Experimental study of thermoplastic properties of agglomerate

Abstract

Traditional routes of ironmaking and steelmaking processes demand high-temperature preparatory steps, such as coking and sintering. These processes are of great concern since they represent a considerable environmental burden. As an alternative, carbon-containing iron oxides agglomerates (sinters) can be used. In this work, the assessment of thermoplastic properties of prepared sinters, especially the determination of softening and liquidus temperatures, was performed by two methods: optical and spindle drop method. For the first-mentioned method, high-temperature observation furnace CLASIC was employed, which enables observation of changes in specimen shape depending on temperature. While in the case of the second method, Furnace Rheometer System FRS 1600 was used. This system allows measuring changes of spindle height as a function of temperature when different normal forces, in specific 3 and 20 N, are applied. Besides, analyzed sinters were of different grain sizes and contained approximately 59 wt.% of iron and 7.2 wt.% of iron(II) oxide. The samples were measured up to liquidus temperature at various heating rates in an inert atmosphere of argon gas. In summary, a good agreement between phase transformation temperatures measured by both methods was achieved, and the influence of experimental conditions on these temperatures was confirmed.