Talk to our gold testing equipment experts for pricing, demo, and customization.
Precision cupellation furnace for gold and silver prill recovery in fire assay — essential gold testing equipment for hallmarking centres, refineries, and mining laboratories
Cupellation Furnace Machines are precision high-temperature muffle furnaces purpose-built for the cupellation stage of the fire assay process — the critical step where lead is oxidized and absorbed from the lead button to isolate a pure gold-silver prill for accurate gravimetric weighing. The cupellation furnace maintains a tightly controlled oxidizing atmosphere at temperatures between 850°C and 1000°C, enabling complete and efficient lead removal from the assay bead without loss of precious metal. As an essential piece of gold testing equipment in any fire assay laboratory, the cupellation furnace works in tandem with the fusion muffle furnace to deliver the complete fire assay workflow — the internationally recognized gold standard for precious metal determination. The process requires no reagents during cupellation itself, relying entirely on controlled oxidation within the furnace chamber to achieve separation of base metals from gold and silver. Cupellation furnaces are indispensable in BIS hallmarking and assaying laboratories, gold and silver refineries, mining assay labs, smelters, jewellery manufacturing quality control, and electronic scrap precious metal recovery operations. With programmable PID temperature controllers, multi-cupel tray capacity, and robust refractory chamber construction, these furnaces deliver the precision and repeatability required for laboratory-grade precious metal analysis. Cupellation Furnace Machines from IndiaLaser are designed for reliable daily operation in demanding assay environments, combining accurate temperature control, long heating element life, and easy maintenance into a compact and efficient laboratory furnace.
We supply both imported and domestically manufactured cupellation furnaces to meet the requirements of every type of gold testing laboratory in India. Our imported models from globally recognized laboratory furnace manufacturers offer advanced PID controllers, superior SiC heating elements, and large multi-cupel chamber capacities for high-throughput assay operations. Our domestic models provide excellent value for smaller hallmarking centres and jewellery testing labs that require reliable cupellation performance at an accessible price point. All models are supplied with certified magnesia cupels, spare heating elements, and complete documentation for BIS assaying laboratory compliance.
After the fire assay fusion stage produces a lead button containing all the gold and silver from the original sample, this lead button is placed on a pre-heated porous magnesia (MgO) cupel inside the cupellation furnace. The furnace is maintained at a carefully controlled temperature between 850°C and 1000°C in an open oxidizing atmosphere. At this temperature, the surface of the molten lead button oxidizes continuously, forming lead oxide (litharge, PbO). The porous cupel absorbs the litharge as it forms, progressively removing the lead from the bead. As the lead is absorbed, the bead shrinks and brightens — a phenomenon called "blick" or the brightening flash — which signals that cupellation is complete and only the gold-silver alloy prill remains. The furnace is then opened and the cupel with the prill is removed using tongs and allowed to cool. The prill is weighed on a precision analytical balance, then subjected to acid parting in dilute nitric acid to dissolve the silver, leaving pure gold for final weighing. The difference between the prill weight and the gold weight gives the silver content. Both values are calculated as a percentage of the original sample weight to report the gold and silver assay result.
Standard specifications for our Cupellation Furnace Machines. Custom configurations available on request.
| Parameter | Specification |
|---|---|
| Technology | High-Temperature Muffle Furnace (Cupellation) |
| Temperature Range | Room Temperature – 1100°C |
| Cupellation Temperature | 850°C – 1000°C (Adjustable) |
| Temperature Accuracy | ±2°C (PID Controller) |
| Chamber Capacity | Up to 18 Cupels per Batch |
| Heating Elements | Silicon Carbide (SiC) Rods / Kanthal Wire |
| Chamber Material | High-Alumina Refractory Lining with MgO Cupel Tray |
| Control System | Programmable PID Digital Controller with Timer |
| Heating Rate | Adjustable up to 20°C/min |
| Atmosphere Control | Open Air / Ventilation Port (Oxidizing Atmosphere) |
| Power Supply | 220V–440V / 50–60Hz (Single/Three Phase) |
| Warranty | 1 Year (Extendable) |
* Specifications may vary by model. Contact us for datasheet.
