800xA APC for grinding and flotation optimization in minerals processing

Advanced process control (APC) using straightforward design and deployment of model predictive control (MPC) with System 800xA DCS enables higher level of automation and optimization of grinding circuit and separation of valuable minerals from waste

In a typical grinding circuit at, for example, a copper mine, the ore is introduced in the mills where abrasion, attrition and impact reduce its size. Usually, the grinding circuit contains at least two interconnected mills with material classifiers (eg,cyclones) separating the fine material from the coarse (that then goes for regrinding).

The process is very energy intensive with power consumption of roughly 20 to 30 MW and feed throughputs of 2,500 to 3,000 t/hr. Process variables are mill loads, motor torque and power, plus pressures and flow rates. The ground product is specified in terms of fineness range.

The typical results of an APC controller are increased throughput, homogeneous product quality and lower maintenance costs.

Further, APC can be advantageously deployed in the flotation plant, where the ground ore, now in slurry form, is “washed” to separate valuable minerals from waste. The goal is maximum production or maximum yield at a given concentrate quality.

APC performs timely adjustments to froth levels, air flows and reagents leading to process stabilization and increased recovery.