| Iron ore pellets have become a high-quality metallurgy feedstock for ironmaking in the blast furnace. The fast development of iron ore pellets production has brought about serious shortage of pellet feed. It is urgent for us to look for the foreign iron mine resources. Brazilian speculariie has been attractting more and more attentions of pellet producers due to its high iron grade and lower price in spite of poor ballability and pellet burning ability. Currently the addition ratio of Brazilian specularite in pellet feed is generally lower than 20%, therefore,it is of importance to develop measures to greatly improve the pelletization of single Brazilian specularite.In the research some measures have been developed for pelletizing Brazilian specularite. Brazilian specularite blended with lower ratio of in-plant iron and carbon-containing dust or lime stone dust, was pretreated by damp mill, greatly improving the ballability and pellet roasting ability. With the optimum pellet feed proportioning and process parameters, the difficulties in pelletization of single Brazilian specularite has been tackled. The optimum pellet feed consists of Brazilian specularite with 9.0% in-plant iron and carbon-containing dust (having 2.03% carbon) and / or 2.93% lime stone dust (basicity: 1.0) added. Under the conditions of 1.5% bentonit A, damp milling at 6% moisture for 6 mins, balling for 15mins at 7% moisture, quality green balls were made with the drop number of 4.1 times from 0.5m and compressive strength of 15.61N per pellet, and the shock temperature of 600℃. The green balls were hardened at 900℃ for 15mins for preheating and at 1200℃ for 15mins for roasting, quality product were manufactured with compressive strength of 3450N per pellet and assaying 66% iron.In this paper, surface wetting heat, surface potential and ballability index of Brazilian specularite,in-plant iron and carbon-containing dust, lime stone dust and the pellet feed were determined respectively. It was shown that the in-plant iron and carbon-containing dust and lime stone dust have superior hydrophility and lower surface potention, improving the wettability of the pellet feed, increasing its activity and surface-attraction force, resulting in stronger green pellets.The hardening mechanism of firing hematite pellets was changed from traditional growth and re-crystallization of original hematite minerals to newly formed hematite minerals due to the lightly reduction of hematite to magnetite followed by the re-oxidization of newly formed magnetite with presence of carbon-bearing dust. In the contrast, the hardening of Brazilian specularite pellets was enhanced by the addition of lime stone dust ,which could be explained that the re-crystallization and growth of hematiteminerals was contributed to the diffusion of Ca2+ into hematite lattice, lowering the melting temperature and enhancing solid phase reactions. Therefore, both in-plant iron and carbon-containing dust and lime stone dust can improve the firing behavior of the Brazilian specularite pellets. It was found under optical microscopy that the microstructure of the fired pellets was obviously improved, when the Brazilian specularite was blended with in-plant iron and carbon-containing dust or lime stone dust, the hematite crystal bonding each other in the pellets was better than those pellets made by single Brazilian specularite.
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