碱法处理含钛高炉渣的矿相变化及工艺条件探索

Technological Conditions and Mineralogical Changes of Alkaline Treatment on Ti-bearing Blast Furnace Slag

采用XRF、XRD和金相显微镜分析含钛高炉渣的化学成分、物相组成和矿物形态,发现渣中含钛量高达20%,主要矿物相为钙钛矿、透辉石和镁铝尖晶石,各物相结合紧密、分布均匀。将Na_2CO_3与含钛高炉渣进行高温混合焙烧,焙烧熟料用去离子水进行水浸处理,以实现对含钛高炉渣中Si、Al组分的提取,同时实现对Ti组分的富集,达到分离三种有价组分的目的。通过研究焙烧温度、碱渣质量比和焙烧时间对组分浸取率的影响以及焙烧过程中矿物相的变化,结果表明:在焙烧过程中镁铝尖晶石先于透辉石与助剂Na_2CO_3发生反应,而钙钛矿不与Na_2CO_3发生反应。优化的焙烧条件为:焙烧温度900℃,碱渣质量比为2∶1,焙烧反应时间180 min,此条件下SiO_2和Al_2O_3的提取率分别达到47.52%和82.97%。

Ti-bearing blast furnace slag is the industrial waste produced by blast furnace imnmaking in Pan- zhihua steel plant, and the results of XRD, XRF and metallurgical microscopy analysis of the slag suggest that the main mineral phase includes perovskite, diopside and spinel with 20% of titanium content, and the mineral facies are closely combined. This research adopted alkaline calcinations to dispose the Ti-bearing blast furnace slag and then used deionized water to leach the masted product for the recovery of Si02, A1203 and the enrichment of titanium component, which can realize separation of the three kinds of valuable component. Through researching the effects of the calcination temperature and time, mass ratio of Na2 CO3 to slag on the extraction efficiency of Si02 and A1203 and the mineralogical changes in the reaction process, the results show that the spinel precedes diopside to react with Na2CO3 but pemvskite does not react with the additives. Under the following optimum conditions： calcination temperature 900℃, mass ratio of Na2CO3 to slag 2 ： 1 and reac- tion time 180 rain, 47.52% SiO2 and 82.97% Al2O3 can be extracted.