赵伟 张州朋 周安宁 杨致远 李振

摘 要：通过单组分镜质组和惰质组的模拟电浮选试验方法，研究了电浮选过程中矿浆pH对煤岩显微组分浮沉特征的影响规律。重点考察了矿浆pH变化对浮选回收率的影响，利用微电泳仪、稳定性分析仪、粒子介面特性分析仪及扫描电镜分析了pH变化对煤颗粒体聚集特征及稳定性的影响机制。最后比较了煤岩显微组分电浮选与传统鼓泡浮选的分离效果。结果表明，不同矿浆pH下，镜质组和惰质组浮物累计回收率的变化规律基本一致，但镜质组的浮物回收率显著高于惰质组。矿浆pH的变化改变了溶液中颗粒的表面电性，从而影响了颗粒在溶液体系中的分散性及聚集狀态。当聚团粒径和湿式比表面积增加时，浮物回收率下降。当pH=5时，电浮选分离神府煤时的浮物回收率为55.12%，浮物中镜质组含量为87.57%，镜质组回收率最高为93.36%.相对于传统鼓泡浮选，电浮选分离煤岩显微组分可获得更佳的煤岩显微组分富集率和回收率，通过调控矿浆pH值可有效改善煤岩显微组分的聚集状态及不同组分间的差异性，进而改善其分离效果。关键词：电浮选;煤岩显微组分;矿浆pH;表面性质;稳定性中图分类号：TQ 536

文献标志码：A

文章编号：1672-9315（2020）06-01055-09

DOI：10.13800/j.cnki.xakjdxxb.2020.0616开放科学（资源服务）标识码（OSID）：

Effects of pulp pH on  electroflotation separations of coal macerals

ZHAO Wei1，2，ZHANG Zhou-peng1，ZHOU An-ning1，2，YANG Zhi-yuan1，2，LI Zhen1，2

（1.College of Chemistry and Chemical Engineering，Xian University of Science and Technology，Xian 710054，China;

2.Key Laboratory of Coal Resources Exploration and Comprehensive Utilization，Ministry of Natural Resources，Xian 710021，China）

Abstract：The simulated electroflotation experiments of purified vitrinite and inertinite were implemented in this paper to explore the effects of solution pH on the flotation characteristics of coal macerals during the process of electroflotation.The effects of pH on flotation recovery were investigated.Microelectrophoresis instrument，stability analyzer，particle interface characteristic analyzer and scanning electron microscope were used to investigate the influence of pH change on the aggregation characteristics and stability of macerals.A comparison of the seperated effects of macerals was finally conducted between electricflotation and traditional bubbling flotation.Findings are as following：Changes in the cumulative recovery rate of floats at different pH are basically the same in vitrinite and inertinite but recovery rate of floats in vitrinite is significantly higher than that in inertinite.pH makes changes to particles in solution system in terms of adjusting their surface electrical properties and the state of dispersion and aggregation，thus changing the stability and settling characteristics of the slurry system.The recovery rate of floats decreases when the agglomeration particle size and wet surface area increase.When the pH is 5 in electroflotation，the recovery rate of floats is 55.12%，the floats in vitrinite account for 87.57%，and the highest recovery rate is 93.36% in vitrinite.With a higher selectivity for coal macerals，electroflotation is better than the traditional bubbling flotation in the rate of enrichment and recovery.By adjusting the pH of the solution，the aggregation state of macerals and the differences between macerals can be effectively improved，thereby improving the separation effects.

Key words：electroflotation;coal macerals;pulp pH;surface property;stability

0 引 言

我国低阶烟煤资源储量丰富，但惰质组分含量普遍较高[1-2]，从煤化工原料精细化供给角度出发，通过高效分选以获得相对富集的煤岩单组分，进而实现不同煤组分的分级分质转化和高附加值利用是煤清洁转化利用的一个重要途径[3-4]。……