Slag control agents

are added to the melting furnace as slag additives in order to alter their compo- sition, or to bind the slag being formed, so that this can then be removed with suitable tools, i.e. tapping the slag. Such agents are also used to remove heavy slag deposits from the furnace walls. Normal soda is also often used for this pur- pose. When using soda however, care must be taken to ensure that the crucible wall itself is not damaged.