Reviews of Metallurgical Technology to Recovery Platinum Group Metals from Secondary Resource in China

China is extremely poor in mineral resources of Platinum Group Metals (PGMs), productive output of PGMs from mineral resource is 2.5 tons per year. At the same time, China is the biggest PGMs consumption country in the world, the mineral resource of PGMs is critical shortage, it shows the importance of recycling the secondary resource of PGMs. Sino-Platinum Metals Resource (Yimen) Co., Ltd. is the leader in recycling of PGMs from secondary resource, and has made outstanding contributions to China PGMs secondary resources recycling. This article elucidates the current situation of secondary resources recovery and development of metallurgical technology for PGMs.

Platinum Group Metals New Material

Platinum group metals (PGM) include six elements, namely Pt, Pd, Rh, Ir, Os and Ru. PGM and their alloys are the important fundamental materials for modern industry and national defense construction, they have special physical and chemical properties, widely used in metallurgy, chemical, electric, electronic, information, energy, environmental protection, aviation, aerospace, navigation and other high technology industry. Platinum group metals and their alloys, which have good plasticity and processability, can be processed to electrical contact materials, resistance materials, solder, electronic paste, temperature-measurement materials, elastic materials, magnetic materials and high temperature structural materials.

Versatile application of wet-oxidation for ambient CO abatement over Fe(OH)_x supported subnanometer platinum group metal catalysts

The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x supported subnanometer Pt group metal(PGM)catalysts for the complete removal of CO under ambient temperature and humidity conditions.Typically,the 1.8 wt%Rh/Fe(OH)x catalyst exhibited better durability during a^1400 min run for wet oxidation than for dry CO oxidation.Multiple characterization results including HR-TEM,H2-TPR,and in-situ DRIFTS suggested that Fe(OH)x,with good reducibility,promoted by the subnanometer Rh clusters,provided sites for the adsorption and reaction of O2 and H2 O to form OH species.Subsequently,these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy(9 kJ mol^-1)than that of dissociated 0 species(22 kJ mol^-1),thus rationalizing the outstanding performance of Rh/Fe(OH)x for wet oxidation.Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH)x as the support.

Recent progress in CO oxidation over Pt-group-metal catalysts at low temperatures

CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures（at or below room temperature）.Au catalysts are the benchmark for judging the activities of other metals in CO oxidation.Pt-group metals（PGMs） that give comparable performances are of particular interest.In this mini-review,we summarize the advances in various PGM（Pt,Pd,Ir,Rh,Ru）catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species.The effects of the size of the metal species and the importance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.

Solar-assisted selective separation and recovery of precious group metals from deactivated air purification catalysts

The mitigation of environmental and energy crises could be advanced by reclaiming platinum group precious metals(PGMs) from decommissioned air purification catalysts. However, the complexity of catalyst composition and the high chemical inertness of PGMs significantly impede this process. Consequently,recovering PGMs from used industrial catalysts is crucial and challenging. This study delves into an environmentally friendly approach to selectively recover PGMs from commercial air purifiers using photocatalytic redox technology. Our investigation focuses on devising a comprehensive strategy for treating three-way catalysts employed in automotive exhaust treatment. By meticulously pretreating and modifying reaction conditions, we achieved noteworthy results, completely dissolving and separating rhodium(Rh), palladium(Pd), and platinum(Pt) within a 12-h time frame. Importantly, the solubility selectivity persists despite the remarkably similar physicochemical properties of Rh, Pd, and Pt. To bolster the environmental sustainability of our method, we harness sunlight as the energy source to activate the photocatalysts, facilitating the complete dissolution of precious metals under natural light irradiation. This ecofriendly recovery approach demonstrated on commercial air purifiers, exhibits promise for broader application to a diverse range of deactivated air purification catalysts, potentially enabling implementation on a large scale.

Oxygen pressure leaching-flotation joint process for Jinbaoshan platinum group minerals

An oxygen pressure leaching-flotation joint process was proposed to treat Jinbaoshan platinum group minerals to produce a desired concentrate. The result demonstrates that leaching parameters which include particle size, stirring speed, liquid-solid ratio, and the dosage of calcium lignosulfonate, simultaneously affect the leaching rates of base metals and the recovery of platinum group metals (PGMs). The complete dissolution of base metals sulfides leads to a reduction in the amount of flotation carrier for enriching PGMs, decreasing the recovery of PGMs. The optimum leaching conditions are determined as follows: liquid-solid ratio of 10 mL/g, 73% occupancy of ore particle size below 0.043 mm, stirring speed of 400 r/min, and 0.6 g dosage of calcium lignosulfonate. Under optimal conditions, the leaching rates of Cu, Ni and Fe are 87.6%, 87.6% and 90.3%, respectively. The grade of PGMs enriched in the flotation concentrate is 420 g/t through the flotation technology.

