High Quality Custom Industrial Flat Top Graphite Crucible with Level Mouth for Induction Melting

Product Description

Product Description

Most graphite crucibles on the market suffer from issues such as insufficient purity, poor thermal stability, susceptibility to cracking due to temperature differences, contamination from metal melt adhesion, and limited size options, which severely impact the purity of the final product and production efficiency. NHD flat-mouth graphite crucibles undergo strict quality control throughout the entire process, from raw material selection to production. We eliminate inferior clay-mixed raw materials and use high-density, high-purity graphite as the base material, which has an extremely low porosity. This eliminates issues such as impurity leaching and metal leakage at the source.

 

The product is manufactured using a one-piece molding process, eliminating any seams. The inner walls undergo precision polishing to achieve a smooth, dense surface. This allows molten metal to flow rapidly at high temperatures without sticking or leaving residues, significantly reducing material loss and ensuring more uniform and precise ingot formation. The proprietary flat-mouth design features a smooth, even opening that is compatible with matching sealed crucible lids. This effectively reduces metal oxidation during high-temperature melting while facilitating manual charging, pouring of molten metal, and cleaning and maintenance, significantly enhancing operational convenience.

Unlike traditional pointed-bottom or round-bottom crucibles, the flat-bottomed design provides a more stable heating surface and a larger opening, greatly facilitating charging and slag removal operations. Our graphite material has an extremely low ash content (typically <500 ppm), ensuring that no impurities are introduced into the molten metal at high temperatures above 1600°C.

 

Product Parameters

Parameter Items	Standard Specifications	Notes
Product Material	High-purity synthetic graphite	No clay impurities, high purity
Graphite Purity	99.9%-99.99% (optional)	Customization available for ultra-high purity
Product Density	≥1.73 g/cm³ (customizable high-density options available: 1.78-1.90 g/cm³)	The higher the density, the better the strength and durability.
Ash Content	≤0.3%	Eliminate material contamination
Temperature Range	Air environment: ≤600°C; vacuum/inert environment: ≤3000°C	Stable performance at high temperatures
Coefficient of Thermal Expansion	Very low	Resistant to sudden temperature changes; less prone to cracking
Surface Treatment	Mirror polish / Anti-corrosion coating (optional)	An antioxidant coating can extend the service life
Structural Styles	Straight-sided with a flat bottom for stability	Compatible with a wide range of devices

 

Why choose a flat-end design?

Comparison Items	Flat-Mouthed Graphite Crucible	Graphite crucible with spout
Ease of loading	Large opening allows for direct feeding of chunked or sliced ingredients	Due to the size of the feed opening, large pieces of raw material must be pre-processed.
Mixing Performance	The carbon rod/stirrer can be inserted vertically	Due to the angle of the mouth
Sealed	The flat lid fits tightly, reducing oxidation	The mouthpiece does not seal completely
Tipping control	Requires a tool for pouring	Precise pouring with a spout
Applicable Scenarios	Batch melting, extended holding time, and processes requiring stirring	Continuous casting, small-batch precision molding
Metal loss	Lower (steam loss is reduced by 15-20% when covered)	Relatively high

Conclusion: Flat-mouthed graphite crucibles are better suited for smelting processes that require repeated charging, prolonged heat retention, and stirring to remove impurities. They are the preferred choice for gold and silver refining, alloy formulation, and laboratory research and development.
 

Customizable in all specifications, with a minimum order quantity of one piece

Custom Projects	Notes
Dimensions	Inner diameter: 20 mm-300 mm; height: 30 mm-500 mm (customizable to any specifications)
Wall Thickness Design	Optimize wall thickness (typically 8-25 mm) based on the type of metal and melting temperature
Capacity marking	Laser-engraved weight markings (e.g., "1 kg Au," "5 kg Ag")
Matching graphite cover	Flat lid or grooved lid available, designed to fit the crucible opening precisely
Special Treatment	Inner surface polished; outer surface coated with an anti-oxidation treatment

 

Application

1. Precious Metal Jewelry Casting Industry:Suitable for the smelting, ingot casting, and jewelry processing of precious metals such as gold, silver, and platinum. Thanks to its high purity and low impurity content, it fully preserves the purity of precious metals. The non-stick inner surface minimizes waste of valuable raw materials, and the flat-bottomed design facilitates manual handling, making it an essential consumable for jewelry manufacturers and custom jewelry workshops.

