Wastes generated by automotive industry – Spent automotive catalysts

2018 ◽  
Vol 3 (8) ◽  
Author(s):  
Martyna Rzelewska ◽  
Magdalena Regel-Rosocka
Keyword(s):  
Metal Ions ◽  
Precious Metals ◽  
Point Of View ◽  
Platinum Group Metals ◽  
Valuable Metal ◽  
Automotive Catalysts ◽  
Secondary Sources ◽  
Liquid Liquid Extraction ◽  
Liquid Phases ◽  
Spent Catalysts

Abstract Rhodium, ruthenium, palladium, and platinum are classified as platinum group metals (PGM). A demand for PGM has increased in recent years. Their natural sources are limited, therefore it is important, and both from economical and environmental point of view, to develop effective process to recover PGM from waste/secondary sources, such as spent automotive catalysts. Pyrometallurgical methods have always been used for separation of PGM from various materials. However, recently, an increasing interest in hydrometallurgical techniques for the removal of precious metals from secondary sources has been noted. Among them, liquid-liquid extraction by contacting two liquid phases: aqueous solution of metal ions and organic solution of extractant is considered an efficient technique to separate valuable metal ions from solutions after leaching from spent catalysts.

scholarly journals Model of Infiltration of Spent Automotive Catalysts by Molten Metal in Process of Platinum Metals Recovery

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Agnieszka Fornalczyk ◽  
Slawomir Golak ◽  
Mariola Saternus
Keyword(s):  
Electromagnetic Field ◽  
Molten Metal ◽  
Metal Flow ◽  
Precious Metals ◽  
Automotive Catalysts ◽  
Catalyst Carrier ◽  
Metals Recovery ◽  
Spent Catalysts ◽  
Hydrodynamic Field ◽  
The Impact

This paper presents the model for the washing-out process of precious metals from spent catalysts by the use of molten lead in which the metal flow is caused by the rotating electromagnetic field and the Lorentz force. The model includes the coupling of the electromagnetic field with the hydrodynamic field, the flow of metal through anisotropic and porous structure of the catalyst, and the movement of the phase boundary (air-metal) during infiltration of the catalyst carrier by the molten metal. The developed model enabled analysis of the impact of spacing between the catalysts and the supply current on the degree of catalyst infiltration by the molten metal. The results of calculations carried out on the basis of the model were verified experimentally.

Biorecovery of Platinum Group Metals from Secondary Sources

2007 ◽  
Vol 20-21 ◽  
pp. 651-654 ◽  
Author(s):  
Angela J. Murray ◽  
I.P. Mikheenko ◽  
Elzbieta Goralska ◽  
N.A. Rowson ◽  
Lynne E. Macaskie
Keyword(s):  
Catalytic Activity ◽  
Precious Metals ◽  
Bacterial Biomass ◽  
Platinum Group Metals ◽  
X Ray ◽  
Secondary Sources ◽  
Price Increases ◽  
Valuable Product ◽  
Platinum Group

Since 1998 demand for the platinum group metals (PGM) has exceeded supply resulting in large price increases. Undersupply, combined with rising costs prompts environmentally friendly recycling technologies. Leachates containing PGM were produced from secondary waste sources using microwave leaching technology with the aim of recovering precious metals using bacterial biomass. Previous studies showed that metallised biomass exhibits catalytic activity; hence metal is not only recovered but can be converted into a valuable product. Cells of Escherichia coli MC4100 that had been pre-metallised with Pt were more effective at reducing PGM from the leachates. The solid recovered from the leachate onto the bacteria was characterised using X-ray Powder Diffraction (XRD) and Energy Dispersive X-ray Microanalysis (EDX). Metallised biomass was tested for catalytic activity (reduction of Cr(VI) to Cr(III)) to compare the ‘quality’ of polymetallic bacterial-based catalysts versus counterparts made from single and mixed metal model solutions.

scholarly journals Recovery of Platinum Group Metals from Spent Automotive Catalysts Using Lithium Salts and Hydrochloric Acid

