Manganese is a silvery-white hard metal that is found in some steels and is often added in small amounts to harden the steel and enhance its corrosion resistance. Melting quartz crucibles with a pour spout cannot be used to pour steels containing high manganese levels.
The reason for this is that manganese has a melting point of nearly 1245 °C and quartz melts at a much lower temperature of 1649 °C. Therefore, when melting the steel in a quartz crucible, it is possible for the manganese in the steel to reach a temperature at which it will melt. This will cause the manganese to form a low-melting slag that could be sucked up into the pour spout of the melting crucible and contaminate the steel being poured. As a result, steel with high manganese levels cannot be poured from a melting quartz crucible with a pour spout.
In order to pour steels with higher manganese levels, crucibles such as graphite or clay-bonded masonry must be used. These crucibles can withstand a much higher temperature than a quartz crucible and are therefore better suited to this application. Both these crucibles are also capable of withstanding the high slag temperatures created during the simultaneous melting of the steel and the manganese. This is necessary to prevent the manganese from forming a low-melting slag and causes the slag to remain in the crucible, thereby preventing its contamination in the steel being poured.
In addition to using a suitable crucible, it is also important to note that pouring steel with high manganese levels requires extreme safety precautions. In order to pour molten steel it is essential that the crucible be heated to its appropriate melting temperature, which for steels containing high manganese levels will be higher than the melting temperature of quartz. As a result, it is important to use a suitable heat source to enable you to safely reach the required melting temperature.
It is also important to ensure that all personnel working with the molten steel take proper safety precautions. In particular, it is important to wear appropriate personal protective equipment such as heat-resistant clothing, face protection and gloves.
In conclusion, melting quartz crucibles with a pour spout cannot be used to pour steels containing high manganese levels. To safely pour steels with a high manganese content, crucibles such as graphite or clay-bonded masonry must be used and appropriate safety precautions, including the use of suitable personal protective equipment, must be adhered to.
