Technology For Recovery Of Metals Research Articles

Opportunities and challenges in supported liquid membrane technology for heavy metal extraction and recovery: a review

The present paper is an extended review on supported liquid membrane (SLM) for extraction and recovery of heavy metals, followed by the problems encountered during implementations and its potential outlooks for future applications. SLM technology integrates the processes of extraction, transport and re-extraction of heavy metals in a single continual system and has been proven with promising potential over other methods. Extraction and recovery of various heavy metal ions with several SLM configurations have been summarised. This review highlights the recent developments of SLM technology and the key issues related to their implementations with the performance efficiency and their apparent limitations. Substantial progress and breakthroughs to promote improvement of SLM are discussed. Future outlooks are also discussed to integrate this technology for better heavy metal extraction and recovery processes and to further broaden the research and development related to SLM.

Opportunities and challenges in supported liquid membrane technology for heavy metal extraction and recovery: a review

Opportunities and challenges in supported liquid membrane technology for heavy metal extraction and recovery: a review

Electronic waste as a secondary source of critical metals: Management and recovery technologies

The wealth of the society depends on several metals, including base metals, precious metals and increasingly rare earth elements (REE). They are collectively termed as technology metals. Numerous applications stimulated the use of technology metals, and their supply is at stake, owing to the high demand and uneven geographical distribution of these metals. Their stable supply is crucial for the transition to a sustainable and circular economy. There is an increasing interest in secondary sources of these metals. This article outlines the global state of electronic waste, its management and the latest technological developments in metal recovery from various streams of electronic waste. An emphasis is given to printed circuit boards (PCB), hard disc drives (HDD) and displays regarding their critical metal content. Physical, pyrometallurgical and (bio)hydrometallurgical metal recovery technologies are overviewed. In addition, perspectives on electronic waste as a secondary source of critical metals are given.

The Effect of Initial Solution pH on Surface Properties of Ferric Ion Precipitates Formed during Biooxidation of Ferrous Ion by <i>Leptospirillum ferriphilum</i>

While bioleaching is a proven technology for the efficient recovery of base metals from sulphide minerals, its sustenance is dependent on the continuous availability of ferric ion, Fe3+, in soluble form, in bioleach liquor. However, the solubility of ferric ion is low at higher pH thus resulting in the formation of various types of ferric ion precipitates, which decreases leaching efficiency by trapping the leached metals in solution through an adsorption. The effect of initial solution pH on the surface properties of ferric ion precipitates was investigated with a view to establish a relationship between operational pH and surface charge on precipitate and to relate this to the precipitates metal adsorption properties. Ferric ion precipitates recovered from a typical biooxidation process were characterized by XRD, SEM, PSD and zeta potential. Potassium-hydronium jarosite were the main phases identified by X-ray diffraction (XRD) analyses. The SEM results revealed that the precipitates had smooth surfaces with development of sharp edges on the precipitates formed at high pH. The precipitates formed at higher pH had less positive charge and scavenged more copper ions due to the high electrostatic attraction forces. The results from this study revealed that surface charge on a precipitate can give an indication of its metal adsorption capacity and that in order to prevent metal loss and improve extraction efficiency, solution conditions should be maintained such that the resulting precipitates have high positive surface charge to promote high electrostatic repulsion forces.

Cost-benefit analysis of copper recovery in remediation projects: A case study from Sweden

Contamination resulting from past industrial activity is a problem throughout the world and many sites are severely contaminated by metals. Advances in research in recent years have resulted in the development of technologies for recovering metal from metal-rich materials within the framework of remediation projects. Using cost-benefit analysis (CBA), and explicitly taking uncertainties into account, this paper evaluates the potential social profitability of copper recovery as part of four remediation alternatives at a Swedish site. One alternative involves delivery of copper-rich ash to a metal production company for refining. The other three alternatives involve metal leaching from materials and sale of the resulting metal sludge for its further processing at a metal production company using metallurgical methods. All the alternatives are evaluated relative to the conventional excavation and disposal method. Metal recovery from the ash, metal sludge sale, and disposal of the contaminated soil and the ash residue at the local landfill site, was found to be the best remediation alternative. However, given the present conditions, its economic potential is low relative to the conventional excavation and disposal method but higher than direct disposal of the copper-rich ash for refining. Volatile copper prices, the high cost of processing equipment, the highly uncertain cost of the metal leaching and washing process, coupled with the substantial project risks, contribute most to the uncertainties in the CBA results for the alternatives involving metal leaching prior to refining. However, investment in processing equipment within the framework of a long-term investment project, production of safe, reusable soil residue, and higher copper prices on the metal market, can make metal recovery technology socially profitable.

