A bsorption and fixation of CO_2 to waste materials that contained Ca

为开发利用电弧炉废渣、还原渣、氧化渣等含钙废弃物吸附固定CO_2的工艺，进行了基础研究。采用离心球磨机和振动球磨机分别在CO_2中湿磨和干磨，研究了不同研磨条件对CO_2吸收量和吸收率的影响。得到的主要结果总结如下：1)湿法研磨使含Ca物料比干法研磨更能吸收CO_2。2)还原渣的CO_2含量和初始速率最大，氧化渣次之。3)振动球磨机对样品的CO_2含量和初始速率均大于离心球磨机。4)振动球磨机研磨还原渣时，实验前期CO_2与水溶液的界面反应决定了其对CO_2的吸附。在试验后期，炉渣入水溶解是控制速率的步骤。在其他实验中，CO_2的吸收是通过炉渣在水中的溶解来测定的。5)湿磨还原渣CO_2吸收量与磨出CO_2量最大差异为104mg(CO_2)/g（渣）。该工艺可达到钢铁工业二氧化碳减排目标的五分之一。更大的振动磨机和间歇湿磨能更有效地吸收CO_2

Fundamental research was carried out in order to develop the process in which CO_2 was absorbed and fixed to Ca containing waste materials, that is, waste torte, reduction and oxidation slag from electric arc furnace. In this study, those materials were wet and dry ground in CO_2 by a centrifugal ball mill and a vibration ball mil Effect of grinding conditions on the amount and the rate of CO_2 absorption was investigated. The main obtained results were summarized as follows;1) The wet grinding enabled Ca contained materials to more absorb CO_2 than the dry grinding.2) The amount and the initial rate of CO_2 of the reduction slag were the largest among them, and those of oxidation slag were second largest.3) The amount and the initial rate of CO_2 of those samples by the vibration ball mill were larger than those by the centrifugal ball mill.4) When the reduction slag was ground by the vibration ball mill, the absorption of CO_2 was determined by the widely defined interfacial reaction between CO_2 and the aqueous solution in the early stage of the experiment. In the latter stage of the experiment, the dissolution of the slag into water was rate controlling step. In the other experiments, the absorption of CO_2 was determined by the dissolution of the slag into water.5) The largest difference between the amount of CO_2 absorption on the reduction slag by wet grindings and that of emission of CO_2 in the grinding was 104mg(CO_2)/g(slag). This process will be able to attain one fifth of reduction target of CO_2 in iron and steel industry. Furthermore, it was revealed that the larger vibration mill and intermittent wet grinding were able to absorbed CO_2 more effectively