Tungsten crucibles are mainly applied to the fields of metallurgy industry, machining, glass and ceramic industry, etc. Tungsten crucibles belong to one of tungsten products, and are mainly divided into sinter molding, impact molding and spin molding. They are formed by performing corresponding processes on pure tungsten plates, tungsten sheets and pure tungsten bars by turning molding, welding molding and many other methods of tungsten bars. Tungsten crucibles can be used in vacuum inert gases at the temperature of lower than 2,600℃.
Tungsten features high melting point and boiling point, good high-temperature strength, wear and corrosion resistance, large thermal conductivity, small thermal expansion coefficient and good hardenability. They are widely applied to rear earth metallurgy, quartz glass, electronic spraying, crystal growth and other industries.
How to clean oxidizing substances on surfaces of molybdenum bars?
Dark oxidizing substances will be formed on surfaces of molybdenum bars through high-temperature sintering of oxyhydrogen flame. What are the substances, molybdenum dioxide or molybdenum trioxide? Now, we need to clean them out. It’s better to soak them in some chemical agents to dissolve them. What methods do you have?
Molybdenum is stable in the air at normal temperature, and can react with oxygen at 500℃ to generate molybdenum trioxide. Molybdenum trioxide is slightly soluble in hydrochloric acid and easily soluble in hot concentrated sulfuric acid and concentrated nitric acid. Moreover, it can be dissolved and removed by diluted sodium hydroxide solution due to its solubility in ammonium hydroxide and aqueous alkali.