Slag design and optimization for iron capturing platinum group metals from alumina-based spent catalysts

Production of petrochemical catalysts accounts for one of the largest shares of platinum group metals(PGMs) consumption;thus,recycling of spent petrochemical catalysts holds great economic value.Conventionally,PGMs are recovered through hydrometallurgical processes which have a low recovery efficiency and produce a large amount of waste.In this regard,this paper proposed a method to use iron-capturing PGMs based on CaO-Al_(2)O_(3)-Na_(2)O slag.This method avoided the formation of Fe-Si alloy and achieved efficient enrichment of PGMs.The droplet force model showed that the recovery efficiency of PGMs could be improved if the slag had low density and low viscosity.Based on this result,FactSage software optimized the composition of slag.Furthermore,the effect of B_(2)O_(3) on the 1400 ℃ liquidus of CaO-Al_(2)O_(3)-Na_(2)O_(3)-B_(2)O_(3) phase diagram was revealed.Moreover,it was found that the recovery efficiency of PGMs exceeded 99% under the following optimized conditions:basicity of 1.0,20 wt%Na_(2)O,15 wt% B_(2)O_(3),15 wt% Fe,3 wt% C and a temperature range of 1400-1500℃.The thermodynamic model revealed the mechanism of iron capture.Different chemical bonds prevented the formation of bonds between the alloy and slag,resulting in the separation of the slag from the alloy.PGMs particles and iron microspheres had significant surface Gibbs free energy.Only when iron microspheres and PGMs particles collided and fused with each other to reduce their surface area could the Gibbs free energy of the system be reduced.

铁捕集富集料中铂族金属的深度富集技术

铁捕集法从二次资源中回收铂族金属的工艺已经得到了工业化应用,捕集过程在电炉或等离子炉中进行。等离子炉熔炼富集物硅含量高,导致其结构致密、惰性、耐腐蚀,需要先除硅才能获得高的溶解率,除硅技术主要有碱融溶-浸出法、氧化分离法等;电炉熔炼富集物硬度极高、难以破碎,工艺上采用高压雾化-酸溶、碎化-酸溶、电解等工艺进行深度富集。本文综述了含铂族金属铁合金深度富集技术的研究现状,并对主要技术存在的优缺点进行了评述。随着各行业对铂族金属需求量的增加,对铂族金属回收率的要求将越来越高,因此,还需进一步完善铂族金属回收技术,提高铂族金属回收率。

云南牟定安益铂钯钛磁铁矿床铂族矿物特征及成因初探

云南牟定安益矿床为一处铂族金属与钛磁铁矿共同产出的大型钛磁铁矿铂族金属矿床。目前对该矿床中铂族元素的赋存状态研究甚少。结合野外宏观地质特征和室内岩矿鉴定,笔者利用TIMA和LA-ICP-MS-Mapping分析方法,对安益矿床中铂族金属矿物学特征进行研究,发现安益矿床中的铂族元素(PGEs)主要以独立矿物的形式存在。铂族矿物(PGMs)多为铂和钯的砷化物、碲化物,如砷铂矿、砷钯矿、黄碲钯矿、碲钯矿等;主要分布于硅酸盐矿物中,其次为硫化物边缘,部分分布于磁铁矿边缘;铂族矿物成因主要有岩浆成因和热液成因2种。岩浆作用形成的铂族矿物分布于硅酸盐矿物中或硫化物边缘,硅酸盐中的铂族矿物是早期PGE与半金属元素形成的纳米团簇颗粒随岩浆演化形成矿物颗粒,被结晶的硅酸盐矿物包裹;分布于硫化物边缘的铂族矿物是残余熔浆结晶的结果。热液作用将PGE以类质同象的形式富集于钛磁铁矿单辉岩的部分矿物中,如热液蚀变较强烈的黄铜矿中含有较高的Rh,这也与铂族矿物集中分布在钛磁铁矿单辉岩中一致。

含铂族金属铁合金碱焙烧脱硅预处理研究

针对含铂族金属铁合金结构复杂、难以溶解的问题,开展碱焙烧脱硅预处理研究以破坏稳定致密的合金结构。经试验验证,适宜的焙烧条件为:碱料质量比1.4、焙烧温度600℃、焙烧时间2.0 h,此条件下合金相完全分解,转化为NaFeO_(2)和Na_(4)SiO_(4),Na_(4)SiO_(4)经水浸脱除,所得水浸渣中硅含量降至0.84%。脱硅预处理后物料结构疏松、活性较高,易于酸溶除铁,有利于铂族金属精炼回收。

