Xiaodong Du’s research while affiliated with University of Science and Technology Beijing and other places

Low-silica pellet is beneficial for blast furnace to reduce the amount of slag and fuel rate. However, the reduction swelling of low-silica pellet is serious. The effects of TiO2 and MgO on such metallurgical properties as reduction swelling, reducibility and smelting performance of pellets have been studied and production of magnesium–titanium-bearing pellet with low silica is proposed in this paper. The MgO in sinter can be transferred to pellet and TiO2 is provided by the pellet for blast furnace to protect hearth erosion. The magnesium–titanium-bearing pellet with low silica, in which the content of MgO is 1.7%, SiO2 is 2.8% and TiO2 is 1.2%, has been produced by the raw materials from Shougang Jingtang United Iron & Steel Co., Ltd. The pellets were used on 5500 m³ blast furnace with a ratio of more than 28% stably and good technical and economical indexes were obtained. The average particle size of sinter was improved when the MgO content of pellet is increased without adding magnesium additives to sinter.

The assimilation properties of iron ores are important during sintering. The amount of formed calcium ferrite was firstly used to evaluate the assimilation. Then, temperature and time of assimilation were proposed rather than the former one, which simplify the process and improve the operahility of experiments. However, the factors affecting the temperature were always neglected and using several indexes to evaluate the assimilation was inconvenient. In this paper, the assimilation reaction characteristic number taking the actual sintering temperature as the reference temperature was put forward to evaluate the assimilation of iron ores. This assimilation reaction characteristic number was a dimensionless number including kinds of important information during the assimilation reaction process. Results showed that the assimilation characteristic number can reflect the overall process of assimilation reaction between ores and CaO, which could help further analyze the assimilation difference of ores.