典型钙/镁基吸附剂对二氧化硒吸附特性研究

针对钙/镁基矿物吸附剂的主要组分CaO、CaCO₃、MgO在500-800 ℃下对Se的吸附特性进行研究，并选取天然矿物方解石、白云石研究其对Se的吸附效果，且对矿物煅烧所得CaO进行吸附实验。结果表明，三种组分中CaO的吸附效果最佳，800 ℃时单位质量CaO对Se的吸附量可达368 mg/g。CaCO₃对Se的吸附在700 ℃时效果最佳且其吸附产物的热稳定性较好。镁基吸附剂仅在中温段对Se具有一定吸附效果。方解石对Se的吸附效果随温度变化趋势与CaCO₃相似，因其较好的孔隙结构，吸附效果略优于CaCO₃。煅烧方解石得到的F-sor对Se的吸附效果优于CaO和CaCO₃煅烧得到的C-sor，这与其良好的比表面积、孔隙结构与抗烧结能力有关，且F-sor吸附产物的热稳定性相对较好。F-sor对Se的吸附量最高可达403 mg/g。

Characteristics of selenium capture by typical Ca-/Mg-based sorbents

The characteristics of Se capture by CaO, CaCO₃, and MgO which are main components of Ca-/Mg-based mineral sorbents at 500-800 ℃ and that by calcite and dolomite were investigated, and the CaO obtained from calcine minerals were also used to capture Se. The results showed that capacity of CaO for Se capture was the highest, and the maximum value at 800 ℃ was 368 mg/g. Capacity of CaCO₃ on Se adsorption at 700 ℃ was the largest and thermostability of the used CaCO₃ was better. Se adsorption of Mg-based sorbents at medium temperature was obvious. The trend for Se adsorption capacity of calcite with increasing temperature was similar to that of CaCO₃. Effect of calcite on Se capture was better than that of CaCO₃, which was attributed to the higher specific surface area and pore volume of calcite. The ability of F-sor obtained from calcined calcite for Se capture was better than that of C-sor from calcined CaCO₃ as well as that of CaO, which was likely due to higher specific surface area and pore volume of F-sor. Moreover, the used F-sor showed better thermostability at higher temperature, and the maximum adsorption capacity of F-sor was 403 mg/g.