移动床内氧化铁还原及还原气体氧化行为分析

Analysis of reduction of iron ore and oxidation of reducing gas in moving bed

为了研究工艺参数对移动床内氧化铁还原及还原气体氧化的影响规律,建立了移动床内氧化铁还原及煤气氧化耦合动力学模型。以C-3000的竖炉预还原为例,动力学模型研究主要结果与实际工艺相吻合。气矿比一定条件下,标况气速提高,会增加移动床的产量,但金属化率和煤气利用率都将下降;标况气速一定条件下,气矿比提高,能够提高金属化率,但产量和气体利用率下降。煤气还原势对移动床内的还原效率有明显影响,为了提高金属化率,建议将还原势提高到95%左右的水平。当标况气速一定时,煤气压力的增加,提高了金属化率和煤气利用率。煤气中的惰性气体含量对移动床内的还原有不利影响。适度增加球团矿比例或向煤气中适度提高氢气含量,有助于移动床内还原效果的提高。

To investigate the influence of technical parameters on reduction of iron ore and oxidation of reducing gas in moving bed,the coupling kinetic model of iron oxide reduction and reducing gas oxidation in moving bed was established.The model was applied in pre-reduction shaft furnace of C-3000,and main calculating results were in a good accordance with production data.At a certain ratio of gas flow to ore mass,improving gas velocity at standard state can increase output of metal iron,yet decrease ratio of metallization and gas utilization rate.At a certain gas velocity at standard state,improving ratio of gas flow to ore mass can increase ratio of metallization,yet decrease output of metal iron and gas utilization rate.Reduction potential of gas has a substantial effect on reduction efficiency.It is suggested to improve reduction potential of gas to a 95% level for a high ratio of metallization.At a certain gas velocity at standard state,increasing gas pressure can improve ratio of metallization and gas utilization rate.Inert gas content has a disadvantageous effect on reduction reaction in moving bed.It is advantageous for improving reduction efficiency in moving bed by adjusting increasing ratio of pellet or adding part of rich-hydrogen gas in reducing gas.