从湿法炼锌浸出液中选择性萃取分离回收铜

针对传统湿法炼锌过程铜回收工艺长、铜回收率低的难题,采用M5640直接从湿法炼锌还原浸出液中萃取分离回收铜,缩短铜回收流程,提高铜回收率。研究了混合时间、溶液pH值、萃取剂浓度、萃取级数等因素对铜萃取率的影响,以及反萃时间、相比等因素对载铜有机相中铜反萃率的影响。结果表明M5640对硫酸锌溶液中的铜离子具有很好的选择性萃取性能,在M5640浓度为15%、溶液pH值为2.0、相比(O/A)为1∶2、萃取时间为5 min的条件下,经过4级逆流萃取,铜萃取率为95.2%,锌萃取率仅为0.5%,铜锌分离系数为4 080。有机相经洗涤后,锌、铁等杂质离子被脱除,载铜有机相采用模拟铜电积废液反萃,经过2级逆流反萃,铜反萃率为97.1%。采用萃取-洗涤-反萃技术从湿法炼锌浸出液中回收铜,铜的总回收率为92.4%。     

含钒废弃物中钒的回收研究现状及展望

这是一篇冶金工程领域的论文。钒是我国稀缺战略金属资源,应用于众多领域,与国民经济密切相关。现如今提钒工艺综合利用价值越来越大,其中溶剂萃取法提钒受到广泛的关注,它具备选择性强,产品纯度高等优点。对此,文章综述了焙烧、浸出、净化富集和沉钒技术工艺,对溶剂萃取法分离钒的研究工作及方法进行了总结,并重点探讨了叔胺萃取剂对钒的提取及其国内外发展的现状。     

Extractive separation of copper and nickel from copper bleed stream by solvent extraction route

Bleed stream from electro refining step of copper smelter was processed to recover the metals as high value products such as copper and nickel powders or salts. The process consists of partial decopperisation of the bleed stream followed by crystallization of a mixed salt of copper and nickel sulphate, leaching of the mixed salt, removal of iron, solvent extraction for the separation of copper and nickel and winning the solution to produce metal powders. After partial decopperisation of copper bleed stream, the resultant solution was subjected to crystallization which produces composite crystals with the chemical composition of 8.4–12.5% Cu, 13.7–14.38% Ni and 1–2 ppm of Fe as impurity. This mixed salt was leached with water and was treated for iron precipitation. The purified solution was subjected to solvent extraction using two solvents namely LIX 84 or Cyanex 272. A 20% LIX 84 in kerosene extracted 99.9% copper and 0.059% nickel at a pH of 2.5, similarly a 5% Cyanex 272 in kerosene extracted 98.06% copper and 0.51% nickel at a pH of 4.85. LIX 84 was used for metal separation in the mixer-settler unit and a flow sheet was developed using this solvent. The pure solutions of copper after stripping it from the loaded organic and nickel left in the raffinate were further electrolysed to produce pure copper (99.9%) and nickel (99.8%) powders, alternatively pure sulphate salts could also be crystallized. Since it is well known that Cyanex 272 is used for the separation of cobalt and nickel, a few experiments were performed on the extraction of copper by using Cyanex 272. A complete study is yet to be done to develop a flow sheet by using this solvent.     

Uranium recovery from strong acidic solutions by solvent extraction with Cyanex 923 and a modifier

Uranium stripping with strong acid solution is always highly desired due to its simple operation and less pollution. However, intensive acid neutralisation for uranium precipitation in the subsequent step limited its application. A new solvent extraction process has been developed to transfer uranium from strong to weak sulphuric acid solutions suitable for uranium precipitation without intensive neutralisation. An organic system consisting of 10% Cyanex 923 and 10% isodecanol as the modifier in ShellSol D70 was optimised for the process. It was found that uranium was extracted efficiently from 4 to 6 M H₂SO₄ solutions with the organic system, and it could be efficiently stripped with 0.2–0.5 M H₂SO₄ solutions. Both extraction and stripping kinetics of uranium were very fast, reaching the equilibrium within 0.5 min. Temperature between 30 and 60 °C has slight effect on uranium extraction and stripping. Four theoretical stages could effectively extract more than 98% uranium from a solution containing 17.5 g/L U and 6.0 M H₂SO₄ at an A/O ratio of 1:1.5, and it could generate a loaded organic solution containing about 12 g/L U. More than 99% U could be stripped from the loaded organic solution containing 14.6 g/L U with 0.5 M H₂SO₄ using five stages at an A/O ratio of 1:3. As a result, the loaded strip liquor containing more than 40 g/L U would be obtained which is suitable for uranium recovery by precipitation using hydrogen peroxide. A conceptual process has been proposed for uranium transfer from strong to weak sulphuric acid solutions for its recovery.     

