Effect of the Lifting Velocity and Container Shape on Angle of Repose of Iron Ore Particles

Tongqing Li,Yuxing Peng,Zhangfa Yu,Zhencai Zhu,Zixin Yin

doi:10.1155/2017/3405432

Abstract

To investigate the impact of lifting velocity and container shape on angle of repose, the fixed-base cylinder method was performed using three types of container shape. The container shape was lifted a series of lifting velocities. Six size fractions of iron ore particles ranging from coarser to fine particles were used as the test materials. And the sand-pile calibration method was then used to calibrate the contact parameters of iron ore particles. Results show angle of repose decreased exponentially with the lifting velocity, while it appeared approximately to be invariant to particle shape, for all size fractions. The sand pile highly depends on the container shape at a low lifting velocity but appears to be invariant to particle size for a high lifting velocity. And then a predictive equation is established and a very close agreement between the predicted and measured angle of repose is attained. Finally, a series of DEM simulations considering the irregular particle shape are conducted by means of sphere clump method to calibrate the contact parameters and are in good visual agreement with the experimental results, indicating the “tuned” contact parameters as well as the applicability of the predicted equation.

Highlights

Size reduction of minerals by grinding hitherto is a significant step in whole stage of mineral processing in which feeds are reduced in size to liberate impurities and to change the particle size distribution
The results presented above contribute to a better understanding of the impact of lifting velocity and particle size on angle of repose of iron ore particles
Three types of container shape were used to conduct the experiments on six size fractions ranging from coarser particles to fine ones

Summary

Introduction

Size reduction of minerals by grinding hitherto is a significant step in whole stage of mineral processing in which feeds are reduced in size to liberate impurities and to change the particle size distribution. The literature reported that the power estimation of tumbling mills plays an important role in determining the grinding efficiency and mill performance [4, 5]. To this end, establishing power equations of tumbling mill has attracted much attention in recent years. The sand-pile calibration has been employed exclusively in determining the input parameters. The aim of this approach was to make an approximate comparison between angle of repose of experimental results and the one obtained by DEM numerical simulations. The investigation of angle of repose is of importance in studying the performance of tumbling mills

Objectives

Methods

Results

Conclusion