Simple and Great Tips for Prolonging the Service Life of the Crucible

Simple Tips that can Prolong the Service life of the Crucible

The crucible is a kind of refractory materials and a kind of kiln furniture that is simple, quite functional and easy to handle. Easy as it is to use the crucible, there are several details needing special attention and care. Adopt the correct ways to preheat the crucible can prolong the service life of the crucible greatly. In this passage, we’ll explore the tiny details for each link of crucible usage.

Preheating

1. When using the crucible for the first time, before filling the feeding in, we will preheat the crucible to about 200 degrees Celsius in 30 minutes, varying for different types of crucible and dry for 60 minutes in an attempt to volatilize the water absorbed from the surface of the crucible. In this way, we are able to prevent burst upon its initial use.

2. After preheating, the crucible should be heated to 900-1000 degrees Celsius (in about 2 hours) as soon as possible, and keep it warm for 20-30 minutes, and then rise to or fall to the working temperature. The purpose of doing so is to quickly pass through the graphite crucible oxidation temperature range.

3. After heating of the crucible for the first time, no further heating is usually required unless the crucible is again damp.

Feeding

1. The metal powder must be dried before being added into the crucible.

2. Put down the crucible gently when adding the feeding, do not throw or pour the metal ingot into the crucible, which may otherwise damage the crucible.

3. Place the ingot in the crucible vertically, and leave enough expansion space between the ingot and the crucible wall. Do not place the ingot horizontally in the crucible, in case it shall swell and break the crucible.

4. Small pieces of metal can be added to the crucible as a bedding for large ingots.

5. During continuous smelting, part of the metal solution can be retained in the crucible to accelerate the melting speed. However, it is necessary to avoid adding large pieces of metal material to a small amount of solution, which might damage the crucible if the solution shall quench or solidify.

6. Avoid spill of the solution while replenishing it, normally no more than 80% of the crucible capacity.

The use of additives

1. Additives can only be added after the metal has completely dissolved. Avoid putting them inside an empty crucible or within solid metal material, nor can the additives directly contact the crucible wall or the outer edge of the crucible, otherwise it will directly damage the crucible.

2. When using additives, it must be added in strict accordance with the prescribed dosage, excessive use of additives will greatly shorten the service life of the crucible.