2. Laboratory Research and Testing:Designed for high-temperature chemical analysis, ash content testing, sample fusion, and sintering experiments on new materials in universities, research institutes, and testing laboratories. It offers excellent chemical stability, does not contaminate experimental samples, provides precise experimental data, and its resistance to temperature fluctuations makes it well-suited for intermittent laboratory operations.

3. Small-scale precision casting:Ideal for precision melting and molding of small hardware castings and alloy components, this process offers high mold accuracy and excellent melt fluidity, effectively reducing defects such as porosity and imperfections in castings and improving the yield rate of precision castings.
    

Company Profile

Established in 2017, located in Fengxin Industrial Area, Yichun City, Jiangxi Province, China, Jiangxi Ningheda New Material Co., Ltd. is the subsidiary company of Jiangxi Ningxin New Material Co., Ltd.

Jiangxi Ningxin New Material Co., Ltd. is an enterprise which specializes in R&D, production and sale of special graphite. The total investment is RMB 520 million. It covers an area of more than 70000 square meters and produces 10000 tons of special graphite annually, which makes Ningxin to be the leading enterprise in the domestic industry.

On November 8^th, 2016, Ningxin was listed of Chinese new third board. The stock abbreviation is Ningxin New Material, and stock code is 839719.
Jiangxi Ningheda New Material Co., Ltd. is mainly engaged in graphite product processing, graphite product matching service, providing graphite materials, graphite electrode and graphite products for the lithium industry, rare earth industry, machinery industry, aerospace, semiconductor and solar photovoltaic industry, together with the corresponding products technical service and technical application of update program


With excellent production technology, good customer service, high market share, and relying on the advantage of new material, capital and management of parent company (Jiangxi Ningxin New Material Co., Ltd.), Jiangxi Ningheda New Material Co., Ltd. develops quickly. We devote to the extension of the special graphite industry chain, and make contributions for building the future whole graphite industry strategy.


1. The processing materials are ultrafine granule structure, high purity and graphite with high graphitization degree.
2. High hardness, good anti-oxidation performance and high machining accuracy
3. Good conductivity, high resistivity, sufficient mechanical strength
4. Small porosity and dense structure.
5. Excellent thermal shock resistance, conductive and thermal conductivity.
6. High temperature resistance, corrosion resistance, acid and alkali resistance, good wear resistance.
7. Surface can be treated with anti-oxidation.

FAQ

• Q1: What is the biggest advantage of flat-mouthed graphite crucibles compared to standard crucibles?

  A:Compared to ceramic, quartz, and clay crucibles, this flat-mouthed high-purity graphite crucible conducts heat faster, heats more evenly, and offers excellent thermal shock resistance, making it less prone to cracking under temperature fluctuations; they offer greater chemical stability, resisting acids, alkalis, and metal corrosion without contaminating the melted material; the flat-mouth design allows for easier operation, broader application scenarios, and a longer service life, making them far more cost-effective than traditional crucibles.

   

• Q2: Will your flat-mouth graphite crucibles oxidize at high temperatures?

  A: All graphite will oxidize slowly in air at temperatures exceeding 500°C. We offer two solutions: 1) We provide high-density material, which oxidizes more slowly than standard crucibles; 2) We can customize an anti-oxidation coating to form a protective layer on the surface. Additionally, the flat-mouth design facilitates a tight seal with the furnace lid, reducing oxygen flow.

   

• Q3: How do I select the appropriate size of graphite crucible?

  A:You can choose a model based on the weight and volume of the material to be melted in a single batch, as well as the dimensions of your melting equipment. As a general rule, we recommend that the amount melted in a single batch does not exceed two-thirds of the crucible's capacity to prevent high-temperature molten material from overflowing. For small-scale experiments and jewelry melting, choose small-capacity models; for industrial batch smelting, opt for large-capacity custom models. Alternatively, provide your equipment specifications, and our professional team will assist with one-on-one selection.

   

• Q4: Does the crucible need to be cooled immediately after use?

  A: Never place a hot crucible directly on a cold metal surface or wet ground, as this can cause severe thermal shock and result in the crucible shattering. Use crucible tongs to remove it and place it on a dry graphite pad, refractory brick, or ceramic plate to allow it to cool naturally to room temperature.

 

• Q5: Can the same crucible be used to melt different metals?

  A:We do not recommend mixing metals. Melting different metals can leave trace impurities, which may cause cross-contamination and affect the purity of the final product. We recommend using a dedicated crucible for each type of metal to ensure melting quality and the accuracy of experimental and production data.

Packaging & Shipping

Packaging: export standard wooden case.
Delivery Detail: 15~30 working days after confirming order.
Sea Port: Shanghai or other port of China Mainland.