稳态浓密机全尾砂脱水规律物理模拟

Physical simulation of dewaterability law of unclassified tailings in steady state thickener

结合沉降和压滤实验研究浓密机内全压力范围下尾砂脱水性能,考察网状结构形成体积分数、压缩屈服应力、干涉沉降系数等参数的变化规律。结果表明:网状结构形成体积分数随絮凝剂单耗增加先升高后降低,单耗20 g/t时网状结构形成体积分数达到最大值;压缩屈服应力随体积分数变化呈幂和指数增长,在低压力区域,絮凝剂单耗对底流体积分数影响较大,在高压力区域,絮凝剂作用逐渐弱化;干涉沉降系数随体积分数变化呈幂增长,在低压力区域,絮凝剂单耗对料浆渗透性影响较大,单耗80 g/t时渗透性良好,在高压力区域,絮凝剂单耗对料浆渗透性影响逐渐弱化。实验范围内,膏体料浆存在脱水拐点,其体积分数为38%～42%。

The dewaterability of tailings was investigated under the condition of all pressure zone in thickener by combining settling and filtration experiments. The dewatering parameters, such as gel point, compressive yield stress and hindered settling function, were statistically calculated. The results indicate that the gel point increases firstly and then decreases with flocculant dosage increasing, the maximum value of gel point is obtained at dosage of 20g/t. The compressive yield stress increases combining power function and exponential function with the concentration. The flocculant dosage has a big effect on concentration at the low pressure zone relatively, and the effect decreases gradually at the high pressure zone. The hindered settling function grows with a power function of concentration. The flocculant dosage has a big effect on concentration at the low pressure zone relatively with obtaining the optimum permeability at the flocculant dosage of 80g/t, and decreases gradually at the high pressure zone. An obvious turning point of volume fraction being from 38% to 42% is observed in the experiments.