In ore-processing plants, the largest source of uncertainty relates to the properties of the ore; plants need to be able to react quickly to any changes. Technology can track material movements and properties all the way from the mine to the processing plant. The software used to deliver this functionality
is able to model the ore movements along the material handling system, including conveyors, silos and conic stockpiles. Ore information can be used by process optimization controllers. They can use forecasts of the ore properties to make predictive adjustments to the grinding and flotation circuit. The result is higher equipment utilization, increased production and lower energy consumption.
A milling circuit is a complex, multi-variable interacting system. Dynamically changing ore conditions and wear parameters pose particular problems for grinding controllers. By integrating data, the automation system optimizes grinding controls, avoiding the need for constant manual tuning. Feed-forward data on ore quality and quantity, rock face production rates or market demand rates can be used to optimize the grinding stage.
Automatic control can lead to significant flotation performance improvement. The controller needs to stabilize the process and to maximize the concentrate production, while guaranteeing a minimum concentrate quality. This pushes the process to an upper limit operating point. To achieve this, optimal set points are automatically chosen by the controller. Online analyzers and blending algorithms reconcile actual feed with quality specifications for better predictability. APC manages blending, grinding and flotation in real-time. Geological models and real-time material tracking provide a short-term feed characteristic schedule to the APC so it can increase performance and quality in real-time.
Underground mine ventilation
In some mines, ventilation accounts for almost 50 percent of energy consumption. Mine vehicles emit diesel exhaust gases that have to be ventilated away. ABB’s automation system knows the whereabouts of each vehicle. And, all vehicle data (including emission levels) is communicated to the system. The ventilation can therefore be continuously optimized for actual need and the air flow can be adjusted at any time. To manage ventilation on demand, a new method for minewide coordinated control of fans and air regulators optimizes energy use by automatically feeding the mine with the required air. The solution relies on feedback from gas, flow or temperature sensors. Multi-variable models describe how changes in the speed of fans affect both the airflow and the pressure across fans. The parameters in the models are obtained empirically from operational data, which makes the model easily adaptable for new conditions. Minimizing energy consumption, while preserving air quality, means energy savings of up to 50% per year.
Dewatering is another problem faced by miners both ancient and modern. Here, again, data integration can be used to great effect to monitor remotely pump condition and performance, maintenance needs, power costs and resource coordination. The energy savings to be made by optimizing pump performance in a mine can be very significant.
With ABB Ability™ Performance Optimization service we identify and tackle the challenges preventing you from operational excellence in a variety of mining processes.
With digital applications from ABB Ability™ MineOptimize portfolio, control engineers can go beyond good process control (keeping the process on setpoint) and think about good process management (keeping the process’s setpoint at a profitable point).