The main raw material of graphite crucible is crystalline natural graphite. Therefore, it maintains the original physical chemical properties of natural graphite. That is: it has good thermal conductivity high temperature resistance, has a small thermal expansion coefficient during high temperature use, has certain strain resistance to rapid heat cold. The ultra-high power graphite electrode has strong corrosion resistance to acids alkaline solutions, has excellent chemical stability. The crucible has many models specifications, it is restricted by the production scale, batch size smelting material variety during application. It can be selected at will, with strong applicability, can ensure the purity of the smelted material.
Precautions for crucible usage:
1. Put it in a dry place after use avoid rainwater intrusion; it must be slowly baked to 500 degrees Celsius before use.
2. Feeding should be based on the capacity of the crucible, avoid squeezing too tightly to avoid thermal expansion cracking of the metal.
3. When taking out the molten metal, use a spoon to scoop it out, use calipers as little as possible. If you use calipers other tools, it should be consistent with the shape of the crucible to avoid excessive local stress shorten the service life.
4. The service life of the crucible is related to the usage. It should be avoided that the strong oxidizing flame is sprayed directly on the crucible, so that the raw material of the crucible will be oxidized short-lived. Graphite crucibles are widely used in the smelting of alloy tool steels the smelting of non-ferrous metals their alloys in the metallurgy, casting, machinery, chemical other industrial sectors because of the above-mentioned excellent properties. has a good technical economic effect.
The raw materials for crucible production can be summarized into three types:
One is crystalline natural graphite
The second is plastic refractory clay
The third is calcined hard kaolin skeleton clinker
In recent years, high-temperature-resistant synthetic materials such as silicon carbide, alumina emery ferrosilicon have been used as the skeleton clinker of the crucible. This clinker has a significant effect on improving the quality of crucible products, enhancing the density mechanical strength of the crucible.
Main uses of graphite crucible:
(1) Evaporation, concentration crystallization of solution
(2) Burning solid matter
Matters needing attention in the use of graphite crucible:
(1) It can be directly heated, can be quenched after heating, use crucible tongs to remove
(2) Place the crucible on the mud triangle when heated
(3) Stir while evaporating; use waste heat to evaporate to dryness
Among the graphite crucibles, there are three kinds of general graphite crucibles, special-shaped graphite crucibles, high-purity graphite crucibles. Various types of graphite crucibles have different raw materials, production methods, process technologies product specifications due to their different properties, uses conditions of use.