纤维素-半纤维素混合物焙烧还原低品位软锰矿的动力学

采用TG-DTG和XRD研究了纤维素、半纤维素及其混合物焙烧还原软锰矿的动力学. 结果表明，与非生物质类还原剂相比，纤维素、半纤维素及其混合物可在低于773 K焙烧还原软锰矿，纤维素和半纤维素单独焙烧还原软锰矿的动力学可采用在JMA方程基础上提出的经验动力学函数a=1-exp{-k0exp(-Ea/RT)[(T-T0)/b]n}描述，表观活化能Ea分别为38.66和30.14 kJ/mol. 混合物还原软锰矿过程的动力学可用单一组分动力学的线性加和表示，即转化率a=Sixiaie(T-T0,i)，且Sixi=1, 式中e(T-T0)是单位阶跃函数，用于避免产生无效的转化率数据.

Roasting Reduction Kinetics of Low-grade Pyrolusite with the Mixture of Cellulose and Hemicellulose

The reduction kinetics of pyrolusite by cellulose and hemicellulose, and their mixture was investigated by TG/DTG and XRD. The results show that compared with the non-biomass reducing agents, pyrolusite can be reduced below 773 K which is close to that of biomass reducing agents. The respective reduction processes follow the empirical equation a=1-exp{-k0exp(-Ea/RT)[(T-T0)/b]n}, and the apparent activation energy is 38.66 and 30.14 kJ/mol for the reduction of pyrolusite by cellulose and hemicellulose, respectively. The reduction kinetics of pyrolusite by the mixture can be described by the summation of the respective kinetics by considering their mass-loss fractions a=Sixiaie(T-T0,i) with Sixi=1, where e(T-T0) is the unit step function to avoid the invalid conversion data.