Advanced thermal processing
At Sibanye-Stillwater Recycling operations, our thermal reduction department is an integral component of our precious metal recycling operations. Designed to safely and efficiently process burnable precious metal-bearing materials, this department focuses on maximizing recovery while minimizing losses from some of the most sensitive and valuable waste streams.
Through meticulous furnace engineering and expert operational control, organic materials surrounding precious metals are thermally reduced under carefully controlled conditions.
Every stage of the process is managed within a tightly controlled operating environment utilizing proprietary environmental controls, calibrated thermal profiles, and electronically monitored processing parameters.
Our proprietary furnace technologies, including the APR³ and APR⁴ systems, are specifically engineered to protect precious metal value throughout the thermal reduction process.
* APR = Advanced Pyrolytic Reduction
The APR⁴ furnace serves as the technological advancement of our Thermal Reduction Department, combining advanced process automation, dialed-in thermal recipes, and real-time electronic tracking systems to deliver consistent, repeatable recovery outcomes across highly variable material streams.
Why thermal reduction matters
Burnable precious metal-bearing materials generated across industrial manufacturing and recycling streams are highly variable and extremely sensitive to processing conditions. Without precise thermal control, volatility and turbulence can lead to significant losses of precious metals.
Partnering with Sibanye-Stillwater Recycling operations ensures:
- Controlled thermal environments that minimize precious metal losses
- Optimized recovery outcomes for high-combustion materials
- Consistent preparation for downstream recovery and refining
- Support for circular economy and sustainability initiatives
- Digitally monitored processing conditions with continuous electronic data tracking and operational oversight
- Customized furnace recipes developed to match the unique combustion characteristics of each material stream
Lot assessment and customized processing
Every lot of burnable precious metal–bearing material arriving at our facility undergoes a detailed review by our internal assessment board. Physical characteristics, volatility, and safety data are analyzed to define ideal furnace conditions for each material. This customized approach reduces the risk of precious metal losses while maximizing recovery efficiency.
Using advanced operational analytics and historical process data, our team develops dialed-in processing recipes tailored to each lot’s specific thermal behavior, combustion profile, and precious metal composition.
Electronic monitoring and data collection throughout the thermal reduction cycle allow operators to continuously validate furnace conditions, maintain process consistency, and support full operational traceability.
APR³ furnace
An oxygen-starved system designed for high-combustion materials and the most vulnerable precious metals. Radiant heat thermally reduces surrounding organics in a turbulence-free environment, preserving the maximum precious metal value.
The APR³ furnace utilizes carefully controlled atmospheric conditions and precision thermal management to minimize volatility and protect sensitive precious metals during reduction.
APR⁴ furnace
The APR⁴ furnace is the latest advancement in Sibanye-Stillwater Recycling operations’ thermal reduction capabilities and represents the next evolution in precious metal thermal processing technology.
A next-generation furnace engineered to process a wide range of precious metals, including gold, silver, platinum, palladium, rhodium, and iridium. Proprietary sensors and data analytics provide continuous monitoring to ensure consistent performance and recovery outcomes.
Customizable and flexible processing
We do not approach burnable precious metal–bearing materials with a one-size-fits-all mentality. Our multiple furnaces, each with distinct processing specialties, allow us to tailor thermal reduction techniques to the specific characteristics of every lot.
The APR⁴ furnace represents the next evolution in precious metal thermal reduction technology:
- Capable of handling complex and varied waste streams
- Equipped with advanced proprietary process controls
- Designed to deliver precise, consistent outcomes across all materials
- Utilizing electronically managed furnace recipes and automated environmental controls for optimized thermal performance
- Supported by continuous electronic data monitoring, tracking, and operational analytics to ensure process consistency and accountability
Know your metals
The Know your metals resource helps you understand how precious metals are used across industries. Explore each metal’s commercial applications, the types of waste streams it commonly appears in, and the recovery technologies used to reclaim it.
