College of Mining Engineering, Taiyuan University of Technology

为了降低浮选精煤滤饼水分、加快成饼速度,选择分子量为700万的非离子型聚丙烯酰胺(PAM)和非离子型表面活性剂(L-64),采用分别添加和混合添加等加药方式,在实验室加压过滤系统进行了脱水试验。通过接触角测量、红外光谱测试、滤液表面张力测量和絮团形态观测的方式研究复合加药强化脱水的机理。结果表明:PAM能加快脱水速度但降水效果一般,L-64能明显降低精煤水分但过滤速度一般;复合添加药剂能有效减少成饼时间和降低滤饼水分,相同药剂添加量的情况下,先加PAM后加L-64更有利于降低滤饼水分,先加L-64后加PAM更有利于减少成饼时间。提出了基于滤饼水分和成饼速度的双目标脱水效率强化水平评价模型,给出了复合药剂的最佳用量。复合加药能提高煤表面的疏水性,降低滤液表面张力,并且形成疏松透气性良好的絮团结构,有利于煤颗粒间毛细水的脱除,具有降低滤饼水分、提高过滤速度的双重功效。

In order to reduce the moisture of flotation concentrate filter cake and accelerate the cake formation speed, non-ionic polyacrylamide (PAM) with molecular weight of 7 million and non-ionic surfactant (L-64) were selected and dewatering tests were carried out in a laboratory pressurized filtration system using dosing methods such as separate addition and mixed addition. The mechanism of enhanced dewatering by compound dosing was investigated by contact angle measurement, infrared spectroscopy, surface tension of the filtrate and floc morphology observation. The results show that, PAM can accelerate the dewatering speed but the effect of water reduction is ordinary, L-64 can obviously reduce the moisture of clean coal but the filtration speed is ordinary; the compound addition of agents can significantly reduce the cake formation time and reduce the moisture of filter cake, under the same amount, adding PAM first and then L-64 is more beneficial to reduce the moisture of filter cake, and adding L-64 first and then PAM is more beneficial to reduce the cake formation time. We also proposed a dual objective dewatering efficiency enhancement level evaluation model based on filter cake moisture and cake formation rate, and gave the optimal dosage of compound agents. The compound dosing can improve the hydrophobicity of coal surface, reduce the surface tension of filtrate, and form a floc structure with good looseness and permeability, which is conducive to the removal of capillary water between coal particles, thus to achieve dual effect of reducing the moisture of filter cake and improving the filtration speed.

1 试验方案
1.1 煤样性质
1.2 表征仪器
1.3 药剂性质
1.4 脱水试验
2 结果与讨论
2.1 高分子絮凝剂强化脱水的效果
2.2 表面活性剂强化脱水的效果
2.3 组合药剂及其添加顺序对脱水的影响
2.3.1 添加顺序对脱水效果的影响
2.3.2 不同药剂用量对脱水的影响
2.4 脱水效率强化水平评价模型
2.4.1 建立模型
2.4.2 数据分析
3 机理研究
3.1 药剂对煤样表面性质的改变
3.1.1 药剂作用后煤样接触角的变化
3.1.2 药剂作用后的煤样表面官能团的变化
3.2 药剂对滤液表面张力的改变
3.3 药剂作用下的絮团影像
3.4 药剂作用下压滤过程中压力曲线的变化
4 结 论

毕海怡, 樊民强, 武晋川, 等.复合药剂强化浮选精煤加压脱水效果研究 [J].煤炭工程, 2024, 56(1):183-190.