钢渣超微粉的粒度分布分析研究

超微粉化是实现钢渣高效利用的重要途径,粒度分布是超微粉的关键性质之一。采用激光粒度分析仪(LSA)考察了分散介质、固体质量浓度、超声分散时间以及搅拌速度对钢渣超微粉的粒度分布(用D_(10)、D_(50)和D_(90)表示,D_(10)、D_(50)和D_(90)分别是样品分布曲线中累积分布为10%、50%、90%时的等效直径)的影响。使用扫描电子显微镜(SEM)观察并计算钢渣超微粉粒度分布,将其结果与LSA测定结果对比验证。结果表明,使用激光粒度分析仪测试钢渣超微粉浓度时,无水乙醇为适宜的分散介质;固体质量浓度在0.10~0.90mg/mL范围时,随质量浓度增加,样品粒度测量结果变小,质量浓度为0.01~0.10mg/mL时,测量的D_(10)、D_(50)和D_(90)变化不大,因此适宜的测量浓度为0.01~0.10mg/mL;超声分散时间应大于30min;搅拌速度对钢渣超微粉粒度测试结果无明显影响。另外,激光粒度分析仪8次测试结果具有高度重复性,其结果与扫描电子显微镜所测粒度分布结果相一致。

Study on particle size distribution analysis of steel slag ultra-fine powder

The ultra-fine powder(UFP) is an important approach to realize high-efficiency utilization of steel slag. The particle size distribution is one of the key properties of UFP. Steel slag UFP particle size distribution (represented by D₁₀, D₅₀ and D₉₀, which meant the equivalent diameter when the cumulative distribution in sample distribution curve was 10%, 50% and 90%, respectively) were measured by the laser particle size analyzer (LSA), and some influence factors of operating conditions were discussed, including dispersing mediums, solid mass concentration, ultrasonic dispersing time and stirring rate. The particle size distribution of UFP was observed and calculated by scanning electron microscope (SEM), and the found results were compared and verified with those obtained by LSA measurement. The results showed that the proper dispersing medium for concentration measurement of UFP by LSA was anhydrous ethanol. The measurement results of sample particle size decreased with the increase of solid mass concentration in range of 0.10-0.90 mg/mL. The change of D₁₀, D₅₀ and D₉₀ was little when the mass concentration was in range of 0.01-0.10 mg/mL. The proper mass concentration for measurement was 0.01-0.10 mg/mL. The ultrasonic dispersing time should be more than 30 min. The stirring rate had no significant influence on the particle size measurement results of UFP. In addition, the results in eight measurements by LSA had high repeatability. The analysis results were consistent with the particle size distribution analyzed by SEM.