The graphite crucible for melting silver has strong resistance to high temperature, small thermal expansion coefficient and small resistance performance, especially for acid and alkali corrosion resistance, it has a good chemical resistance to corrosion.
The graphite crucible for melting gold is dipped and coated with anti oxidation coating, the high temperature graphite will penetrate into the pores of the graphite crucible, and empty the space to form a protective film.This layer of protective film which can effectively cut off the oxidizing reaction after the contact of the air with the crucible, it won’t crack and shed in the high temperature can make graphite crucible in the construction of the delay and the oxidation, which prolongs the service life of the graphite crucible.
The graphite crucible has no any material produced in the high temperature and the room temperature by using this oxidation technology . It also can effectively protect the chemical reaction which the graphite crucible do at the high temperature .
The graphite crucible for melting silver , also named silicon carbide crucible is a kind of crucible with excellent performance which comes from the excellent properties of silicon carbide . The chemical formula of silicon carbide is SiC, the chemical six party crystal, stable structure. The silicon carbide is made from quartz sand, coal and sawdust, etc. as raw materials and smelted by resistance furnace in the high temperature ,it is a most widely used and economical raw material in the contemporary refractory materials.
The graphite crucible for melting gold is a silicon carbide crucible, the raw materials are quartz, coke and sawdust, etc., it’s forged in the high temperature electrical furnace, so the SiC also known as emery, its pure substance is a colorless and transparent crystal, it will show a pale yellow or gray and gray blue if it has a small amount of impurities . Due to the tight structure of silicon carbide, so hard, hardness second only to the natural diamond, it is visible to the hardness of the large. Not only that, the melting point of this material is as high as 2700 degrees celsius. The crucible made from this kind of material , the refractoriness is greatly improved, the density of unit volume increased, the heat transfer is fast, it has the characteristics of acid and alkali resistance and oxidation resistance and so on. Its life is 3 -5 times than graphite crucible.