Au
Gold
Ag
Silver
Pt
Platinum
Pd
Palladium
Rh
Rhodium
Ir
Iridium
Gold
Gold is a critical precious metal valued for its excellent conductivity, corrosion resistance, and stability, with extensive use in semiconductor fabrication, electroplating, connector fabrication and assembly, medical device and jewelry manufacturing.
Gold frequently occurs in industrial waste streams such as spent plating solutions, filters, resin, sludges, stamping scrap, contact pins and karat jewelry.
Silver
Silver is a widely used precious metal known for its high electrical conductivity, antimicrobial properties, and reflectivity, making it essential in microelectronics, medical applications, film coating, chemical processing, jewelry manufacturing, electroplating and stamping industries.
Silver-bearing waste streams often include spent plating baths, filters, sludges and stampings.
Explore silver-bearing waste streams:
Platinum
Platinum is a critical precious metal widely used in pharmaceutical catalysts, jewelry manufacturing, automotive catalytic converters, fuel cell/electrolyzer applications, fiberglass manufacturing, and the aircraft/aerospace, microelectronics and medical industries.
Due to its chemical stability and catalytic properties, platinum frequently appears in industrial waste streams such as spent catalyst, acidic process solutions, plating baths, filter media, implantable medical components, fiberglass bushings and refractory, fuel cell MEAs, thermocouple wire, machining kerf, shavings and turnings.
Explore platinum-bearing waste streams:
- Jewellery manufacture
- Discarded electronic devices and electronics manufacturing
- Electroplating operations
- Medical device manufacturing and healthcare operations
- Defense manufacturing and maintenance operations
- Glass manufacturing
- Pharmaceuticals manufacture
- Industrial catalysts
- Automotive catalytic converters
- Nitric acid manufacture
Palladium
Palladium is a precious metal widely used in automotive catalytic converters, specialty chemical catalyst, conductive pastes, microelectronics/ceramic capacitors.
Owing to its excellent catalytic performance and electrical conductivity, palladium is commonly found in industrial waste streams such as spent catalysts, sludges, filter media, fired/green ceramic, thick film wipes & jars, canned/decanned catalytic converters and spent environmental catalysts.
Explore palladium-bearing waste streams:
- Jewellery manufacture
- Discarded electronic devices and electronics manufacturing
- Electroplating operations
- Medical device manufacturing and healthcare operations
- Defense manufacturing and maintenance operations
- Pharmaceuticals manufacture
- Industrial catalysts
- Automotive catalytic converters
- Nitric acid manufacture
Rhodium
Rhodium is a rare and valuable precious metal primarily used in automotive catalytic converters, chemical catalysts, fiberglass manufacturing, and plating industries.
Its high reflectivity and resistance to corrosion result in rhodium being found in waste streams including catalytic converters, spent plating baths, filters, fiberglass bushings and refractory.
Explore rhodium-bearing waste streams:
Iridium
Iridium is an extremely durable and corrosion-resistant precious metal used in chemical processing equipment, fuel cell manufacturing, specialty catalyst, and medical devices.
Due to its use in high-temperature and highly corrosive environments, iridium is commonly found in waste streams including electrolyzer scrap, spent coating solutions, spent catalyst and filters, medical device components such as electrodes, marker bands and cath tips.
Explore iridium-bearing waste streams:
Integrated processing across departments
The thermal reduction department works in close coordination with our mechanical reduction and wet chemistry departments, enabling seamless material flow, optimized recovery pathways, and consistent evaluation and refining outcomes across the precious metal recycling process.
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Mechanical reduction
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Thermal reduction
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Wet chemistry
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Precious metal melt
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Auto catalyst recycling
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Electronic material classification
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Bead blasting
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Cleaning & recovery
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Granulation
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Transportation & logistics
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Analytical laboratory
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Partner with Sibanye-Stillwater Recycling operations
We support our partners with customized recycling programs aligned to their business and sustainability goals. Our technical teams collaborate closely with customers to improve recovery efficiency, ensure regulatory compliance, and convert complex burnable waste streams into measurable value.
