氯化钠强化煤泥浮选过程的机理探讨

Exploration of the mechanism of flotation process intensification with the use of chloride

煤泥浮选是选煤厂提质增效的重要环节,以无机盐离子为基本要素的溶液化学环境对煤泥.浮选过程具有重要影响。文章以溶液体系中常见的无机盐一NaCl为调控因素,研究了NaCl对无烟煤煤泥浮选过程的影响。采用气泡尺寸检测、气泡破裂时间检测、聚焦光束反射测量等技术手段研究了NaCl对浮选体系气泡尺寸和颗粒聚集行为的影响。结果表明:NaCl可以显著降低气-液两相体系的气泡尺寸,0.4mol/L的NaCl对气泡尺寸的降低作用与9 mg/L的仲辛醇相当;NaCl促进了矿浆体系中的颗粒聚集,0.6mol/L NaCl溶液的加入使矿浆中颗粒的平均弦长由28.5μm增大至40μm;NaCl对气泡尺寸和颗粒聚集行为的调控作用对煤泥浮选过程具有显著的促进作用,在氯化钠浓度为0.6 mol/L条件下,浮选精煤可燃体回收率可从26.32%提高至74.04%.

Fine coal flotation is an important process link of coal preparation plant for upgrading of coal product and improvement of coal cleaning efficiency.It is found that the chemical environment of the solution with inorganic salt ions as basic element exerts an important impact on fine coal flotation process.The following effects produced by conditioner NaCl,an ordinary inorganic salt in solution system,are investigated:effect of NaCl on fine anthracite coal flotation process,and the effect of NaCl on bubble size and aggregation behavior of particles in flotation system as revealed by measurements of bubble size and break-up time with technical means and FMRM Particle Track G400.Study results show that the use of NaCl can lead to noticeable reduction of the size of the bubble of vapor-liquid phase,and the use of the NaCl with a concentration of0.4 mol/L can produce a result comparable to that of using 9 mg/L octanol;addition of NaCl can help promote the aggregation of particles in pulp system,and the average chord length of particles is seen to be increased from 28.5μm to 40μm after the addition of the 0.6 mol/L NaCl solution;the conditioning effect on bubble size and aggregation behavior of particles produced by NaCl plays a significant role in enhancement of fine coal flotation process;and in the case of adding a NaCl solution with a concentration of 0.6 mol/L,the recovery of combustible matter in flotation concentrate can be increased to 74.04%|.