Does ex ante application enhance the usefulness of LCA? A case study on an emerging technology for metal recovery from e-waste

PurposeA large proportion of the environmental impacts of a technology is determined by decisions made at the early development stages. Therefore, effective approaches to grasp the potential environmental performance of a technology early in development are needed. This paper reflects on the usefulness of ex ante application of LCA using a case study on the appraisal of the potential environmental impacts of a lab-scale novel process for bioleaching of e-waste for metal recovery.MethodsThe LCA framework was applied at an early stage to the novel bioleaching process to embed it in a life cycle context, linking it to upstream and downstream flows. Then, a short-term future scaled-up scenario was defined using a proxy technology and estimated data. Environmental hotspots of this scenario were identified, and its environmental impacts were compared with those of a current industrial pyrometallurgical technique, involving an integrated smelter refinery.Results and discussionLCA displays potential environmental hotspots related to energy and material inputs for the bioleaching process and solvents for copper recovery, despite uncertainties. Comparison with an existing integrated smelter refinery technology returned an inferior environmental performance. These results could not be considered accurate given the early-stage application, yet they served as valuable preliminary information. The uncertainties also prompted further enquiry about the chosen product system boundary, the role of the emerging technology and the comparability of the technologies.ConclusionsThe ex ante application of life cycle assessment on an emerging technology brings a systematic rigour and discipline to an ambiguous situation at the start of technological development. Applying the LCA framework broadens the scope of the research, introducing a systems approach and long-term view. Environmental aspects and alternative perspectives on the novel technology are also brought into the research domain. The approach creates new knowledge on the novel technology’s potential development, and developmental challenges are given definition at an early stage.The LCA outcomes should not be regarded as a final result but have a signalling purpose as a contribution to technological development. Though imprecise with much conjecture involved, such an approach gives a valid mock-up of a plausible future providing useful provisional insights to be built upon. Applying ex ante LCA and an exploratory scenario to an emerging technology is of great service as a developmental design tool and can be further refined in later development stages.

A multilevel sustainability analysis of zinc recovery from wastes

As waste generation increases with increasing population, regulations become stricter to control and mitigate environmental emissions of substances, e.g. heavy metals such as zinc and copper. Recovering these resources from wastes is the key interest of industries. The objective of this paper is the sustainability and feasibility evaluations of zinc recovery from waste streams. Sustainability and feasibility of a resource recovery strategy from wastes in a circular economy are governed by avoided environmental impacts and cost-effective transformation of an environmental contaminant into a valuable resource, e.g. as a coproduct by making use of an existing infrastructure as much as possible. This study, for the first time, gives a comprehensive overview of secondary sources and processes of recovering zinc, its stock analysis by country, regional and global divisions by a Sankey diagram, policies to regulate zinc emissions and avoided environmental impacts by zinc recovery. Two representative cases are further investigated for economic feasibility analysis of zinc recovery from (1) steelmaking dust and (2) municipal solid waste (MSW). The amount and value of zinc that can be generated from dust emitted from various steelmaking technologies are estimated. Additional revenues for the steelmaking industrial sector (with electric arc furnace), at the plant, national (UK), regional (EU) and global levels are 11, 12, 169 and 1670 million tonne/y, or 19–143, 20–157, 287–2203 and 2834–21740 million €/y, respectively. The second case study entails an integrated mechanical biological treatment (MBT) system of MSW consisting of metal recovery technologies, anaerobic digestion, refuse derived fuel (RDF) incineration and combined heat and power (CHP) generation. An effective economic value analysis methodology has been adopted to analyse the techno-economic feasibility of the integrated MBT system. The value analysis shows that an additional economic margin of 500 € can be generated from the recovery of 1t of zinc in the integrated MBT system enhancing its overall economic margin by 9%.

New technologies and technical facilities for disposal of ash and slag waste produced by thermal power plants

The study describes main scientific and practical results obtained when researching new technologies and technical facilities for disposal of ash and slag wastes produced by thermal power plants. The issues of environmental safety provision in the area of thermal power plants are discussed and technologies for magnetic recovery of precious metals from ash and slag wastes are proposed. The data obtained is implemented in methodological documents, technical facilities and introduced into the industry with an economic effect.

