ABB stabilizes power supply at Manganese Metal Company refinery

Manganese Metal Company (MMC) operates its refinery in Mbombela, Mpumalanga, South Africa. The plant is the world’s only non-China-based producer of high-grade electrolytic manganese metal (EMM) and the largest global refinery of 99.9% selenium-free EMM. Approximately 95% of its output is exported to more than 120 customers in 20 countries, supplying sectors including lithium-ion battery manufacturing, alloying, welding and electronics.

Given the continuous and energy-intensive nature of electrolytic manganese production, stable and reliable power supply is essential to maintaining product quality and competitiveness.

Power instability and aging equipment challenges
MMC faced operational disruptions due to power fluctuations from the electrical grid, which placed strain on aging transformer and rectifier systems. Older rectifier technology was prone to trips during adverse weather conditions and grid disturbances, leading to unplanned outages.

Because manganese electrolysis requires continuous operation, downtime directly affects production output and market commitments. The plant required a solution capable of mitigating grid instability without interrupting ongoing operations.

Deploying high-performance rectifier control
To address these issues, ABB implemented its AC 800PEC high-performance controller in combination with six high-power MCR1000 rectifier units.

The AC 800PEC controller is designed for demanding power conversion and rectifier applications, offering rapid and precise response to voltage and current fluctuations. Fast control loops with cycle times down to 100 microseconds enable stable regulation under dynamic grid conditions.

Coupling the advanced controller with high-power rectifier technology enhanced system robustness and ensured consistent DC power supply for the electrolysis process.

Reducing outages and improving operational predictability
Following the upgrade, MMC reported a significant reduction in unplanned outages linked to grid instability. The improved control response has stabilized power delivery to the electrolytic cells, reducing trips and protecting critical equipment from stress.

The modernization has improved predictability in production planning and strengthened the plant’s ability to operate continuously despite challenging grid conditions in South Africa.

Supporting long-term competitiveness
For MMC, the deployment establishes a more resilient electrical infrastructure aligned with its role as a key global supplier of high-purity EMM. Stable rectifier performance directly supports output consistency, energy efficiency and equipment longevity.

The project illustrates how high-performance rectifier control systems can mitigate external power fluctuations in energy-intensive metal refining operations, ensuring operational continuity and supporting competitiveness in global markets.