Chinese name: graphite crucible mbth: Main raw materials of graphite crucible: graphite, silicon carbide, etc. Features: natural graphite and artificial graphite: high temperature resistance, strong thermal conductivity, etc. Subject: Metallurgical description, raw material ratio, types, production technology, characteristics, maintenance and preservation. The graphite crucible is made of natural flake graphite as the main raw material and plastic refractory clay or carbon as the binder. It has the characteristics of high temperature resistance, strong thermal conductivity, good corrosion resistance and long service life. In the process of high temperature use, the thermal expansion coefficient is small, and it has certain strain resistance to rapid cooling and rapid heating. It has strong corrosion resistance and excellent chemical stability to acid and alkali solutions, and does not participate in any chemical reaction during smelting. The inner wall of graphite crucible is smooth, molten metal is not easy to leak and adhere to the inner wall of crucible, which has good fluidity and castability and is suitable for casting in various molds. Because graphite crucible has the above excellent characteristics, it is widely used in the smelting of alloy tool steel, nonferrous metals and their alloys. Raw material ratio The main raw materials of graphite crucible are graphite, silicon carbide, silicon dioxide, refractory clay, asphalt and tar. Graphite is the main raw material for crucible production, accounting for 45 ~ 55% of the ingredients, and flake graphite and needle (block) graphite are preferred. Scaly carbon graphite is widely used in graphite crucibles produced in China, and the carbon content is generally 85 ~ 93%. Choose graphite particle size according to the performance, use, model and specification of crucible. Generally, the large crucible with the volume greater than 100# adopts large flake graphite with 32 meshes or more; The medium-sized crucible with 60 # ~ 80 # volume adopts 80 mesh flake graphite; Small crucibles under 50# are made of 100 mesh flake graphite; The special-shaped crucible for hand molding adopts-100 mesh fine flake graphite. Refractory clay mainly plays the role of plastic inorganic binder. Clay is required to have pure composition, strong plasticity and stable physical and chemical properties. And has high fire resistance and good thermal effect. Due to the different substances and conditions used in crucible melting, the proportion of various raw materials in production ingredients is also different. It should be reasonably determined according to the performance, purpose and use conditions of the crucible. I graphite crucible is mainly used for melting metal materials. It can be divided into natural graphite and artificial graphite. 1) natural graphite It is made of natural flake graphite as the main raw material and clay and other refractory raw materials, which is generally called clay graphite crucible, while asphalt as binder is called carbon binder crucible, and clay binder crucible is made only by the sintering force of clay. The former is superior in strength and thermal shock resistance. Used for melting steel, copper, copper alloy and other non-ferrous metals, with a capacity ranging from 250g to 500kg. This crucible includes skimming spoon, cover, connecting ring, crucible support, stirring handle and other auxiliary documents. 2) Artificial graphite The above natural graphite crucibles usually contain about 50% clay minerals, while the impurities (ash) of artificial graphite crucibles are less than 1%, which are used for refining high-purity metals, high purity graphite (ash