Worldwide iron ore production continues to increase, driven by growth in steel output in China, with export output from Australia and Brazil expanding, whereas exports from India and Chinese domestic production are expected to decline in the medium-term (Ericsson, Lof and Ostensson, 2012).In the south-east Asian region, it is expected that sinter plant fine ore Fe feed grade will decrease gradually and ore sizing will become finer, as high-grade deposits decline and lower-grade resources are increasingly exploited. Increasing ore goethite content is a major issue for Australian ores, particularly with respect to reactivity during sintering. The cost and quality of coking coal and focus on emissions control are also issues that will only become more important with time. As a result, there is a critical need to understand the fundamental sintering characteristics of different ore types in order to optimise changing ore properties in sinter blends comprising the primary blast furnace feedstock.CSIRO operates the only Australian facility for industry-standard pot-grate sinter testing of iron ores and has extensive experience in evaluating and optimising blends containing a wide range of Australian and international ores. CSIRO has also developed unique laboratory-scale tests to separately study the behaviour of fine, reactive iron ore components and coarse nucleus particles at a more fundamental level, as well as investigating reaction mechanisms during silico- ferrite of calcium and aluminium (SFCA)and SFCA-1 formation via in situ high temperature X-ray and neutron diffraction studies (Webster et al, 2013). The aim is to integrate the results of fundamental, laboratory-scale and pilot-scale sintering tests to provide an in-depth understanding of the iron ore sintering process.In this presentation, the fundamental melting properties of hematitic, hematite-goethite and goethitic fine ores have been evaluated using the method described in Clout and Manuel (2003), where the mechanism leading to high temperature strength development in magnetite blend sintering was identified as magnetite-magnetite grain bonding. At the lower temperatures required for sintering hematitic ores, SFCA, derived from the reaction between the fine (nominally -1 mm) fraction of the ore and fluxes, is the primary bonding phase formed in the sinter matrix. Understandably, the nature of the reactions that occur in the reactive matrix during heating and cooling have a primary influence on the properties of the resulting sinter product.The aim of the laboratory-scale melting test is to evaluate the development of sinter matrix strength during melting of the fluxed, fine reactive (nominally -1 mm) component of the ore. This test simulates the initial melt formation that occurs in the granule adhering fines layer during the sintering process, resulting in inter-granule bonding. The strength of these bonds has a critical influence on the overall strength of the sinter. Fluxed -1 mm ore blends are compressed into tablets and fired using a standard heating profile, in a controlled, low oxygen potential atmosphere. The matrix strength is expressed as a laboratory-scale tumble index (TI), which correlates with the industry standard pot grate tumble test; a laboratory scale TI of ~80 per cent correlates to a pot-grate TI of 65 per cent.Three mineralogically and texturally distinct ores were compared: a hematite ore (Sample H, 67.05 per cent Fe, 1.59 per cent LOITOTAL), a hematite-goethite ore (Sample H-G, 60.74 per cent Fe, 5.87 per cent LOITOTAL) and a goethite ore (Sample G, Fe 58.23 per cent Fe, 9.84 per cent LOITOTAL). Figure 1 shows the develop-ment of strength for each fluxed ore with increasing temperature. The overlapping profiles correlate with the structures developed within the sinter matrix, evaluated by sectioning the fired samples and examining them microscopically, as well as the mineralogy and textural characteristics of the ores.The melting profiles are a key to the complementary properties of the three ore types represented and to understanding their individual strengths and limitations within a sinter blend.*This is an abstract only. No full paper was prepared for this abstract.*CITATION:Ware, N, Manuel, J R, Raynlyn, T and Lu, L, 2013. Melting behaviour of hematite and goethite fine ores and its potential impact on sinter quality, in Proceedings Iron Ore 2013 , pp 485-486 (The Australasian Institute of Mining and Metallurgy: Melbourne).