On-Line Mill Charge Analysis for Throughput and Liner Life Optimization

摘要

In many cases, grinding mill power draw, bearing pressure and other typically available measurements are not ideal variables for optimal grinding process control. To address the need for a more reliable state indicator and robust control, Outotec has developed a system for analyzing and controlling a grinding mill's volumetric charge. The analysis is based on a sensor that attaches directly to a liner bolt, combining both strain gauges and accelerometers to accurately determine the position and volume of the mill's charge. The system also provides other vital information related to the mill's operation, such as media trajectory estimates and overall vibration levels. To maximize reliability while minimizing the time needed for maintenance and re-mounting of the equipment during relining operations, the system features continuous inductive charging and a quick mounting mechanism that utilizes super-strong magnets and latches. The embedded multivariable mill controller option provides new opportunities for reacting faster to common process disturbances, such as ore hardness and size changes, by adjusting the mill's ore feed, water feed and rotational speed. The combination of a reliable mill state measurement and advanced control helps the whole grinding circuit to achieve maximized throughput, increased availability and less liner damage, all of which can easily be translated to significant economic gains. These benefits are demonstrated by industrial case examples.