Recovery of metal values from copper converter and smelter slags by ferric chloride leaching

A study of the recovery of copper, nickel and cobalt from copper converter and smelter slags by leaching with ferric chloride is reported. The converter slag from Ghatsila, India contained 4.03% copper, 1.99% nickel and 0.48% cobalt and the smelter slag contained 1.76% copper, 0.23% nickel and 0.19% cobalt. Various parameters including the effect of stirring, leaching time, leaching temperature, concentration of ferric chloride, solid-liquid ratio and particle size, on the extraction of copper, nickel and cobalt have been studied. 92% copper, 28% nickel and 24% cobalt could be extracted from converter slag under optimum conditions, whereas 54% copper, 71% nickel and 44% cobalt could be extracted from smelter slag.     

焙烧氰化尾渣有价金属回收试验研究

辽宁新都黄金有限责任公司焙烧氰化尾渣中具有回收价值的有价组分主要为金、银、铜、铅、锌等。针对其尾渣性质,采用氯化焙烧工艺进行有价金属回收试验研究。结果表明:在氯化钙添加量7%、氯化焙烧温度1 100℃、时间1.5 h的工艺条件下,有价金属Au、Ag、Cu、Pb、Zn的挥发率分别达到92.25%、75.81%、82.66%、99.31%、91.06%。通过梯度升温干燥等措施,可以有效提高干球团强度。     

废杂Cu冶炼烟尘碱法工艺制备高活性Zn粉

采用清洁工艺回收再生Cu烟尘中的金属资源,并副产高附加值的产品。工艺流程包含微波碱浸、净化除杂和电解等工序。在浸出环节,通过微波(30 s×4循环)辅助,利用浓度为200 g/L的Na OH可浸取出约83%(质量分数)的Zn,而大部分Cu留在浸出渣中;微波辐射促进了Zn溶出,提高了溶液中Zn2+的相对浓度,并且降低了Na OH的使用量。在净化阶段,采用Na2S粉作为净化剂,使得杂质金属残留浓度低于100 mg/L。电解净化后的碱液,可获得Zn粉;最佳电解条件为:反应温度35℃,电流密度1 000~1 500 A/m2,Zn2+浓度30~40 g/L,Na OH浓度180~220 g/L。采用扫描电镜、X射线衍射仪和马尔文激光粒度仪来表征产品Zn粉。此清洁工艺投资成本低,设计简单,在工业危险废物Zn回收领域具有良好前景。     

黄金冶炼厂中萃取法提铜研究

本文针对黄金冶炼厂中萃取法提铜,通过实验研究,探讨萃取剂和稀释剂的选择,并提出萃取法提铜的主要思路,最后分析了杂质对萃取提铜需要。分析结果表明,在黄金冶炼厂,通过萃取法在废水、废渣中可以提出大量的铜,既有助于提升黄金冶炼厂的经济效益,也可以降低对周围生态环境造成的污染,值得高度重视。     

Viscosity of copper slags from chalcocite concentrate smelting

The viscosity of smelting slags from the Glogow copper plant in Poland was measured using a concentric cylinder viscometer. These slags contain typically 45 pct SiO₂, 16 pct CaO, 8 pct MgO, 11 pct Al₂O₃, and only 5 to 7 pct total iron. The viscosity was measured as a function of the CaO, MgO, SiO₂, Cu₂O, Cr₂O₃, and Fe₃O₄ contents in the temperature range from 1473 to 1623 K. Silica and chromium oxide additions increased the viscosity, while small additions of the other oxides decreased the viscosity. However, at large additions of CaO or MgO, cooling resulted in a rapid increase in the viscosity upon reaching the transition temperature. This critical transition temperature increased with increasing additions of CaO and MgO. This was explained by the precipitation of solid particles upon reaching the saturation limit. Depending on the slag composition, the activation energy for viscous flow was found to be in the range from 200 to 370 kJ/mol.     

