Beyond the Burn
Smelter operations sit at the heart of metal production — the pivot point where raw concentrate becomes metal. Yet, running a smelter is anything but straightforward. From balancing feed variability to managing increasingly tight emissions targets, operational leaders and metallurgists are grappling with a wide range of challenges that can affect safety, throughput, and cost-efficiency. While commodity-specific issues exist, many smelter challenges are shared across base metals (such as copper, nickel, lead, and zinc) and rare earth operations. And in the current climate, where margins are squeezed, data is growing faster than teams can act on it, and environmental regulations continue to evolve, these headaches are only intensifying.
This guide outlines the top ten smelter challenges impacting today’s mining value chain . For each one, we’ve broken down why it matters, what helps in addressing it, and how Mipac supports clients in overcoming these issues through technology, engineering, and a deep understanding of the process.
1. Feed Variability and Blend Management
Why it matters
Smelters are designed to operate within a band of feed composition, but in reality, concentrate supply can vary wildly in terms of mineralogy, moisture content, and impurity levels. Feed variability, particularly with copper, can cause unstable furnace operation, affect recovery rates, and increase the risk of slag foaming or accretion.
What helps
Automated blending systems and real-time feed material characterisation allow smelters to adapt their process conditions dynamically. A strong link between mine/stockpile and mill data, feed QA systems, and predictive analytics can stabilise operations even with variable concentrate quality.
Our solution
Mipac has supported clients with implementing PI System infrastructure, such as in the Kansanshi Smelter project, to enable real-time tracking of feed composition and its impacts downstream. Our control strategies help sites adjust furnace parameters in response to feed changes, optimising throughput and maintaining product quality.
2. Slag Management and Recovery Losses
Why it matters
Slag is a necessary by-product of smelting, but it also represents a significant source of metal loss. Poor slag chemistry, incomplete reaction times, or excessive temperature swings can trap valuable metals in slag, reducing recovery and affecting downstream refining stages. For copper and nickel smelters, efficient slag tapping and metal-slag separation are critical to maximising yield.
What helps
Real-time slag composition and tapping frequency monitoring, coupled with advanced control systems, allows operators to fine-tune furnace conditions. Predictive tools can also forecast slag build-up and help maintain optimal operating windows.
Our solution
Mipac engineers work with smelters to configure custom process control solutions that improve furnace stability and reduce metal losses to slag. Our solutions integrate data from gas analysers, thermocouples, and tapping schedules to help operations teams proactively manage slag recovery.
3. Furnace Stability and Accretion Control
Why it matters
Furnace instability—driven by feed changes, oxygen enrichment levels, or operational upsets—can cause dangerous accretion build-up. Accretions not only reduce furnace volume but also increase the risk of damage to refractory linings, unscheduled shutdowns, and catastrophic failures.
What helps
Tightly integrated monitoring and control of oxygen injection, feed rate, and bath temperature are key. Operators benefit from visibility into furnace health indicators such as acoustic sensors and heat flux data.
Our solution
At sites like Kansanshi or Mt Isa Mines, Mipac has helped smelter teams build data-driven dashboards and alerts that pre-empt furnace instability. Our engineers also support instrumentation audits and upgrades to improve the fidelity of input data used in control logic.
4. Refractory Wear and Campaign Planning
Why it matters
The refractory lining of a smelting furnace is both a protective barrier and a costly operational expense. Once degraded, it poses a safety risk and necessitates furnace relines, leading to weeks of downtime. Poor campaign planning or misalignment between process conditions and refractory design can significantly shorten service life.
What helps
Thermal monitoring, erosion pattern tracking, and proper alignment between operating parameters and lining material help extend furnace campaigns. Scheduled maintenance, informed by predictive wear models, reduces the risk of unplanned outages.
Our solution
Mipac helps clients use historical process and temperature data to develop heatmaps of refractory wear. By combining this with visual inspection data, we support better maintenance scheduling and can optimise furnace campaigns for both safety and uptime.
5. Emissions Control and Energy Efficiency
Why it matters
Modern smelter operations face a dual challenge: reducing emissions while managing their carbon footprint. Whether it’s SO₂ capture, NOₓ reduction, or managing off-gas systems, failure to comply with environmental thresholds can lead to fines, permit issues, and reputational damage. Meanwhile, energy inefficiencies directly impact OPEX.
What helps
Improved gas capture systems, advanced combustion efficiency monitoring, and better plant and emissions data integration can drive real improvements. Smelters benefit from digital twins and real-time energy performance indicators.
