研究了微波场中氟碳铈矿和独居石混合稀土精矿的升温特性,结果表明,稀土精矿在微波场中的升温过程分为初期慢速升温和后期快速升温两个阶段,升温速率有一个温度突变点,突变点温度与微波功率、矿物含水量有关。升温过程的升温速率与微波...研究了微波场中氟碳铈矿和独居石混合稀土精矿的升温特性,结果表明,稀土精矿在微波场中的升温过程分为初期慢速升温和后期快速升温两个阶段,升温速率有一个温度突变点,突变点温度与微波功率、矿物含水量有关。升温过程的升温速率与微波功率和加热时间有关,其升温速率方程符合T = at + b线性关系。展开更多
The CeO_2 superfine powder was prepared by the co-precipitation method, using the industrial grade Ce_2(CO_3)_3 and NH_4HCO_3 as starting material and precipitating reagent, respectively. The precipitated precursons a...The CeO_2 superfine powder was prepared by the co-precipitation method, using the industrial grade Ce_2(CO_3)_3 and NH_4HCO_3 as starting material and precipitating reagent, respectively. The precipitated precursons and the calcinated products were characterized by the thermogravimetric analysis/thermoanalysis (TGA/DTA), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The results show that using NH_4HCO_3 as a precipitating reagent, the precipitate decomposed full as it was heated to 360 ℃. The CeO_2 superfine powder formed by calcinating the precipitate belongs to a cubic CaF_2-type structure and has the first mean particle diameter 140 nm and second mean particle diameter 630 nm. The CeO_2 powder particles aggregate and grow with raising the calcination temperature.展开更多
文摘The CeO_2 superfine powder was prepared by the co-precipitation method, using the industrial grade Ce_2(CO_3)_3 and NH_4HCO_3 as starting material and precipitating reagent, respectively. The precipitated precursons and the calcinated products were characterized by the thermogravimetric analysis/thermoanalysis (TGA/DTA), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The results show that using NH_4HCO_3 as a precipitating reagent, the precipitate decomposed full as it was heated to 360 ℃. The CeO_2 superfine powder formed by calcinating the precipitate belongs to a cubic CaF_2-type structure and has the first mean particle diameter 140 nm and second mean particle diameter 630 nm. The CeO_2 powder particles aggregate and grow with raising the calcination temperature.