高炉炉尘回收有色金属的工业实践

高炉炉尘含有铁、碳和少量有色金属。采用回转窑还原烟化富集工艺处理后可产出氧化锌粉。烟化残渣用选矿工艺处理可回收铁、碳,并可用于生产建材。烟化富集物经多段湿法工艺分离,可提取金属锌、铟、锡、铋、镉,做到固废物再资源化,实现工业化生产。     

Recovery of metal values from copper smelter flue dust

A hydrometallurgical process has been developed for the recovery of valuable metals from the flue dust of a copper smelter. The dust containing various metals, such as lead, zinc, copper, bismuth, indium, cadmium, iron, arsenic etc., was treated using this hydrometallurgical process to recover all these metals and also to solve environmental pollution problems. Leachings were carried out under atmospheric and elevated pressure utilizing sulfuric acid. Sulfuric acid pressure leaching in the absence of oxygen provided the best separation of copper and arsenic. About 80% of arsenic went into solution during leaching, and more than 90% of copper remained in the residue as cupric sulfide. Zinc, cadmium and indium from the solution and bismuth, copper and lead from the residue were recovered by various well-known processes. Arsenic and iron were removed from the solution by oxidation and precipitation as ferric arsenate. Both laboratory and bench-scale experiments were carried out with satisfactory results.     

Zinc electrowinning from flue dusts at a secondary copper smelter and connected adhesion problems of the metal deposits

The secondary copper smelter “Metallhütte Carl Fahlbusch” (MCF), Rastatt, Federal Republic of Germany is discussed, with particular consideration of the MCF zinc electrowinning process from low-grade, chloride-containing flue dusts. The investigations performed were focussed on the adhesion of zinc deposits on the aluminium cathodes. With laboratory tests using the tankhouse electrolyte and an apparatus for measuring the adhesion force, the influence of the electrolyte impurities lead, cadmium, cobalt, nickel, tin and antimony on the adhesion behaviour and on the current efficiency have been determined. Field tests to affect the adhesion of the zinc deposits on aluminium cathodes by dip pretreatment of the cathodes with glue or sodium resinate reveal that with only small sodium resinate additions in the dipping bath better stripping can be achieved.     

Numerical simulation of copper recovery from converter slags by the utilisation of spent potlining (SPL) from aluminium electrolytic cells

An innovative method was devised to improve copper recovery and operational efficiency of the Cu converter slag-cleaning furnace, by utilising both carbon and fluoride values of an otherwise environmental hazardous material (i.e. spent potlining (SPL)) produced from the aluminium industry. Results based on numerical modelling show that 90% Cu recovery could be achieved by adding as little as 3–4?wt-% of SPL to the molten converter slag. The fluorides and sodium-containing compounds in the SPL reduced the slag viscosity, resulting in a much faster settling rate of matte droplets. In this process, the SPL could be detoxified by destroying the cyanides to form harmless N₂ gas, and inertising the fluorides in a much diluted form in the ferro-silicate slag, ensuring a safe disposal to the environment.     

The nature and source of copper smelter particulate emissions

Particles from the inlet, outlet, and bin of electrostatic precipitators (ESPs) operating on copper reverberatory furnace and converter off-gas streams were characterized by their chemical, mineral-ogical, morphological, and electrical properties. Reverberatory furnace particles, nominally less than 10 microns in size, are believed to be formed by condensation of PbSO₄ and ZnSO₄ onto oxide particles (Fe₃O₄, Cu₂O, SiO₂) originating in the slag or concentrate. The very fine particles from the dual-nature converter dust were similar in characteristics and probably in origin to the reverberatory furnace particles. The coarse (up to 500 microns) slag (Fe₃O₄, SiO₂) and matte (Cu₂S, Cu) particles in the converter samples probably arose from entrainment by flowing or bubbling gases. The properties of all three sample portions varied depending on the source of the sample and the effectiveness of electrostatic precipitation. University of Arizona     

Dissolution behavior of Fe,Co, and Ni from non-ferrous smelter slag in aqueous sulphur dioxide

Large amounts of non-ferrous slags containing Co, Ni, and Cu are produced and stockpiled by metallurgical industries. These industries also produce sulphur dioxide, an air pollutant. Using sulphur dioxide as a leaching reagent to leach the valuable metals from slag would reap both economical gains and environmental benefits. Extraction of these metals using aqueous sulphur dioxide (SO₂(aq)) is being carried out in our group.     

