Nonferrous and precious metal smelting graphite

2020/03/23
Smelting metal graphite crucible

Smelting metal graphite crucible

Graphite crucible is widely used in all kinds of furnace to melting, such as jewelry, gold, silver, copper, brass, iron, aluminum, zinc, lead and so on.It is widely used in nonferrous metal and precious metal industry, mould industry, glass industry, rare earth industry, photovoltaic industry, laboratory analysis industry and other fields

Physical and chemical index:

The Graphite crucible have adopted three kinds of materials:Fine-grain Specialty Graphite, High pure graphite, Isostaic graphite.

		Fine-grain Specialty Graphite	High pure graphite	Isostaic graphite
Item	Unit	Typical value	Typical value	Typical value
Max grain size		0.8mm	≤325mesh	5-22vm
Bulk density	g/cm3	1.73-1.76	1.68-1.85	1.8-1.85
Specific resistance	Μ Ω .m	7.5	≤14	≤15
Bending strength	M pa	11-12.5	≥25	12.5
Compressive strength	M pa	27-34	≥50	34
Thermal Conductivity	W/(m .k)	150-160	≥130	160
C.T.E.(100-600)℃	10-6/℃	2.2	≤2.5	2.1
Ash content	%	0.09	≤0.15	0.09

As long as you provide us with your use, we will choose the suitable crucible for you.

1. According to your application. For example if you need crucible to melt jewelry, gold, silver and other precious metal. We will suggest the high purity graphite for you, because it does not have impurity and will not influence your precious metal.

2. According to your working temperature. For example, if your working temperature is within 500 degree, the ordinary graphite with density 1.75g/cm3 is OK. If your working temperature is more than 2000 degree, I think we must consideration the isostatic graphite with the high density.

3. According to your thermal shock property. For example, in the same temperature 200 degree, the different time will bring different influence.

4. According to your acid-base property. For example, if your working environment is strong acid or strong base, we will suggest impregnation for you.

How to use

1.The crucibles should be put on the pallets instead of the ground and stored in a dry place with good ventilation.

2. Use the proper base to support the crucibles. Attention! The base should be with a bigger diameter than the crucibles’ bottom and with the same material as the crucibles’.

3.Make sure the furnace lining works well .Make sure the crucible and furnaces are concentric.

4. Use pincers to put the metal into crucible carefully

5. Check the burner position in order to ensure the flame is under the joint of crucible and base plate, flame cannot touch the crucible directly.

6. Don’t add up refining agent into the crucible before the aluminum ingot melting is forbidden

7.Clear up slag regularly using proper tool to protect inside wall of the crucible.

Heating Method

Preheating: Please preheat the crucible approaching to furnace 4-12 hours, or burning wood inside the crucible for 2 hours.

Make sure the drying time long enough in order to preheat and remove moisture, avoid cracks, make working service life longer.