Our solution
Mipac engineers design and tune control loops that optimise oxygen enrichment and combustion for efficient furnace operation. Our work with PI Vision dashboards helps plant operators monitor SO₂ and energy metrics in real-time, making it easier to meet compliance targets while reducing energy use.
Read more about how we...
Enhanced the operational stablility at a North American smelter operation
6. Converter and Anode Furnace Alignment (Copper)
Why it matters
Inefficiencies in the flow of copper from furnace to converters and anode furnaces can cause bottlenecks , metal losses, and inconsistent product quality. These issues can stem from batch timing, material transfer lags, or poor communication between teams.
What helps
Integrated control systems and synchronised batch sequencing allow smoother transitions and improved process stability. Detailed tracking of metal chemistry throughout the process ensures quality consistency.
Our solution
We’ve helped clients use AVEVA PI AF (Asset Framework) to model end-to-end smelter flows and optimise batch transitions. By connecting data from primary smelting to subsequent smelting stages, Mipac improves the coordination between smelting stages, reducing reprocessing and increasing throughput.
7. Instrumentation Reliability and Calibration
Why it matters
Instrumentation in smelters is exposed to extreme temperatures, corrosive gases, and high levels of dust — a brutal environment that can quickly compromise accuracy. Faulty readings from thermocouples, pressure sensors or flow meters can cascade into poor control decisions, affecting product quality and furnace safety.
What helps
A proactive calibration schedule, backed by robust instrumentation audits, helps ensure sensors are accurate and resilient. Smelters also benefit from ruggedised instruments and diagnostics that flag issues before failure.
Our solution
Across several sites, Mipac engineers have undertaken partial to full instrumentation audits, identifying high-risk areas and recommending replacements and recalibration plans. We bring this same expertise to smelters, helping them reduce instrumentation drift and improve control reliability.
8. Operator Knowledge Gaps and Interface Complexity
Why it matters
Smelter operations are complex systems, and operator experience is critical to interpreting alarms, understanding process behaviours, and making timely interventions. However, turnover, training gaps, and overly complex control interfaces can leave even good operators under-equipped to act effectively.
What helps
User-friendly HMI design, alarm rationalisation, and ongoing training programs help bridge knowledge gaps. Tools that turn raw data into actionable insights — like role-based dashboards — also enhance operator confidence.
Our solution
Mipac develops intuitive PI Vision dashboards that present smelter health and key performance indicators in ways tailored to different roles. We also support alarm rationalisation and operator training as part of control system upgrades, reducing error risk and improving plant response time.
9. Downtime from Maintenance and Shutdown Coordination
Why it matters
Scheduled shutdowns are unavoidable in smelting operations, but poor coordination and a lack of system visibility can extend downtime unnecessarily. Equipment may not be ready, task conflicts may arise, or unexpected delays can snowball into significant production losses.
What helps
Digital shutdown management tools, integrated task tracking, and better cross-team communication reduce shutdown duration and cost. Visibility into critical path activities and dependencies is key.
Our solution
Mipac’s TCard software helps smelters manage shutdowns by visually tracking task status and flagging blockers in real time. Our clients use TCard to coordinate teams, allocate resources efficiently, and improve post-shutdown reviews.
10. Regulatory Compliance and Reporting
Why it matters
Environmental, health and safety regulations continue to tighten across all commodities. Copper smelters, in particular, must manage arsenic, lead, and SO₂ emissions to increasingly stringent thresholds. Compliance isn’t just about avoiding fines — it’s also about maintaining a social licence to operate and managing ESG performance expectations.
What helps
Automated reporting systems that compile data from multiple sources — including stack monitoring, process control systems, and lab results — ensure reports are timely, accurate, and audit-ready. Digital traceability and version control also help avoid gaps in record-keeping.
Our solution
Mipac implements integrated data platforms that automate environmental and production reporting. For example, at Kansanshi Smelter, we delivered a PI-AF-based system that aggregates and formats data for regulatory submission, reducing admin workload and improving audit outcomes. Learn more about the project here.
Some final thoughts
Smelting remains one of the mining value chain's most complex, capital-intensive, and finely balanced processes.
The challenges are many — from feed variability to emissions, from furnace wear to data integrity — and they touch every part of the operation. But with the right combination of experience, engineering, and digital tools, these hurdles become manageable. In many cases, they become opportunities for improvement.
Mipac’s decades of smelter experience — across copper, nickel, lead, and other commodities — position us to support you wherever you are on your improvement journey. Whether you need better instrumentation data, tighter control logic, or dashboards that turn raw process data into action, we’re ready to help.
Explore our smelter project case studies and digital solutions here
or contact us today and we’ll put you in a touch with one of our smelter experts.
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