Cupellation is the last and most important step in fire assay process and as such, the quality of cupel is extremely crucial.
During cupellation, the lead is oxidized to litharge (PbO), most of which is absorbed by the cupel. Gold, silver, platinum and other precious metals form a bead in the cupel. The bead is subsequently treated to determine its precious metal content.
Our magnesia cupel uses high-quality raw materials and a unique formula. And its composition includes up to 95% magnesium oxide and special flux. It can absorb more lead oxide than ordinary bone ash ones. So our magnesia cupel has strong mechanical strength and perfect quality uniformity.
| Item |
Result |
| MgO |
≥95% |
| Al2O3 |
≥1.2% |
| SiO2 |
≤2.5% |
| CaO |
≤1.3% |
| Working Temperature |
890ºC-1100ºC |
| Specific Gravity: |
2.35 |
| Porosity: |
12%-15% |
| Lead Absorption |
70% |
| A: Height of cupel |
| B: Diameter of Top |
| C: Diameter of Bottom |
| D: Height of Ridge |
| E: Diameter of Inner Top |
| F: Depth of cup |
| Size |
A |
B |
C |
D |
E |
F |
| mm |
mm |
mm |
mm |
mm |
mm |
| 4A |
22 |
27 |
20 |
7.5 |
24 |
6 |
| 4AS |
22 |
27 |
20 |
8 |
24 |
9 |
| 6A |
26 |
40 |
30 |
6 |
30 |
12 |
| 7 |
22 |
39.5 |
29 |
6.5 |
31.2 |
11 |
| 7A |
32 |
40 |
30 |
12 |
30 |
12 |
| 7AL |
28.5 |
39.7 |
30 |
6 |
31.2 |
12.3 |
| 7AS |
34 |
40 |
30 |
14 |
30 |
12 |
| 8 |
27.1 |
44.3 |
34.6 |
9 |
34.2 |
8.5 |
| 8A |
35 |
45 |
37 |
13 |
38 |
13 |
| 9A |
34 |
51 |
39 |
14 |
40 |
15 |
High quality magnesite is the majoritary component of magnesia cupels.
As a rule of thumb, magnesia cupels have a superior quality and offer many advantages:
- Great mechanical strength, and are not affected by atmospheric conditions (not hygroscopic). .
- The prill or bead does not adhere to the fire assay cupel surface,
- When using magnesia cupels, the assay have a reduced tendency to freeze.
- No cracking or spiting, and the beads do not attach to the fire assay cupel surface.
- Magnesia cupels provide security and quickly absorb great amounts of litharge without cracking or pitting.
- Our magnesia cupels allow to reduce the Cupellation temperature and time, resulting in minimal losses, higher accuracy and better yields.
- Perfect uniformity of Quality of cupels
- Quality and performance are continuously improved
Cartons with pallets, or as your request.
Hebei Fiza Technolory Co., Ltd, is a professional manufacturer of assay litharge, assay flux, crucible (Clay crucible, Ceramic Crucible), Magnesia cupel and Magnesia Bullion Block and with perfect management system and mature production technology.
The crucible, cupel and other fire assay consumables are made of high quality raw materials, high temperature resistance, good thermal conductivity, high melting purity, strong corrosion resistance and long service life.
Our staff of sales and technical support is available to help you in selecting the right protection for your application as well as to provide you with samples of our products for evaluation. At High Five, we are committed to providing the highest level of customer service, competitive pricing, speedy delivery and a comprehensive, cutting-edge product offering. Our ultimate goal is your satisfaction.
Fiza Technology HK Limited is our registered subsidiary in Hong Kong, this company is special in doing business with the foreign companies. The company locals in FLAT/RM A1 06F MAI TAK INDUSTRIAL BUILDING 221 WAI YIP STREET KWUN TONG KL HONGKONG.
Welcome to contact me for Quotation!
Vivien Liang
Audited Supplier 
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