从含钌废料中回收钌的研究进展

从铂族金属废料中回收再利用钌对于实现行业可持续发展、节约资源和环境保护都有着重大影响。钌废料一般包括含钌废催化剂、含钌合金材料、含钌核废料和其他含钌废料等。综述了不同钌废料的综合回收处理方法,分别介绍了氧化蒸馏法转化可溶性盐、熔融—还原—氧化法、熔融—氧化—蒸馏法、微波浸出—浊点萃取法、蒸馏—熔融—还原法、熔融—还原—氧化法、离子交换法、氧化挥发法、电解法、生物吸附法和物理吸附法等工艺,总结了现有钌废料回收技术的优缺点,并对未来钌废料回收工艺的发展方向进行了展望。

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。

铂族金属循环利用技术开发现状及展望

铂族金属(PGMs)是汽车、石化、能源、国防装备等领域不可或缺的战略性金属资源,但PGMs矿产资源极度匮乏,供需矛盾突出;开展PGMs循环利用是保障PGMs安全供应、支撑关联产业高质量发展的重要举措。本文分析了PGMs的供给和应用情况,明确了当前PGMs市场的供需态势;全面梳理了PGMs湿法回收(含氰化法、盐酸+氧化剂工艺),火法回收(含铅捕集、铜捕集、锍捕集、铁捕集工艺)的技术特征与应用情况;着重从焙烧‒浸出、铁捕集‒酸浸、低温铁捕集‒电解‒离心萃取工艺等方面阐述了PGMs火法‒湿法联合回收技术的研发与应用进展。其中,低温铁捕集‒电解‒离心萃取成套工艺延续了低温铁捕集研究思路,通过低熔点渣型设计将铁捕集温度由1800℃以上降至约1400℃,富集得到Fe-PGMs合金后经电解进一步富集PGMs,再经离心萃取提纯依次得到Pd、Pt、Rh,实现了短流程分离提纯PGMs,具有绿色、高效、低成本的诸多优点。着眼PGMs循环利用产业高质量发展,建议围绕“PGMs富集、分离提纯、污染防控”全流程开展基础研究和技术攻关,加快建设PGMs循环利用全链条标准体系和绿色低碳的产业生态环境,全面开展业务流程的“互联网+”能力建设以实现“回收‒处理‒再利用”全流程的智能化。

Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton exchange membrane fuel cells

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton exchange membrane fuel cells(PEMFCs).However,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist inevitably.In the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O species.By quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,respectively.Half-wave potential(0.915V_(RHE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/C.Moreover,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar H_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical calculation.This work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

失效汽车尾气催化剂中铂族金属回收的研究进展

失效汽车尾气催化剂是回收铂族金属(铂、钯、铑)的重要二次资源。本文介绍了失效汽车尾气催化剂中铂族金属的回收工艺流程,包括失效催化剂预处理、铂族金属富集、分离与精炼三部分;详细介绍了两种高效预处理技术、两种富集方法以及四种分离与精炼工艺,总结了各种方法的原理、工艺流程、优缺点及改进方向。回收企业应根据回收规模和环保政策采用合适的回收工艺,以实现不同回收工艺之间的优势互补,未来需重点研发回收率高且环境友好的清洁回收工艺。

失效汽车催化剂中铂族金属火法富集概述

铂族金属作为重要的战略资源,在军事、航天、半导体、汽车等行业中有着广泛的应用,对于我国的发展起着不可或缺的作用。本文综述了目前失效汽车催化剂中铂族金属的火法回收现状,总结了各种方法的工艺流程和目前主要应用方向,包括金属捕集法中使用不同捕集剂造成的机理差异。对主要工艺路线存在的优缺点进行分析评述并提出改进方向。当下应大力发展协同捕集新技术,在保证回收率的同时还要控制富集后的合金成分以便于精炼,达成不同捕集剂之间的优势互补,为实现未来更加高效、绿色的铂族金属二次资源回收。

