Mining operations are becoming more complex. The decline in mineral grades, strict regulations and today’s economic scenario are demanding mining companies to optimize their operations, processes and use less consumables (from energy to reagents) and be more cost effective.
As an aggravating factor, the retiring workforce combined with the lack of qualified new professionals arriving to industrial sectors has become a major problem. Some studies consider that in a few years, the gap between required workforce and available applicants will be close to 30% in the mining industry.
This unbalance between complex / more demanding operations with the lack of resources is driving the requirement for intelligent / advanced but easy to use optimization / process control tools.
What is advanced process control (APC)
Several of the mineral process control systems still rely on simplistic optimization approaches (PIDs, Loops). According to research from the University of Pretoria, more than 75% of Minerals Processing Plants are still using basic control strategies.
Advanced process control is a software tool that collects information from the process / field (supervision, historians, and control systems) applies the right control strategy (according to the process requirements) to deliver the best set points to the system. APC strategies are also able to work with constraints and resolve conflicting process objectives.
APC reduces operator stress since that APC is able to analyze multiple variable scenarios and reacts quickly against process changes. In addition such tools are a strong ally for young operators (still gaining experience).
APC simultaneously address several challenges of mineral / metal process applications:
- Reduce Variability
- Energy (some studies indicate that 70% of the energy required in the beneficiation & processing of ores is consumed by crushing and grinding)
- Consumables optimization (more complex processes usually consume more chemicals per ore weight)
Areas of applications:
Due to its flexibility, APC can be applied in several mineral processing / metal applications – some examples:
• Grinding Circuits (Grinding circuits optimization is one of the best targets for APC strategies, since it has an inherent low efficiency and a non-linear behavior)
• Refining /Thermal process (Furnaces)
APC is also a control system agnostic, being easily integrated with any PLC, DCS and hybrid control systems.
As any powerful software tool, complexity can limit process / control / operators technology adoption. A modern APC tool must be simple to use and deliver some basic requirements/ features:
- Easy to use
- Little maintenance
- Testing / Simulation
- Reusable tools (other mines, processes)
- Support for generic equations
- Rich graphical interface and visualization tools
- Tablet and touch screen friendly
- Diverse control strategies (Rules, Model Predictive Controls…..)
- Live trends (performance vs. constrains)
This post is only a simple example of how technology tools can address complex mineral process challenges, relieving operators form stressful and demanding tasks and empowering them to focus on core activities.
And you? What is your experience with advanced control? …please, leave your comment, share your experience and suggestions for other topics