Effect of pH on the Performance of Sulfate and Thiosulfate-Fed Sulfate Reducing Inverse Fluidized Bed Reactors

AbstractSulfate-reducing bacteria (SRB)–based technologies have gained a lot of attention in the field of wastewater treatment, especially to treat metal-contaminated wastewaters. An inverse fluidized bed (IFB) bioreactor is a versatile bioreactor configuration that uses SRB technology for metal removal and recovery from wastewater. Apart from sulfate, which is commonly used as an electron acceptor, thiosulfate is another potential candidate for this process. In this study, the performance of two IFB bioreactors that were operated at pH 7.0 (R1) and 5.0 (R2) using sulfate and thiosulfate as the electron acceptors were evaluated. The electron donor used in this study was ethanol and the chemical oxygen demand (COD) to electron acceptor ratio (SO42− or S2O32−) was kept constant at 1.0. By using sulfate as the electron acceptor, the average COD removal efficiency was 75.0 and 58.0% at pH 7.0 and 5.0, respectively, while the sulfate removal efficiency was 74.4 and 50.4%, respectively. The average sulfide prod...

コバルトリッチクラストからの金属回収技術の現状と課題

The cobalt rich manganese crusts are distributed on the flat top or the slope of seamounts in the economic zone and the open sea around Minami Torishima Island. Cobalt rich manganese crust and manganese nodule are iron manganese oxide mainly composed of oxide of Mn and Fe. However, their distribution condition and composition are different. Manganese nodule contains some 2.0% of copper and nickel together. On the other hand, the cobalt rich manganese crust includes less copper and nickel than manganese nodule does, but contains a higher level of cobalt and platinum. Metal Mining Agency of Japan (MMAJ), which is current Japan Oil, Gas and Metals National Corporation (JOGMEC), has selected“ Smelting and Chlorine Leaching” as the most suitable technique from the viewpoint of nickel, cobalt and copper's recovery from the manganese nodule. (Kojima, in 1996) For the treatment of cobalt rich crust, JOGMEC has established an improved metal recovery technology, which is called the“ Improved Smelting and Chlorine Leaching”, after the investigation from 2003 through 2008. . In the“ Improved Smelting and Chlorine Leaching”, JOGMEC has introduced“ slag cleaning” process for cobalt and another process for platinum in order to enhance the recovery level. Also JOGMEC found technique to recover metal using bioleaching effectively.

A New Technology for Recovery of Metals from Waste Printed Circuit Boards

Recycling of metallic fractions from waste printed circuit boards (PCBs) using gravity separation and hydrometallurgy was investigated. The obtained research fruits were listed as follows: (1) When being pulverized to finer than 0.4mm, waste PCBs could be generally dissociated from plastics. (2) Shaking table was shown to be suitable for processing pulverized PCBs. Pulverized PCBs containing 6.97% copper was enriched to 33.55% in a single operation and the copper recovery was 90.3% in the best size range of separation. (3) Pressure oxidation leaching was shown to be effective for separating copper from aluminum and tin. The leaching extraction of aluminum and tin were 86.6% and 96.3%, copper extraction was 1% or less under the optimal conditions.

Metal Recycling Technologies for Battery Waste

This review is related to the process development for batteries and related waste. The review’s primary focus is the metal recovery and remediation of the following types of battery waste: alkaline (Zn-MnO2), saline (Zn-carbon), lithium (Li-SOCl2, Li-MnO2), nickel-cadmium (Ni-Cd), nickel-metal hydride (NiMH), lead-acid, lithium-ion (Li-CoO2, Li-MnO2) and lithium-polymer. Various treatments have been developed to diminish the impact of hazardous metals on the environment and to preserve the valuable metal (e.g., Cd, Co, Cu, Fe, Li, Mn, Ni, Pb and Zn) resources. Three main technological approaches, namely, pyrometallurgy, hydrometallurgy and physical treatments, have been proposed. This paper covers the developments in the field of technology for metal recovery from battery waste based on an analysis of 14 patents. Keywords: Battery waste, hydrometallurgy, metal, physical treatment, pyrometallurgy, recycling.

