不同反应性炭的气化差异及对铁矿还原的影响

纯氧高炉和煤气化耦合联产是降低炼铁和煤气化工艺能耗和碳排放的重要手段,而研究不同反应性炭的气化差异及其对铁矿石还原影响是实现煤气调质与降低焦比的关键.在模拟纯氧高炉与煤气化耦合联产工艺条件下进行了木炭、兰炭、焦炭的气化和烧结矿、球团矿的还原试验研究.研究结果表明,3种炭与CO2和水蒸气的反应性由强到弱的顺序为木炭＞兰炭...

Gasification differences of different reactive carbons and their effects on iron ore reduction

Coupling of pure oxygen blast furnace and coal gasification is an important way to reduce energy consumption and carbon emission in ironmaking and coal gasification process. The key to realize gas conditioning and coke ratio reduction is to study the gasification difference of different reactive carbons and its impact on iron ore reduction. The experimental studies for gasification of charcoal, semi-coke and coke and the reduction of sinter and pellet ore were carried out under condition of simulating the coupling process of oxygen blast furnace and coal gasification. The results show that the order of reactivity for three carbons with CO₂ and steam is charcoal > semi-coke > coke, the reaction starting temperatures with CO₂ are 650.0, 730.0 and 877.5 ℃,respectively, and the reaction starting temperatures with steam are 613.5, 672.0 and 841.5 ℃, respectively. The characteristic reaction temperatures of three carbons with steam are all lower than that with CO₂. The activation energies of charcoal, semi-coke and coke with CO₂ are 109.51, 119.31 and 176.84 kJ/mol, respectively, while the activation energies with steam are 167.59, 211.67 and 238.65 kJ/mol, respectively. Among the three kinds of carbons, charcoal has the best reactivity and the lowest activation energy. Addition of high reactive carbon can promote the reduction of iron ore, thus the promotive action of charcoal and semi-coke is better than that of coke. Compared with the situation that is no carbon addition, after adding the most reactive charcoal, the reduction degree of sinter and pellet increase by 13.72% and 18.37% respectively. Compared with adding coke, adding the most reactive charcoal increases the reduction degree of sinter and pellet by 2.07% and 14.98% respectively. In blast furnace, an appropriate amount of high reactive carbon can be used to replace coke, so as to reduce the coke ratio, promote the conversion of CO₂ to CO and steam to H₂ and improve the quality of gas.