Crucible is a relatively common product in graphite now, but many carbon people don’t know much about it, so today’s article brought by Ju Xiaobian will give you a popular science about the crucible

The crucible is made of crystalline natural graphite as the main raw material, plastic refractory clay as the binder, and mixed with different types of clinker. It is mainly used for smelting special alloy steel, smelting non-ferrous metals, and their alloys. In terms of product performance and usage, graphite crucible is an indispensable part of refractory materials.

Crucibles can be divided into three categories: graphite crucibles, clay crucibles, and metal crucibles. Among them, there are three types: ordinary graphite crucible, special-shaped graphite crucible, and high-purity graphite crucible. All kinds of graphite crucibles have different raw materials, production methods, process technologies, and product models and specifications due to their different properties, uses, and conditions of use.

The main raw material of graphite crucible is crystalline natural graphite. Therefore, it maintains the original physical and chemical properties of the natural ink. That is: it has good thermal conductivity and high-temperature resistance, the thermal expansion coefficient is small when used at high temperatures, and it has certain strain resistance to rapid heat and rapid cooling. It has strong corrosion resistance to acid and alkali solutions and excellent chemical stability.

There are many types and specifications of the crucible, and the application is not limited by the production scale, batch size, and variety of smelting materials. It can be selected arbitrarily, has strong applicability, and can guarantee the purity of the smelted material.

Due to the above-mentioned excellent properties, graphite crucibles are widely used in the smelting of alloy tool steel and the smelting of non-ferrous metals and their alloys in metallurgy, casting, machinery, chemical, and other industrial sectors. And has a good technical and economic effect.

The types of crucibles are roughly divided into three categories: the first category is copper smelting crucibles, the specification is "No."; 100 crucibles for steel smelting.

Crucible specifications (dimensions) are usually indicated by serial numbers.  The volume of the No. 1 crucible can melt brass, and its weight is 180g. The melting amount of the crucible when melting different metals or alloys can be calculated by multiplying the corresponding metal and alloy coefficient by the bulk density specification number of the crucible.

The raw materials for crucible production can be classified into three types. One is crystalline natural graphite, the other is plastic refractory clay, and the third is a calcined hard kaolin-like skeleton clinker. In recent years, high-temperature-resistant synthetic materials such as silicon carbide, alumina corundum, and ferrosilicon have been used as the skeleton clinker of the crucible. The clinker has a significant effect on improving the quality of crucible products, enhancing the density and mechanical strength of the crucible.

There are three ways to shape the crucible. The more primitive and ancient molding method is manual molding. The second is rotational molding and the third is compression molding.

A graphite crucible is a high-grade refractory container made of natural flake graphite, wax stone, silicon carbide, etc. It is used for smelting and casting copper, aluminum, zinc, lead, gold, silver, and various rare metals.

1. Put it in a dry place after use to avoid rainwater intrusion; it must be baked slowly to 500 degrees Celsius before use.  2. Feeding should be carried out according to the capacity of the crucible, and it should not be squeezed too tightly, to avoid cracking of the crucible due to thermal expansion of the metal.

3. When taking out the molten metal, it is best to scoop it out with a spoon and use calipers as little as possible. If tools such as calipers are used, they should conform to the shape of the crucible to avoid excessive local force and shorten the service life.

4. The service life of the crucible is related to its usage. Avoid direct spraying of strong oxidizing flames on the crucible, to avoid short life due to oxidation of crucible raw materials.

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