Efficacy of mangrove leaf powder for bioremediation of chromium (VI) from aqueous solutions: kinetic and thermodynamic evaluation

Biosorption of heavy metals by bio-materials has been posited as a potential alternative to the existing physicochemical technologies for detoxification and recovery of toxic and valuable metals from wastewaters. In this context, the role of mangrove leaf powder (MLP) as biosorbent for chromium removal was investigated. In the present study, the effect of process parameters such as particle size, solution pH, initial concentration of Cr(VI) ion and adsorbent dose on chromium removal by MLP was investigated. The maximum sorption was observed at particle size 0.5 mm and pH 2.0. The adsorption data follow the pseudo second-order kinetics model. The isotherms denote that Langmuir model is the best fitted than Freundlich model. The maximum adsorption capacity (Q0) of 60.24 mg/g of Cr(VI) at 30 min on MLP was determined using the Langmuir model. The adsorption isotherm model indicates that the chromium is adsorbing as monolayer on the surface of MLP with heterogeneous energetic distribution of active sites. Various thermodynamic parameters, such as Gibb’s free energy (∆G°), enthalpy (∆H°) and entropy (∆S°) have been calculated. The thermodynamic data revealed that the adsorption of chromium ions onto MLP is endothermic in nature and a spontaneous process. The results of the present study suggest that MLP is an effective bioremediation measure for removal of high concentration of Cr(VI) in waste waters.

Electroplating Sludge Metal Recovery Technology Resources Research

The electroplating sludge contains a variety of heavy metal elements, is an inexpensive and renewable resource. This situation on the domestic electroplating sludge conducted a preliminary investigation, reviewing of domestic and foreign electroplating sludge metal recovery technology research, and currently more processing techniques were evaluated.

전기전자제품(電氣電子製品)의 제조공정(製造工程)에서 발생(發生)하는 폐기물(廢棄物)로부터 금속회수(金屬回收)에 관한 기술(技術) 동향(動向)

제품을 제조하는 대부분의 공정에서는 불량품이나 스크랩 등의 폐기물이 발생한다. 전기전자 제품을 생산하는 공정에서도 금속을 함유한 복합물질의 폐기물이 다량 발생하며, 이로부터 금속을 회수하는 것은 자원재활용의 측면 뿐 아니라 매립 등의 처리에 대한 환경부담을 줄이는 효과가 있다. 이 논문에서는 전기전자 제품을 제조하는 공정에서 발생하는 불량품을 포함한 폐기물로부터 금속을 회수하는 기술에 대하여 1975년부터 2011년까지 공개/등록된 미국, 일본, 유럽, 한국의 특허와 SCI급 논문을 조사하였다. 키워드를 이용하여 조사하였고 필터링 하여 특허와 논문을 수집하여 연도별, 국가별, 기관별, 기술별로 분석하였다. 분석결과, 특허의 경우는 한국, 일본, 미국 순으로 많이 제출하였고 논문의 경우에는 대만, 미국 순이었다. Recently, the recovery of resources from waste material of manufacturing electric and electronic equipment has been investigated. It is very important to extract metallic components from electric and electronic manufacturing processes with the view point of recycling of the used resources as well as an environmental protection. In this paper, open/registered patents of US, JP, EP, and KR and SCI journal related to metal recovery technologies from wastes produced in the electric and electronic manufacturing processes between 1975~2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers were analyzed by the years, countries, companies, and technologies.

A comparison of the electrochemical recovery of palladium using a parallel flat plate flow-by reactor and a rotating cylinder electrode reactor

The production of catalytic converters generates large amounts of waste water containing Pd 2+, Rh 3+ and Nd 3+ ions. The electrochemical treatment of these solutions offers an economic and effective alternative to recover the precious metals in comparison with other traditional metal recovery technologies. The separation of palladium from this mixture of metal ions by catalytic deposition was carried out using a rotating cylinder electrode reactor (RCER) and a parallel plate reactor (FM01-LC) with the same cathode area (64 cm 2) and electrolyte volume (300 cm 3). The study was carried out at mean linear flow velocities of 1.27 < ν < 11.36 cm s −1 (120 < Re = υd e / v < 1080) for the FM01-LC reactor and 20 < ν < 140 cm s −1 (7390 < Re = υd/ v < 51,700) for the RCER. The morphology of the palladium deposits at the entrance and at the exit of the electrolyte compartment of the FM01-LC reactor showed the effect of the manifold distributors during the electrolysis; the manifolds generate micro turbulences, increasing the mass transport coefficient in these areas and favouring rapid recovery of palladium ions. More uniform high purity palladium deposits were obtained on the surface of the RCER. The cumulative current efficiency to recover 99% of Pd 2+ ions in the parallel plate electrode reactor was 35% while the recovery of 97% of Pd 2+ in the RCER was 62%. The volumetric energy consumption during the electrolysis was 0.56 kW h m −3 and 2.1 kW h m −3 for the RCER and the FM01-LC reactors, respectively. Using a three-dimensional stainless steel electrode in the FM01-LC laboratory reactor, 99% of palladium ions were recovered after 30 min of electrolysis while in the RCER, 120 min were necessary.

