Hydrometallurgical detoxification and recycling of electric arc furnace dust

Electric arc furnace dust(EAFD)is a hazardous waste but can also be a potential secondary resource for valuable metals,such as Zn and Fe.Given the increased awareness of carbon emission reduction,energy conservation,and environmental protection,hydrometallurgical technologies for the detoxification and resource use of EAFD have been developing rapidly.This work summarizes the generation mechanisms,compositions,and characteristics of EAFD and presents a critical review of various hydrometallurgical treatment methods for EAFD,e.g.,acid leaching,alkaline leaching,salt leaching,and pretreatment–enhanced leaching methods.Simultaneously,the phase transformation mechanisms of zinc-containing components in acid and alkali solutions and pretreatment processes are expounded.Finally,two novel combined methods,i.e.,oxygen pressure sulfuric acid leaching combined with composite catalyst preparation,and synergistic roasting of EAFD and municipal solid waste incineration fly ash combined with alkaline leaching,are proposed,which can provide future development directions to completely recycling EAFD by recovering valuable metals and using zinc residue.

Kinetics of simultaneous leaching of Ag and Pb from hydrometallurgical zinc residues by chloride

The leaching kinetics of silver and lead simultaneously from zinc residue by chloride was investigated.The effects of stirring speed,temperature,sodium chloride concentration,particle size and liquid/solid ratio on Ag and Pb dissolution in sodium chloride were studied.It was determined that the dissolution rates increased with increasing sodium chloride concentration,temperature and decreasing particle size.The dissolution kinetics followed a shrinking core model,with inter-diffusion through gangue layer as the rate determining step.This finding is in accordance with the apparent activation energy(E_a) of 26.8 kJ·mol^(-1)(Ag) and 26.5 kJ·mol^(-1)(Pb),and a linear relationship between the rate constant and the reciprocal of squared particle size.The orders of reaction with respect to sodium chloride concentration,temperature and particle size were also achieved.The rate of reaction based on diffusion-controlled process can be expressed by semi-empirical equations.

Optimization of brine leaching of metals from hydrometallurgical residue

An orthogonal array,L16(45),was used to examine the effects of four parameters,including NaCl concentration,H2SO4 concentration,temperature and pulp density,on the recovery of Cu,In,Pb and Zn from a hydrometallurgical residue via brine leaching.The results show that temperature of leaching solution has a significant effect on the recovery of Cu,In and Zn,while H2SO4 concentration has an obvious influence on these metals extraction.Both pulp density and NaCl concentration significantly affect Pb extraction.Based on the orthogonal array experiments,the optimum conditions for the extraction of Cu,In,Pb and Zn from hydrometallurgical residue are NaCl concentration of 250 g/L,H2SO4 concentration of 1.00 mol/L,temperature of 85℃,and pulp density of 100 g/L.After 1 h of treatment at these optimum conditions,over 91% of the metals are extracted from the residue.Brine leaching is therefore suitable for the recovery of metals from hydrometallurgical residues.

Hydrometallurgical process for extracting bismuth from by-product of lead smelting based on methanesulfonic acid system

A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxidation leaching,and electrodeposition.The optimum conditions of the bismuth extraction process were determined by a single-factor test.The bismuth plate with a purity of 99.8%was obtained under the optimum conditions.Cyclic voltammetry and linear sweep voltammetry were applied to investigating the cathode reaction mechanism of electrorefining.The results show that lead deposition,bismuth deposition,and hydrogen evolution occur at the cathode,and the reactions of metals deposition are irreversible and diffusion-controlled.In addition,decreasing the temperature and acidity can improve the purity of the cathodic product(lead powder)in the electrorefining process.

Application of a Sulfur Removal Hydrometallurgical Process in a Lead-Acid Battery Recycling Plant in Costa Rica

This study presents the implementation of a desulphurization process for lead recycling under different chemical and physical conditions using pyro-metallurgical processes. Desulphurization was done using a hydrometallurgical process using sodium carbonate as a desulphurization agent and different lead-bearing loads compositions. Waste characterization included: SO2 concentrations in the stack emissions, total lead content in the furnace ash, the total lead content in the slag, and the toxicity characteristic leaching procedure (TCLP). A significant reduction in SO2 emissions was achieved (~55% reduction) where mean SO2 concentrations changed from 2193 ± 135 ppm to 1006 ± 62 ppm after the implementation of the modified processes. The desulfurized lead paste (i.e. the metallic fraction lead of the battery) of the modified process exhibited an improvement in the concentration of the lead in the TCLP test, with an average value of 1.5 ppm which is below US EPA limit of 5 ppm. The traditional process TCLP mean value for the TCLP was 54.2 ppm. The total lead content in the bag house ashes shows not significant variations, when comparing the desulphurization (67.6% m/m) and non-desulphurization process (64.9% m/m). The total lead mean content in the slag was higher in the desulphurization process (2.49% m/m) than the traditional process (1.91% m/m). Overall, the implementation of a new desulphurization method would potentially increase the operation costs in 10.3%. At the light of these results, a combination of hydrometallurgical and pyro-metallurgical processes in the recycling of lead-acid batteries can be used to reduce the environmental impact of these industries but would increase the operational costs of small lead recyclers.

