Abstract: This paper introduced the evaluation methods of mixing and analyzed the applied range of three common evaluation methods，including coefficient of variation，contact number，and Lacey index. Lacey index is suitable for evaluating radial mixing of particle. This paper also discussed the effects of sampling towards Lacey index under the condition of three-component radial mixing experiments. The results showed that the main reason of the mixing change is the different particle sizes in different samples，resulting in S2 number change. The results revealed the optimum sampling of 6×6 with the side length size of 14 mm，slightly longer than lateral dimensions.

Key words: three-component particles, radial mixing, mixing degree, number of Lacey

摘要： 简介了各种混合度评价方法，对3种较常用混合度评价方法——变异系数、接触数及Lacey指数的应用范围进行了分析，其中Lacey指数适合评价径向颗粒混合。以回转装置内三组元颗粒径向混合实验为背景，讨论取样方式对Lacey指数算法的影响。研究表明：取样方式引起混合度数值变化的根本原因在于不同样本内大小颗粒比例不同，进而引起S2数值发生变化。本文通过分析，获得了最佳取样方式为：样本边长尺寸比颗粒最佳混合时横向尺寸略大，本实验最佳取样为6×6取样方式，即边长尺寸为14 mm。

关键词: 三组元颗粒, 径向颗粒混合, 混合度, Lacey指数