| Smelting reduction began in the 1920s. In the contemporary world, the main processes include COREX, DIOS, AISI, HIsmelt, CCF and so on. COREX is the only industrialization form of non-BF ironmaking technology, the others are all at industry experimental stage and need further research and improvement. COREX process uses lump coal as fuel and reducing agent. However, It is difficult to get lump coal, and the pulverized coals usually account for approximately 35% .In 2006, Shanghai Baoshan Steel Corporation pudong steel company introduced the biggest smelting ironmaking device COREX 3000 from VAI, but the new factory of pudong steel company has no sinter and blast furnace ironmaking system, thus the pulverized coals are very difficult to use effectively. How to effectively use the pulverized coals is one of the urgent questions that need to solve by the enterprises. Today, the blast furnace pulverized coals injection technology has been already quite mature, and some plants have adopted blind coal and soft coal mixed injection. In some advanced plants, coal rate has already achieved 300kg/t. On the base of the BF injection experience, the CISDI ENGINEERING CO., LTD put forwards a technique project that pulverized coals are injected directly into the smelter gasifier. Therefore, this topic mainly studies whether the pulverized coal can be effectively used through direct injection as the blast furnace by experiments, including the status of pulverized coal in the smelter gasifier.On the basis of theoretical calculation, the following conclusion were drawn through carrying on the different size pulverized coal injection and mixed size pulverized coal injection experiment.①It is feasible that pulverized coal injection from the tuyere in COREX smelting reduction process.②When we carried on the sole coal injection experiment, along with the pulverized coal size reduced, its burning rate greatly increased. When the pulverized coal size reduced to a certain degree, the influence on its burning rate would not be obvious if the pulverized coal size was continually reduced.③In terms of the pulverized coal burning rate only, -100 mesh is the most ideal size. ④In terms of comprehensive factors, such as production cost, the safe production and the pulverized coal burning rate, and so on, -24 mesh is the best size for the sole coal to inject.⑤In the pulverized coal injection quantity experiment, Pulverized coal quantity increased from 16g/min to 60g/min, proved nearly 4 times ,its burning rate did not obviously decrease; we can not obtain the biggest amount of pulverized coal injection under the laboratory condition.⑥When the multi-granularity mixed size injection experiment was being conducted, with the coarse particle size pulverized coal's proportion increasing, its burning rate decreased.⑦Comparing with the result with sole -24 mesh pulverized coal injection, when the -100 mesh 15% and -200 mesh pulverized coal 5% were put into -24 mesh pulverized coal during the experiment, the pulverized coal burning rate had a distinct increase under the same condition. In the process of production, many kinds of size pulverized coal product are inevitably produced. When deal with the lump coal, different size pulverized coal mixed injection is the best plan, which is obtained in this experiment, because it not only conforms to the production reality but also can satisfy the demand of pulverized coal burning rate.
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