有色冶炼含砷固废的综合处置技术研究进展

有色金属冶炼过程产生的大量含砷固废会给生态环境和人类健康造成严重的潜在威胁。为了推动有色冶炼含砷固废综合处置技术的普及与发展,首先,结合冶炼工艺介绍了含砷固废的来源及走向,并详细分析了不同类型含砷固废的性质;然后,针对含砷固废的特点,介绍了几种常见含砷固废处置工艺,包括火法处理工艺、湿法处理工艺以及联合处理工艺等,以及它们各自的应用场景及瓶颈问题;最后,聚焦含砷碱浸液的高效处置难题,介绍了化学沉淀处理技术、蒸发结晶处理技术在碱性含砷废水处理方面的研究情况,并提出了可能存在的解决方案。研究内容对于认识有色冶炼含砷固废污染问题,了解含砷固废处置技术现状,推动有色冶炼行业绿色可持续发展具有一定的借鉴意义。

铜阳极泥中有价元素湿法回收工艺研究进展

我国铜生产量居世界第一,其中80%采用火法冶炼工艺。冶炼过程中产生的铜阳极泥富含Cu、Ag、Au、Se、Te等多种有价元素,具有很高的回收价值。本文分析对比了铜阳极泥的主流处理工艺,其中,湿法工艺作为一种低能耗高效浸出工艺,近些年被广泛地研究。文章系统综述了铜阳极泥湿法处理工艺研究进展,归纳了铜阳极泥氧化浸出、物理强化浸出等预处理方法,总结了铜阳极泥中Cu、Se、Te以及贵金属Ag、Au的回收方法及反应机理。基于当前的研究进展,未来应重点关注湿法工艺的绿色性,开发用于浸出、配合、萃取等过程的绿色试剂,并加强对阳极泥中稀贵金属(Pt、Pd、Rh等)回收的研究,同时需要提升不同元素选择性分离的能力,以获得高纯度产品。

铜冶炼烟尘金属分离及资源回收研究进展

以铜冶炼烟尘为研究对象,分析其理化及矿物学性质,对比铜冶炼烟尘金属分离与回收方法,包括碳热还原法、硫酸浸出法、碱性浸出法和湿法-火法联合工艺,总结各方法的原理、典型工艺、现状和存在问题,阐述非常规冶金方法在铜冶炼烟尘金属分离中的应用,展望铜冶炼烟尘资源回收的发展方向。研究结果表明:铜冶炼烟尘中砷、铜、锌含量受冶炼工艺、原矿品质的影响,不同元素赋存形态存在差异。碳热还原法可以通过金属砷酸盐和氧化物分解的方式释放砷,从而实现砷与其他有价金属的分离;硫酸浸出法可以高效浸提铜冶炼烟尘中的金属,实现多元素的回收;碱性浸出法可选择性浸提砷;湿法-火法联合工艺结合了火法工艺选择性分离砷和湿法工艺高效提取金属的优点,对于复杂高砷铜冶炼烟尘处理具有优势。铜冶炼烟尘兼具资源属性和环境风险,实现清洁生产及多金属资源化利用仍是关键,砷的无害化处置与锌、铜、铅等有价金属的高效协同回收工艺及分离机制、全过程物质流与环境效应是铜冶炼烟尘资源回收的发展方向。

传统铀水冶工艺对稀土元素分布模式的影响及其在核法证中的应用

从生产过程的角度研究了稀土元素分布模式在核法证溯源中的适用性。通过跟踪调查某传统铀水冶厂从铀矿石到重铀酸钠的生产过程,在低本底(<0.512 ng/mL)、低检出限(<0.007 5 ng/mL)的实验条件下,对铀矿石、澄清浸出液、萃余液和重铀酸钠样品进行了前处理后,采用TRU树脂分离稀土元素、电感耦合等离子体质谱(ICP-MS)测定稀土元素的含量,并绘制了稀土元素分布模式图。结果表明,上述4种样品整体上都是轻稀土富集,Eu亏损明显,稀土元素分布总体呈右倾斜深谷状。这说明经历了传统铀水冶工艺的铀材料仍会基本保留铀矿石的稀土特征,稀土元素分布模式有助于查明铀材料的来源和历史。

