Recycling of Spent Catalysts Containing Precious Metals

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.

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Modelling Methods of Magnetohydrodynamic Phenomena Occurring in a Channel of the Device Used to Wash out Spent Automotive Catalyst on Metallic Substrate by a Liquid Metal

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.566 ◽

2016 ◽

Vol 879 ◽

pp. 566-571

Author(s):

Agnieszka Fornalczyk ◽

Roman Przylucki ◽

Sławomir Golak ◽

Mariola Saternus

Keyword(s):

World Literature ◽

Precious Metals ◽

Coupled Analysis ◽

Computational Techniques ◽

Catalytic Converters ◽

Advantages And Disadvantages ◽

Spent Catalysts ◽

Physical Fields ◽

Modelling Methods ◽

Temperature And Flow Fields

The recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material because as the devices. they have to be periodically renovated and eventually replaced. Among automotive catalysts withdrawn from use, these with metallic carrier constitute quite a big group. Metallic carriers are usually obtained from steel FeCrAl , which is covered by a layer of PGM acting as a catalyst. World literature describes a number of pyro-or hydrometallurgical methods used for recovery of platinum from used automobile catalytic converters. However, all methods, available in the literature, are used to recover platinum from ceramic carrier. This paper presents the new method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out platinum by using mangetohydrodynamic pump. The article includes the description of the methods used in modelling magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields) occurring in this particular device for this kind of waste. The general phenomena and ways of coupling the various physical fields for this type of calculation have also been described. The basic computational techniques with a discussion of their advantages and disadvantages have been presented.

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A “Wastes-Treat-Wastes” Technology: Role and Potential of Spent Fluid Catalytic Cracking Catalysts Assisted Pyrolysis of Discarded Car Tires

Polymers ◽

10.3390/polym13162732 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2732

Author(s):

Baishun Zhao ◽

Chuansheng Wang ◽

Huiguang Bian

Keyword(s):

Catalytic Cracking ◽

Precious Metals ◽

Cost Effective ◽

Fluid Catalytic Cracking ◽

Spent Catalyst ◽

Waste Tires ◽

Waste Tire ◽

Spent Catalysts ◽

Fcc Catalysts ◽

Cracking Catalysts

Spent fluid catalytic cracking catalysts (FCC catalysts) produced by the petrochemical industry are considered to be environmentally hazardous waste, and precious metals and heavy metals deposited on the surface make them difficult to treat. Even so, these catalysts retain some of their activity. The pyrolysis of waste tires is considered to be one of the most effective ways to solve the fossil fuel resource crisis, and this study attempts to catalyze the pyrolysis of waste tires using spent catalysts to increase the value of both types of waste. FCC catalysts reduced the activation energy (E) of waste tire pyrolysis. When the catalyst dosage was 30 wt.%, the E of tread rubber decreased from 238.87 kJ/mol to 181.24 kJ/mol, which was a 19.94% reduction. The E of the inner liner decreased from 288.03 kJ/mol to 209.12 kJ/mol, a 27.4% reduction. The spent catalyst was more effective in reducing the E and solid yield of the inner liner made of synthetic rubber. It should be emphasized that an appropriate increase in the heating rate can fully exert the selectivity of the catalyst. The catalyst could also be effectively used twice, and the optimum ratio of catalyst/waste tires was about 1/4.5. Compared with specially prepared catalysts, it is more cost-effective to use such wastes as a catalyst for waste tire pyrolysis.

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Recovery of precious metals from electronic waste and spent catalysts: A review

Resources Conservation and Recycling ◽

10.1016/j.resconrec.2018.10.041 ◽

2019 ◽

Vol 141 ◽

pp. 284-298 ◽

Cited By ~ 66

Author(s):

Yunji Ding ◽

Shengen Zhang ◽

Bo Liu ◽

Huandong Zheng ◽

Chein-chi Chang ◽

...

Keyword(s):

Electronic Waste ◽

Precious Metals ◽

Spent Catalysts

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Modelling Methods of Magnetohydrodynamic Phenomena Occurring in a Channel of the Device Used to Wash Out the Spent Automotive Catalyst by a Liquid Metal

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0122 ◽

2016 ◽

Vol 61 (2) ◽

pp. 713-718

Author(s):

A. Fornalczyk ◽

R. Przylucki ◽

S. Golak ◽

J. Willner

Keyword(s):

Liquid Metal ◽

Automotive Industry ◽

Precious Metals ◽

Coupled Analysis ◽

Computational Techniques ◽

Advantages And Disadvantages ◽

Spent Catalysts ◽

Physical Fields ◽

Modelling Methods ◽

Temperature And Flow Fields

AbstractThe recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material as the devices have to be periodically renovated and eventually replaced. This paper presents the method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out by using mangetohydrodynamic stirrer. The article includes the description of the methods used for modeling of magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields) occurring in this particular device. The paper describes the general phenomena and ways of coupling the various physical fields for this type of calculation. The basic computational techniques with a discussion of their advantages and disadvantages are presented.

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Wastes generated by automotive industry – Spent automotive catalysts

Physical Sciences Reviews ◽

10.1515/psr-2018-0021 ◽

2018 ◽

Vol 3 (8) ◽

Cited By ~ 3

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.

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Towards Understanding the Cathode Process Mechanism and Kinetics in Molten LiF–AlF3 during the Treatment of Spent Pt/Al2O3 Catalysts

Metals ◽

10.3390/met11091431 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1431

Author(s):

Andrey Yasinskiy ◽

Sai Krishna Padamata ◽

Srecko Stopic ◽

Dominic Feldhaus ◽

Dmitriy Varyukhin ◽

...

Keyword(s):

Precious Metals ◽

Cyclic Voltammograms ◽

Spent Catalyst ◽

Tungsten Electrode ◽

Primary Metal ◽

Aluminum Reduction ◽

Electron Process ◽

Alumina Solubility ◽

Spent Catalysts ◽

The One

Electrochemical decomposition of spent catalyst dissolved in molten salts is a promising approach for the extraction of precious metals from them. This article reports the results of the study of aluminum electrowinning from the xLiF–(1-x)AlF3 melt (x = 0.64; 0.85) containing 0–5 wt.% of spent petroleum Pt/γ-Al2O3 catalyst on a tungsten electrode at 740–800 °C through cyclic voltammetry and chronoamperometry. The results evidence that the aluminum reduction in the LiF–AlF3 melts is a diffusion-controlled two-step process. Both one-electron and two-electron steps occur simultaneously at close (or same) potentials, which affect the cyclic voltammograms. The diffusion coefficients of electroactive species for the one-electron process were (2.20–6.50)∙10−6 cm2·s–1, and for the two-electron process, they were (0.15–2.20)−6 cm2·s−1. The numbers of electrons found from the chronoamperometry data were in the range from 1.06 to 1.90, indicating the variations of the partial current densities of the one- and two-electron processes. The 64LiF–36AlF3 melt with about 2.5 wt.% of the spent catalysts seems a better electrolyte for the catalyst treatment in terms of cathodic process and alumina solubility, and the range of temperatures from 780 to 800 °C is applicable. The mechanism of aluminum reduction from the studied melts seems complicated and deserves further study to find the optimal process parameters for aluminum reduction during the spent catalyst treatment and the primary metal production as well.

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