铜阳极泥氯化浸金液连续萃铜试验

针对铜阳极泥氯化浸金液含铜高造成稀贵金属置换困难且损失量大的问题,采用Lix984萃取分离铜,进行萃取槽连续试验,考察铜萃取率变化,分析存在的问题并探讨解决方案。试验发现采用Lix984从含铜10～20g/L和Cl-～200g/L的氯化浸金液中分离和回收铜,技术上可行。在萃取混合时间3min、萃取相比(O/A)2/1、反萃水相为180～260g/L硫酸条件下,经过4级萃取、2级洗涤和2级反萃,铜直收率可达99%以上。金、银、钯、铅、镍等不被萃取,仅有少量夹带,可洗涤回收。萃取过程发生界面污物累积和乳化,主要与料液含固量高、金属离子水解、相比和搅拌速度不当、萃取剂降解等因素有关,可通过精滤、过渡槽调pH值、实时监控流量和转速、定期补充萃取剂和清除第三相等措施,实现萃取稳定运行。     

Dynamic modelling of copper solvent extraction mixer–settler units

The copper Leaching, Solvent Extraction and Electrowinning circuit (LX–SX–EW) is one of the most effective processes for extracting copper from low grade ores. This work focuses on the liquid–liquid extraction SX sub-process, since many difficult to handle operational problems within LX–SX–EW circuits are related to SX malfunction. Controlling these problems better can reduce operational costs and increase recovery and copper production. Realistic dynamic simulation is a standard tool nowadays to design and assess more effective control strategies. In this work we present a general dynamic model for SX mixer–settlers, and applied it to two different units, one located in an extraction stage and the other in a stripping stage of a copper plant. The model includes a non-trivial settler hydrodynamics represented by a set of nonlinear differential equations for both mixer and settler units. The mixer is modelled as a continuous stirred tank reactor and the settler as a hydrodynamic circuit combining series and parallel connections of continuous stirred tank and plug flow reactors. The model was calibrated with industrial plant data, resulting in realistic simulations of outlet copper concentrations. Using the proposed model, we obtained better fitting than that achieved with simpler settler models that include only a time delay. The model fitting parameters provide sufficient flexibility to accurately reproduce the dynamics of different units in industrial plants.     

Recovery of dissolved platinum group metals from copper sulphate leach solutions by precipitation

The pregnant leach solution produced in the final leaching stage of base metal refineries (BMRs) operated by platinum producers contains impurities such as selenium and tellurium as well as other precious metals (OPMs, which include Rh, Ru and Ir). The aim of this project was to propose operating conditions for a thio-urea precipitation process that would allow maximum OPM recovery and impurity precipitation from the leach solution with minimal copper and nickel co-precipitation. Experimental results illustrating the effects that operating temperature (80 °C and 160 °C), pressure (atmospheric pressure and seven bar), stirring rate (250 rpm and 500 rpm) and thio-urea quantity (200% and 320% excess) have on the precipitation behaviour are presented.Virtually all of the Rh contained in the solution was precipitated irrespective of the values of the process variables studied. The maximum percentage Ru and Ir precipitation achieved were 87% and 60%, respectively. Complete Se precipitation was observed at all process conditions, while Te precipitation increased as the operating temperature was increased. Increasing the reagent quantity and temperature did, however, also result in increased copper and nickel co-precipitation.Regression models were used to perform numerical analyses to determine suitable operating conditions. Predictions with this numerical approach suggested that precipitation with 200% excess thio-urea at a temperature of 80 °C and a pressure of 7 bar would yield 98% Rh, 75% Ru, and 48% Ir precipitation with less than 5% Cu and Ni co-precipitation; these results could be experimentally validated.     

