冷却方式对低钛高炉渣矿物组成和矿相结构的影响

应用X射线衍射仪、偏光显微镜和扫描电镜对水淬和空冷低钛高炉渣的矿相组成、显微结构、TiO2分布规律及其差异性进行研究.结果表明：水淬渣和空冷渣中主要矿物组成均为玻璃质、钙钛矿、钙铝黄长石和镁硅钙石，但是两种炉渣中各矿物组分含量相差较大，空冷渣中钙铝黄长石和钙钛矿的平均体积分数分别为62.5%和12.5%，是水淬渣中钙铝黄长石和钙钛矿的2.27倍和1.92倍，而玻璃质的平均体积分数不足水淬渣的1/3.水淬渣和空冷渣中矿相显微结构差异较大，空冷渣中钙铝黄长石为钉齿状，而水淬渣中钙铝黄长石为呈羽毛状和针状，且结晶粒度较小，钙钛矿在水淬渣和空冷渣中分别呈星点状和树枝状分布，两种炉渣中镁硅钙石都为纺锤体形；水淬渣中TiO2主要分布在钙钛矿、玻璃质和钙铝黄长石中，而空冷渣中TiO2主要分布在钙钛矿和钙铝黄长石中，并且空冷渣中钙钛矿TiO2的分布率比水淬渣高8.41%，空冷方式更有利于将TiO2聚集在钙钛矿中.

Effect of cooling methods on the mineralogical composition and microstructure of low titanium-containing blast furnace slag

The mineralogical composition, microstructure and TiO2 distribution rule of low titanium-containing blast furnace slags after water cooling and air cooling were investigated by X-ray diffraction, polarization microscopy and scanning electron microscopy. The results show that main mineralogical compositions in these slags are all vitreous, gehlenite, perovskite and merwinite, but the con-tents of mineral components in the two kinds of slags have much larger differences. The average contents of gehlenite and perovskite in the air-cooled slag are 62. 5% and 12. 5%, which are 2. 27 and 1. 92 times as large as those in the water-cooled slag, respectively. The content of vitreous in the air-cooled slag is less than a third of that in the water-cooled slag. The mineralogical microstructure of the water-cooled slag is pretty different from that of the air-cooled slag. Gehlenite in the water-cooled slag is dentate, but in the water-cooled slag it is feathery and needle-shaped, and its grain size is smaller. Perovskite forms as star points and dendritic in the water-cooled slag and the air-cooled slag, respectively. Merwinite is spindle-shaped both in the water-cooled slag and the air-cooled slag. It could be concluded that TiO2 in the water-cooled slag mainly distributes in perovskite, vitreous glassy and gehlenite, but TiO2 in the air-cooled slag mainly distributes in perovskite and gehlenite, and the distribution ratio of TiO2 in the air-cooled slag is 8. 41% higher than that in the water-cooled slag. Air cooling is more beneficial to increase TiO2 content in perovskite.