Softening and Melting Behaviour of Sinter and Pellets

Abstract

To evaluate high temperature properties of blast furnace burdens, a series of reduction under load tests were carried out under simulated blast furnace conditions, using sinter, self-fluxing pellets, and acid pellets. To investigate the softening and melting mechanism, structural analyses were conducted on those samples recovered after interrupting the test.
The results obtained are summarized as follows.
1) Formation of molten slag is involved in the assimilation of slag during softening and melting processes, and the basic path for this assimilation is considered to be toward the final composition (average slag composition before reduction) along the expanding direction of the low melting temperature range with heating.
2) The difference in softening and melting behaviour of these burden materials is directly due to the quantity of molten slag formed in the slag assimilation process. It is indirectly due to the differences in reducibility at temperatures above 1000°C in addition to the composition and volume of gangue before reduction.