P204-TOPO混合萃取体系从湿法炼锌含铟硫酸锌溶液中萃取回收铟

为解决湿法炼锌硫酸锌溶液中传统溶剂萃取回收铟过程需使用高浓度盐酸反萃,且反萃后贫有机相中夹带氯离子危害湿法炼锌的难题.采用P204-TOPO混合萃取体系从含铟浸出液中选择性萃取铟,载铟有机相采用硫酸反萃,实现无氯体系回收铟.研究发现,混合体系萃取铟过程属于阳离子交换,TOPO与P204发生缔合作用,减弱了P204与铟离...     

A study on the chemical stability of the Versatic 10–Acorga CLX50 synergistic system

Synergistic solvent extraction (SX) utilises combinations of extractants and synergists to enhance the selectivity of the organic extraction system. It has previously been shown by work conducted at the AJ Parker CRC/CSIRO Minerals that the selectivity of Versatic 10 for nickel over calcium was substantially improved by adding the Avecia reagent Acorga CLX50 to the organic system as a synergist. However, the chemical stability of this reagent under conditions relevant to an operating circuit had not been established.This study aimed to assess the chemical stability of Acorga CLX50 in a Versatic 10/Acorga CLX50/Shellsol 2046 system under conditions used at the Bulong Nickel SX circuit. This was achieved by monitoring physical and compositional changes in the organic solution with time when tested under the following conditions: continuous batch mixing with synthetic strip solution over 12 weeks at 40 °C, continuous batch mixing with synthetic strip solution over 16 days at elevated temperature (60 °C), and continuous extraction-stripping operation using a mixer/settler with synthetic aqueous leach solution and spent nickel electrolyte from the Bulong plant over 16 days at 40 °C.Minor changes in physical properties associated with the addition of Acorga CLX50 to a mixture of Versatic 10/Shellsol 2046 were observed, namely a decrease in interfacial tension and an increase in primary and secondary phase disengagement times after both organic continuous and aqueous continuous mixing. Importantly, no adverse changes in the physical properties of any of the organic solutions from the three tested systems were noted as a function of extended mixing time and/or mixing temperature. Similarly, no loss of Acorga CLX50 or ongoing generation of degradation products associated with the presence of Acorga CLX50 was observed in any of the organic solutions from the three tested systems, by gas chromatography or high performance liquid chromatography.From these results it can be concluded that the Versatic 10/Acorga CLX50/Shellsol 2046 organic system is chemically stable under the conditions tested and the addition of Acorga CLX50 does not, directly or indirectly, lead to the generation of species that adversely affect phase separation.     

Alleviation of organic solvent inhibition with improved copper recovery from low grade sulphide ore by bioaugmentation with newly isolated Candida sp. OR3 and OR6

Organic compounds used in solvent extraction (SX) processes severely inhibit copper bioleaching microorganisms. In this experimental study, it was found that bioleaching microorganisms at 0.5% and 0.75% organic (SX) resulted in lower Cu recovery from low grade sulphide ore. Two new Candida species OR3 and OR6 were isolated from the liquid phase in solvent extraction process and these isolated strains were tolerant and capable of growing on 1% organic phase. The inhibition of organic phase to bioleaching microorganisms was alleviated by the addition of the 2 isolates and as a result the Cu recovery remained at high level. This is the first study which shows that the organic SX mixture inhibition to acidophilic microorganism can be overcome by the addition of other microorganisms.     

