Reliable Result: Solving Precision in Fire Assay
Fire assay is the industry-standard method for obtaining analytical data from ores or alloys. During this process, a sample containing gold is melted in a clay crucible with a flux mixture, including lead flux, in a fusion furnace. Through a melting process at temperatures exceeding 1000°C, precious metals are separated and collected in lead buttons. Subsequently, the lead is oxidized using a cupellation furnace, resulting in the extraction of pure precious metals.
The key features of fire assay include
- High Accuracy: Fire assay is known for its high accuracy in determining the content of precious metals in ores or alloys.
- Precise Temperature Control: The process involves melting samples at specific temperatures to separate precious metals from other elements.
- Separation of Precious Metals: Precious metals like gold and silver are separated from other elements through the use of fluxes and lead.
- Reliable Results: Fire assay provides reliable results, making it a widely accepted method in analytical chemistry and metallurgy.
- Industry Standard: Fire assay is considered the industry standard method for obtaining analytical data from high-grade ores.
- Adaptability: The process can be adapted to analyze various types of samples, making it versatile for different applications in mineral analysis.
Important Operations of Fire Assay
- Fusion
Fusion involves melting the sample with a flux mixture, typically containing lead flux, in a high-temperature furnace. During fusion, the sample and flux mixture form a molten mass, allowing the precious metals to combine with the lead flux and separate from the other components of the sample.
- Cupellation
The cupellation furnace in fire assay is essential for the cupellation process, which separates precious metals from other elements accurately. It provides precise temperature control, heating the lead button between 960°C to 1000°C. This allows for the oxidation of lead and absorption into the cupel while preserving the integrity of the precious metal bead. The furnace ensures uniform heating, promoting consistent oxidation and absorption, preventing uneven reactions, and ensuring accurate determination of precious metal content.
- Parting
Weighing gold and silver particles. Afterwards, treating particles with nitric acid to dissolve silver. After the silver is removed, the gold-containing sample is weighed to determine its weight.
Fire Assay Major Equipment and Consumables
- Crucible
Clay crucibles, crafted from refractory clay, withstand extreme temperatures exceeding 1200°C in fire assay fusion. Resistant to heat, they ensure sample containment, uniform melting, and integrity of the fusion process. Chemically inert, they prevent contamination, preserving the purity of resulting precious metal alloys.
- Cupel
Cupels, made from porous materials such as bone ash or magnesia, absorb lead oxide during the cupellation process in fire assay. They act as vessels for the lead button containing precious metals, enabling the absorption of lead oxide while safeguarding the purity of precious metals. Cupels are pivotal in precisely determining the precious metal content by providing a controlled cupellation environment, thereby upholding the integrity of the resulting metal bead.
- Crucibles Tumbler
Crucibles Tumbler is mainly used in batch mixing of fire assay mineral samples and fluxes, improving the preparation efficiency of laboratory samples and reducing manual processes. It is an essential piece of equipment for fire assay laboratories.
- Crucible Loader
The crucible loader can load and unload batches of crucibles, which reduces the need for manual handling and also protects the operator from heat radiation damage. The crucible loader is currently available in an electric and a manual mode.
- Fire Assay Multiload and Multipour System
Allows for efficient loading and unloading of crucibles, enhancing productivity.
Fire assay are essential processes in the analysis of precious metals, providing accurate analytical data critical for various industries. By employing these techniques, laboratories can achieve precise and reliable results, meeting the stringent demands of quality assurance and research.
At Qingdao Decent Group, we offer a comprehensive range of equipment, utensils, and consumables specifically designed to support sample preparation and fire assay processes. Our high-quality products and solutions are tailored to meet the diverse needs of mineral laboratories, ensuring accurate and reliable analysis of precious metals.
