Reduction processes for highly dispersed cobalt oxide

Translated from Poroshkova Metallurgiya, No. 11(359), pp. 82–86, November, 1992.     

用含钴催化剂废料制取氧化钴的研究

用含钴催化剂废料作原料，采用酸溶－沉淀法工艺制取氧化钴。经过多次实验结果表明，该工艺技术是可以行的，并获得了较好的技术经济指标。工业氧化钴含钴达到７１．０６％，钴的回收率大于８５％。该工艺对于实现工业化生产很有价值和意义。     

快速比浊法测定氧化钴和碳酸钴中微量氯

试验了用硝酸 ( 1 +1 )浸取试样中微量氯离子 ,共存的大量钴用氢氧化钠沉淀分离 ,方法用于生产获得满意结果     

静电纺丝法制备氧化钴纳米纤维

采用硝酸钴与聚乙烯吡咯烷酮(polyvinylpyrrolidone, PVP)为原料制备纺丝液, 利用扫描电子显微镜、同步热分析仪、X-射线衍射仪以及透射电子显微镜对前驱体纤维及煅烧后纤维进行表征与分析, 研究静电纺丝技术制备氧化钴纳米纤维的可行性及最佳实验条件。结果表明: 在PVP(K30)质量分数为43%, 硝酸钴质量为2 g以及最佳设备参数条件下, 可以制备出直径约600 nm、均匀光滑的硝酸钴/PVP前驱体纤维, 经600℃高温煅烧后, 可得到直径约30 nm的氧化钴纳米纤维。     

ICP-AES测定氧化钴中杂质

利用仪器所带软件 ,拟定了氧化钴中铅、锌、铁、镉、铜、锰的分析方法 ,试验选定了各元素的分析谱线及仪器的工作参数。氧化钴试样用盐酸分解 ,在体积分数为 5 %的盐酸介质中同时测定 ,结果满意。     

Reduction kinetics of molybdenum oxide in slag

The reduction rate of Mo oxide in slag by iron-carbon melt under different stirring conditions, reaction temperatures and slag composition has been investigated. Results indicate that the reduction of Mo oxide is a fast reaction; both stirring and temperature have evident influence upon the reaction; while the initial concentration of Mo oxide and content of fluoride in slag have also some influence upon the reaction. The reduction of Mo oxide is an apparent first order reaction. At 1440–1500°C, the reduction rate of Mo oxide is mainly controlled by Mo transfer in slag, with its diffusion activation energy of 223 kJ/mol. At 1500–1590°C, the transfer of Mo in metal turns to be the main limiting step, with its diffusion activation energy of 81.5 kJ/mol.     

Reduction of tungsten oxide to tungsten metal

Tungsten oxide, WO_2.96, was reduced toα-W in hydrogen for various time periods over the temperature range 500°C to 900°C. Intermediate oxides were determined using X-ray diffraction analysis of the semireduced powders. Several dopant conditions were used, to find the effect on oxide structures and reaction kinetics of the usual dopants K, Si and Al. The scanning electron microscope was employed to determine the morphology of the crystallites at intermediate and final stages of reduction. This research was supported in part by the U.S. Energy Research and Development Administration, Contract E(11-1)-1198.     

Kinetics of cobalt sulfide reduction in the presence of calcium oxide

Kinetic measurements have been made on the hydrogen reduction of solid cobalt sulfide in the presence of calcium oxide. The cobalt metal yield was compared with that of the direct reduction reaction over the temperature range 600 to 800°C at various hydrogen flow rates, and calcium oxde to cobalt sulfide mixing ratios. It was found that the presence of calcium oxide caused a sharp increase in the reaction rate—for example a 15 fold increase in conversion was achieved at 700°C after 24 min of reaction. Low hydrogen flow rates were found to be desirable, and an optimum mixing ratio of 3.0 established.     

不同生物质还原氧化铁的特性

以木屑、玉米秸秆、咖啡废渣和水解木质素4种生物质为还原剂,采用TG-FTIR联用、XRD、SEM等方法分析了各物质的化学成分及官能团构成,研究了不同生物质中碳和氢对氧化铁的还原反应特性。研究表明,生物质还原氧化铁的作用由气体和固定碳决定,其中气基还原的特征温度为806~822 K,碳还原的特征温度为1 116~1 132 K。4种生物质中,碳还原氧化铁的能力由强到弱依次是木屑>水解木质素>咖啡废渣>玉米秸秆,氢还原能力大小则为玉米秸秆>咖啡废渣>木屑>水解木质素。     

The activity coefficient of cobalt oxide in silica-saturated iron silicate slags

The solubility of cobalt oxide in silica-saturated iron silicate slags (1.16 to 10.00 wt pct) in equilibrium with cobalt-gold-iron alloys (1.10 to 6.52 wt pct cobalt) and oxygen pressures of 10₋₉ to 10₋₁₀ atm (1 atm = 1.013 x 105 Pa) has been investigated at 1573 K. The activity coefficient of cobalt oxide, γ_CoO, has been calculated relative to pure solid cobalt oxide as standard, namely, γ_CoO = 0.91 ± 0.09 and a relationship derived between weight percent cobalt in slag, Co (wt pct), oxygen pressure, pO₂, and activity of cobalt relative to liquid cobalt,aCo, namely, Co (wt pct) = 1.32 x 10⁶ pO ₂ ^1/2 a_Co ± 10 pct Both errors are calculated at the 95 pct confidence level. Formerly Senior Lecturer in Pyrometallurgy, Murdoch University, Murdoch, Western Australia Formerly Postgraduate Student, Murdoch University, Murdoch, Western Australia     

电炉还原熔炼氧化钴矿的生产实践

介绍了刚果(金)钴铜冶炼厂电炉还原熔炼处理钴铜氧化矿工艺的设计特点及生产实践。     

电炉还原熔炼氧化钴矿的生产实践

介绍了刚果（金）钴铜冶炼厂电炉还原熔炼处理钴铜氧化矿工艺的设计特点及生产实践。