粉煤灰浓硫酸焙烧法提取Al2O3工艺中焙烧过程十分重要,研究发现适当提升硫酸浓度、酸灰质量比和温度可增大Al转化率,而延长焙烧时间影响并不显著;在硫酸浓度80%、酸灰质量比1.5：1、温度270℃和时间60 min条件下,Al转化率可达92%~95%。T...粉煤灰浓硫酸焙烧法提取Al2O3工艺中焙烧过程十分重要,研究发现适当提升硫酸浓度、酸灰质量比和温度可增大Al转化率,而延长焙烧时间影响并不显著;在硫酸浓度80%、酸灰质量比1.5：1、温度270℃和时间60 min条件下,Al转化率可达92%~95%。TG/DSC与XRD分析表明,焙烧过程反应主要分为3个阶段：80~206℃时形成中间产物Al（HSO4）3及H2O气化;206~241℃时生成Al（HSO4）3及Al2（SO4）3·H2O;241~304℃时由Al2（SO4）3·H2O和Al（HSO4）3二者分解转化成Al2（SO4）3。由Kissinger微分法与Ozawa积分法分别计算出3个阶段表观活化能后取二者平均值,分别为52.61、74.11、96.08 k J·mol-1,并获得频率因子、反应级数和动力学方程,所获结果可为粉煤灰硫酸焙烧法提取Al2O3焙烧工艺设计和过程优化提供理论参考和基础数据。展开更多
Mixtures of NaHSO4·H2O and LiCoO2 extracted from spent lithium-ion batteries were prepared with molar ratios of 1：1, 1：2 and 1：3. The chemical evolution of the LiCoO2 and NaHSO4-H20 mixtures during the roastin...Mixtures of NaHSO4·H2O and LiCoO2 extracted from spent lithium-ion batteries were prepared with molar ratios of 1：1, 1：2 and 1：3. The chemical evolution of the LiCoO2 and NaHSO4-H20 mixtures during the roasting process was investigated by means of thermogravimetric analysis and differential scanning calorimetry （TG-DSC）, X-ray diffraction（XRD）, scanning electron （XPS）. The results show that the chemical reactions in microscopy（SEM）, and X-ray photoelectron spectroscopy the LiCoO2 and NaHSO4·H2O mixtures proceed during the roasting process. The Li element in the product of the roasting process is in the form of LiNa（SO4）. With the increase of the proportion of NaHSO4·H2O in the mixtures, the Co element evolves as follows： LiCoO2→Co3O4→Na6Co（SOa）4→Na2Co（SO4）2. The roasting products exhibit dense structures and irregular shapes, and the bonding energy of Co increases.展开更多
文摘粉煤灰浓硫酸焙烧法提取Al2O3工艺中焙烧过程十分重要,研究发现适当提升硫酸浓度、酸灰质量比和温度可增大Al转化率,而延长焙烧时间影响并不显著;在硫酸浓度80%、酸灰质量比1.5：1、温度270℃和时间60 min条件下,Al转化率可达92%~95%。TG/DSC与XRD分析表明,焙烧过程反应主要分为3个阶段：80~206℃时形成中间产物Al（HSO4）3及H2O气化;206~241℃时生成Al（HSO4）3及Al2（SO4）3·H2O;241~304℃时由Al2（SO4）3·H2O和Al（HSO4）3二者分解转化成Al2（SO4）3。由Kissinger微分法与Ozawa积分法分别计算出3个阶段表观活化能后取二者平均值,分别为52.61、74.11、96.08 k J·mol-1,并获得频率因子、反应级数和动力学方程,所获结果可为粉煤灰硫酸焙烧法提取Al2O3焙烧工艺设计和过程优化提供理论参考和基础数据。
基金Supported by the National Natural Science Foundation of China（No.51264027） and the National Basic Research Program of China（No .2012CB722806）.
文摘Mixtures of NaHSO4·H2O and LiCoO2 extracted from spent lithium-ion batteries were prepared with molar ratios of 1：1, 1：2 and 1：3. The chemical evolution of the LiCoO2 and NaHSO4-H20 mixtures during the roasting process was investigated by means of thermogravimetric analysis and differential scanning calorimetry （TG-DSC）, X-ray diffraction（XRD）, scanning electron （XPS）. The results show that the chemical reactions in microscopy（SEM）, and X-ray photoelectron spectroscopy the LiCoO2 and NaHSO4·H2O mixtures proceed during the roasting process. The Li element in the product of the roasting process is in the form of LiNa（SO4）. With the increase of the proportion of NaHSO4·H2O in the mixtures, the Co element evolves as follows： LiCoO2→Co3O4→Na6Co（SOa）4→Na2Co（SO4）2. The roasting products exhibit dense structures and irregular shapes, and the bonding energy of Co increases.
