LI Ning
,
CHEN Jin
,
YAN Hong
,
FENG Xiumei
,
CUI Huijun
,
LIU Jinying
钢铁研究学报(英文版)
To avoid the nonuniform phenomena of heat and mass transfer of metallurgical powdery materials caused by conventional heating method, the temperature rise characteristics of carboncontaining chromite ore fines in the microwave field were investigated using microwave heating in a microwave metallurgical furnace. The experimental results show that the carboncontaining chromite ore fines have better temperature rise characteristics in the microwave field at a frequency of 245 GHz. After heated in the microwave field of 10 kW, the temperature of 1 kg carboncontaining chromite ore fines rose up to 1 100 ℃ in 7 min, at a temperature rise rate of 1571 (℃·min-1·kg-1), whereas the temperature of 1 kg carboncontaining magnetite ore fines rose only up to 1 000 ℃ in 10 min, at a temperature rise rate of 100 (℃·min-1·kg-1). With increasing carbonfitting ratios and by adding calcic lime, their heating effects changed regularly.
关键词:
carboncontaining chromite ore fine;carboncontaining magnetite ore fine;microwave field;temperature rise characteristics
CHEN Jin
,
WANG Shebin
,
ZHANG Meng
,
LIU Jinying
,
ZHOU Jianxiong
钢铁研究学报(英文版)
The kinetics of voluminal reduction of chromium ore fines containing coal (COFCC) by microwave heating was studied. When the molar ratio of carbon to oxygen was 084 and that of CaO to SiO2 was 039 in COFCC, the temperaturerising rate of COFCC by microwave heating was 625 ℃/min, 6875 ℃/min, 7059 ℃/min, and 7222 ℃/min at 1 000 ℃, 1 100 ℃, 1 200 ℃, and 1 300 ℃, respectively. The results show that the voluminal reduction of COFCC by microwave heating at solidsolid phase is first order reaction, with the apparent activation energy of 51480 kJ/mol. The limiting step of reaction rate for the overall reaction is the mass transfer of CO in the reduced product layer between dielectric particles of chromium ore and coal.
关键词:
kinetics;microwave heating;voluminal reduction;chromium ore fine
