MillStar

Product Overview

Distributed by Molycop, Mintek’s MillStar Smart Process Control System is a sophisticated, real-time optimisation and control solution designed to enhance the performance of milling operations in mineral processing. Using advanced algorithms and predictive models, MillStar improves throughput and energy consumption, minimises variability in product quality, reduces wear on equipment and enhances overall operational reliability. 

Optimise milling operations with MillStar

Due to the complex nature of milling circuits, conventional control often fails to address common problems. Among these are: 

• long process response times 
• multivariable interactions and disturbances 
• non-linear systems with varying dynamics 
• constraints on variables 
• lack of reliable process measurements. 

The MillStar Smart Process Control System enables a typical payback period of just a few months. MillStar provides a robust control solution that enables mill operators to:

• stabilise the mill feed
• control product quality to the downstream processes
• optimise throughput and grinding efficiency.

Milling is a highly interactive dynamic system that changes constantly. With MillStar Model Based Control, mineral processing operations can predict future behaviour and stabilise their circuit.

Milling feed control

The smooth operation of a milling circuit is difficult to achieve due to the varying nature of the feed material and the unfavourable dynamics between feeders and the weightometer. These dynamics degrade the performance of the PID controller, making feed optimisation more challenging. 

MillStar’s Mill Feed Controller will compensate for the feed dynamic by modelling feeder responses, adapting for any model errors and adjusting the feeder speeds in a desired ratio.

Power optimisation

Productive milling operations often run close to the maximum mill power draw, where the power-load relationship is highly non-linear and varies with changes in ore, steel load and liner conditions. Traditional control and modelling techniques are insufficient in these circumstances. To address this, Molycop offers a Power Optimiser that: 

• continuously ‘seeks’ the optimum mill operation by changing the solids feed or load setpoint
• uses the changes in the mill load and power to automatically detect whether the mill is overloaded or underloaded 
• uses safety controllers to change the solids feed rate and feed water to prevent mill overloads 
• estimates the power load curve and optimum load. 

Mill Discharge Control

The MillStar Sump/Product Stabilisation:

• takes into account multivariable interactions between input and output mill discharge variables 
• controls the sump level and cyclone overflow product size and/or density 
• minimises flow variation to the downstream processes 
• optimises usage or surge capacity of sumps, hoppers and conditioning tanks 
• handles constraints of the sump level (to prevent pump surging and spillage) and cyclone density (to prevent pipeline chokes and pressure variations). 

A Model Predictive Controller (MPC) has been specifically designed for milling circuits, providing the following advantages: 

• Comprehensive multivariable controller can efficiently eliminate interaction between variables.
• Explicitly handles limits on input and output variables to ensure all variables are kept within their allowed operating range.
• Very efficient in handling long time delays and slow-reacting processes.
• Special features to handle noise, integrators and model errors.