级组成对絮凝沉降性能的影响规律。结果表明,不同粒级尾砂的矿物成分和密度存在差异。由于絮团的“整体效应”和絮凝剂的选择性吸附,随着尾砂组分中+0.15 mm粒级、-0.15+0.074 mm粒级和-0.074+0.037 mm粒级总含量增加,尾砂絮凝沉降速率和尾砂底流浓度均增加,底流浓度增加主要源于合理的尾砂级配使尾砂堆积密度增加。最后分别构建了尾砂沉降速率和底流浓度与各粒级含量的函数关系式,其可用于尾砂絮凝沉降性能的预测。

Effect of Particle Size Distribution on Flocculation and Sedimentation Process of Tailings

With artificially blended tailings samples, the influence of particle size distribution on their flocculation and sedimentation performance was quantitatively analyzed by static flocculation and sedimentation tests. The results show that the mineral composition and density of tailings in varied size ranges are different. Because of the “overall effect” of flocs and the selective adsorption of flocculant, both the settling velocity of flocs and the underflow concentration increase with the increasing of the total content of particles within +0.15 mm, -0.15+0.074 mm and -0.074+0.037 mm ranges in the tailings. The underflow concentration increase may be attributed to an increase in the packing density of tailings owing to the rational graded size range. Eventually, function formulas of settling velocity and the underflow concentration with the contents of varied size ranges were obtained, which can be used for predicting flocculation and sedimentation performance of tailings.