基于CO_2封存的盐酸浸取超贫钒钛磁铁矿尾矿实验研究

CO_2 Sequestration Based Dissolution Study of Extremely Poor Vanado-titanomagnetite Deposit Tailings

随着技术进步,超贫钒钛磁铁矿被广泛开采,产生大量富含镁钙的尾矿,该尾矿可用于封存CO_2。本文选取承德超贫钒钛磁铁矿尾矿作为研究对象,对其进行物相鉴定、常量元素分析、粒径分析及盐酸浸取动力学分析。结果显示尾矿主要含角闪石及辉石,其钙镁含量较高,为30%左右,颗粒较细,平均粒径小于50μm。钙镁浸出率随着温度升高而增加,85℃时镁钙浸出率达到26.5%和27.0%。通过实验数据拟合可知,反应速率受固体产物层内扩散控制,尾矿活化能约为43 kJ/mol。按目前的水平,开采河北承德超贫钒钛磁铁矿将产生约250×10~8t尾矿,根据本实验最高钙镁浸出率计算,CO_2封存量可达20×10~8t。

Extremely poor vanado-titanomagnetite deposits are exploited with the progress of technology. In that case, a large number of tailings were produced and the tailings can be used to sequestrate CO2. This article mainly focuses on carbon dioxide sequestration by mineral carbonation with the extremely poor vanado-titanomagnetite deposit tailings in Chengde City, Hebei Province. By analyzing mineral phases,element composition, particle sizes, and leaching experiments, it was found that the tailings, which mainly consist of amphibole and pyroxene, were rich in magnesium and calcium （ 30% ） and small in size （ average particle diameter 〈50jjim）. The leaching ratio of Mg and Ca increased with temperature. The leaching ratio of Mg and Ca were 26. 5% and 27. 0% at 8 5% . By model fitting,we found that the reaction rate of this experiment was controlled by diffusion through ash layer and the activation energy of the tailings was about 43 kj/mol. With the current intensity of mining, Chengde is expected to produce 25 billion tons of the extremely poor vanado-titanomagnetite deposit tailings, which allow 2 billion tons of C02 to be stored according to the highest leaching ratio of Mg and Ca in this experiment