氯化锌-甲醇废液的综合利用研究

一种处理三氟氯乙烯工业副产物氯化锌－－甲醇废液的方法，废液中加入稀盐酸溶解后，先精馏分离出甲醇，然后用化学方法除去铁和重金属杂质，得到精制氯化锌溶液，将精制氯化锌溶液蒸发浓缩可得无水氯化锌，进一步将氯化锌溶液转化为氧化锌。     

阴离子交换色谱法分离含钴溶液中锌、镉、铜等杂质

采用阴离子交换色谱法,研究了某锌厂冶炼废渣的硫酸化焙砂浸出液中钴与锌、镉、铜等杂质离子的分离工艺,确定了最佳工艺参数：将料液配制成含2 mol/L Cl–1和0.1 mol/L Na2SO3的溶液,调节pH值为 4.5,搅拌数分钟,料液pH值降低至 4.0后,用201?7阴离子交换色谱柱进行分离,柱后流出液中锌、镉、铜等杂质的含量达到钴冶金工艺要求,钴的损失为0.7%左右.     

Determination of the heat change in solvent extraction of metals. The extraction of zinc (II) from hydrochloric acid solutions by high molecular weight amines in various organic solvents

The heat change associated with the uptake of zinc (II) has been examined by using a twin type isoperibol calorimeter in the extraction of zinc (II) from hydrochloric acid solutions by trioctylamine hydrochloride (TOAHCl) and trioctylmethyl-ammonium chloride (TOMAC) in various organic solvents such as benzene, chlorobenzene, o-dichlorobenzene, toluene, m-xylene, nitrobenzene, carbon tetrachloride and 1, 2-dichloroethane. It was found that the dependence of apparent molar heat change (the value of the heat change detected with regard to the concentration of zinc (II) reacted) on the aqueous chloride concentration could be attributed to the change in the distribution of zinc (II) chloride species in the aqueous phase. Taking account of this fact, variable Y, which constitutes the sum of the change in enthalpies for the relevant steps in the extraction of zinc (II), except the transformation of ZnCl_j^(2-j)+ to ZnCl₄^2-, in the aqueous phase, is introduced. From the values of Y obtained, it is concluded that in the extraction by TOMAC, Y correlates with the solubility parameter of diluent, suggesting that the organic phases may be regarded as regular solutions, while in the extraction by TOAHCl, no clear-cut relation holds between Y and the physico-chemical constants of the diluent such as dipole moment, dielectric constant and solubility parameters.     

次氧化锌浸取净化新工艺

研究了以炼铅厂含锌烟灰为原料,经盐酸浸取、高锰酸钾氧化、锌粉置换制备氯化锌溶液的工艺。以锌的浸出率最高,杂质铅的浸出率最低,铁、锰、铅、镉、铜脱除最彻底为目标,实验得出最佳的酸浸和净化条件：40 g次氧化锌、71 mL浓盐酸、130 mL水在30 ℃下浸取50 min后,过滤,洗涤滤渣,滤液定容为250 mL,取200 mL滤液,滤液中加高锰酸钾0.013 6 g,10 ℃下氧化2 h后过滤,取200 mL二次滤液向其中加锌粉0.12 g,40 ℃下反应50 min后过滤,得浓度为1.63 mol/L的氯化锌溶液。在上述工艺条件下,锌的浸出率为94.2%,氯化锌溶液中杂质离子含量满足HG/T 2323-2012《工业氯化锌》中优等品的要求,可用来生产符合GB/T 19589-2004《纳米氧化锌》规定的Ⅰ类纳米氧化锌。     

Green process to recover magnesium chloride from residue solution of potassium chloride production plant

The green process to recover magnesium chloride from the residue solution of a potassium chloride production plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The residue solution contains magnesium chloride above 25 wt-%, potassiumchloride and sodium chloride together below 5 wt-% and a few other ions such as Br⁻, SO₄ ²⁻ and Ca²⁺. The recovery process contains two steps: the previous impurity removal operation and the two-stage evaporation-cooling crystallization procedure to produce magnesium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria. __________ Translated from Modern Chemical Industry, 2008, 28(1): 58–61 [译自: 现代化工]     

