The External Desulphurisation of Hot Metal.

Abstract

This thesis is based on works trials and laboratory model studies. Iron samples taken on the works showed that a sample from the torpedo gave an adequate estimate of the iron sulphur level. The mixing characteristics of iron during the calcium carbide based torpedo injection process were examined using a model. The modelling criterion was that the energy input per unit mass of liquid should be the same for the model and the plant. The mixing time was primarily dependent on the lance immersion depth and the rate at which the gas evolving agent was introduced to the iron. The effect on the process of torpedo internal skulls was demonstrated. The results of this model work were confirmed by plant data, and were used in making adjustments to the operation of the plant. A torpedo model was used to study the effects of its mouth shape on desulphurisation slag removal. The most significant factor was the metal pouring rate but the mouth shape determined the ease of removing the large lumps of slag which occur.