Effect of surface-active species on the foam stability in the EAF slag system

To determine the proper slag chemistry for sound slag foaming characteristics, the concept of a gas hold-up index (epsilon(G)) was introduced using a special device during an EAF operation. The gas hold-up index became larger with smaller bubble sizes in the final foaming slag, indicating there was a strong relationship between foam stability and bubble size. Proper slag basicity was determined by measuring gas hold-up indices and effects of the slag components were also defined by the index. Trends of foam stability as a function of basicity and possible surface-active elements were considered to evaluate the foam stability. Gas bubble sizes associated with the foam stability were also dealt with by measuring final foamy slags.