铜离子对硫酸锌溶液中钴返溶的影响及机理

本文研究了对湿法炼锌过程中钴的返溶的影响因素,对反应时间,氧化,锌粉粒度,Cu2 等因素进行了系统的研究.当锌粉量一定时,小颗粒锌粉有较高的初始置换速率,但是也更容易返溶.大颗粒锌粉置换速率慢,但是几乎不返溶.添加了铜离子,返溶明显,而没有添加铜离子的溶液,虽然除钴效果稍差,但是不会返溶或者返溶不明显.然而铜离子的存在对钴的返溶究竟起着何种作用还有待于进一步研究.在锌粉置换过程中,钴返溶的正确的反应为:Zn Co2 →Zn2 Co(s),Co(s) 2OH-→Co(OH)2 2e.     

Mechanism of cobalt removal from zinc sulfate solutions in the presence of cadmium

The effect of cadmium and copper, temperature and reaction time on the removal of cobalt from zinc sulfate solutions using zinc dust was experimentally studied. The results show that the rate and extent of cobalt removal are enhanced when cementation takes place in the presence of less than 400 mg/L of cadmium. Cementation residues were analyzed using electron probe micro-analysis (EPMA) to investigate the distribution of phases in the cementation products and the mechanism of cobalt removal. It was found that formation of Zn–Co and Zn–Cd alloys on the zinc dust particles can enhance cobalt removal whereas the presence of Zn–Cu and Cu–Cd alloys can inhibit cobalt removal.     

高钴硫酸锌溶液两段高温锑盐净化除钴的生产实践

介绍了两段高温锑盐净化工艺的基本原理,操作条件及生产实践。该工艺可将高钴硫酸锌溶液中的钴从60～90mg／L除至1mg/L以下。     

高钴硫酸锌溶液两段高温锑盐净化除钴的生产实践

介绍了两段高温锑盐净化工艺的基本原理,操作条件及生产实践。该工艺可将高钴硫酸锌溶液中的钴从60～90mg／L除至1mg/L以下。     

湿法炼锌过程中贫镉液除钴的研究

进行了湿法炼锌过程中钴的开路研究，贫镉液用沉钴剂氧化除钴，可使溶液残钴降至5mg/L以下。     

湿法炼锌过程中贫镉液除钴的研究

进行了湿法炼锌过程中钴的开路研究,贫镉液用沉钴剂氧化除钴,可使溶液残钴降至5 mg/L以下。     

新型除钴剂DCR硫酸锌浸出液净化除钴的工艺

研究了新型除钴剂(简称DCR试剂)脱除硫酸锌浸出液中杂质钴的工艺,考察了除钴剂用量、反应时间、反应温度、亚硝酸钠的添加量对除钴效果的影响.试验结果表明较优的工艺条件为:除钴剂为4 g/L,时间为60 min,温度为60℃,亚硝酸钠的添加量为0.6 g/L.在此条件下,钴的脱除率达到98.42%.     

Study of the kinetics of silver ions cementation onto copper from sulphuric acid solution

The kinetics of silver cementation with copper from sulphuric acid solution has been studied with a rotating cylinder. Two independent methods have been used to monitor the concentration of Ag⁺ ions in the solution: atomic absorption spectrophotometry (AAS) method and a continuous method with the use of an ion-selective electrode. The reaction has been found to follow first-order kinetics with respect to silver ion concentration. The initial rate of the reaction is limited by diffusion through the mass transfer boundary layer. The rate constant for initial period of cementation is independent of the absence or the presence of oxygen in the solutions and is independent of the presence of Cu²⁺ ions up to the concentration of 2×10⁻⁴ M. After the initial period of cementation a rate enhancement has been observed. In solutions containing 20 mg/L of Ag⁺ ions, the rate enhancement is associated with changes in the structure of the deposit which involve an increase in the effective surface area during the process. However, the rate enhancement phenomenon in the absence of oxygen at 100 mg/L of Ag⁺ is attributed not only to an increase in the effective surface area but also to a chemical reaction between Cu⁺ and Ag⁺ ions.     