非金属掺杂提升铂族金属电催化剂性能

铂族金属(PGM)催化剂被认为是用于能量转换和存储设备(如燃料电池和水电解器)的最佳催化剂之一,但活性和稳定性不足极大地限制了其商业化应用.近年来,非金属原子(氢、硼、碳、氮、磷和硫等)掺杂策略引起了广泛关注,该方法可以对铂族金属的精细电子和配位结构进行调控,从而优化铂族金属的电催化活性和稳定性.非金属掺杂具有独特的优势:首先,非金属的原子半径较小,可以进入铂族金属的间隙位点,为调节铂族金属的电子结构提供了更多的可能性;其次,掺杂的非金属会诱导强电荷转移,并与主体金属产生s,p-d杂化,这与金属-金属合金中的d-d轨道耦合不同;第三,非金属掺杂的铂族金属基催化剂由于具有较强的非金属-金属键,从而表现出较好的耐久性.本文详细探讨了非金属掺杂铂族金属催化剂的合成和应用,并揭示了非金属掺杂的催化机理和构效关系.本文总结了非金属掺杂铂族金属基催化剂在电催化领域的一些代表性进展,讨论了影响催化剂活性和稳定性的关键因素,并介绍了非金属掺杂改善铂族金属基催化剂性能的基本原理.探讨了非金属掺杂铂族金属基催化剂的表征技术和理论方法,其中包括可直接观测到非金属原子的先进成像技术以及原位表征方法,辅助以密度泛函理论以及分子动力学模拟等理论计算方法,以进一步揭示催化剂性能增强机制.详细列举了非金属掺杂铂族电催化剂的合成方法,从气相沉积、高温热解、湿化学合成到电化学原位合成,提供了详尽的合成方案,并提出了针对贵金属活性中心的非金属修饰策略,旨在为未来材料设计提供启示.概述了非金属掺杂铂族金属基催化剂在电催化中的应用,重点揭示了非金属掺杂带来的结构-性能构效关系.在活性方面,非金属掺杂可以从配体效应、应力效应、微应变等方面影响铂族金属的d带重心,从而影响活性位点与反应中间体的吸附,而这种影响作用也因每种非金属的电负性、原子半径、掺杂方式等不同而不同,可通过调控掺杂种类/方式实现精细调控;同时,非贵金属的协同效应可以增强对OH的吸附,抑制活性位点的毒化.在稳定性方面,非金属可以通过与金属形成稳定的金属-非金属键抑制金属的溶解,或者减弱金属与氧的相互作用,防止其被氧化;同时,非金属的掺入可以提高金属的功函数,提高其溶解电位,从而提升催化剂稳定性.最后,本文提出了该类电催化材料面临的机遇和挑战,其中包括:(1)开发更加可控的非金属掺杂策略;(2)更加深入地研究非金属掺杂带来的构效关系;(3)探索新的非金属掺杂催化剂,并进一步拓展到其他催化领域;(4)发展抑制非金属组分溶解的通用策略;(5)重视催化剂在器件层面的性能评估.综上,本文不仅为非金属掺杂贵金属基催化剂进一步的研究提供启示,还为深入理解催化、纳米材料的合成提供参考.

铁捕集合金中铂族金属的高效回收工艺研究

以废汽车尾气净化催化剂铁捕集合金粉为研究对象,提出采用硫酸除铁-氯化浸出工艺回收Pt、Pd、Rh,主要考察了氯化浸出过程中盐酸浓度、温度、液固比、氧化剂用量、硝酸体积分数、反应时间等因素对铂族金属浸出率的影响。结果表明,在硫酸浓度3.2 mol/L、反应温度70℃、溶解时间1 h、液固比5 mg/mL的条件下,铁合金粉的浸出渣率为14.37%,铂族金属溶解分散率低于0.5%;在HCl浓度8 mol/L、浸出温度90℃、液固比5 mg/mL、氯酸钠加入倍数2、搅拌速率300r/min、硝酸体积分数10%、氯酸钠和硝酸氧化反应时间均为1 h的最佳条件下,Pt、Pd、Rh的浸出率均大于99%。

铂族金属助力提升新质生产力

基于新质生产力的概念,阐述了新质生产力的本质是“生产力”、新质生产力的特点在于“新”、新质生产力的关键在于“质”的概念。产业是发展新质生产力的主要载体,对铂族金属在新质生产力相关行业中的作用进行了分析。对铂族金属在传统行业包括汽车、化工,新兴产业如氢能、其他绿色能源、智能网联新能源汽车、电子、创新药和医疗科技、新材料及绿色回收的应用进行了分析。对铂族金属助力新质生产力的发展进行了展望。

中国铂族金属资源安全:建立产业循环型战略储备机制的思考与启示

随着我国成为全球最大的铂族金属消费国和进口国,自身资源禀赋不佳、本土供应能力有限等问题愈发突出,导致对外依存度持续攀升,铂族金属资源安全形势异常严峻。基于对全球和我国铂族金属供需概况等产业发展现状及存在问题的深入分析,本文探索性地提出了建设产业循环型铂族金属战略储备机制的概念。该机制旨在通过整合矿产资源开发、回收再利用、交易市场建设以及科研创新,构建一个全面而高效的铂族金属供应安全保障体系,从而提升我国在全球铂族金属市场中的话语权,并为铂族金属产业的可持续发展提供新的战略思路。