Magnesium Oxide Cupel

Magnesium Oxide Cupel

Magnesium Oxide Cupel

  • Custom sizes and standard sizes in stock
  • Quick Lead Time
  • Competitive Price

Magnesium Oxide Cupel is a high-purity refractory container designed for use in fire assay and precious metal analysis. Made from dense magnesium oxide, it can withstand extreme temperatures without cracking or deforming, ensuring accurate and consistent melting and refining of samples. Its excellent thermal stability and resistance to chemical corrosion make it suitable for use with gold, silver, and other noble metals. The cupel effectively absorbs oxidized impurities during the assay process, maintaining clean separation and reliable analytical results. We can supply high-quality magnesium oxide cupels with various specifications and competitive prices, offering customized solutions to meet specific requirements.

Or email us at sales@heegermaterials.com.

Magnesium Oxide Cupel Data Sheet

ColorYellow, Light yellow, or White
MaterialsMgO
Purity96% min

Magnesium Oxide Cupel Description

Magnesium Oxide Cupel is produced from premium-grade raw materials with a unique formulation containing about 96% magnesium oxide and 4% fluxing agents. This composition allows it to absorb more lead oxide than traditional bone ash cupels, resulting in excellent porosity, mechanical strength, and consistent performance. During fire assay and cupellation, the cupel effectively absorbs lead oxide without splashing, leaving behind high-purity gold and silver alloy grains. It maintains structural integrity without cracking or pitting at high temperatures and remains unaffected by humidity or freezing conditions. After use, the precious metal grains can be easily separated from the cupel surface.

Magnesium Oxide Cupel Specifications

TypeHeight(H) mmTop OD(D) mmBottom OD(D2) mmTop ID(D1) mmInner Depth(H1) mmHeight of Ridge(H2) mm
2X1724191884.5
3202620235.58
4A2227202467.5
42229232468
52635262786.5
6A-2626403031.211.86
6A-2929403031.211.89
7A32403031.211.812
7AS(7X)35403031.211.815
7AS-15324030321512
827.144.334.634.28.59
8A354537381313
8AM354537331215
8S404434381413
930514340115
9A34391514
1030.26049.752.611.511
114456.848.847.814.810
147011088802414

Magnesium Oxide Cupel Features

  • Premium Raw Materials and Advanced Formulation: Made with high-purity magnesium oxide and precise additives to ensure optimal absorption and consistency in every batch.
  • Smooth Surface and Uniform Quality: Each cupel has a dense, even texture with a clean finish, ensuring accurate and repeatable fire assay results.
  • Strong Mechanical and Thermal Stability: Maintains structural integrity under high temperatures with excellent resistance to cracking, pitting, and thermal shock.
  • Weather-Resistant Performance: Unaffected by humidity or freezing conditions, allowing long-term storage without degradation in quality.
  • Efficient Lead Oxide Absorption: Capable of rapidly absorbing a large proportion of lead oxide during cupellation, ensuring high recovery rates of gold and silver.
  • Environmentally Safe and Reliable: Free from lead contamination, ensuring clean processing and minimal loss of precious metals.
  • Precision Manufacturing and Quality Control: Produced with modern machinery under ISO 9001-certified systems, guaranteeing consistent performance and dimensional accuracy.
  • Customizable Options: Heeger Materials (HM) provides high-quality Magnesium Oxide Cupels available in various sizes and specifications, with custom solutions to meet specific testing needs.

Magnesium Oxide Cupel Applications

  • Fire Assay Analysis: Used in laboratories for determining precious metal content in ores, concentrates, and alloys through the cupellation process.
  • Gold and Silver Refining: Efficiently separates precious metals from lead and other impurities, ensuring accurate recovery of high-purity gold and silver.
  • Mining and Metallurgical Testing: Essential for quality control and assay testing in mining operations, smelting plants, and metal refining facilities.
  • Analytical Laboratories: Applied in research and testing institutions for reliable quantitative analysis of noble metals.
  • Industrial Quality Assurance: Used in production environments where precise metal content verification is required for raw materials and finished products.