Role of Biosorption in Environmental Cleanup

Pollution has been the major problem since decades, destructing our environment and resources. Among all types of pollutions, heavy metal pollution is causing major threat to the biosphere. It is mainly resulted due to the release of Industrial wastes into the atmosphere. Industries follow various chemical procedures to remove harmful pollutants from the industrial effluents associated with various disadvantages as a result many eco-friendly techniques have come into light keeping due to the disadvantages of the chemical techniques. Biosorption of heavy metals by microbial cells has been recognized as a potential alternative to existing technologies for recovery of heavy metals from industrial waste. Present review focuses on the biosorption of different metals by different means which lead to the eco friendly clean up of the environment without causing any damage as such to the surroundings/ without the release of chemicals into the atmosphere, this article mainly deals with the biosorption of Fe, Cr (VI),U, Pb, Cu2+, Cd(II), Mn, Zn, Ni, Lanthanides, Ni and the role of this technique in cleaning up of the environment.

Biosorption and recovery of heavy metals from aqueous solutions by Eichhornia crassipes (water hyacinth) ash

Heavy metal’s release without treatment poses a significant threat to the environment. Heavy metals are non-biodegradable and persistent. In the present study the ash of water hyacinth (Eichhornia crassipes), was used to remove six metals from aqueous solutions through biosorption. Results of batch and column experiments showed excellent adsorption capacity. Removal of lead, chromium, zinc, cadmium, copper, and nickel was 29.83, 1.263, 1.575, 3.323, 2.984 and 1.978 µgg-1, respectively. The biosorptive capacity was maximum with pH &gt;8.00. Desorption in µgg-1 of ash for lead, chromium, zinc, cadmium, copper, and nickel was 18.10, 9.99, 11.99, 27.54, 21.09, and 3.71 respectively. Adsorption/desorption of these metals from ash showed the potential of this technology for recovery of metals for further usages. Hydrogen adsorption was also studied with a Sievert-type apparatus. Hydrogen adsorption experiments showed significant storage capacity of water hyacinth ash.

Vetivera Sp as a Low Cost Adsorbent to Adsorb Cr (VI) from Electroplating Industrial Effluent

Chromium (Cr) plating is one of the most widely used forms of electroplating. It is also an important source of heavy and toxic metal discharges into wastewater lines. In the present study the biosorption capacity of Vetivera root has been studied with reference to removal of Cr (VI) from the chromium plating effluent. The results of biosorption studies in terms of pH, agitation time and dosage of adsorbent, revealed higher metal removal up to 150 ppm/g of adsorbent. Metal [Cr (VI)] removal within 120 min was enhanced up to 78.5%. Cr (VI) removal is higher at lower pH of 2.5. The reuse of plant biomass was subjected to elution studies using various eluting agents such as HNO3, HCl, H2SO4, Thiourea and EDTA. The retention capacity of Vetivera was almost constant after three cycles of elution. Hence, this process can be used as an alternative to classical cost effective technology for heavy metal recovery and would also be efficient for effluent treatment system.

Reduction of Heavy-Metal Content in Overburden Material by Bacterial Action

In previous studies it has been showed that bacterially produced sulphuric acid is a good leaching agent for laterite tailings. In this work we evaluated heavy metals leaching from low grade laterite ore for cobalt and nickel extraction using sulphuric acid produced in situ by Acidithiobacillus thiooxidans under different culture conditions. In studies where that material was initially added to the cultures, considerable percentages of metals were leached (100 % Mn, 70 % Co, 7.5 % Ni, less than 5 % of Cr and Fe) after 18 days of incubation at low pulp densities (1 % and 2.5 %) of overburden. The maximum percentages were reached when cultures pH was approximately or below than 1.5. At higher pulp densities material was added to the cultures after different pre-cultivating times; also higher sulphur amounts were assayed; in such way about 100 % Mn, 60 % Co, 9 % Ni and Fe and 2.5 % Cr were leached. Although toxic metals were not completely leached, sequential extractions results indicate that these metals are not readily available. All studies finally suggest that bioleaching is a suitable technology for recovery of valuable metals as Co and remediation of mining residues by extraction of heavy metals.