A critical review on solvent extraction of rare earths from aqueous solutions

Rare earth elements have unique physicochemical properties that make them essential elements in many high-tech components. Bastnesite (La, Ce)FCO₃, monazite, (Ce, La, Y, Th)PO₄, and xenotime, YPO₄, are the main commercial sources of rare earths. Rare earth minerals are usually beneficiated by flotation or gravity or magnetic processes to produce concentrates that are subsequently leached with aqueous inorganic acids, such as HCl, H₂SO₄, or HNO₃. After filtration or counter current decantation (CCD), solvent extraction is usually used to separate individual rare earths or produce mixed rare earth solutions or compounds. Rare earth producers follow similar principles and schemes when selecting specific solvent extraction routes. The use of cation exchangers, solvation extractants, and anion exchangers, for separating rare earths has been extensively studied. The choice of extractants and aqueous solutions is influenced by both cost considerations and requirements of technical performance. Commercially, D2EHPA, HEHEHP, Versatic 10, TBP, and Aliquat 336 have been widely used in rare earth solvent extraction processes. Up to hundreds of stages of mixers and settlers may be assembled together to achieve the necessary separations. This paper reviews the chemistry of different solvent extractants and typical configurations for rare earth separations.     

Membrane transport of copper with LIX-860 from acid leach waste solutions

A membrane transport process is described. The process was developed for use in the recovery of copper from nitric acid leach residual solutions. The flux and the extraction extent of copper with 5-dodecylsalicylaldoxime dissolved in Kermac 500-T (an industrial diluent) were measured at 30°C by using a membrane extractor made of a holow fibre. The content of carrier extractant in the wall of the porous fibre presented the biggest influence on metal extraction rate and its extractability. The results were explained by a diffusion model which considers that the extraction chemical reaction would occur at the inner interface of the liquid membrane, taking account that diffusion of copper-oxime complex through the membrane would be the rate-controlling step.     

谢 铿 王海北 刘三平 苏立峰

对内蒙古某公司湿法炼锌产生的铅银渣和铁矾渣进行扩大试验,采用"洗涤—净化—萃取"工艺回收渣中夹带的水溶锌,铅银渣和铁矾渣中锌洗涤回收率分别达到42%和90%左右,铁去除率大于98%,萃取后得到的富锌溶液可送电积车间生产电锌。该工艺流程简单、原料适应性强、经济效益和社会效益显著。     

Recovery of germanium from waste solar panels using ion-exchange membrane and solvent extraction

Germanium was recovered from the waste solar panels using the processes of selective catechol complexation, membrane adsorption and elution, and solvent extraction. Because the solar panels included a high concentration of germanium, the key technique used was high selectivity against silicate ion using hydrometallurgy. Due to the selective complexation of germanium ions with catechol, the operation at low pH enhanced the selectivity. 0.1 M hydrochloric acid was used to elute the germanium ions. To remove the catechol from the germanium containing solution, solvent extraction using trioctylphosphine oxide was performed, demonstrating that 81% of catechol was removed. Compared with the initial percentage of germanium to silica, the concentration of silicate was 39 times higher in the germanium-concentrated solution, indicating that the proposed sequential process was very a powerful technique for the recovering germanium.     

Study on separation of heavy rare earth elements by solvent extraction with organophosphorus acids and amine reagents

The present work describes a study of the separation of rare earth elements (REE) from heavy REE concentrate through solvent extraction. Seven extractants were investigated: three organophosphorus acids (DEHPA, IONQUEST^®801 and CYANEX^®272), a mixture of DEHPA/TOPO (neutral ester) and three amines (ALAMINE^®336, ALIQUAT^®336 and PRIMENE^®JM-T). The organophosphorus extractants were investigated in hydrochloric and sulphuric media whereas the amines performance was assessed in a sulphuric medium. The variables investigated were: concentration of the extractant agent, aqueous phase acidity, aqueous/organic volumetric ratio, contact time, stripping agent concentration (hydrochloric acid solution) and the selective stripping step. In the extraction step, the best separation factors for the adjacent elements were obtained with DEHPA and IONQUEST 801. For 1.0 mol L⁻¹ DEHPA in an initial acidity of 0.3 mol L⁻¹ H⁺, the separation factor was 2.5 Tb/Dy, 2.1 Dy/Ho, 1.9 Ho/Er, 2.0 Ho/Y and 1.1 Y/Er; for 1 mol L⁻¹ IONQUEST 801 in 0.3 mol L⁻¹ of H⁺ it was 2.7 Tb/Dy, 2.4 Dy/Ho, 2.1 Ho/Er, 2.1 Ho/Y e 1.5 Y/Er. The study concluded that for the extractants investigated, IONQUEST 801 is the most indicated for the separation of heavy REE because it has lower affinity with the REE compared to the affinity of DEPHA/REE, which makes the strip of the REE from Ionquest 801 easier than from DEHPA. Moreover, the number of stages necessary for the stripping of the REE from IONQUEST 801 is much lower than that observed when DEPHA is employed.     

