The Latest in Sample Preparation and Fire Assay Solutions for Precious Metal Analysis in 2024

Innovative Solutions: Customizing Fire Assay Tools for Precious Metal Analysis

Sample preparation and fire assay processes are indispensable steps in the analysis of precious metals such as gold, silver, and platinum group elements. These processes are mainly utilized in mineral laboratories and pilot plants, where accurate and reliable results are crucial for various applications in mining, metallurgy, and research.

Qingdao Decent Group is a primary supplier for the sample preparation and fire assay processes, providing turnkey solutions to mineral laboratories and pilot plants.

Qingdao Decent Group Factory

Sample Preparation

Sample preparation is a critical aspect of assaying, as the accuracy of the results heavily relies on the careful selection and preparation of the ore sample. The goal is to ensure that the sample is representative of the entire bulk ore. This involves reducing the sample size either manually or using automated machines, with successive reductions to achieve finer particle size.

Sample Preparation Line

The key features of sample preparation include

• • Representative Sampling: Ensuring the sample accurately represents the entire bulk material.
• • Size Reduction: Reducing the sample size through crushing, grinding, or homogenization for easier handling.
• • Homogenization: Achieving uniformity in the sample to ensure consistent results across analyses.
• • Extraction Techniques: Isolating the mineral of interest from the sample using specialized techniques.
• • Interference Removal: Eliminating substances that could interfere with the analysis to enhance accuracy.
• • Mineral Conversion: Converting the mineral into a suitable form for detection, separation, or determination.
• • Decomposition Promotion: Liberating elements of interest through decomposition techniques for sub-sampling.
• • Quality Control: Adhering to strict storage, protection, and quality procedures to meet sample preparation standards.

Main Equipment

Drying

Drying in sample preparation is essential for mineral analysis, as it helps eliminate moisture from samples to ensure accurate and reliable results. Drying involves removing moisture or water content from samples through various methods such as air-drying, oven-drying, or desiccation. By eliminating moisture, drying prevents potential reactions or alterations in samples during subsequent processing steps, such as crushing, grinding, or chemical analysis. Additionally, drying ensures the preservation of sample integrity, prevents microbial growth, and facilitates the handling and storage of samples.

Drying Oven

Crushing

The role of crushers in sample preparation is crucial for mineral analysis, as they facilitate the initial stage of reducing the size of bulk materials to a manageable level. Crushers break down large chunks of materials into smaller particles through mechanical force, enabling easier handling and subsequent processing steps. This size reduction process is essential for ensuring representative sampling and achieving uniformity in the sample, which are critical factors in obtaining accurate and reliable analytical results in mineral analysis.

Lab Crushers

Grinding

The grinding machines or pulverizers are designed to further reduce the size of samples after initial crushing, resulting in finer particles suitable for analysis. The sample can be ground in the pulverizer bowl for 3 minutes so that 95% of the sample can pass through the 75 micron screen.

Pulverizer Bowls

Sieving

Sieving involves passing a sample through a sieve or mesh with uniform openings to separate particles into different size fractions. This process ensures that the sample is homogenous and representative, as it removes any oversized or undersized particles that could skew analytical results. By achieving uniform particle size distribution, sieving facilitates accurate and reproducible analysis of mineral samples, enabling researchers to obtain reliable data for various applications in mining, metallurgy, and research.

Standard Sieve Shaker

Splitting

Splitting involves dividing the sample into smaller portions using various techniques such as riffling, quartering, or coning and quartering. This process ensures that each sub-sample retains the same characteristics as the original sample, allowing for accurate and representative analysis. By creating multiple sub-samples, splitting enables researchers to perform replicate analyses, validate results, and ensure the reliability of analytical data.

Jaw Crusher and Rotating Sample Divider Combo DJRC80

Mixing

Mixing is the process of thoroughly blending various components of the sample to achieve a uniform mixture. It ensures the even distribution of additives or reagents throughout the sample, promoting consistent reactions with the sample matrix in subsequent processing steps. This homogenization eliminates any heterogeneity within the sample, ensuring equal representation of all portions in subsequent analyses. By minimizing sampling errors, mixing contributes to reliable and reproducible analytical results.

Tools

The role of various tools such as workstations and benches in sample preparation is to provide a designated space for conducting sample preparation activities efficiently and effectively. These tools serve as dedicated work areas where researchers and technicians can perform a wide range of tasks related to sample preparation, including weighing, mixing, grinding, and sieving.

Workstations

Workstations are equipped with essential features such as ample workspace, storage compartments, and ergonomic design to facilitate sample preparation tasks. They provide a centralized area for organizing equipment, tools, and samples, enhancing workflow efficiency and productivity. Workstations may also include built-in features such as sinks, fume hoods, and electrical outlets to accommodate specific sample preparation requirements.

Self-Contained Workstation DSW350

Benches

Benches serve as sturdy platforms for supporting equipment and tools used in sample preparation. They provide a stable surface for performing tasks such as weighing, grinding, and mixing samples. Benches are typically constructed from durable materials such as stainless steel or chemical-resistant laminate to withstand the rigors of sample preparation activities. They are available in various sizes and configurations to accommodate different laboratory setups and workflows.

Laboratory Workbench

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 cupel, 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.

Fire Assay Process

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.

Furnace Chamber And Tile

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.

Cupellation Furnace

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.

Main Equipment

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.

Assay Litharge

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.

Magnesia Cupel

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 Tumbler

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 Multiload and Multipour System

Fire Assay Tools

Tool Rack

Mobile Laboratory- Revolutionizing On-Site Testing

Mobile laboratories revolutionize sample preparation and fire assay by enabling on-site testing in remote areas. This innovation streamlines analysis, expedites decision-making, and saves resources by eliminating the need to transport samples. Mobile labs facilitate real-time analysis directly at the mining site, ensuring timely insights crucial for exploration and mining operations. Additionally, they offer flexibility and customization to meet diverse sampling needs, enhancing efficiency and adaptability in various environments and applications.

Container Laboratory

Container Lab Inside View

Containerized Lab Group

Conclusion

Sample preparation and 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.

For inquiries about our products and how they can enhance your laboratory operations, please contact us. Thank you for considering Qingdao Decent Group as your partner in achieving precise and reliable precious metal analysis.

Contact Us

Qingdao Decent Electromechanical Tech Co., Ltd
Room 408 Huaren Building, No. 187 Zhuzhou Road, Laoshan District, Qingdao City, Shandong Province, China
Mobile / Whatsapp / Wechat: +86-18669806318
Email: hydewang@decent-group.com
Website: https://www.decent-group.com