Magnesium Oxide Material Properties

PropertyValueUnit
Specific Gravity (S.G)3.58g/cm³
Porosity10%
Vickers Hardness (HV1)650HV
Flexural Strength105MPa
Compressive Strength275MPa
Young’s Modulus2.1 x 10¹¹Pa (N/m²)
Fracture Toughness1.8MPa·m^1/2

PropertyValueUnit
Coefficient of Thermal Expansion40℃ to 400℃10.0 × 10⁻⁶/°C
40℃ to 800℃10.5 × 10⁻⁶/°C
Thermal Conductivity42W/m·K
Specific Heat0.92J/g·°C
Dielectric Strength (Thermal Shock Resistance)17kV/mm

PropertyValueUnit
Volume ResistivityAt 20°C> 1014Ω·cm
At 500°C> 108Ω·cm
Permittivity (Dielectric Constant)@ 1 MHz9.8C²/(N·m²) or (Dimensionless)
Dielectric Loss Tangent@ 1 MHz1 × 10⁻⁴

Magnesium Oxide Ceramic Machining

Magnesium Oxide Ceramic Machining

Magnesium oxide can be machined in green or bisque form before sintering, and to a limited extent in its fully sintered state. In its pre-sintered state, the material is relatively soft and easier to shape, but like many ceramics, it undergoes significant shrinkage—up to 20%—during sintering, which can affect final dimensions. Fully sintered magnesium oxide is very hard and brittle, requiring diamond tools and precision equipment for any post-sintering machining.

Machining Methods and Considerations

  • Green or Bisque Machining: Easier to cut and form, suitable for complex shapes before firing.
  • Sintering Shrinkage: Expect about 15–20% dimensional reduction during sintering, which impacts tolerance control.
  • Post-Sintering Machining: Requires diamond grinding tools due to the material’s hardness and brittleness.
  • Fragility: Fully sintered MgO is prone to chipping and fracture if not handled with care during machining.
  • Tooling and Time: Machining dense MgO ceramics is time-consuming and requires specialized equipment.

Magnesium Oxide Ceramic Packaging

Magnesium oxide ceramic products are typically packaged in vacuum-sealed bags to prevent moisture or contamination and wrapped with foam to cushion vibrations and impacts during transport, ensuring the quality of products in their original condition.

ceramic products packing-HM

Get A Quote

We will check and get back to you in 24 hours.

To customize your magnesium oxide cupel, please provide the following details:

  1. Dimensions: Top Diameter x Bottom Diameter x Height x Wall Thickness
  2. Material Grade: Specify the material grades.
  3. Purity of the material
  4. Shapes: Cylinder, Conical Cylinder, Rectangular, T-shape, or customized.
  5. Tolerances: Specify the tolerances you can accept.
  6. Surface Finish: polished, rough, etc.
  7. Quantity of the crucibles you need
  8. Alternatively, you can provide a drawing with your specifications.

Once we have these details, we can provide you with a quote within 24 hours.

We carry a wide variety of magnesium oxide ceramic products in stock, and for these, there is generally no minimum order requirement. However, for custom orders, we typically set a minimum order value of $200. The lead time for stock items is usually 1-2 weeks, while custom orders usually take 3-4 weeks, depending on the specifics of the order.

During the fire assay process, the cupel absorbs lead oxide formed by oxidizing lead from the sample, allowing precious metals like gold and silver to remain as metallic beads for accurate measurement.

MgO provides exceptional heat resistance, corrosion resistance in molten metal environments, and excellent thermal shock stability, ensuring the cupel performs well even under repeated heating cycles.

Advanced Ceramic Hub, established in 2016 in Colorado, USA, is a specialized supplier and manufacturer of magnesium oxide ceramic (Si3N4). With extensive expertise in supply and export, we offer competitive pricing and customized solutions tailored to specific requirements, ensuring outstanding quality and customer satisfaction. As a professional provider of ceramics, refractory metals, specialty alloys, spherical powders, and various advanced materials, we serve the research, development, and large-scale industrial production needs of the scientific and industrial sectors.

Enquiry Form

Related Products

  • Cr2VTiAlC2 MAX Phase Powder

    Cr2VTiAlC2 MAX Phase Powder Cr2VTiAlC2 MAX Phase Powder is a layered ceramic-metallic material offering excellent conductivity, oxidation resistance, and mechanical stability…

  • Yttria Stabilized Zirconia Powder

    Yttria Stabilized Zirconia Powder Yttria stabilized zirconia powder is engineered by doping zirconium dioxide with 3–15 mol% yttrium oxide, resulting in…

  • Alumina Foam

    Alumina Foam Alumina Foam is a highly porous ceramic material made from aluminum oxide (Al₂O₃), known for its excellent thermal stability,…

  • Yttria Stabilized Zirconia Tube

    Yttria Stabilized Zirconia Tube Yttria Stabilized Zirconia Tube is a high-performance ceramic component known for its exceptional thermal stability, ionic conductivity,…

  • Alumina Fasteners

    Alumina Fasteners Purity: 95%, 96%, 99%, 99.5%, 99.7%, 99.95% Alumina Fasteners are primarily made of high-purity aluminum oxide (Al2O3) through high-temperature…

  • Silicon Nitride Ceramic Ball

    Silicon Nitride Ceramic Ball Purity: ≥99% Diameter: φ0.8-φ50.8 mm, or customized Silicon Nitride Ceramic Ball is known for its lightweight and…