The Effects of Lime Properties on Basic Oxygen Steelmaking

Abstract

Observations covering periods of good and bad conduct of heats pointed at the lime as being the cause of the metallurgical differences. A good parameter for metallurgical properties of burnt lime is its dissolving rate in water. Analysis furnishes information about the burning degree of the lime. Soft burnt lime leads to a more rapid dephosphorization and better desul-furization, as well as an easier conduct of heat with reduced slopping. Hard burnt lime has a poor solubility in slag, and pieces of lime remain undissolved. Slopping increases; the final composition of iron and slag and the final temperature are more widely scattered. Hard burnt lime is denser, the crystallite grain is larger. Annular shaft kilns with waste gas recirculation are being started up by the supplier for the production of soft burnt lime. Sizing the burnt lime by utilizing differences in density is also intended.