PANG Jian-ming
,
GUO Pei-min
,
ZHAO Pei
钢铁研究学报(英文版)
The reduction-degree of the sample increases and the utilization ratio of gas decreases when the reaction lasts longer time, which indicates that the reaction is faster at the beginning of reduction, while it becomes slower in subsequent process. The higher the reaction temperature, the higher the utilization ratio of gas and the reduction-degree are, but the difference of utilization ratio among the different temperatures becomes smaller with time. The utilization ratio of gas can reach about 8% and the reduction-degree is 80% for 20 min reduction at 850 ℃, indicating that the reduction reaction by CO is very fast at high temperature. The higher the reaction temperature, the higher the apparent reaction rate constant is, but the difference of apparent reaction rate constant among the different temperatures becomes bigger. The apparent activation energy is about 5911 kJ/mol in the fluidized bed experiment. The increase of reduction-degree with gas velocity shows quite good linearity, indicating that at high temperature even higher velocity of reducing gas can be used to improve the productivity of reactor when CO is used as reducing gas. With the increase of charge height, the metallization ratio and the reduction-degree decrease, but the utilization ratio of gas increases.
关键词:
CO
,
fluidized bed
,
fine powder
,
iron ore
,
reduction-degree
XIA Wentang
,
REN Zhengde
,
GAO Yifeng
钢铁研究学报(英文版)
The selective HCl leaching method was used to remove phosphorus from high phosphorus iron ores. The hydroxyapatite in high phosphorus iron ores was converted into soluble phosphate during the process of HCl leaching. The effects of reaction time, particle size, hydrochloric acid concentration, reaction temperature, liquidsolid ratio and stirring strength on the dephosphorization ratio were studied. The results showed that the dephosphorization ratio can exceed 98% under the conditions of reaction time 30-45 min, particle size <0147 mm, hydrochloric acid concentration 25 mol/L, reaction temperature 25 ℃, liquidsolid ratio 5∶1 and stirring strength 502-1276 s-1. After dephosphorization reaction, the content of phosphorus in iron ore complied completely with the requirements of steel production.
关键词:
high phosphorus
,
iron ore
,
dephosphorus
,
selective leaching
,
hydrochloric acid
,
dephosphorization ratio