Understanding the role of each furnace type helps you build the right fire assay laboratory setup for your gold testing requirements.
| Feature | Cupellation Furnace ✓ | Fusion Furnace | Combined Furnace |
|---|---|---|---|
| Stage in Fire Assay | Stage 2 — Lead Removal | Stage 1 — Metal Collection | Stage 1 + 2 Combined |
| Operating Temperature | 850°C – 1000°C | 950°C – 1200°C | 850°C – 1200°C |
| Atmosphere Required | Oxidizing (Open Air) | Reducing / Neutral | Switchable |
| Output | Gold-Silver Prill (Bead) | Lead Button | Gold-Silver Prill |
| Cupel Required | Yes (MgO Cupel) | No (Fireclay Crucible) | Yes (Both) |
| Best For | Dedicated cupellation labs | High-volume fusion only | Compact lab setups |
Common questions about cupellation furnaces, the cupellation process, and gold testing laboratory setup in India.
A Cupellation Furnace is a specialized high-temperature muffle furnace used to separate and recover gold and silver from a lead button produced during the fire assay fusion stage. In the cupellation process, the lead button is placed on a porous magnesia (MgO) cupel inside the furnace at 850°C–1000°C. The furnace maintains an oxidizing atmosphere, causing the lead to oxidize into litharge (PbO), which is absorbed by the cupel, leaving behind a tiny pure precious metal bead — called the prill — containing only gold and silver. This prill is then weighed and parted to determine the exact gold and silver content of the original sample. Cupellation furnaces are essential in fire assay laboratories, gold refineries, BIS hallmarking centres, and mining assay labs.
A Fusion Furnace operates at higher temperatures (950°C–1200°C) and is used for the first stage of fire assay — melting the ore sample with lead oxide flux to collect all precious metals into a lead button. A Cupellation Furnace operates at a slightly lower and more precisely controlled temperature range (850°C–1000°C) and is used for the second stage — oxidizing the lead from the lead button in an open oxidizing atmosphere to leave behind only the gold-silver prill. Both are muffle furnaces but are optimized for different thermal and atmospheric conditions. Some combined fire assay furnaces can perform both stages in one unit.
Cupellation furnaces process lead buttons obtained from fire assay fusion of gold ore samples, mine concentrates, doré bars, bullion, jewellery scrap, electronic scrap gold concentrates, dental gold, and any precious metal alloy that has undergone the fire assay fusion stage. The process is specifically optimized for gold and silver recovery, with the resulting prill suitable for gravimetric weighing and acid parting to determine individual gold and silver content.
The price of a Cupellation Furnace in India typically ranges from ₹1 Lakh to ₹8 Lakhs depending on chamber capacity (number of cupels), temperature rating, controller sophistication, heating element type, and brand. Small laboratory models for hallmarking and jewellery testing are available at the lower end, while high-capacity mining and refinery models command higher prices. Contact us for the latest pricing, live demos, and customized quotations.
Yes. BIS-approved Assaying and Hallmarking Centres that conduct fire assay testing as part of their purity verification process require a cupellation furnace as part of their laboratory setup. The fire assay method — which includes both fusion and cupellation stages — is recognized by BIS as a reference method for gold purity determination. Centres performing fire assay must have both a fusion muffle furnace and a cupellation furnace, or a combined fire assay furnace capable of both stages.
Yes, IndiaLaser provides free on-site installation and hands-on operator training with every cupellation furnace purchase. Our engineers guide your laboratory team through furnace commissioning, cupel tray loading, temperature profile setting, oxidizing atmosphere management, prill recovery procedures, and safe operating practices — ensuring your team can confidently conduct accurate fire assay cupellation from day one.
Looking for a cupellation furnace price in India? IndiaLaser offers the best cupellation furnaces for gold testing laboratories — from compact benchtop models for BIS hallmarking centres and jewellery assay labs to high-capacity industrial units for gold refineries and mining laboratories. Whether you need a laboratory cupellation furnace for fire assay gold testing, a high-capacity cupellation muffle furnace for mining assay labs, or a combined fire assay and cupellation furnace for compact hallmarking setups, we have the right solution for your gold testing equipment requirements. Our cupellation furnaces are available in Delhi, Mumbai, Chennai, Bengaluru, Hyderabad, Pune, Ahmedabad, Surat, Jaipur, Kochi, and across India with fast delivery, genuine spare parts, and dedicated after-sales support. Compare our cupellation furnaces with fusion furnaces and combined fire assay units, or contact our team for a customized quotation and laboratory setup guidance today.
Get the best price, free demo, and expert guidance from IndiaLaser's gold testing equipment team.
Submit Enquiry →
