Monitoring of M10000 IsaMill process performance by passive acoustic emissions.

A passive acoustic emission monitoring system is described which has been tested on two M10000 IsaMills. The analyser detects acoustic emission stress waves generated by grinding media impacts with the mill liner, and locally propagating stress waves can be detected on the exterior lining surface using mounted broadband accelerometers. A six-month field trial showed large variations in acoustic emission power signature with process conditions. Analysis of the enveloped acoustic emission power output showed a strong correlation with mill process conditions, in particular grinding media relative loading, feed pulp density, feed volumetric flow rate and feed type. Accelerometers placed along the length of the mill body provided information on the relative deportment of the grinding media. The enveloped acoustic emission power detected by the mill body, discharge pipe and bearing housing sensors all captured information which was strongly correlated with mill operating parameters and process state.
A passive acoustic emission monitoring system is described which has been tested on two M10000 IsaMills. The analyser detects acoustic emission stress waves generated by grinding media impacts with the mill liner, and locally propagating stress waves can be detected on the exterior lining surface using mounted broadband accelerometers. A six-month field trial showed large variations in acoustic emission power signature with process conditions. Analysis of the enveloped acoustic emission power output showed a strong correlation with mill process conditions, in particular grinding media relative loading, feed pulp density, feed volumetric flow rate and feed type. Accelerometers placed along the length of the mill body provided information on the relative deportment of the grinding media. The enveloped acoustic emission power detected by the mill body, discharge pipe and bearing housing sensors all captured information which was strongly correlated with mill operating parameters and process state.