Correlations between segregation intensity and material properties such as particle sizes and adhesions and novel methods for assessment
Correlations between segregation intensity and material properties such as particle sizes and adhesions and novel methods for assessment
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DOI：
10.1016/j.powtec.2021.04.023
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发表时间：
2021-04-18
影响因子：
5.2
通讯作者：
Bradley, Michael S. A.
中科院分区：
文献类型：
--
作者：
Deng, Tong;Garg, Vivek;Bradley, Michael S. A.
在大多数粉末工业中，当粉末的均匀性是一个问题时，粉末分离的评估是必不可少的。本研究的重点是探索大粒径范围粉末的偏析可能性与一些常见的材料性能（如粒度、粒度比和附着力）之间的相关性，从而开发一种基于材料性能评估粉末偏析强度的简单方法，尽管目前的研究仅针对表面轧制偏析。在本研究中，根据不同的粒径范围和颗粒粘结力选择了不同牌号的碳酸钙共混物。样品的偏析是通过测量偏析指数来确定的。偏析指数定义为表面偏析仪上下两段偏析样品的细粒浓度变化与平均浓度的比值。在进行偏析试验之前，先测量了混合样品的粒度分布，然后对相同的共混物进行了偏析试验。使用Wolfson中心开发的机械表面能测试仪，还通过测量“键数”来检测和表示原始混合物的粉末附着力。实验结果表明，偏析指数与材料的粒度、粒度比、键数等性能之间存在一定的相关性，并符合多个经验函数。随着相关性的确定，开发了评估表面偏析的新方法；一种方法只考虑颗粒大小，另一种方法同时考虑由键数确定的颗粒大小和颗粒附着力。(c) 2021 Elsevier B.V.版权所有
Assessment of powder segregation is essential in most powder-based industries when homogeneity of the powder is a concern. This study focuses on exploring correlations between segregation possibilities of the powders with a wide size range and some common material properties such as particle size, size ratio and adhesion, so that a simple method for assessing segregation intensity of a powder just based on the material properties can be developed, although the current study is designed for surface rolling segregation only.In this study, eight blends were made from different grades of calcium carbonate, which were selected based on different particle size ranges and particle adhesions. Segregation of a sample was determined by measuring segregation index, which was defined as a ratio of fines concentration change between segregated samples at the top and bottom sections of a surface segregation tester and the averaged concentration. Particle size distributions of the blended samples were measured before segregation tests and then the segregation tests were completed for the same blends. Powder adhesion of the virgin blends was also examined and represented by measuring the "bond number" using a mechanical surface energy tester developed at the Wolfson Centre.The experimental results showed correlations between the segregation index and the material properties such as particle size, size ratio and bond numbers, and was fitted to multiple empirical functions. With the correlations determined, novel methods for assessing surface segregation have been developed; one method considers just the particle sizes and the other one considers both particle sizes and particle adhesion identified by the bond number. (c) 2021 Elsevier B.V. All rights reserved.