Method of operating a centrifugal plasma arc furnace

A method of treating waste material in a plasma arc furnace having a rotatable chamber which method comprises the steps of:

• placing a mass of iron bearing metal into the rotatable chamber prior to introduction of any of the waste material into the chamber;
• rotating the chamber;
• heating the iron bearing material to a molten state with the plasma arc;
• introducing the waste material into the chamber after the iron bearing material is made molten;
• heating the waste material with the plasma arc to melt the waste material into a slag;
• and
• introducing oxygen into the chamber during heating of the waste material;
• continuing rotation of the chamber and exposure to oxygen after the chamber has been filled to its capacity with waste material;
• said continued rotation and exposure to oxygen being performed for a period of time suitable to produce iron oxides in the slag which iron oxides are predominantly in a magnetite state, whereby the slag is mixed to a desirably homogenous condition while retaining a relatively low viscosity that facilitates its removal from the chamber;
• and
• discharging the iron bearing, molten slag from the chamber.