Method for obtaining high purity ductile iron

Abstract

A method for making high quality liquid iron with substantially no residual chemical elements and a controlled content of carbon, manganese, phosphorous, sulfur and silicon in the final metal. Sponge iron, as raw material, is melted in a vessel or converter with a basic refractory lining. The energy required for melting the sponge iron is provided by the exothermic reaction of carbon from any coal or carbonaceous material and oxygen in solution within the metal bath and by the combustion of other hydro-carbon fluids, all injected to the bath through nozzles preferably located in the bottom of the converter. Further energy is obtained with the post-combustion of gases leaving the metal bath when ascending to the upper port of the converter. Alloy additions might be made by injection in order to obtain a liquid bath chemical composition which permits that the final liquid metal be used as starting material with excellent properties for the fabrication of high quality iron, particularly ductile iron, which has a very stringent condition for reaching desired properties. Specifically important is the chemical analysis of the metal bath before solidification of the final cast piece. Final liquid metal from the converter can be solidified in form of small ingots for easy further handling. These ingots are excellent as starting material for ductile iron fabrication.

Dependencies are inferred from the claim text.