材料期刊网

本文在模拟高炉条件下动态测定烧结矿还原粉化的热转鼓中,对我国高品位细磁精矿制成的不同碱度烧结矿进行了低温还原粉化率的测定。并与澳大利亚赤铁矿粉制成的烧结矿进行对比。通过测定发现我国高品位细磁精矿烧结矿在碱度1.7—1.8左右、还原温度为500℃时,有最高的还原粉化率,大于或低于此碱度的烧结矿,还原粉化率减轻。澳大利亚赤铁矿粉烧结矿在低碱度(R=0.9)时有严重的低温还原粉化率,但随着碱度上升,粉化率减轻。通过改变还原温度、以H_2代替CO作还原剂、同时对各种烧结矿还原前后的矿物组成及显微结构进行岩矿相鉴定,获得了烧结矿还原粉化的机理性说明。此外还在高炉内对烧结矿进行了还原粉化试验。

An investigation was carried out on the reduction disintegration properties of two typical sinters made from Chinese high grade magnetite iron ore concentrates produced by Qian'an and Ma'anshan areas. The test was carefully compared with that of Australia hematite ore fines in a specially designed rotary tube. It was found that the worst resistance to the reduction disintegration seems to be displayed for the Chinese sinters with the basicity CaO/SiO_2 in the region about 1.7—1.8 and under temperature of reduction at 500℃, as weU as it has much improved since the CaO/SiO_2 ratio beyond the region, namely 1.0 or 2.5. WhiLst the reduction disintegration index of the Australia hematite sinter decreases with the increase of its basicity.By changing the test temperature of reduction and adopting H_2 as a reducing gas instead of CO, an examination of the sinters on the entire reduction process under petrographic microscope shows that the reduction disintegration properties of Chinese magnetite sinters with different basicities are closely related to their mineral composition and microtexture. The carbon deposition may bc also an important factor affecting their reduction strength. However, the phase transformation of Fe_2O_3 during reduction influenced them slightly due to its small content.Experiments were also made of the properties of the sinters in 55m~3 blast furnace, in which a perforate steel probe tube filled with several Myers of testing sinter and coke was inserted. The result is very conformable to that in the rotary tube.