基于激光粒度分析仪的硅灰粒度检测条件研究

摘要

以中位径(D50)为评价指标,采用激光粒度分析仪(LSA)研究了硅灰溶液质量浓度、超声分散时间、超声分散频率、分散介质以及激光粒度分析仪测试精度对硅灰粒度检测结果的影响,并对比研究了激光粒度分析仪与气体吸附BET法测得的硅灰比表面积的相关性.结果表明:高精度激光粒度分析仪(测试范围0.02～2 000.00 μm)适用于硅灰粒度分布的检测,且具有高度重复性.与乙醇相比,水对硅灰具有更好的分散效果,适宜作为硅灰粒度检测的分散介质.以水为分散介质的硅灰最佳检测质量浓度为5～15 g/L.对硅灰溶液超声分散的频率应≥40 kHz,最佳分散时间应在10 min以上.激光粒度分析仪与气体吸附BET法测得的硅灰比表面积具有一定的相关性,但激光粒度分析仪测得的硅灰比表面积较气体吸附BET法测得的小.%The effects of mass concentration of silica fume solution,ultrasonic dispersing time,ultrasonic dispersing frequency,dispersing medium and test precision of laser particle size analyzer(LSA) on particle size measurement of silica fume were investigated using median particle diameters(D50) as evaluation indicator.The correlation of specific surface area of silica fume measured by laser particle size analyzer and gas adsorption using the BET method was studied.The results indicate that the laser particle size analyzer with high accuracy(test range 0.02-2 000.00μm) is applicable to particle size measurement of silica fume and it has high degree of reproducibility.The dispersion effect of water is better than that of alcohol.When the mass concentration of silica fume solution is 5-15 g/L using water as dispersing medium,the ultrasonic dispersing frequency is higher than 40 kHz and the ultrasonic dispersing time is longer than 10min,the optimum dispersion effect of silica fume can be achieved.There are some correlation between silica fume specific surface area measured by laser particle size analyzer and that by gas adsorption using the BET method,but the former is smaller than the latter.