Research On Sticking During Iron Ore Reduction In Fluidized Bed

COREX process uses non-coking coal as the main fuel. The structure of energy sources is improved thoroughly. The advantage of COREX process is faded in. POSCO has developed FINEX process depending on COREX process. The most advantage of FINEX is that fluidized bed is used as pre-reducing unit instead of shaft which needs lumps as raw material. The main problem that is met in the course of development is sticking during iron ore reduction in fluidized bed. The way that is used to prevent sticking by POSCO is reducing restorage temperature and adding fuel. Althoug it can prevent sticking, the rate of reductive gas and speed of iron ore reduction will be taking down because of temperature falling in fluidized bed. And then the cost of iron pig is rising. This paper introduced tests on sticking and gave some advice in order to find the most advisable way of preventing sticking.Sticking for iron ore reduction in fluidized bed is the key problem which embarrasses the alteration. This paper has described the test about sticking and given theoretic analysis and some suggestions.Not only some normal equipments, for example gas analyzer, analytical balance and so on, but also non-conventional equipment—visual fluidized bed have been used in this experiment. The reactor through which a tester can observe sticking phenomenon well and truly was made up by quartz glass pipe.There were two steps in this experiment. Research on the mechanism of sticking was the first one. Experimental research has been carried out by using the eyeable fluidized bed. Those specimens have been analysed and observed bytesters through an electron microscope. Research on the methods of preventing sticking was the second one. Fuel and flux, which were needed in the process have been interfused into iron ore. And then the experiment repeatly uses the mixture in order to find out the preventing effect.The mechanism of sticking has been explored after those experiments, and meanwhile the method for preventing sticking has also been discovered. When coke powder were mixed into iron ore, sticking in fluidized bed would not happen. This paper summarizes that the alteration from COREX to FINEX is possible and eligible molten iron can be produced in the process of FINEX.