(1. 北京科技大学 土木与资源工程学院,北京 100083;
2. 河南理工大学 土木与环境工程学院,焦作 454150;
3. 昆明理工大学 国土资源工程学院,昆明 650093)
摘 要: 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%。
关键字: 稳态浓密机;脱水性能;压缩屈服应力;干涉沉降系数
(1. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Civil and Environment Engineering, Henan Polytechnic University, Jiaozuo 454150, China;
3.Faculty of Land Resources Engineering , Kunming University of Science and Technology, Kunming 650093, China)
Abstract: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.
Key words: steady state thickener; dewaterability; compressive yield stress; hindered settling function