激光粒度仪法测定HDPE粉末粒度及粒度分布的研究

将HDPE粉末分散在乙醇-水介质中,用激光粒度仪动态测定其粒度及粒度分布。     

粒度测试及激光衍射粒度测试法在涂料工业中的应用

介绍了涂料工业中常用的几种测量粒度及粒度分布的方法及适用范围,并从几个方面阐述了激光衍射粒度测试法作为一种新颖的颗粒粒度测量技术在涂料工业中的应用。     

用激光粒度分析仪检测细粒径SiO2基相变调湿复合材料的粒度分布

以SiO2为载体、棕榈醇-棕榈酸-月桂酸为相变材料,采用溶胶-凝胶法制备细粒径SiO2基相变调湿复合材料,以中位径(d50)为评价指标,采用激光粒度分析仪研究了溶液溶质浓度、超声时间、超声频率及分散介质对材料粒度的影响. 结果表明,激光粒度分析仪可用于检测SiO2基相变调湿复合材料的粒度分布,水对材料的分散效果比乙醇好,以水为分散介质,材料最佳溶质浓度为5~10 g/L,最佳超声时间为15 min以上,最佳超声功率大于400 W.     

激光衍射法测定细微滑石粉粒度的研究

文章研究了分别以焦磷酸钠、六偏磷酸钠、乙醇、乙二醇单丁醚作为分散剂时使用激光粒度仪对细微滑石粉粒度的测定情况,确定了使用乙醇:乙二醇单丁醚=2:1的混合溶剂进行预分散,再加入水中使用激光粒度仪测定粒度的最佳方法。使用该方法测得的细微滑石粉粒度(D90)RSD为0.49%。     

气相流化床聚乙烯颗粒粒径分布的定制

基于气相法聚乙烯流化床反应器颗粒粒径分布的预测[1],提出了颗粒粒径分布定制模型.通过模型的优化计算,可得到催化剂粒径及其分布、操作气速、反应温度、乙烯浓度和丁烯浓度等生产操作参数,由此进行生产可获得具有良好流态化特性的聚乙烯颗粒粒径分布,能为生产具有特定粒径分布的聚乙烯颗粒提供理论指导.模型由工业装置的生产数据分析了计算结果的合理性.最后,以三种粒径分布的聚乙烯颗粒为例讨论了模型的可行性.同时,运用粒子群优化算法求解模型的非线性规划问题,算法具有调整参数少、收敛速度快和全局优化等优点.     

激光颗粒仪测定聚四氟乙烯细粒模压粉的平均粒径

运用激光粒度仪研究了聚四氟乙烯细粒模压粉的平均粒径和粒径分布的测定方法，通过试验确定了分散方法、分散剂用量、试样量、分散时间等影响因素，以建立稳定的测量体系。     

激光粒度仪测定煤油/水乳液粒度分布的实验研究

考察了利用激光粒度仪测定乳液的粒度分布和平均粒径(D4,3)的实验方法和实验条件。采用单因素实验方法重点考察了实验条件(分散剂的浓度和进样量)和仪器参数(超声、搅拌转速和循环流速)对乳液液滴粒径分布的影响,得出测定煤油/水乳液粒度分布的最佳条件为:搅拌转速为750rpm、循环流速为8mL/s、分散剂SDS浓度为0.50×10-2 g/L和进样量为0.50mL,且不超声。     

激光光散射法测定粒度在陶瓷行业中的应用

本文介绍了激光光散射法测量粒度的原理,以及激光粒度分析仪的特点,并探讨了激光光散射法测量粒度在陶瓷生产中的应用。     

马尔文激光粒度仪在载体硅胶生产中的应用

概述了马尔文激光粒度仪湿法测定载体硅胶样品粒径分布的方法。对分散剂、泵速及超声波的选择条件进行了优化,并对重复性进行了测试。结果表明,在马尔文激光粒度仪湿法测定条件下,实验选择二次蒸馏水作为分散剂,2500r／min为最佳泵速,15W／cm^2的超声波强度和10s的超声波开启时间作为最佳超声波条件。该方法容易建立,精密度高,非常适合在生产过程中对载体硅胶粒径分布的测定。     

图像粒度法和激光粒度法在长6油层中粒度检测方法适用性研究

研究碎屑沉积和碎屑岩的粒度大小和各种粒级的分布特征的方法称为粒度分析。粒度分析是判别沉积环境和水动力条件的重要物理标志,而且对碎屑岩系油气储层评价也极为重要[3]。选取适合勘探区域内储层特征的粒度分析方法,方能更好地为油田勘探以及后续的开发生产提供更准确的信息。目前,长庆油田和延长油田在研究＂三低＂储层（低孔、低渗、低产）的物性时,实验室粒度分析主要依靠图像粒度法和激光粒度法。本文以鄂尔多斯盆地坪桥区北部为研究区块,就上述两种检测方法在陕北斜坡中部长6油层中的适应性展开讨论。     

