Magnesia Cupel

Qingdao Decent Group cupel is a shallow, porous crucible with approximately 96% magnesia. It is especially used to separate gold, silver, and precious metals from lead buckles in the process of Pb-Fire assay. By using high-quality raw materials and scientific formulas, Qingdao Decent Group's fire assay magnesia cupel has a smooth surface, high mechanical strength, and will not crack and pit during high-temperature cupellation.

Consult Online

Leave Message

Product Details

Manufacture high-quality fire assay cupels with a 96% magnesia content

Cupellation is the second and most important step in the fire assay process. Therefore, the quality of the cupel is crucial. Qingdao Decent Group aims to manufacture a full range of fire-assay cupels with premium quality and competitive cost.

Our magnesia cupel uses high-quality raw materials and a unique formula. And its composition includes up to 96% magnesium oxide and special flux. Our magnesia cupel absorbs more lead oxide than ordinary bone ash cupels. So our magnesia cupel has strong mechanical strength and perfect quality uniformity.

In the process of cupellation, the magnesia cupel will not cause splashing of lead, and can quickly absorb a large amount of lead oxide. And the magnesia cupels will not crack and pit. After the cupellation process, the gold-silver particles in the cupel can be easily removed.

Our magnesia cupels can be stored for a long time without compromising quality. It does not require pre-drying for the first use and always maintains a low loss of gold, silver and precious metals. What's more, our fire assay cupels are regularly sample tested in our own laboratory to ensure that we always provide our customers with quality cupels.

[ Key Advantages ]

• High quality, perfect uniform appearance, smooth surface

• High mechanical strength • High thermal shock resistance

• Rapid absorption of lead oxide, low loss of gold and silver

• No lead spatter, no cracks, no pitting

• Easy to remove beads

• Customized according to customer needs

[ The Process of Cupellation ]

Cupellation is the second step of the fire assay process. During cupellation, put the lead button which formed in fusion into the cupel, and melt it at 900 degrees Celsius in the cupellation furnace. The molten lead contacts with the oxygen in the air to become lead oxide. Due to the effect of surface tension, most of the lead oxide is absorbed by the porous cupels, and a small part of the lead oxide is volatilized. Gold and silver are not oxidized, but become alloy particles and remain at the bottom of the cupel, awaiting the next gold separation treatment.

[ Technical Parameters ]

cupel and drawing index

Cupel Size	Height "H"-mm	Outer Dia "D"-mm	Base Dia "D2"-mm	Cup Dia "D1"-mm	Cup Depth "H1"-mm	Ridge Height "H2"-mm	Pcs/Ctn	Ctns/Pallet
2X	17	24	19	18	8	4.5	1080	54
3	20	26	20	23	5.5	8	500	54
4A	22	27	20	24	6	7.5	500	54
4	22	29	23	24	6	8	486	54
5	26	35	26	27	8	6.5	324	75
6A-26	26	40	30	31.2	11.8	6	300	60
6A-29	29	40	30	31.2	11.8	9	240	75
7A	32	40	30	31.2	11.8	12	200	75
7A	32	40	30	31.2	11.8	12	300	48
7AS(7X)	35	40	30	31.2	11.8	15	200	60
							200	75
							300	48
7AS-15	32	40	30	32	15	12	300	48
8	27.1	44.3	34.6	34.2	8.5	9	240	48
8A	35	45	37	38	13	13	200	48
8A	35	45	37	38	13	13	200	50
8AM	35	45	37	33	12	15	200	48
8S	40	44	34	38	14	13	200	48
9	30	51	43	40	11	5	120	75
9A	34	51	39	40	15	14	120	75
10	30.2	60	49.7	52.6	11.5	11	75	75
11	44	56.8	48.8	47.8	14.8	10	80	75
14	70	110	88	80	24	14	12	75