【摘要】 利用热重分析（TGA）和实验装置进行了半焦直接还原铁矿石试验,对比了不同还原温度和气氛下还原产品的性质。由TGA,焦矿质量比为1∶1的半焦铁矿石混合物由室温加热至1 100℃,N₂,H₂和CO气氛下还原过程可分为3个阶段,其中N₂下3个阶段活化能随温度逐渐增加,而H₂和CO下则先增加后降低。由固定床还原产物分析结果,温度和气氛对半焦直接还原铁反应过程及反应程度均有一定影响。3种气氛下,900℃后产物中主要为金属Fe,但引入还原性气体H₂,CO可有利于低温下铁矿石的还原。N₂气氛下反应至900℃后半焦可对铁矿石进行还原,但得到的海绵铁金属化率低于90%,无法满足直接炼钢要求,可通入H₂、CO等活性气氛,提高还原产品的品质。更多还原

【Abstract】 Experiments on iron ore direct reduction by char were carried out using thermogravimetric analysis（TGA） and laboratory test equipment. The properties of the reduced products at different reduction temperatures and atmospheres were compared. TGA shows that the reduction process of 1 ∶1 char-ore mixture can be divided into three stages from room temperature to 1 100 ℃. The activation energy of three stages increases with temperature in N₂ atmosphere, but increases first and then decreases in H₂ and CO atmosphere. According to analysis results of the products from fixed-bed direct reduction, the reaction temperature and atmosphere have certain influences on the reaction process and degrees of reduction reactions. Under the three atmospheres, the metallic is the main types of iron in the product after 900 ℃, however, the introduction of reducing gases such as H₂ and CO will benefit to the reduction at lower temperature. Iron ore can be reduced by char after 900 ℃ in N₂ atmosphere, but the metallization rate of direct reduction iron is <90%（mass fraction）, unsatisfying the requirements of direct steelmaking. Active atmosphere such as H₂ and CO can help to improve the quality of reduction products.更多还原