混凝土用硅灰粒度分布参数检测条件的研究

为了准确快速测量混凝土用硅灰的粒度分布,以中位径(D50)和粒度分布曲线为评价指标,采用激光粒度仪系统研究了分散剂种类、分散剂浓度、硅灰在介质中浓度、超声分散时间、分散温度以及超声分散频率对硅灰检测结果的影响.结果表明,激光粒度分析仪适用于硅灰粒度分布的检测,且具有高度重复性.六偏磷酸钠和十二烷基苯磺酸钠对硅灰具有显著的分散效果,六偏磷酸钠作为硅灰分散剂的最佳浓度为0.5～1.1 g/L.未使用分散剂时,硅灰最佳分散条件为5 ～ 15 g/L分散浓度、10 min分散时间、40℃分散温度和40 kHz分散频率;六偏磷酸钠加入后,硅灰最佳分散条件为5 ～30 g/L分散浓度、5 min分散时间、20℃分散温度和32 kHz分散频率.     

Modeling,Simulation, and Experimental Evaluation of Particle Size Distribution in Stabilized Fluidized Bed Adsorption System

Fluidized beds containing solid particles of a wide size distribution is of significant practical importance. In such systems, the overall behavior depends on the opposing effect of mixing and classification. In the present work, the mixing and segregation behavior of liquid fluidized beds containing particles of different sizes is described mathematically. Particle size distribution (PSD) is studied in a glass column of 5 cm internal diameter and 250 cm length. Ion exchange resins were used as a solid phase with a particle size range of 50 to 650 µm. The bed was fluidized at constant and low water flow velocity and the particle size measurement was carried out at different locations over the column length by analytical scanning electron microscope. Particle size fractionation data obtained by Malvern Mastersizer-2000, version 5.4, was utilized in the solution of developed model equations to obtain PSD. It is apparent that the mixing model along with the classification model represents better results than any other model given by various researchers in the literature. The proposed model is in good agreement with the PSD data given by Malvern particle size analyzer.     

A Population Balance Model for Disperse Systems： Particle Size Distribution in Suspension Polymerization

On the basis of population balance a mathematical model is developed to describe the formation of polymer partlcle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and the gel effect are analyzed in particular. Parameters of the models are esthnztted by experimental. on reaction conversion and particle size distributlon. The results show that the model is suitable for predicting polymerization processes.     

声波多尺度分析方法在流化床平均粒径检测上的应用

平均粒径是流化床聚合工艺的重要参数,亟需在环保安全、不侵入流场的条件下,快速准确地检测.流化床声信号与平均粒径相关,可对其进行小波(包)分析,提取尺度和频度特征,构建能量模式,用于粒径判别,其判别能力与尺度相关.可选定适当的尺度,采用特征筛选和Bayes方法建立判别模型,预报性能优良,计算量甚小,适于在线检测.用于聚乙烯实例,效果令人满意.     

污水厂生化尾水深度化学除磷效果优化及其对颗粒态磷粒径分布的影响

后置化学除磷工艺是实现城市污水处理厂出水总磷(TP)达到地表水IV类标准的经济有效方法。选择合适的除磷剂和助凝剂,以及优化运行参数是保证深度除磷的重要因素。选取聚合氯化铝(PAC),聚合硫酸铁(PFS)和聚合硅酸铝铁(PSAF)作为除磷剂,磁粉和聚丙烯酰胺(PAM)作为助凝剂,利用实际污水处理厂二沉池出水,在不同组合方式和投加量条件下,分析出水中溶解态TP(DTP)和颗粒态TP(PTP)浓度特征,采用正交试验优化深度化学除磷工艺。结果表明,单独采用除磷剂时,PFS对TP去除效果优于PSAF和PAC,投加量为40 mg/L时即可满足出水TP含量小于0.3 mg/L的要求。以PSAF为除磷剂时,PAM和磁粉为助凝剂可以促进除磷剂PSAF对TP的去除效果,减少除磷剂的使用。通过对化学除磷工艺出水的颗粒物粒径分析,发现微粒径的PTP是高标准出水中TP的主要存在形态,优化后置化学除磷条件形成较大TP颗粒粒径,以促进微粒径PTP的重力分离或采用过滤截留分离含磷微絮体是实现深度除磷的技术关键。     

Effect of process water chemistry and particulate mineralogy on model oilsands separation using a warm slurry extraction process simulation

Variability in ore composition and process parameters is known to affect bitumen recovery from natural oilsands. In this work, we extend our earlier investigations with model oilsands systems (MOS) to determine the effects of calcium, magnesium and bicarbonate ion concentrations in the process water and their interactions with ‘active’ solids such as: kaolinite, montmorillonite and ultra-fine silica. Our results demonstrate that solids mineralogy and decreasing particle size produce negative outcomes on bitumen recovery related to concomitant effects on bitumen droplet size during flotation. In some cases, certain process water chemistries were found to restore recovery, but clay concentration was the key factor.Naturally acidic oilsands are known to give poor bitumen recoveries. An MOS prepared with connate water at pH 2 responded in the same way. Comparison with a typical oilsands showed no significant differences in middlings pH and the large, negative effect on bitumen recovery was not reversed by higher caustic loading during separation. This result may be caused by irreversible co-flocculation of bitumen and mineral particles during preparation of the MOS and may reflect similar behavior in comparable natural samples.