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6843
Author(s):  
Shunsuke Kuzuhara ◽  
Mina Ota ◽  
Ryo Kasuya
Keyword(s):  
Precious Metals ◽  
Lithium Ion ◽  
Platinum Group Metals ◽  
Leaching Rate ◽  
Electrolytic Solution ◽  
Matrix Component ◽  
Aqua Regia ◽  
Automotive Catalysts ◽  
Chlorine Gas ◽  
Platinum Group

The recovery of platinum group metals (PGMs) from waste materials involves dissolving the waste in an aqueous solution. However, since PGMs are precious metals, their dissolution requires strong oxidizing agents such as chlorine gas and aqua regia. In this study, we aimed to recover PGMs via the calcination of spent automotive catalysts (autocatalysts) with Li salts based on the concept of “spent autocatalyst + waste lithium-ion batteries” and leaching with only HCl. The results suggest that, when Li2CO3 was used, the Pt content was fully leached, while 94.9% and 97.5% of Rh and Pd, respectively, were leached using HCl addition. Even when LiF, which is a decomposition product of the electrolytic solution (LiPF6), was used as the Li salt model, the PGM leaching rate did not significantly change. In addition, we studied the immobilization of fluorine on cordierite (2MgO·2Al2O3·5SiO2), which is a matrix component of autocatalysts. Through the calcination of LiF in the presence of cordierite, we found that cordierite thermally decomposed, and fluorine was immobilized as MgF2.

scholarly journals Leaching of gold from flotation waste by thiourea

2021 ◽  
pp. 98-105
Keyword(s):  
Precious Metals ◽  
Point Of View ◽  
Gold Content ◽  
Waste Sample ◽  
Secondary Sources ◽  
Tailings Pond ◽  
Electronic Engineering ◽  
Wide Range ◽  
The World ◽  
Toxic Fumes

Throughout human history, gold has been the most sought-after and well-known precious metal in the world. It is synonymous with wealth in the financial market and jewellery. However, its use has a wide range of applicability in biomedicine, electronic engineering and other industries. Primary gold resources are limited and have been significantly depleted in recent decades. To cover the current demand, it is necessary to process secondary sources containing gold such as heaps, tailings, lean ores or electrical waste. New and especially more efficient technological procedures are needed for the processing of these secondary sources. From an environmental point of view, a hydrometallurgical process is considered to be more appropriate than a pyrometallurgical process, in which very toxic fumes enter the air. This work investigates the leaching of gold from flotation wastes using thiourea. It is flotation waste that is the target group of materials that are a source of precious metals. An interesting gold content is present in our waste sample (Hodruša Hámre tailings pond), but its evaluation depends on the setting of suitable technological conditions. In this work, thiourea is used as an alternative leaching agent to toxic cyanide, which is banned in Slovakia and many countries around the world due to its high environmental risk. The results of the study are described with respect to the gold recovery under optimized thiourea leaching conditions.

scholarly journals Recovery of Palladium(II) and Platinum(IV) in Novel Extraction Systems

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 285
Author(s):  
Zuzanna Wiecka ◽  
Martyna Rzelewska-Piekut ◽  
Irmina Wojciechowska ◽  
Karolina Wieszczycka ◽  
Magdalena Regel-Rosocka
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Organic Phase ◽  
Alkyl Chain ◽  
Platinum Metal ◽  
Platinum Group Metals ◽  
Component Mixture ◽  
Quaternary Pyridinium Salts ◽  
Liquid Liquid Extraction ◽  
Stripping Efficiency

Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the metal ions to the organic phase. As the best extractant among the investigated ones, D3EI-PrCl (with straight alkyl chain at substituent) can be pointed out, however, problems with effective stripping or phase disengagement after stripping should be indicated as a drawback of the organic phases used. Further investigation should focus on the improvement of the organic phase properties (e.g., increase in hydrophobicity of the extractants and addition of an organic phase modifier) towards stripping efficiency.

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