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。     

Electrowinning of cobalt I. Winning from pure cobalt sulphate bath

Electrowinning of cobalt from a pure cobalt sulphate bath was carried out. Effects of current density, cobalt concentration in the bath, temperature, etc. on current efficiency and on the nature of the deposit were studied. The results indicate that bath pH and temperature play major roles in the cobalt deposition. A high current efficiency can be achieved at relatively low temperature and relatively high bath pH (pH > 4.0). Further, at relatively low bath pH and high temperature (～60°C), a high current efficiency can also be obtained; however, in the former case the deposited cobalt is dull and brittle and malleable in nature.     

从含钴转炉渣中回收钴的方法及应用

为实现钴资源的综合利用, 对含钴转炉渣回收钴的方法及其研究进展与应用情况进行了综述。冶炼时, 钴主要以化学溶解的方式进入转炉渣, 根据其在冶炼过程中进入转炉渣情况及转炉渣存在的现状, 介绍了浮选、火法冶炼、湿法分离、萃取法、微生物浸出等分离回收方法, 并讨论了各种分离回收方法的优势及局限性。其中, 具有高选择性、高回收率、流程简单、操作连续、易于实现自动化等优点的溶剂萃取法, 以及具有污染小、成本低、高效等特点的微生物浸出法, 拥有较好的应用前景。     

铁氰化钾电位滴定法测定粗制氢氧化钴中钴

锰会干扰电位滴定法对钴的测定,而粗制氢氧化钴中锰含量较高(质量分数达8%),因此,将电位滴定法应用于测定粗制氢氧化钴中钴时,需要考虑锰的干扰。实验通过对HG/T4506—2013工业氢氧化钴中钴标准检测方法的前处理阶段做出改进,用盐酸溶解样品后,在含磷酸的溶液中用高氯酸将锰(II)氧化为锰(III),再用氟化氢铵络合掩蔽锰(III)从而消除了锰的干扰。在氨性环境中,用过量的铁氰化钾将钴(II)铵络离子氧化成钴(III)铵络离子,再用钴标准滴定溶液返滴定过量的铁氰化钾,最终建立了电位滴定法测定粗制氢氧化钴中钴的方法。参照粗制氢氧化钴中锰与钴的质量比,配制锰与钴的质量比在13.7%~52.0%范围内的粗制氢氧化钴模拟样品,按照实验方法进行测定,钴的回收率在99%~101%之间,这说明锰对钴测定的干扰可忽略。将方法应用于粗制氢氧化钴的检测,相对标准偏差(RSD,n=15)为0.19%~0.26%,加标回收率为99%~104%。采用实验方法测定粗制氢氧化钴实际样品,测得结果与电位滴定法-电感耦合等离子原子发射光谱法相结合所测得的结果基本一致。     

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     

多波长分光光度法同时测定钴精矿中钴和镍

探讨了在pH 7.8时,Co(和Ni(与二甲酚橙(XO)显色的反应条件,建立了K-矩阵分光光度法同时测定钴和镍的分析方法。钴和镍的络合物表观摩尔吸光系数分别为2.42×106L.mol-1.cm-1,1.63×105L.mol-1.cm-1;方法相对标准偏差分别为4.8%,3.9%;平均加标回收率分别为110.0%,94.1%。方法已用于不同比例合成样品和钴精矿中钴和镍的定量分析。     

Oxidation of cobalt sulfide

Dense plate of cobalt sulfide was oxidized in a mixed O₂-N₂ gas stream at 873 to 1123 K. Atomic fraction of sulfur of the sulfide was between 0.505 and 0.525, and the partial pressure of oxygen in the gas stream was varied between 5.05 x 10₃ and 2.02 x 10₄ Pa. At lower temperature, cobalt diffused from the interior of sulfide to the surface due to the lower sulfur activity, and a dense oxide layer was formed without the evolution of SO₂ gas. The oxidation rate was controlled by the diffusion of cobalt in the sulfide in the initial few minutes, and it was controlled by the diffusion of cobalt through the oxide layer in the subsequent oxidation. At higher temperature, the oxidation of cobalt sulfide proceeded accompanying the evolution of SO₂ gas due to the higher sulfur activity, and a porous oxide was formed. The oxidation rate was determined by the mass transfer of oxygen through the gas boundary film and the oxide layer.     

