粗糙石英纳米孔隙甲烷流动分子模拟

为研究纳米孔隙中的气体流动特征,采用蒙特卡洛和分子动力学模拟方法研究石英纳米孔隙中的甲烷赋存与流动特征,分析纳米孔隙大小、孔隙压力、孔隙压力梯度及孔隙表面粗糙度对气体吸附和流动的影响。结果表明:可以用修正滑脱的泊肃叶方程描述石英纳米孔隙中的甲烷流动;纳米孔隙中的尺寸效应使气体的物性变化偏离体相特征;较高压力下,孔隙中的吸附气和自由气密度较高,气体分子间相互作用强,不利于气体的流动;粗糙孔壁吸附位点减少降低吸附性能,孔隙表面粗糙单元降低甲烷流动的有效孔径,与甲烷的相互作用增强,流动阻力增大,阻碍气体的流动。该结果对页岩气产能评价及提高气体采收率具有指导意义。

微灌石英砂颗粒表面滞纳能力计算与分析

微灌砂颗粒的滞纳能力,直接影响到砂滤层过滤性能,从而对滤层过滤效果产生重要影响,分析石英砂颗粒表面对过滤水中杂质颗粒的滞纳能力十分重要。选取3种微灌石英砂滤料的砂颗粒(粒径范围为1.00~1.18、1.18~1.40和1.40~1.70 mm)作为样本,采用三维表面形貌仪对砂颗粒表面轮廓最大高度和与轮廓最大高度对应的波纹宽度进行测量。对砂颗粒滞纳水中杂质颗粒的机理进行分析,建立了砂颗粒表面轮廓的几何模型和砂颗粒表面杂质颗粒受力的数学模型,并计算了砂颗粒对水中杂质颗粒的滞纳能力。适当增加砂滤料的粒径,可以提高砂滤层过滤性能的稳定性。

Influence of surface roughness on flotation kinetics of quartz

Surface roughness of quartz particles was determined by measuring the specific surface area of particles.The wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation cell.Experimental results show that the rod mill product has higher roughness than the ball mill product.For the particles with larger surface roughness,the flotation kinetics constant is also higher.Finally,empirical relationships between surface roughness(r) and the flotation kinetics constant(k) of quartz particles as k=A+Br+Cr0.5lnr+D/lnr+E/r and k=A+Br are presented,in which A,B,C,D and E are constants related to experimental conditions and mineralogical properties of mineral.