低成本连续化的氯化锌制造工艺

以锌灰和废盐酸为原料，用连续反应装置生产氯化锌，不仅成本低，而且无气体逸出；用蒸发器代替敞开式的石墨板蒸发器，不仅节省能量，而且无蒸汽四逸；采用可回收滤渣的工艺，既回收了有利用价值的铅、铜、三氧化二铁等物质，又解决了重金属的污染问题。经厂家的生产实践证明，这种氯化锌制造工艺既避免了污染，又能获得较好的经济效益。     

Solid state complexes of poly(L‐lysine) with metal chlorides from the 1st row of the d‐block

Solid state characterization of poly(L‐lysine)hydrobromide was obtained via differential scanning calorimetry, thermogravimetric analysis, optical microscopy and infrared spectroscopy. The glass transition temperature of poly(L‐lysine)hydrobromide is 178°C. This thermal transition has not been reported previously. Poly(L‐lysine)'s T_g decreases when complexes are produced with the following divalent transition metal chlorides; cobalt chloride hexahydrate, nickel chloride hexahydrate, copper chloride dihydrate and anhydrous zinc chloride. At 10 mol% salt, nickel, chloride decreases T_g by 45°C, and the general trend is Ni²⁺Co²⁺Zn²⁺Cu²⁺. The depression of poly(L‐lysine)'s T_g correlates well with ligand field stabilization energies for pseudo‐octahedral and pseudo‐tetrahedral dⁿ complexes (n = 7, 8, 10) from the 1^st row of the d‐block. However, d⁹ copper(II) complexes cannot be included in this empirical correlation. Infrared spectroscopic evidence suggests that Co²⁺, Ni²⁺ and Zn²⁺ coordinate to the carbonyl oxygen in the main chain of the polymer. When transition metal ions coordinate to C? O, the network of hydrogen bonded amide groups is disrupted, which lowers the glass transition. The amide I region of the infrared spectrum reveals a hydrogen bonded C? O stretch @ 1655 cm^?1 that is characteristic of poly(α‐amino acid) random coil conformations, and a metal‐ligand coordinated C? O stretch @ 1625 cm^?1 in complexes with divalent cobalt, nickel and zinc. The amide II region of the infrared spectrum near 1550 cm^?1 is also sensitive to the formation of coordination complexes with these d‐block metal chlorides.     

Influence de l'antimoine et du cuivre sur la cementation du cobalt par le zinc

Zinc sulphate solution (160g/l Zn²⁺) used for zinc electrowinning is purified for cobalt by cementation with metallic zinc powder. Industrial practice shows that considerable acceleration of this operation is achieved by the presence of trace impurities in solution. Eventually, CuSO₄ and Sb₂O₃ are deliberately added to the solution. The aim of this work is to elucidate the mechanism of action of those impurities.Zn²⁺ ions present in the solution are responsible for the slow speed of cobalt deposition (160g/l Zn²⁺; 10 mg/l Co²⁺).The cathodic part of the cementation reaction was simulated on a flat electrode through potentiostatic deposits at ?730 mV/ENH (potential at zero current of metallic zinc in the solution). The deposits were studied by anodic dissolution, radioactive tracers, X-ray diffraction and fluorescence, atomic absorption spectrophotometry, optical and electronic microscopy (transmission and scanning). The results were compared with cementation on zinc plate and zinc powder.Antimony and copper are deposited together with cobalt and form alloys with reduced cobalt activity. Total voltage available to overcome the inhibitor effect of zinc ions is thus increased and the reduction of cobalt ions accelerated. Antimony, copper and cobalt triple alloys resist particularly well to corrosion with hydrogen evolution. Copper has a higher accelerating effect on cobalt cementation than antimony, but the latter stabilizes the deposit very effectively.The electrochemical methods used and the knowledge of the mechanism of action of the impurities open new trends for industrial practice.     