Reaction mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust

Abstract

The experiments in this paper were performed to research the mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust. The reduction potential of zinc during cementation was determined to investigate the morphology of products. Residues after the cementation process from zinc sulphate solution were analyzed by SEM and EPMA to investigate the morphology of products. Different temperature will cause different structure of particles. The reaction mechanism of cobalt removal by zinc dust is thought to be as follows: first, the Co2+ forms Co–Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; second, the Co–Zn alloy continues reacting to Co with Co2+, which is the control process of the whole reaction.     

Adsorption of cobalt by lignite

Studies similar to earlier ones which had established the feasibility of extracting nickel by the lignite adsorption route were conducted on the adsorption extraction of cobalt on lignite, and with equal success.Optimal values of variables such as pH, sorbent/sorbate ratio, adsorbent particle size, contact time, temperature, and the effect of excess ammonium carbonate were evaluated.The rate of adsorption of cobalt was found to be slower than that for nickel. However, the recovery of over 99% cobalt from ammoniacal carbonate solutions, at optimal conditions, was comparable to that for nickel.The cobalt was recoverable as metal, by ignition of the loaded lignite, or in solution, by elution with sulfuric acid in single or multiple stages.     

锌湿法净化系统钴的积累及钴平衡控制研究

本文分析了锌湿法冶炼锑盐净化工艺中钴积累的原因,以及钴积累对净化效果的影响,提出解决钴积累及保持系统钴平衡的方法。     

Hydrogen reduction of cobalt ferrite

The kinetics of reduction of cobalt ferrite by hydrogen as a function of reduction temperature and pressure have been measured by thermogravimetric analysis. A minimum in the rate as a function of temperature has been observed and its cause attributed to the formation of a cobalt-wiistite subscale at higher reduction temperatures. A mathematical model, based on one derived by Spitzer, Manning, and Philbrook,¹ has been used to interpret the results in terms of the rate constants for the individual steps in the reaction. Optical microscopy has been used to characterize the morphology of the reduction product and, additionally, partially reduced single crystals of cobalt ferrite have been examined by transmission electron microscopy to characterize the microstructure of the reaction interface. A fine network of pores in the reduced scale was shown to allow the reducing and product gases to reach the immediate vicinity of the chemical reaction. The structure of the porosity and consequently the effective gaseous diffusion coefficient in the scale were both shown to be functions of the reduction temperature and pressure. The interface reaction was shown to follow Langmuir-Hinshelwood kinetics. A model was developed to explain such kinetics by incorporating a solid-state diffusion step. Such a step was considered necessary to explain the development of the observed microstructures. An ‘incubation time’ for the development of a continuous cobalt-wüstite subscale at higher reduction temperatures was attributed to the different growth kinetics for the spinel-metal and spinel-wüstite interfaces.     

过硫酸铵氧化沉淀法富集净化钴渣中钴的试验研究

某公司生产初期采用α-亚硝基-β-萘酚除钴工艺回收湿法炼锌净化钴渣中的钴,存在药剂消耗量大、钴渣含钴低、生产亏损的问题,后采用过硫酸铵氧化沉淀法富集钴,形成了一种钴的富集倍数高,成本低、流程短、易操作、环保的净化渣回收钴的实用方法.该方法分三个阶段:酸浸阶段包括稀酸选择性浸出和逆流酸性浸出,在较优工艺参数下,钴的浸出率...     

Biliary excretion of cobalt in rats

The excretion of 58Co2+ via bile, urine and intestinal wall after intravenous administration of 58CoCl2 in two doses (177 and 1770 micrograms of Co2+ per kg B. Wt.) was studied in rats. The cumulative biliary excretion reached 24 hours after administration of lower dose 2.67 +/- 1.98% and higher dose 7.33 (4.6-10.9) % of the amount given. The highest excretion rate of 58Co was detected between 10 and 30 minutes after administration. After administration of higher dose of 58Co the lower urinary excretion was observed [73.6 +/- 4.0% resp. 47.9% (45.5-52.5)] of the amount given. There were no differences between both doses studied in the excretion of 58Co via the wall of gastrointestinal tract.