Crucible is an important part of chemical instruments. It is a vessel for melting and refining liquid metal and heating and reacting between solid and liquid. It is the basis for ensuring the smooth progress of chemical reactions.
- (1) Burning solid matter
- (2) Evaporation, concentration or crystallization of the solution (if there is an evaporating dish, the evaporating dish should be selected. Of course, the crucible can also be used for the evaporation, concentration or crystallization of the solution)
Precautions for use
- (1) It can be directly heated, and can not 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
Crucibles can be divided into three categories: graphite crucibles, clay crucibles and metal crucibles.
Among the graphite crucibles, there are three kinds of general graphite crucibles, special-shaped graphite crucibles, and high-purity graphite crucibles. Various types of graphite crucibles have different raw materials, production methods, process technologies, and product specifications due to their different properties, uses and conditions of use.
The types of crucibles are roughly divided into three categories: the first type of copper smelting crucible, its specification "number"; the second type is copper alloy crucible, the special round has 100 numbers, the round has 100 numbers, the third This kind of crucible for steelmaking has 100 numbers.
Crucible specifications (size) are usually expressed by the size of the serial number. Crucible No. 1 has a volume capable of melting 1000g of brass, and its weight is 180g. The melting amount of the crucible when smelting different metals or alloys can be calculated by multiplying the corresponding metal and alloy coefficient by the specific weight of the crucible.
Crucible production materials can be summarized into three types. One is crystalline natural graphite, and the other is plastic refractory.
Nickel crucible is suitable for NaOH Na2O2, Na2CO3 NaHCO3 and alkaline solvents containing KNO3 to melt samples, but not suitable for KHSO4 or NaHS04, K2S2O7 or Na2S2O7 and other acidic solvents and sulfur-containing alkaline sulfide flux melting samples.