Arsenate capacities of copper smelting slags

The arsenate capacity model, based on the Reddy-Blander model, was developed for copper smelting slags. The arsenate capacities of FeO-SiO₂, CaO-SiO₂, MgO-SiO₂, FeO-FeO_1.5-CuO_0.5-MgO-SiO₂, and FeO-FeO_1.5-CuO_0.5-CaO-MgO-SiO₂ slags in equilibrium with different grades of copper mattes (21 to 79 wt pct Cu) at 1573 K were studied. The calculated arsenate capacities using the RB model in copper slags a priori is in very good agreement with the available experimental data. The results show that the calculated arsenate capacities for these slags are found to be directly related to two independent experimental quantities: the equilibrium constant K of the arsenate forming reaction 2/3;MO (1)+As (1)+5/4O₂ (g)=M_3/2AsO₄ (l, s), and the activity of the base metal oxides in the binary MO-SiO₂ slags. Furthermore, this arsenate capacity model can be used for a priori prediction of arsenic behavior in a wide range of slag and matte composition, temperature, and in copper smelting conditions. Such predictions are very useful in understanding the behavior of arsenic in the current and eventually future nonferrous metal processes. This article is based on a presentation given in the Mills Symposium entitled “Metals, Slags, Glasses: High Temperature Properties & Phenomena,” which took place at The Institute of Materials in London, England, on August 22–23, 2002.     

大型有色冶炼厂总图设计中节约用地的探讨

论述了有色冶炼厂总图布置中节约用地的必要性,介绍了近年来大型有色冶炼厂在节约用地方面取得的进步,提出了节约用地的途径和方法,为今后有色冶炼厂总图布置提供参考.     

比利时Hydrometal工厂有色金属的回收利用

Hydrometal工厂可以提供完善的技术用于将已经废弃的金属废料再次引入到工业循环阶段,因此,不但节约了资源和能源,而且也更加环保。本文讨论的两个研究案例是关于比利时的一套完整的湿法冶金循环利用装置。(1)在锌泥的工艺处理过程中,残留的低质酸及碱通过几个连续的选择性浸出沉淀工序可以用来生产铜、镍、钴及锌精矿。(2)对铜阳极泥进行处理,回收其中的贵金属成分。根据铜阳极泥的成分,可以生产出单独的或者混合的铜、铋、碲、硒和银/贵金属精矿。     

大型有色冶炼厂总图设计中节约用地的探讨

论述了有色冶炼厂总图布置中节约用地的必要性,介绍了近年来大型有色冶炼厂在节约用地方面取得的进步,提出了节约用地的途径和方法,为今后有色冶炼厂总图布置提供参考。     

Hydrogen reduction of copper bleed solution from an Indian copper smelter for producing high purity copper powders

A bench scale investigation on the hydrogen reduction of a highly acidic copper bleed solution to produce high purity copper powder is discussed in this paper. A titanium lined autoclave of 1 L capacity was used for this study. The parameters optimized on the bench scale were validated by performing hydrogen reduction of copper in a larger autoclave. Effect of various parameters viz., time of reduction, temperature of reduction, pressure variation, iron dose, volume of copper solution etc. were studied. Experiments were performed with synthetic and actual solution obtained from a copper plant. A 99% copper powder recovery is achieved by hydrogen reduction at a pressure of about 2400 kPa, reaction temperature of 453 K, stirring speed of 400 rpm for a reaction time of 2 h. The fine copper powder thus obtained had a good metallic lustre. Kinetics of reduction of copper was examined by drawing samples at different times and analyzing the percent copper reduction. The copper depleted solution was further purified with respect to the residual copper and can be processed for the recovery of nickel powder by hydrogen reduction.Properties of the copper powder obtained from the large-scale experiments from actual plant and synthetic solutions have been evaluated for powder metallurgical applications. The raw and annealed copper powders obtained from the synthetic copper solution were found to have an apparent density of 3.50 g/cm³, flow rate 35.6 g/min, hydrogen loss 0.2%, purity 99.8% and green density of 8.6 g/ cm³ while the powder from actual plant solution was found to have an apparent density of 3.59 g/ cm³, flow rate 46.0 g/min, hydrogen loss 0.6%, purity 99.4% and green density 8.6 g/ cm³. Thus, the copper powder produced by hydrogen reduction was found suitable for the application.     

