Laboratory Nickel Crucible - 700°C Heat Resistant, Suitable for Various Experiments，30ml/50ml/100ml

Nickel Crucibles
The melting point of nickel is 1455°C, and it has strong resistance to alkali and corrosion. Nickel crucibles are commonly used for melting iron alloys, slag, clay, refractory materials, etc.
When using a nickel crucible, the sample temperature should not exceed 700°C because nickel can be easily oxidized at high temperatures.
Nickel crucibles cannot be used for burning precipitates.
Nickel crucibles are suitable for fusing samples with alkaline solvents such as sodium hydroxide, peroxide, carbonate, bicarbonate, and potassium nitrate. They are unsuitable for acidic solvents like potassium hydrogen sulfate or sodium hydrogen sulfate, potassium pyrosulfate or sodium pyrosulfate, and sulfur-containing alkaline sulfides.
Molten salts of aluminum, zinc, lead, tin, mercury, and other metals can make nickel crucibles brittle. Borax cannot be melted in nickel crucibles either.
Nickel crucibles often contain trace amounts of chromium, which should be noted during use.
New nickel crucibles should first be burned in a muffle furnace until they turn blue-purple to remove surface oil stains. Then, they should be boiled briefly with a 1:20 HCl solution and rinsed clean with water.
Alkaline fluxes can be fused in nickel crucibles, generally not exceeding 700°C. Sodium oxide can also be fused in nickel crucibles, but the temperature should be below 500°C and the time short; otherwise, severe erosion will occur, increasing the nickel salt content in the solution and making it an impurity in the analysis.

Acidic solvents and sulfur-containing solvents cannot be used in nickel crucibles. If sulfur compounds need to be fused, it should be done under conditions with excess sodium peroxide. Molten salts of aluminum, zinc, tin, lead, and other metals can make nickel crucibles brittle. Compounds of silver, mercury, vanadium, and borax cannot be burned in nickel crucibles. Nickel dissolves easily in acid, so acid should not be used when leaching molten blocks. A new nickel crucible should be burned at 700°C for several minutes before use to remove oil stains and form an oxide film on its surface, extending its service life. After treatment, the crucible should appear dark green or gray-black. Before each use, it should be washed by boiling in water. If necessary, a small amount of hydrochloric acid can be added and boiled briefly, then washed with distilled water and dried for use.