水质硬度对煤和蒙脱石颗粒分散行为的影响

Effects of Water Hardness on the Dispersion of Fine Coal and Montmorillonite

根据扩展的DLVO(derjaguin-landau-verwey-overbeek)理论,计算了两种水质硬度条件下煤和蒙脱石颗粒之间的相互作用势能,分析了硬度对颗粒分散行为的影响,并在沉降试验的基础上分析了颗粒之间的凝聚模式.结果表明:当水质硬度由1.0 mmol/L增至10.0 mmol/L时,煤颗粒之间总作用势能由正变负,颗粒之间发生凝聚;蒙脱石颗粒之间以及蒙脱石和煤颗粒之间总作用势能,在此硬度范围内始终为正值,因此,颗粒之间不凝聚而始终处于分散态.凝聚沉降试验证实了随着硬度提高,煤颗粒之间由分散态转化为凝聚态,凝聚颗粒离散沉降;蒙脱石颗粒之间在此硬度范围内形成网架结构整体压缩沉降;当水中同时含蒙脱石和煤颗粒时,煤颗粒被包裹在网架结构中呈整体压缩沉降.

The interaction energies between coal and montmorillonite particles were calculated using extended DLVO （derjaguin-landau-verwey-overbeek） theory and the coagulation mechanisms were analyzed based on settling experiments for coal-montmorillonite suspensions under the different conditions of water hardness. The results show that when water hardness increases from 1.0 mmol/L to 10.0 mmol/L, the total potential energy value between coal particles changes from positive to negative which causes particles coagulating, while the total potential energy values between montmorillonite particles and montmorillonite and coal particles are negative all the while, so no coagulation occurs. A flocculent structure is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the structure in the water hardness range. Coal and montmorillonite particles settle down entirely.