Agglomeration of iron ore fines is necessary to enable them to be used as a feed to iron-making blast furnaces. Extensive study by CSIRO has shown that briquetting is a good potential alternative process for agglomerating fines. This article describes comprehensive work to determine the effects of briquetting conditions on the quality of green and fired briquettes produced from Australian haematite–goethite iron ore fines. Four variable (feed moisture and three machine operating conditions), three level, Box-Behnken experimental designs were used firstly to determine the optimum conditions for briquetting iron ore fines with a Köppern briquetter. These machine operating conditions were used to determine the effects of feed moisture, basicity, grind size and firing temperature on the production of fired briquettes. Feed moisture levels, size distribution of the feed and rolls speed were found to affect the yield and thickness of the green briquettes. Basicity levels (measured as the ratio of CaO to SiO 2 contents) over the range 0.95–1.60 had minimal effects on the properties of the green briquettes. When green briquettes were fired at 1270, 1290 and 1310°C in a rotary pot, the firing temperature was shown to have a major effect on fired briquette properties. The modelling work demonstrated reliable predictability of green and fired briquette properties which gives a possibility for process optimisation.
Vining et al. (Wed,) studied this question.