Preparation of ultrafine rhenium powders by CVD hydrogen reduction of volatile rhenium oxides  

采用CVD法还原挥发性铼的氧化物制备超细铼粉(英文)

作　　者：白猛[1] 刘志宏[1] 周乐君[1] 刘智勇[1] 张传福[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第2期538-542,共5页中国有色金属学报（英文版）

摘　　要：A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials. In the process, volatile rhenium oxides, such as ReO4 and Re2O7, were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate, and carried into reduction zone by carrier gas, and there reduced into rhenium powders by hydrogen gas. Thermodynamic calculations indicated that Re207 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate. This result was further validated via DSC-TGA analysis of ammonium perrhenate. The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a Ds0 of 308 nm. The specific surface area and oxygen content were measured to be 4.37 m^2/g and 0.45%, respectively.研究了一种以高铼酸铵为原料,采用化学气相沉积（CVD）制备超细铼粉的新方法。通过控制氧分压,使得NH4ReO7分解为具有挥发性的ReO4、Re2O7,再采用载气将其输运至还原区,经氢气还原生成超细铼粉。热力学计算表明,在NH4ReO7分解过程中,控制氧分压高于101.248Pa时,Re2O7将不会分解为低价氧化物,DSCTGA分析结果也证实了这一点。采用该方法制备的铼粉,粒度为100~800nm,D50为308nm,比表面积为4.37m2/g,氧含量为0.45%。

关 键 词：ultrafme rhenium powders ammonium perrhenate chemical vapor decomposition oxygen partial pressure 

分 类 号：TB44[一般工业技术]