示波极谱法快速测定锌电解液中痕量钴

研究了在HAc -NaAc -NH4 Cl-柠檬酸钠 -丁二酮肟 -乳化剂OP体系中 ,用示波极谱法测定锌电解液中的痕量钴。试验发现 ,加入适量的乳化剂OP ,可使锌波峰电位向负方向移动 ,而对钴波峰电位几乎无影响 ,大大减弱了锌波对钴波的干扰。Co -丁二酮肟 (DMG)络合物在 -0 .93V (vs.SCE)处 ,产生一灵敏的络合吸附波。钴浓度在 0 .0 0 16～ 0 .1μg/mL时 ,与峰电流有良好的线性关系 ,其检出限为 1.2× 10 - 6 μg/mL。将本法应用于锌电解液中痕量钴的     

钴溶液硫化沉淀法除砷的热力学研究

进行了钴溶液硫化沉淀法除砷的热力学研究.研究了钴溶液中砷的各种配合物含量的变化,绘制了25℃时As-S-H2O系中含砷离子随pH值及硫用量[S]/[As]变化的分布曲线,考察了工艺参数对除砷的影响.研究表明：pH值和硫化剂的用量对溶液残砷量有重要影响,控制硫加入量能够使溶液中的含砷化合物较彻底地形成As2S3沉淀.     

从钴铜矿浸出液中萃取-电积铜

介绍了用萃取-电积脱铜技术替代铁屑置换或碳酸钠中和沉淀,从氧化钴铜矿浸出液中脱除铜的生产实践及主要技术经济指标。     

从钴铜矿浸出液中萃取-电积铜

介绍了用萃取-电积脱铜技术替代铁屑置换或碳酸钠中和沉淀,从氧化钴铜矿浸出液中脱除铜的生产实践及主要技术经济指标。     

α-亚硝基-β-萘酚的合成及其在硫酸锌溶液中除钴工艺的研究

以β-萘酚,亚硝酸钠为原料系统研究了α-亚硝基-β-萘酚在冰乙酸溶液中的合成工艺。考察了反应时间、反应温度、反应pH值、物料比例对合成α-亚硝基-β-萘酚产率的影响。试验结果表明在最优工艺条件下其合成产率可达95.15%。进行了α-亚硝基-β-萘酚沉淀分离硫酸锌溶液(中浸上清)中钴的条件和优化试验,对药剂的用量、反应时间、反应温度、pH范围等因素进行了考察,确定了α-亚硝基-β-萘酚沉钴的最佳反应条件。采用该工艺可将硫酸锌溶液中的钴含量降至0.2 mg/L。     

分光光度法和光度滴定法联合测定湿法炼锌流程中钴渣浸出液中锌钴镍

湿法炼锌流程中钴渣浸出液中含有高浓度的Fe²⁺和Mn²⁺,用分光光度法测定Co²⁺和Ni²⁺时,Fe²⁺-EDTA会严重干扰Co²⁺和Ni²⁺的测定;在用光度滴定法测定Zn²⁺和Co²⁺合量时,Ni²⁺对二甲酚橙指示剂具有封闭作用,Mn²⁺亦与EDTA螯合,导致滴定结果偏高。为消除Fe²⁺和Mn²⁺对Zn²⁺、Co²⁺和Ni²⁺测定的干扰,实验进行氧化分离Fe²⁺和Mn²⁺预处理,在NaAc/Hac缓冲体系下,以EDTA作显色剂用分光光度法测定Co²⁺、Ni²⁺。在波长466nm处,Co²⁺的线性范围为50~500mg/L时与吸光度呈线性,相关系数R²为0.9992;在384nm处,Ni²⁺的线性范围为50~500mg/L时与吸光度呈线性,相关系数R²为0.9998。根据分光光度法测出Ni²⁺物质的量,加入1.1倍的丁二酮肟以除去Ni²⁺,用二甲酚橙为指示剂,EDTA鳌合-光度滴定法测定Zn²⁺、Co²⁺合量,扣减Co²⁺含量得出Zn²⁺含量。选取4个锌湿法炼锌流程中钴渣浸出液实际样品,按照实验方法中的分光光度法测定Co²⁺和Ni²⁺,光度滴定法测定Zn²⁺、Co²⁺合量,Zn²⁺、Co²⁺和Ni²⁺测定结果的相对标准偏差(RSD,n=6)均不大于0.70%,加标回收率分别为99.59%~100.41%、99.69%~100.64%、99.92%~100.08%。     

