钪精矿与硫酸法钛白废液协同浸出分离钪

Synergism Extraction of Scandium from Scandium Concentrate and Titanium Dioxide Wastewater

含钪钒钛磁铁尾矿经过分选工艺富集至含钪量为66.2_(4) g·t^(-1)的钪精矿;含钪钛白废酸采集于四川德阳地区,其钪含量为3.661 mg·L^(-1)。钪精矿采用焙烧改性处理后,利用含钪钛白废液作为协同浸出分离钪的浸出剂。研究结果表明:在无盐焙烧、焙烧温度为850℃,焙烧时间2.0 h,浸出温度80℃,浸出时间2.0 h,浸出液固比8 mL/g,助剂为NH_(4)F,助剂用量为12%条件下浸出效果最佳,钪的浸出率可达到83.90%,浸出渣钪含量下降到11.50 g·t^(-1)。钪精矿、焙烧矿和浸出渣的SEM-EDS,XRD表征表明:主要含钪矿物辉石类、长石类等经过焙烧改性后,为钛白废液浸出钪创造了有利条件,钪离子在酸浸时能够被有效地释放,实现了从废渣和废酸中协同强化浸出钪的目的。同时热重分析显示钪精矿在焙烧时会有两次失重现象。浸出过程中的热力学分析证明了浸出反应的可行性。

Vanadium titanium magnet tailings containing scandium are sorted and enriched to scandium concentrate with the scandium content of 66.24 g·t^(-1),and titanium dioxide wastewater containing scandium is collected in Deyang,Sichuan province,its scandium content is 3.661 mg·L^(-1).After roasting and modification pretreatment of scandium concentrate,the titanium dioxide wastewater produced by sulfuric acid process was used as leaching agent for the co-leaching of scandium.The results show that under the conditions of salt-free roasting,roasting temperature of 850℃,roasting time of 2.0 h,leaching temperature of 80℃,leaching time of 2.0 h,liquid-solid ratio of 8 mL/g,leaching additive of NH_(4)F and leaching additive consumption of 12%,the leaching effect is the best.The leaching rate can reach 83.90% when the scandium content of leaching residue is reduced to 11.50 g·t^(-1).The results of SEM-EDS and XRD analysis of scandium coarse concentrate,roasted ore and leaching residue show that after roasting and modification,pyroxene and feldspar minerals can effectively decompose,creating favorable conditions for the leaching of scandium with titanium dioxide wastewater,and realizing the purpose of synergic strengthening leaching and separation of scandium.Thermogravimetric analysis of scandium coarse concentrate shows that there will be two weight-loss phenomena during roasting of scandium coarse concentrate.Thermodynamic analysis during the leaching process proves the feasibility of the reaction.