有色金属冶炼烟气中单质汞脱除研究现状

由于汞具有剧毒性、易挥发性和长距离迁移性等特点,汞污染已经成为全球性的环境问题。目前,有色金属冶炼行业是我国大气汞排放的主要来源之一,占总排放量的30%左右。面对汞污染的压力,如何实现有色金属冶炼烟气中汞的高效脱除已经成为研究热点。针对有色冶炼烟气中汞排放的特征,阐述了烟气中汞形态转化和分布规律,综述了冶炼行业汞污染治理的研究现状,主要介绍冷凝法、吸附法、催化氧化法和液相吸收法等,对各种方法进行详细的描述,并对现有有色金属冶炼行业汞污染防治技术现状进行了总结和建议。      

Diffusion of copper in liquid fayalite slags

Abstract

A modified version of the capillary reservoir technique was used to determine the diffusivity of Cu in silica-saturated fayalite slag. Values of the diffusion coefficient increased from 1.0% × 10^?5 to 7.0 × 10^?5 cm²/sec over the temp. range 1150–1300°C. From a series of diffusion experiments conducted at constant copper activity, the calculated activation energy for diffusion was 39,000 ± 12,000 cal/mole. Under isothermal conditions, the diffusion coefficient was found to be independent of the , oxygen partial pressure over the slag phase. The range of oxygen partial pressures investigated was from 10^?8 to 10^?12 atm.

Résumé

Par une version modifyée de la technique du réservoir capillaire les auteurs ont déterminé la diffusion du cuivre dans des laitiers de fayalite saturé en silice. Dans l'intervalle de tempérapture de 1150 à 1300°C, le coefficient de diffusion augmente de 1.0 × 10^?5 à 7.0 × 10^?5 cm²/sec. L' énergie d'activation pour la diffusion, calculée à; partir d'une série d'expériences faites à une activité du cuivre constante, est de 39,000 ± 12,000 cal/mole. Dans des conditions isothermes il a été trouvé que le coefficient de diffusion était indépendant de la pression partielle d'oxygene au dessus du laitier. Le domaine des pressions partielles d'oxygene étudié était de 10^?8 à 10^?12 atm.     

Settling of copper drops in molten slags

The settling of suspended metal and sulfide droplets in liquid metallurgical, slags can be affected by electric fields. The migration of droplets due to electrocapillary motion phenomena may be used to enhance the recovery of suspended matte/metal droplets and thereby to increase the recovery of pay metals. An experimental technique was developed for the purpose of measuring the effect of electric fields on the settling rate of metallic drops in liquid slags. Copper drops suspended in CaO−SiO₂−Al₂O₃−Cu₂O slags were found to migrate toward the cathode. Electric fields can increase the settling rate of 5-mm-diameter copper drops 3 times or decrease the settling until levitation by reversal of the electric field. The enhanced settling due to electric fields decreases with increasing Cu₂O contents in the slag.     

从焙烧氰化尾渣中回收金、银的试验研究

通过试验提出一种从焙烧氰化尾渣中回收金、银的工艺方法。该工艺是将氰化尾渣加添加剂再磨至-400目含量大于95%,以除去矿样中的砷,并使氰化尾渣中脉石包裹的金、银暴露;然后用30%除杂剂加热浸取杂质,并除去金矿物表面的钝化膜。处理后的矿样采用氰化法进行浸取金、银。试验结果表明,该工艺可使焙砂氰化尾渣中金、银的氰化浸出率分别达到65.00%和41.49%。