December 1, 2025

Loop Tuning Audits for mineral processing plants

Is plant instability costing you performance?

Plant instability is a silent productivity killer and a cost escalator. Even world-class operators often switch to manual control when loops misbehave: not because they want to, but because they have to.

Every time a loop is left in manual, or a non-optimised loop controls the process, your plant loses efficiency, recovery, and effective energy consumption, and costs increase.

A Loop Tuning Audit is the fastest, most cost-effective way to restore stability, unlock hidden performance, and build trust in automation. If you’re an Operations Superintendent, Metallurgist, or Plant Manager, this is where optimisation starts.

What Is a Loop Tuning Audit?

A Loop Tuning Audit is a structured, expert-led review of your plant’s control loops and strategy. Think of it as a health check for your control system.

During the audit, we:

By fixing the basics, you create a stable foundation for advanced control and digital transformation.

Why your plant needs one

Poorly tuned loops cost more than you think. A Loop Tuning Audit delivers immediate value:

“Every day your loops run in manual mode, or poorly running and suboptimal loops are controlling the process, you lose recovery, energy efficiency, and operator confidence. These losses compound over time.”

Not sure if a Loop Tuning Audit will save you money

Download our Plant Stability Health Check to uncover where instability is hiding in your processing plant

Common pain points solved by a Loop Tuning Audit

Even the best-run plants face recurring control challenges that quietly erode performance. From manual overrides to oscillating valves, these issues aren’t just frustrating. They cost recovery, energy, and operator confidence.

Here are the most common pain points a Loop Tuning Audit can eliminate.

Reliance on manual operation
Operators frequently override loops they don’t trust, reducing automation benefits and increasing variability not only in the circuit controlled by the loop but also in downstream processes.

Shift-to-shift inconsistency
Plant performance changes depending on who’s on duty, leading to unstable recovery and throughput.

Unstable control loops
Oscillations and poor PID tuning can cause increased reagent usage, reduced throughput, and reduced efficiency, leading to operating outside processing parameters.

Accelerated equipment wear
Instability causes valves and instruments to cycle excessively, driving up maintenance costs.

What happens if loops stay in manual mode?

When control loops are left in manual, operators often make large corrective changes only after a deviation is detected; usually too late. In automatic mode, the system makes frequent, small adjustments to keep the process stable. This prevents surges that damage productivity and efficiency.

Manual operation bypasses the automation designed to maintain variables within operating limits. The result is:

Our proven 6-step audit method

We follow a practical, results-driven approach designed to minimise disruption and maximise impact:

Remote Data Review
Analyse historical loop behaviour using metrics like variance of error, time in manual vs auto, and deviation patterns.
On-Site Instrumentation Inspection
Validate signal quality and reliability for problematic loops.
Operator & Team Engagement
Speak with control room operators, maintenance staff, and metallurgists to understand real-world pain points.
Loop Performance Review & Step Testing
Assess loop behaviour, run step tests, and retune PID parameters where necessary.
Disturbance Testing
Verify that newly tuned loops can handle real-world variability and remain stable.
Reporting & Recommendations
Provide a clear report detailing changes made, insights gained, and next steps tailored to your site.

Here are some of the questions we get from decision makers

How long does it take to tune the performance of critical loops?

Typically 2-3 days onsite, depending on plant size and loop count

Do we need downtime?

No. Audits and loop performance reviews require an operating plant.

What’s required for our visiting Mipac engineer?

We’ll need to meet with your operational staff in the office, the control rolm and out in the field. Along with this we’ll also need access to an engineering workstation for PID tuning and the instrumentation involved in the loops being assessed.

When will we see results?

Often immediately for simple tuning issues. Complex problems may need a tailored plan.

Is it expensive?

No. Compared to ongoing losses and costs degrading your profitability, it’s low-cost with fast ROI.

Will it work in our plant?

Yes. Control challenges are universal. We’ve solved them across grinding, flotation, thickening, filtration, leaching neutralisation, tailings circuits and materials handling

How does a loop tuning audit compare to APC?

A loop tuning audit fixes the basics: stabilising PID loops and validating instrumentation, so your control system runs reliably. APC builds on that foundation with advanced algorithms to optimise entire circuits. Without a tuning audit, APC can’t deliver its full potential.

Why a Mipac Loop Tuning Audit delivers measurable value

When control loops misbehave, the cost isn’t just frustration. It’s lost recovery, wasted energy, and reduced throughput. Every day your plant runs in manual mode, these losses compound. Our Loop Tuning Audit is engineered to stop that bleed and unlock hidden performance.

What sets us apart:

Most sites see measurable improvements within days, with little to no downtime.

Grinding, flotation, and tailings circuits are all covered.

We align tuning with your long-term optimisation roadmap, including APC and digital twin projects.

By stabilising loops, we reduce manual interventions and alarm fatigue, empowering your team to trust automation.

“Unlike some tuning checks, our audit combines remote data analytics, onsite validation, and operator engagement to deliver measurable improvements – often within days.”

The cost of inaction

Leaving loops untuned means:

The longer you wait, the more these losses accumulate.

Ready to take control of your plant’s stability?

Step 1: Take the Plant Stability Self-Assessment

Download our free checklist and quickly identify signs of instability in your grinding, flotation, tailings, or other circuits.

Step 2: If your plant shows signs of instability, get in touch

Get in touch and we’ll arrange a call with one of our Loop Tuning experts from Mipac’s Process Optimisation team.

Together, we’ll review your results and outline the fastest way to restore stability and unlock hidden performance.