TITLE:
Morphology Study of Particle Breakage Mechanisms in a Horizontal Stirred Mill: Automated and Manual Point Counting Approaches
AUTHORS:
Reem Roufail, Bern Klein
KEYWORDS:
Comminution, Morphology, Breakage Mechanism, Stirred Mill, Grinding, Manual Point Counting
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.9 No.5,
September
30,
2021
ABSTRACT: High-speed stirred mills are utilized to grind particles below 10mm. Grinding sulphide minerals to as low as 10mm achieve adequate mineral liberation for successful downstream mineral processing operations, such as flotation and leaching. Particle breakage mechanism such as fracture or abrasion, determines the morphological surface features of the product particles. It is anticipated that particles, which break along grain boundaries (intergranular) produce rough surfaces, whereas particles that break across the grain boundaries (transgranular) possess smoother surfaces. In this study, particles are ground in a stirred mill and their morphological features were analyzed using automated and manual detection methods. Literature and conventional belief are that high-speed stirred mills break particles by attrition. This paper showed that fracture is also an important breakage mechanism along with attrition. Breakage mechanism is a factor of input stress intensity, in the form of the mill agitator speed, and type of mineral. It is observed that at higher agitator speed galena fractures along the grain boundaries, whereas quartz, abrade across the grain boundaries.