Low carbon process development for iron production

An arc plasma torch system for iron production with low carbon exhaust has been developed. Instead of using cokes, H₂ and CH₄ gas are used as plasma forming gases for direct reduction of iron oxide. Three carbon rods are used as electrodes, and each electrode is connected with one phase of three phase A.C. power supply. Arc discharge is sustained between the two of three electrodes, and electrodes manipulating device is designed to feed the electrodes into furnace to maintain fixed electrode gap during operation. Plasma gas is injected from the bottom of furnace, and the exhausted gas flow is upward. Temperature and enthalpy distribution of arc plasma are obtained for various operating conditions such as applied voltage, arc current, plasma gas flow rate etc., by numerical method. Chemical equilibria of materials are calculated using conventional code for these data. The relation among iron production rate, operating conditions (input power, gas flow rage) and carbon dioxide exhaust rate are discussed.