Evaluation of levels and methods of zinc application to rice in sodic soils

Field experiments were conducted in zinc-deficient sodic soil to study the effect of levels and methods of zinc fertilization on yield, concentration and uptake of zinc by rice. Zinc was incorporated in the soil at the rate of 0, 5.6, 11.2 and 22.4 kg Zn per ha as zinc sulfate; sprayed on the plants at 1% and 2% zinc sulfate solution; and roots of rice seedlings were dipped in 2% and 4% ZnO suspensions in water. Grain yield, zinc content and its uptake increased in all the experiments up to 22.4 kg Zn per ha. Soil applied zinc was significantly correlated with yield of rice (r = 0.80^**) and zinc uptake (r = 0.89^**). Zinc content in 45-day old plants gave a significantly higher correlation with grain yield (r = 0.84^**) than the zinc content of rice straw and grain at maturity. Roots of rice seedlings dipped in 2% or 4% zinc oxide suspension in water were not only comparable with soil application of Zn at 5.6 and 11.2 kg Zn per ha, but also proved to be more economical for sodic soils showing moderate zinc deficiency.     

Kinetics and mechanism of the formation of doped skeletal copper catalysts: the effect of zincate compared to undoped and chromate-doped systems

Addition of zincate to the leach liquor for the preparation of skeletal copper increases the copper surface area; however it does not stabilize the structure against rearrangement. The leaching kinetics have been studied using a rotating disc electrode (RDE) at 269–293 K in 2–8 M NaOH and 0.0005–0.1 M Na₂ZnO₂. Zincate ions precipitate as zinc oxide, due to the local consumption of hydroxide ions near the leach front as the aluminium dissolves. This oxide hinders the aluminium dissolution, slowing the leaching rate. It also hinders copper dissolution/redeposition and prevents copper diffusion, thus reducing the structural rearrangement significantly, and causing the formation of a much finer copper structure with increased surface area. The zinc oxide redissolves as the leach front passes, releasing the copper to rearrange once more, thereby allowing the surface area to decrease with time. The activation energy for leaching was found to be 84 ± 6 kJ mol^–1.     

Electrodeposition of zinc from high acid zinc chloride solutions

Electrowinning of zinc from zinc chloride solutions, acidified by HCl, was conducted in a cation exchange membrane cell. The current efficiency was correlated with the deposit morphology. The deposits having lesser surface defects, which act as active sites for hydrogen adsorption, exhibited higher current efficiency. The (1 1 0) preferred texture was observed on the deposits grown in high acid solution containing gelatin. High temperature (40 ºC) and high current density decreased the current efficiency and the preferred texture.     

Raman spectroscopic studies of the polyacrylonitrile-zinc complexes in aqueous solutions of zinc chloride and bromide

Raman spectroscopic studies of the dissolution of polyacrylonitrile (PAN) in aqueous zinc halides are reported. The dissociation constants of aqueous PAN-zinc chloride and PAN-zinc bromide containing 60-75% wt/wt and 65-80% wt/wt zinc in aqueous polyacrylonitrile solutions, respectively, have been measured by Raman spectroscopy. Intensity measurements allowed for a quantitative measurement of the amount of free and complexed CN groups to be made, utilising the 2259 and 2290cm^?1 v(CN) stretching Raman bands. The degree of complexation was found to be small in many of the solutions. The effect of the addition of salt on the structure of the v(OH) band at 3000-3800 cm^?1 was studied for the aqueous zinc salts and an aqueous sodium thiocyanate solution. The low wavenumber regions of the Raman spectra, Δv = 100-350cm^?1, for both zinc chloride and zinc bromide solutions of PAN have also been studied.     

