Removal of Copper from Carbon Saturated Molten Iron by Using FeCl₂

Abstract

Possibility of removal of copper from molten iron by using FeCl₂ is experimentally examined in a small size experimental apparatus. Pulverized FeCl₂ is injected with nitrogen gas into molten iron saturated with carbon. The iron chloride is first vaporized in molten iron and then reacts with copper alloyed in molten iron. 0.7 and 0.06% of copper contents are decreased to 0.5 and 0.04%, respectively, under 230hPa in partial pressure of FeCl₂ at 1450°C.
Rate equation can be written as an apparent first order reaction for the copper contents:
-log[%Cu]_t/[%Cu]_o={exp(-3.72 × 10³/T+1.04)}t, where T is temperature in Kelvin and t is time in minute.
No effect of mass of specimen on the reaction rate is observed under the experimental condition. Rate determining step of the reaction is estimated as diffusion process of copper in the molten metal. It is estimated that the minimum ratio of mass of FeCl₂ to molten iron is 18.5kg-FeCl₂/1t-iron when 0.5% of the copper content change to 0.1%.