Role of reduced diameter disks in the performance of an IsaMill™

Abstract

IsaMill™ is utilized mainly for ultrafine grinding of low-grade ores. Although highly efficient, it has certain operational challenges, such as frequent replacement of liners of disks and inner shells. To circumvent this challenge, a design modification of the disks, by introducing a reduced diameter disk (RDD), is commonly implemented. A discrete element method (DEM) based model is developed to investigate the effects of RDD and mill loading on media dynamics, force distribution, power draw, and collision energy. It is demonstrated that implementation of RDD results in a reduction of normal and shear stress on mill parts indicating a reduction in wear. Analysis of media dynamics shows that media mobility decreases hence decreasing total collision energy when RDDs are applied. This reduced mobility can potentially affect the grinding performance of the mill. A single-objective optimization approach based on collision energy data is employed to determine an optimal design configuration of the mill.

Keywords:

• IsaMill™
• stirred media mill
• fine grinding
• discrete element method
• reduced diameter disk

Acknowledgments

The authors acknowledge and appreciate the encouragement and support of Mr. K. Ananth Krishnan, CTO, and Dr. Gautam Shroff, Head of TCS Research, Tata Consultancy Services (TCS) for pursuing this research, and for the permission to publish this work.