氟碳树脂漆副产含锌废料的综合利用

氟碳树脂漆生产过程中,副产氯化锌-甲醇-锌粉混合废液。该副产物因含氯化锌和甲醇等有毒有害物质,直接排放会造成严重的环境污染;而且锌质量分数高达30%,充分利用可节约宝贵的锌资源。通过燃烧除甲醇、溶解分离锌粉、净化除杂质离子的工艺路线,制得纯氯化锌溶液,并进一步加工成碱式碳酸锌。通过实际生产运行,取得很好的经济效益,同时避免了环境污染。     

A comparative study of the oxidative and reductive dissolution of magnetite in acidified CuSO4-acetonitrile-H2O and CuCl2−NaCl−H2O leach solutions

The oxidative and reductive dissolution of magnetite in acidified aqueous acetonitrile and acidified aqueous NaCl solutions have been investigated by electrochemical methods and correlated with the proton activity in these fundamentally different solution systems. The results are compared with the rates of magnetite dissolution in the presence of copper(II) and copper(I).Under anodic or oxidizing leach conditions magnetite forms a passive Fe₂O₃ film which inhibits reaction, but under cathodic or reducing leach conditions in the presence of copper(I), magnetite is believed to dissolve via (FeOH)⁺ intermediate and reacts up to 600 times faster. The rate of dissolution of magnetite depends on its potential and the activity of the proton. The rate follows a Butler-Volmer relationship with a Tafel slope of 120–130mV per decade and exhibits a proton reaction order between 0.85 and 1.0. After allowing for changes in proton activity there is no significant difference between the rate of dissolution of magnetite in the sulphate and chloride leach solutions and no discernable effect of the presence of acetonitrile in the mixed solvent system. Electrochemical studies and leaching studies in which the potential is controlled by the Cu(II)–Cu(I) couple are in good agreement and lead to a fundamental understanding of the optimum conditions required to leach copper selectively from a Cu–Fe₃O₄ calcine derived from the segregation roasting of chalcopyrite concentrates.     

微波条件下氯化锌对乙醇抽提神府煤的影响

微波条件下,研究了在乙醇抽提神府煤中加入氯化锌对其结果的影响。采用气相色谱/质谱联用的方法分析了乙醇和乙醇-氯化锌抽提物的组成;利用傅里叶红外光谱技术分析了神府脱矿物质煤、乙醇抽余煤和乙醇-氯化锌抽余煤的结构。分析结果显示:在乙醇溶剂中添加少量的氯化锌,其抽提物的组成发生了改变;乙醇-氯化锌抽余煤与原脱矿物质煤和乙醇抽余煤相比,芳环吸收强度降低,表明在抽提过程中可能伴随着烷基化反应的发生。     

氯化铁浸出废金属回收海绵铜的工艺研究

采用氯化铁选择性浸出工艺对废金属进行综合利用,制备氯化铁及海绵铜。主要考察了废金属浸出、海绵铜洗涤工艺的可行性,并确定浸出工艺的最佳条件。结果表明:在搅拌速度150 r/min、氯化铁溶液质量分数29.91%、浸出剂量为理论量105%、反应温度60℃、反应时间1.0 h的条件下,铁浸出率为94.86%,铜浸出率为3.57%。浸出渣经盐酸溶液洗涤,能有效提高海绵铜的品质。     

Copper Leaching from Copper Residue with Oxygen in Sulfuric Acid/Chloride Solution

1INTaoDUCTI0NSe1ectiveokidationleachingofnickelmatteforniCkelextraction[1]leavesbehindcopperintheleachingresidue,referredtoascopperresidue,whichneedstobefurthertreatedforcopperrec0veryNickelmattecomp0sedprincipallyofsyllthesizednickelandc0ppersuffidehanerals.Nickelinthematteispresentpred0minantlyasheazlewooditeNi3S2andmostlydissolvedfromthematteintheselectiveokidationleaching,whilec0pperoccursinformofchalcociteCu2Sordjur1eiteCu1.98Sinthematteandremainsalm0stintactthroughouttheleaching[2'…     

Conversion of soybean oil into ion exchange resins: Removal of copper (II), nickel (II), and cobalt (II) ions from dilute aqueous solution using carboxylate‐containing resin

