As beneficiation and diamond recovery operations worldwide continue to evolve, the demand for a stable, high-performance supply of Dense Media Separation (DMS) ferrosilicon has never been greater. Against a backdrop of tightening global capacity and increasing compliance and operational pressure on key suppliers, high performance abrasives supplier Sigma has emerged as a next-generation producer, defined by resilience, scalability, and metallurgical precision.

“Where supply meets science - Sigma delivers stability, precision and trust.”

Integrated Production Platform

Operating from a modern 10 000 m² integrated manufacturing facility in Gauteng, Sigma runs one of South Africa’s most advanced DMS ferrosilicon platforms, combining milled and water-atomised production under rigorous quality control.

Independently verified capacities include:

• 53 000 t/y induction melting (no granular constraints)
• 25 000 t/y milled ferrosilicon (270D equivalent)
• 15 000 t/y atomisation line, ensuring consistent high-density supply

Engineered for modular scalability, Sigma can install an additional milling unit within six months of order, providing a low-capex expansion path to capture incremental market growth.

“Scalable by design. Reliable by nature.”

Purity, Process Control and Consistency

Sigma’s production philosophy rests on three pillars: purity, process control, and consistency. Both granular (milled) and atomised ferrosilicon are produced exclusively from Blue Steel and 75% ferrosilicon feedstock, with no reductants introduced during processing. The result is a chemically stable composite with superior density uniformity, magnetic recovery, and predictable rheology, which is critical for efficient media circulation and optimised plant recovery.

“Consistency isn’t a promise - it’s a process.”

Advanced R&D and Analytical Capability

Supporting its production platform, Sigma operates a dedicated in-house research and development (R&D) facility and analytical laboratory, driving real-time metallurgical insight and continuous improvement.

Capabilities include:

• 100 kg Induction furnace - Inductotherm Power-Trek 125-30 power source
• Dedicated water and gas atomisation capability
• XRF, Leco and PSD 
• ISO-accredited quality systems ensuring full traceability and compliance

“Every batch analysed. Every result verified. Every client assured.”

Leadership and Technical Heritage

At the heart of Sigma’s success is a leadership team shaped by decades of metallurgical expertise and a deep understanding of the DMS sector. Ryan Industries Group CEO Andrew Ryan and Sigma Wear Parts MD Edward Ryan represent the second generation of the Ryan family - pioneers in atomised and granulated abrasives. As majority shareholder, Andrew Ryan has been instrumental in establishing and leading Thor Foundry, Sigma Abrasives and Beta Steel, as well as designing and commissioning five abrasive manufacturing plants.

This enduring heritage of technical mastery continues to guide Sigma’s long-term strategy, built on predictability, repeatability and cost efficiency.

DMS Specialist Andre Hefer brings over 31 years of ferrosilicon manufacturing expertise, excelling in operations management, performance optimisation and sustainable supply strategies. He aligns work streams with business objectives, fosters resilient, purpose-driven organisational cultures, and drives Sigma’s growth in line with clients’ beneficiation goals.

 “Experience isn’t inherited - it’s engineered through generations of precision, purpose, and partnership.”

Culture, People and Organisational Strength

Sigma employs a dedicated team of 48 skilled operatives and technical specialists, each aligned with Sigma’s values of excellence, ownership, and resilience. Empowerment and accountability are embedded in the organisation’s DNA. Management encourages line-function decision-making, enabling rapid, informed action on the production floor.

Rooted in stakeholder engagement and a shared sense of purpose, Sigma’s culture bridges technical precision with human capability to deliver consistent, measurable results.

“Empowerment at every level builds resilience at every stage.”

Proven Track Record

Since 2013, Sigma has produced milled ferrosilicon, adding atomised ferrosilicon production in 2018. Over a decade of refinement has shaped a platform defined by reliability and performance continuity. Sigma’s repositioning directly addresses market instability and compliance lapses among key suppliers. Reasserting confidence, continuity, and credibility across beneficiation and diamond recovery sectors.

“A decade of delivery - engineered for the decades ahead.”

With an expanding international footprint across Africa, Europe, and Asia, Sigma positions itself as a strategic global partner, offering assured performance, responsive technical support, and long-term supply stability.

As traditional supply models face structural and compliance headwinds, Sigma represents the next generation of DMS ferrosilicon manufacturing, technically advanced, operationally resilient, and commercially stable.

From its 10 000 m² integrated facility and robust R&D systems to its experienced leadership and ISO-disciplined production, Sigma stands as a South African-built alternative; defined by precision, continuity, and trust.