关键词: 四水氯化亚铁, 流态化, 煅烧

Abstract: The FeCl₂·4H₂O crystals were fluidizely calcinated by air in a φ44mm fluidized bed reactor. The process of producing Fe₂O₃ by FeCl₂·4H₂O using fluidzed calcination was studied. The conversion of FeCl₂·4H₂O crystals with reaction time was obtained by measuring the chloride ion concentration in tail gas absorption solutions with chloride ion selective electrode,and process influence factors was investigated,including superficial gas velocity,average grain diameter and bed temperature. The result indicated that the fluidzed calcination was surface reaction controlled process. Apparent gas velocity was increased,the reaction rate was accelerated,the calcination time was shortened. When the apparent gas velocity at 0.64m/s,the external diffusion was eliminated,and the reaction was controlled by surface reaction. Then,increasing the apparent gas velocity had no obvious effect on the calcination reaction. The generated Fe₂O₃ was loose,and it was peeled off the surface of the particles as well as flowing out of the furnace with air by calcining FeCl₂·4H₂O crystals in fluidization state,which was similar to the shrinking reaction process. The FeCl₂·4H₂O crystals' temperature rising rate and calcination reaction rate speed were accelerated with the increase of apparent gas velocity in the environment of fluid-bed calcination. However,the increasing of superficial gas velocity has no obvious effect on the calcination reaction in the environment of good fluidization. The smaller of the FeCl₂·4H₂O crystals' initial average particle size,the variation of reaction rate with time was more obvious,and the completing time of the calcination reaction was shorter. The bed temperature has a significant effect on the calcination reaction,and the calcination reaction is proportional to the particle surface area.

Key words: ferrows chloride (FeCl₂·, 4H₂O), fluidization, calcination