蛇纹石型红土镍矿开发处理研究现状

镍资源主要分为硫化镍矿、红土镍矿与海底含镍锰结核。随着硫化镍矿的逐渐枯竭,红土镍矿的开发利用引起了广泛的关注。针对硅、镁含量较高的蛇纹石型红土镍矿,系统综述蛇纹石型红土镍矿的火法处理工艺、湿法处理工艺以及火法-湿法联合处理工艺,简述各工艺的国内外研究新进展,并展望蛇纹石型红土镍矿未来的发展方向。

废汽车尾气催化剂特性解析及其对稀贵金属回收的影响

废汽车尾气催化剂是重要的稀贵金属二次资源,随着未来报废汽车的逐渐增加,废汽车尾气催化剂的数量相应增加。当前从废汽车尾气催化剂中回收稀贵金属(铂族金属、稀土金属和稀有金属等)的方法较多,但由于对废汽车尾气催化剂的特性了解不够全面,大多数回收方法在回收率、环境友好性、经济性上都不够理想,亟需对废汽车尾气催化剂进行科学全面地了解。对废汽车尾气催化剂的基本特征、物相及成分组成、废汽车尾气催化剂中PGMs、Ree、Zr等稀贵金属元素的赋存形式、元素迁移及分布状态、熔化过程等进行研究,全面了解废汽车尾气催化剂;揭示了催化剂中铂族金属被部分氧化、活性组分发生渗透转移、有价元素的非均匀分布、催化剂涂层烧损开裂、杂质元素的污染等因素共同造成了催化剂失效退役的失活机理;采用火法熔炼,合理设计选择熔炼渣剂及捕集剂回收其中的稀贵金属,可以有效地避免废催化剂自身特性所带来稀贵金属回收率低效的问题。

球磨辅助柠檬酸-过氧化氢体系浸出废旧锂电池中有价金属研究

采用球磨辅助柠檬酸-过氧化氢体系浸出废旧锂电池正极材料中有价金属,结果表明:球磨对反应液体施加机械能,诱导其结构及物理化学性质发生变化,诱发化学反应,提高反应速率,缩短浸出时间;在浸出时间30 min、浸出温度60℃、柠檬酸浓度0.8 mol/L、H_(2)O_(2)质量分数20%、液固比6∶1、球磨机转速60 r/min条件下,锂浸出率99.6%、镍浸出率99.5%、钴浸出率99.3%、锰浸出率98.5%。该方法成本低、效率高,可为废旧锂电池回收提供一定参考。

湿法冶金工艺处理含铁含锌除尘灰的技术发展现状

随着工业化进程的不断推进,含铁含锌除尘灰对环境造成的影响越来越大。湿法冶金工艺作为一种环保、高效的处理方法,在处理含铁含锌除尘灰方面具有显著的优势。综述了含铁含锌除尘灰的来源、特性以及湿法冶金工艺在处理含铁含锌除尘灰方面的技术发展现状。分析了各种浸出方法的原理、特点及优缺点。剖析了湿法冶金工艺在处理含铁含锌除尘灰的挑战与对策,最后,探讨了湿法冶金工艺在处理含铁含锌除尘灰方面的未来发展趋势,指出了绿色环保技术、高效资源利用技术、跨学科综合研究及工业化应用与示范等方面的发展方向。以了解当前技术水平,为相关领域的技术进步和产业发展提供参考。

湿法炼锌过程中应用铈基除氟剂的研究

为实现湿法炼锌工艺氟资源回收利用,本研究提出利用碳酸铈吸附湿法炼锌电解液中的氟。分析吸附时间、吸附温度、吸附剂投加量对碳酸铈除氟能力影响,得到了碳酸铈最佳吸附条件为吸附时间20 min、投加量0.7268 g、吸附温度55℃,评估了含氟废渣作为抛光粉的可行性。采用离子色谱与热力学和动力学结合的方式,探究碳酸铈除氟机理。结果表明吸附是熵增吸热过程,符合准二级吸附动力学模型,R2为0.99909。