硫酸锌溶液冷却结晶除钙镁生产实践

对几种不同的除钙镁工艺进行了对比分析,研究了冷却沉降法除硫酸锌溶液中的Ca、Mg,实验表明,冷却沉降法是一种节能、高效的工艺方案,控制温度25℃、pH=3.8～4.5、晶种加入量4 g/L、沉降时间100 min,可获得较好的工艺指标。     

硫酸锌溶液深度净化除钴的现状与发展

概述了近年来国内外硫酸锌溶液深度净化除钴现状和方法，简述了各种方法的工艺流程、除钴原理，比较了各种方法的优缺点。从安全、环保及经济等角度考虑，以锑盐作活化剂锌粉置换除钴工艺较好，是湿法炼锌厂较普遍采用的方法。     

Hydrometallurgical extraction of zinc from Jordanian electric arc furnace dust

Zinc was extracted in a Jordanian Steel Plant using an electric arc furnace dust. Sulfuric, nitric and hydrochloric acids were used at different concentrations to recover zinc from dust particles. The highest zinc extraction was obtained at low acid concentration of less than 1 mol/L in the order of H₂SO₄ followed by HNO₃ and then HCl. The kinetics of zinc extraction using H₂SO₄ showed a maximum zinc recovery of 72% obtained by using 0.1 mol/L acid concentration, 900 rpm agitation speed and 50 °C.     

The effect of certain surfactants on the cementation of nickel from zinc sulphate solutions by suspended zinc particles in the presence of copper

The effect of surfactants nonylphenolpolyethylene glycol (D1), dinaphthylmethane-4,4′-disulphonic acid (D2) and polyethylene glycol with molecular weight 400 (D3) on both nickel-zinc dust cementation kinetics and the structure of obtained deposits was investigated. Experiments were carried out in the presence of copper to increase the low cementation rate of nickel. The reaction of nickel cementation was found not to follow first-order kinetics due to hydrogen evolution which takes place along with the cementation reaction. Two rate regions were observed. Hydrogen evolution in the presence of D1 is lower than with D2, D3 and without surfactants. D1 and D3 decrease but D2 has no effect on nickel cementation. The influence of D1 and D3 is higher at the beginning of the process. Higher temperature improves nickel cementation only in the initial period. The structure of cementation products depends on the temperature. Uniform layers of lamellar crystallites on the surface of zinc particles were observed at 65°C with and without surfactants. At 85°C the morphology changes to massive spheroid formations of lamellar crystallites. The presence of D1 and D3 decreases both the crystallite size and deposit porosity. The lowest porosity was found in the presence of D3. The inhibition effect of D1 on the hydrogen evolution contributes to decrease in zinc consumption during the cementation of nickel.     

氧化钴生产过程的非草酸盐沉钻工艺研究之二碳铵(反加)法自硫酸钴溶液中沉钴

通过系统的沉淀剂筛选试验，确定了碳酸氢铵是适宜的非草酸盐沉钴剂，采用沉钴剂反加法再辅以添加适量的分散剂和絮凝剂，可自硫酸钴溶液中以高于97％的沉钴率沉出含钴沉淀产物，沉淀产物不含氯根，其煅烧产物疏松、理化性能优异，符合用户的质量要求。沉淀工序的加工成本可降低～50％。     

Effect of Mn ions on the electrodeposition of zinc from acidic sulphate solutions

The effect of Mn²⁺ ions on current efficiency (CE), deposit morphology and polarization behaviour during electrodeposition of zinc from acidic sulphate solutions was investigated. In the conditions studied, Mn²⁺ ions had no significant effect on CE over the concentration range of 1–10 g dm^− 3. However, a decrease in CE of more than 35% was obtained at 50 g dm^− 3. The cathodic polarization curves and the corresponding kinetics analysis demonstrated that this decrease in CE at higher concentrations of Mn²⁺ ions was due to the strong depolarizing effect of MnO₄⁻ ions and other oxidized products of manganese. Moreover, the kinetics analysis of anodic polarization suggested that the presence of Mn²⁺ ions catalyzed the oxygen evolution reaction. The addition of Mn²⁺ ions was also observed to change the surface morphology and deposit quality of the electrodeposited zinc, affecting the crystallographic orientation by significantly inhibiting the growth of (002) and (100) planes.