An ion‐exchange resin containing carboxylic acid groups was prepared by reaction of epoxidized soybean oil with triethylene tetramine, followed by hydrolysis of glycerides by using sodium hydroxide solution. The cation exchange capacity of the resins was determined to be 3.50 mequiv/g. The adsorption capacity for Cu²⁺, Ni²⁺, and Co²⁺ on the obtained resin at pH 5.0 was found to be 192, 96, and 78 mg/g, respectively. Effect of pH on the adsorption capacity for copper (II), nickel (II), and cobalt (II) ions were also studied. Cu²⁺, Ni²⁺, and Co²⁺ were adsorbed at a pH above 3. These metal ions adsorbed on the resin are easily eluted by using 1N HCl solution. The selectivity of the resin for Cu²⁺ from mixtures containing Cu²⁺/Co²⁺/Ni²⁺ ions in the presence of sodium chloride was also investigated © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2386–2396, 2002     

Synergistic extraction and separation of Fe(III) and Zn(II) using TBP and D2EHPA

Waste chloride pickle liquors from hot-dip galvanizing plants, steel plants and flue dust contain reasonable amounts of heavy metals such as Zn, Cr, Ni, etc. Iron is invariably associated with most of these materials and comes into solution during leaching. Thus, the synergistic extraction of zinc(II) and iron(III) from leach solutions in tri-n-butyl phosphate (TBP)–di(2-ethylhexyl) phosphoric acid (D2EHPA) system diluted in kerosene was investigated. The Zn and Fe concentrations in the leach liquor used in the present study were 2 g/L. Experiments were carried out in the pH range of 0.5–4.0, temperature of 25°C, using sole D2EHPA, sole TBP and D2EHPA–TBP mixtures at different ratios. Results showed that the co-extraction of zinc(II) and iron(III) increased with increasing equilibrium pH using D2EHPA. It is demonstrated that the mixtures of TBP and D2EHPA are more efficient and selective than D2EHPA alone. At low pH values, the separation factor is low when pure D2EHPA is used as an extractant; however, using TBP as a synergist, the separation factor increases and results in a better separation of zinc from iron. Increasing TBP to D2EHPA ratios in the organic phase caused a slight shift to the right in the extraction isotherm of iron and a marked shift to the right in the extraction isotherm of zinc, and the maximum separation factor of 13.3 × 10³ was achieved at a TBP to D2EHPA volume ratio of 4:1 (0.58 M TBP: 0.12 M D2EHPA). Furthermore, the effect of equilibrium pH, organic to aqueous phase ratio and Cl^? concentration on the selective extraction was investigated. Using two extraction stages at the O/A ratio of 2:1 and pH_e (equilibrium pH) of 3 and 1 for zinc and iron, respectively, 99% of zinc(II) and 96.25% of iron(III) were extracted.     

Hydrometallurgical Recovery of Zinc from Fine Blend of Galvanization Processes

Abstract

In many factories, which are working in the field of steel industry, there are galvanization units in which steel products are galvanized for corrosion protection. About 15% of the total amount of the used zinc are accumulated as zinc ash and dust at the surface of molten zinc bath and in the chimney respectively. In a previous work, zinc was successfully recovered from the coarse ash by applying pyrometallurgical processing. In this work, zinc fine blend (of fine ash and flue dust) was hydrometallurgically treated using sulfuric acid. Two alternative techniques were applied for producing zinc sulfate salt or pure zinc metal. In the first technique, the salt was separated from the leach solution as zinc sulfate hydrate (ZnSO₄ · H₂O). It was crystallized by concentrating the leach liquor to a density of 1.52 g/cm³. The purity of the produced zinc sulfate was 99.5%. In the second technique, the leach solution has been purified with respect to the soluble impurities using precipitation. The electrowinning technique was applied for producing a pure zinc metal from the purified solution. Electrolysis was performed at ambient temperature (25–28°C) with current density (c.d.) of 40 mA · cm^?2. The recovery of zinc proceeds down to a concentration of 50 g · l^?1 with acceptable cathodic current efficiency of 96.5%, and energy consumption for the electrolysis step of 2.75 KWh/Kg. The zinc purity in the deposit obtained from the electrolysis was 99.9%.