铝灰综合利用技术及应用研究

文章简要介绍了铝灰的来源和分类,概述了一次铝灰提铝的不同方法和应用,综述了二次铝灰湿法处理、火法处理、湿法火法联合处理及其他技术的研究和应用现状。针对铝灰综合利用目前存在的问题,提出了分质梯级利用技术,详细介绍了其工艺流程及优势,展望了铝灰综合利用的未来发展趋势。

工业铝灰处理和资源化利用技术进展

介绍了铝灰的来源、组成及分类,概述了当前一次铝灰和二次铝灰的处理技术现状,分析了目前常见的湿法处理工艺、两段法连用处理工艺、火法处理工艺等二次铝灰资源化技术,并进行了比较。在此基础上,提出“两磨两筛+炒灰提铝+高温催化脱氮协同固氟+水洗脱氯+结晶回收盐”的铝灰集成化处理技术。该工艺可以实现铝灰中有价金属的高效回收,解决铝灰中氮化铝的活性难题,降低了二次铝灰和除尘灰的浸出毒性,最终实现对二次铝灰的无害化处理和绿色回收利用。

从废旧锂电池正极材料中回收镍钴锰锂的研究

提出一种新型的从废旧锂电池正极材料中回收镍、钴、锰、锂的工艺。采用两次碳热还原-湿法浸出工艺回收正极材料中的镍、钴、锰以及锂金属,并对正极材料中有价金属的回收机理及工艺进行研究。结果表明,采用两次碳热还原工艺优先提取锂金属,在焙烧温度650℃、掺碳量8%、水浸时间2 h、热解温度95℃,热解时间4 h的最佳条件下,锂回收率能达到88.7%,制备的产品碳酸锂纯度为98.84%;采用湿法浸出工艺回收镍、钴、锰有价金属,在高酸浸出工序双氧水加入量为理论量的1.2倍,浸出温度60℃,浸出时间2 h,溶液pH值1.5,除铁铝工序温度90℃、反应时间2 h,溶液pH值3.5的最佳条件下,镍、钴和锰回收率分别达到99.4%、99.5%、98.9%。

氧化锌烟尘浸出脱砷技术研究与应用

目前湿法炼锌工艺采用的原料主要是氧化锌烟尘、焙烧矿,氧化锌烟尘是由湿法炼锌产出的酸浸渣和火法炼铅产出的熔渣经烟化炉还原挥发产出的二次资源,焙烧矿是由沸腾炉将硫化锌精矿焙烧制得,文章主要从氧化锌烟尘浸出过程分析,在浸出后的溶液中利用臭氧、高锰酸钾的强氧化性将亚铁离子氧化,控制溶液终点pH值,利用铁盐水解吸附除杂,有效将溶液中的砷杂质去除。

螯合沉淀法去除稀土冶炼废水中的重金属试验研究

研究了采用螯合沉淀法从稀土冶炼废水中去除铅、锌、镉等重金属,筛选了重金属螯合剂,并通过单因素和正交试验确定了影响重金属去除的主要因素及最佳工艺条件。结果表明:以二甲基二硫代氨基甲酸钠(福美钠)为螯合剂能有效去除稀土冶炼废水中的总铅、总锌、总镉;螯合剂用量对重金属去除率的影响最大,搅拌速度次之,反应时间、废水pH的影响较小;在废水pH=9.5、反应时间15 min、福美钠加入量30 mg/L、搅拌速度180 r/min条件下,经螯合沉淀处理的出水中ρ(∑Pb)<0.2 mg/L、ρ(∑Zn)<1.0 mg/L、ρ(∑Cd)<0.05 mg/L,符合排放标准要求。

Recycling of spent lithium-ion batteries as a sustainable solution to obtain raw materials for different applications

Lithium-ion batteries(LIBs)containing graphite as anode material and LiCoO_(2),LiMn_(2)O_(4),and LiNi_(x)Mn_(y)Co_(z)O_(2) as cathode materials are the most used worldwide because of their high energy density,capacitance,durability,and safety.However,such widespread use implies the generation of large amounts of electronic waste.It is estimated that more than 11 million ton of LIBs waste will have been generated by 2030.Battery recycling can contribute to minimizing environmental contamination and reducing production costs through the recovery of high-value raw materials such as lithium,cobalt,and nickel.The most common processes used to recycle spent LIBs are pyrometallurgical,biometallurgical,and hydrometallurgical.Given the current scenario,it is necessary to develop environmentally friendly methods to recycle batteries and synthesize materials with multiple technological applications.This study presents a review of industrial and laboratory processes for recycling spent LIBs and producing materials that can be used in new batteries,energy storage devices,electrochemical sensors,and photocatalytic reactions.