Molten metal gets poured into what they call a crucible tundish furnace. In order for wrought copper alloys to be successfully formed, the furnace must be operable within a controlled atmosphere.
The tundish is able to maintain a large volume of molten copper, just as long as the temperature is being controlled. The furnace is stationed above a water cooled graphite die. Any doss that enters the tundish furnace will quickly float to the top of a metal bath from which it can be removed.
The next process in the production of wrought copper alloys is this. But hang on a second, there is a deliberate omission. The entrainment of slag in cast bars will not be possible. Castings must be free of solid inclusions. There must be no porosity from gas or shrinkage. Copper must enter a freezing zone. The temperature must be appropriately controlled in order to enable any detected shrinkage pores manifest in prior cast materials to be filled.
It takes just a fraction of a second before a rapid freezing process begins. A severe segregation of alloying elements can be avoided. Further processing techniques are utilized to further reduce segregation and vastly improve casting strength by way of generating fine grain structures within the casting. The frozen layers of copper rapidly shrink away from the graphite die. It is withdrawn from the die by way of using electrically driven pinch rolls.
The newly solidified portion of the casting exits the freezing zone. The die is then gravity filled with the molten copper from the tundish. And so it goes that a solidification process will commence all over again. Once casting has achieved its desired length, it will be cut off with a flying saw that is positioned just below the pinch rolls.