Fire Assay Cupel Multiple Sizes 96% MgO High PbO Absorption for Gold Assay

Y&X fire assay cupels are engineered for the cupellation stage of gold, silver, and precious metal analysis. Manufactured from 96% magnesium oxide with a specialized fluxing agent formulation, these cupels feature smooth surfaces, uniform shapes, and exceptional mechanical strength.

During cupellation, the porous cupel efficiently absorbs molten lead oxide (PbO), while gold and silver remain as a precious metal bead for subsequent analysis. Multiple cupel sizes are available to meet diverse fire assay laboratory requirements.

• 96% MgO formulation optimized for fire assay cupellation
• PbO absorption exceeding 70% of the cupel's own weight
• Multiple diameters, heights, and cavity sizes available
• Smooth surface and uniform product shape
• High mechanical strength
• Designed to resist cracking, pitting, and lead spitting during cupellation
• Excellent thermal shock resistance; no pre-drying required
• Precious metal bead is easily removable after cupellation
• Custom sizes and packaging available

Model	Height H (mm)	Top OD D (mm)	Bottom Dia. D2 (mm)	Cavity Dia. D1 (mm)	Cavity Depth H1 (mm)	Pcs/Carton
2X	17	24	19	18	8	1008
3	20	26	20	23	5.5	500
4A	22	27	20	24	6	500
4	22	29	23	24	6	486
5	26	35	26	27	8	324
6A-26	26	40	30	31.2	11.8	300
6A-29	29	40	30	31.2	11.8	240
7A	32	40	30	31.2	11.8	200 / 300
7AS (7X)	35	40	30	31.2	11.8	200 / 300
7AS-15	32	40	30	32	15	300
8	27.1	44.3	34.6	34.2	8.5	240
8A	35	45	37	38	13	200
8AM	35	45	37	33	12	200
8S	40	44	34	38	14	200
9	30	51	43	40	11	120
9A	34	51	39	40	15	120
10	30.2	60	49.7	52.6	11.5	75
11	44	56.8	48.8	47.8	14.8	80
14	70	110	88	80	24	12
Straight 40	32	40	40	--	--	200

Different packing configurations are available for some models.

Cupel selection should be based on required outside diameter, cavity diameter, cavity depth, lead button size, and cupellation furnace configuration.

If replacing existing cupels, provide the model or dimensions for precise specification matching.

Suitable for: Gold Mine Assay Laboratories • Fire Assay Laboratories • Geological Exploration • Commercial Testing Laboratories • Precious Metal Refineries • Gold and Silver Analysis

During cupellation, insufficient PbO absorption can affect the final precious metal bead, while cracking or pitting may result in sample loss. Consistent cupel dimensions and absorption performance are critical for reliable fire assay testing.

Y&X conducts periodic laboratory testing to monitor product quality and ensure batch consistency.

Yes. Multiple specifications from 2X to 14 and Straight 40 are available. Custom sizes and packaging can also be provided.

Provide your current cupel model, dimensions, lead button information, or furnace requirements, and we will assist with specification matching.

Y&X Beijing Technology Co., Ltd. supplies fire assay equipment and consumables for gold, silver, and precious metal analysis, including cupels, cupel blocks, fusion furnaces, and cupellation furnaces.

Custom specifications and packaging are available according to laboratory requirements.