溶剂萃取过程絮凝物的形成及控制

工业溶剂萃取工厂都会受到由固体颗粒所引起的絮凝物的影响 ,它影响着萃取过程相的连续性、乳化物的稳定性、水流和空气的分布。本文主要从有机相、水相、固体微粒和空气四方面对絮凝物的成因及其控制和处理方法进行了初步的探讨     

Production of high-purity molybdenum compounds from a Cu–Mo acid-washed liquor using solvent extraction. Part 2: Pilot and plant operations

Laboratory studies on the recovery of molybdenum from acid wash liquor, reported in Part 1 of this series of papers, identified the optimum process conditions for the production of high purity molybdenum trioxide and calcium molybdate. Pilot and plant scale operations were conducted as a result of the design developed during our laboratory studies.Molybdenum was selectively recovered from a wash liquor containing 10 g/L Mo via a 2-stage extraction using 10% v/v Alamine diluted in Anysol 150 diluent as extractant. The use of 10% v/v isodecanol (IDA) was found to enhance the extraction of molybdate from the wash liquor. The organic extractant liquor had to be scrubbed with water to remove the ammonium sulphate crud formed when ammonium hydroxide solution (20% w/v) was used to strip the molybdate from the loaded organic. The pilot scale study (0.2 m³/day) and plant operation (30 m³/day) were able to be continuously operated to recover 99% Mo from the wash liquor, from which high purity MoO₃ and CaMoO₄ of >99.9% purity could be recovered.     

Production of high purity molybdenum compounds from a Cu–Mo acid-washed liquor using solvent extraction. Part 1: Laboratory studies

Solvent extraction, using Alamine 304-1 for loading (extraction) and ammonia for stripping, was used for selectively recovering molybdenum from acid wash liquor produced by a Mo processing plant. The results showed that the extraction could be completed in 3 stages, using Alamine 304-1 as the extractant (10%, v/v in Anysol 150 diluent), with almost all the Mo(VI) recovered from an acidic sulfate wash liquor, containing 10–15 g/L Mo(VI), 10 g/L Cu(II) and 2 g/L Fe(III), using an O/A volumetric ratio of 3:2. Using ammonia (12.5%, w/v), at an O/A ratio of 5:1, all the Mo(VI) from an Alamine liquor containing 17.5 g/L Mo could be removed in one strip, yielding a solution with 87.0 g/L Mo(VI). High purity (>99.9%) MoO₃ and CaMoO₄ were produced from this pure liquor via an intermediate hydrate precipitate (MoO₃ · H₂O). The study also showed that understanding the stability and speciation of various soluble and solid Mo species are essential for the development of an efficient recovery process.     

Iron recovery from sulphate leach liquors in zinc hydrometallurgy

Iron is usually present in leach solutions and its elimination is a major operational problem in zinc hydrometallurgy. The recovery of iron from such solutions is usually carried out by precipitation as jarosite, goethite or hematite. These residues, contaminated with heavy metals ions such as Zn, Pb, In, Ga, Ge, Co and sulphur, are environmentally unacceptable and their disposal in controlled ponds is very expensive. This fact justifies the interest in producing iron as a marketable product––pure hematite. With this purpose solvent extraction is being investigated as a promising alternative for the recovery of iron from leach solutions.     

The Mount Isa Mines limited copper solvent extraction and electrowinning plant

This paper describes the development, engineering and initial operation of a relocatable 10 tonne per day copper solvent extraction and electrowinning plant. Plant design incorporates Krebs mixer-settlers, Dremco and Copper Refineries cell house ideas and various innovative engineering solutions. Use is made of up to date process control systems, giving a minimum of plant manning. Plant performance meets or exceeds design requirements for throughput and product quality. Significant modifications have been made to the chalcocite heap leaching system to raise copper dissolution rates. These are described together with plant performance data from the first 18 months of operation.