Catalytic converters contain the catalytic substance in their structure, which is a mixture of Platinum Group Metals (PGMs): platinum, palladium and rhodium. The prices of these metals and a growing demand for them in the market, make it necessary to recycle spent catalytic converters and recovery of PGMs. The ceramic monolith of catalytic converters is still a predominant material in its construction among of multitude of catalytic converters which are in circulation. In this work attempts were made to leach additional metals (excluding Pt) from comminuted ceramic monolith. Classic leachant oxidizing media 10M H2SO4, HCl and H3PO4 were used considering the possibility of dissolution of the ceramic monolith.
J. Willner, J. Kaduková, A. Fornalczyk, A. Mrážiková, R. Marcinčáková and O. Velgosová
The main task of automotive catalytic converters is reducing the amount of harmful components of exhaust gases. Metallic catalytic converters are an alternative to standard ceramic catalytic converters. Metallic carriers are usually made from FeCrAl steel, which is covered by a layer of Precious Group Metals (PGMs) acting as a catalyst. There are many methods used for recovery of platinum from ceramic carriers in the world, but the issue of platinum and other metals recovery from metallic carriers is poorly described. The article presents results of preliminary experiments of metals biooxidation (Fe, Cr and Al) from spent catalytic converters with metallic carrier, using bacteria of the Acidithiobacillus genus.
J. Willner, A. Fornalczyk, J. Cebulski and K. Janiszewski
Automotive catalytic converters have a limited life time, after which the catalyst must be replaced or regenerated. The spent catalytic converters contain small amount of precious metals. Recovery of these metals is essential for environmental and economic reasons. The waste electronic equipment is also an attractive source for recovery of precious metals. Precious metals in electronic scraps are concentrated mainly in printed circuits and integrated circuits - so generally in elements that are the most diverse in their composition. Material heterogeneity of these elements is the reason why there is no universal method for processing this type of scrap. Methods used in the world for recovery of precious metals from spent auto catalytic coverters and electronic wastes by pyrometallurgical and hydrometallurgical methods were mentioned in this paper. The results of simultaneous melting of electronic waste with spent automotive catalysts were presented. The printed circuit boards were used as the carrier and as a source of copper. The precious metals present in the catalyst were collected in copper.
A. Fornalczyk, S. Golak, R. Przyłucki and J. Willner
The lifetime of a catalytic converters is limited. Today’s environmental regulations require that used converters should be properly recycled as a valuable source of precious metals, Al2O3 and steel scrap. The precious metals used in the devices perform catalytic functions. They are suspended in a ceramic or metal carrier. This paper deals with the recovery of precious metals from automotive converters using a metal-collector method. In order to speed up the washout of the precious metals from the capillary structure of the converter, the movement of the liquid metal-collector was forced by the electromagnetic field. The research was aimed at improving the effective velocity of the liquid metal flow through the carrier by means of a device with a double windings. Various ways of power supply were considered. The calculation experiment was performed as a weakly coupled analysis of the electromagnetic field and flow field.
J. Sedlakova-Kadukova, R. Marcincakova, A. Mrazikova, J. Willner and A. Fornalczyk
The role of iron in metal-bearing waste bioleaching was studied. Four various types of waste (printed circuit boards (PCBs), Ni-Cd batteries, alkaline batteries and Li-ion batteries) were treated by bioleaching using the acidophilic bacteria A. ferrooxidans and A. thiooxidans (separately or in mixture). Role of main leaching agents (Fe3+ ions or sulphuric acid) was simulated in abiotic experiments. Results showed that oxidation abilities of Fe3+ ions were crucial for recovery of Cu and Zn from PCBs, with the efficiencies of 88% and 100%, respectively. To recover 68% of Ni from PCBs, and 55% and 100% of Ni and Cd, respectively, from Ni-Cd batteries both oxidation action and hydrolysis of Fe3+ were required. The importance of Fe2+ ions as a reducing agent was showed in bioleaching of Co from Li-ion batteries and Mn from alkaline batteries. The efficiency of the processes has increased by 70% and 40% in Co and Mn bioleaching, respectively, in the presence of Fe2+ ions. Based on the results we suggest the integrated biometallurgical model of metal-bearing waste recycling in the effort to develop zero-waste and less energy-dependent technologies.
J. Sedlakova-Kadukova, O. Velgosova, M. Vosatka, J. Lukavsky, J. Dodd, J. Willner and A. Fornalczyk
The application of green synthesis in the nano-science and technology is of great importance in the area of the preparation of various materials. In this work, three selected algal species Parachlorella kessleri, Dictyosphaerium chlorelloides and Desmodesmus quadricauda were successfully used for the preparation of silver nanoparticles (AgNPs). Presence of AgNPs was confirmed by UV-vis spectroscopy and transmission electron microscopy. AgNPs produced by P. kessleri had narrow size distribution and average sizes of 7.6 nm. However, nanoparticle production lasted for long time. Nanoparticle formation by D. chlorelloides was the fastest, although, their average sizes were 23.4 nm with broad size distribution. Nanoparticles produced by D. quadricauda had average sizes 23.9 nm but they were the least stable, aggregated and precipitated from solutions within 3 days. These results confirmed that the size distribution and mean diameter of the nanoparticles, crucial for various applications, can be controlled by the organism selection.
A. Fornalczyk, R. Przylucki, S. Golak and J. Willner
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 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.
A. Mrážiková, J. Kaduková, R. Marcinčáková, O. Velgosová, J. Willner, A. Fornalczyk and M. Saternus
The objective of this work was to evaluate the influence of static, stirring and shaking conditions on copper, zinc, nickel and aluminium dissolution from printed circuit boards (PCBs) using the mixed acidophilic bacterial culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results revealed that static conditions were the most effective in zinc and aluminium dissolution. Zinc was removed almost completely under static conditions, whereas maximum of nickel dissolution was reached under the stirring conditions. The highest copper recovery (36%) was reached under stirring conditions. The shaking conditions appeared to be the least suitable. The relative importance of these systems for the bioleaching of copper and nickel decreased in the order: stirring, static conditions, shaking.
A. Fornalczyk, M. Kraszewski, J. Willner, J. Kaduková, A. Mrážiková, R. Marcinčáková and O. Velgosová
Metal supported auto catalysts, have been used in sports and racing cars initially, but nowadays their application systematically increases. In Metal Substrate (supported) Converters (MSC), catalytic functions are performed by the Platinum Group Metals (PGM): Pt, Pd, Rh, similarly to the catalysts on ceramic carriers. The contents of these metals make that spent catalytic converters are valuable source of precious metals. All over the world there are many methods for the metals recovery from the ceramic carriers, however, the issue of platinum recovery from metal supported catalysts has not been studied sufficiently yet. The paper presents preliminary results of dissolution of spent automotive catalyst on a metal carrier by means of acids: H2SO4, HCl, HNO3, H3PO4. The main assumption of the research was the dissolution of base metals (Fe, Cr, Al) from metallic carrier of catalyst, avoiding dissolution of PGMs. Dissolution was the most effective when concentrated hydrochloric acid, and 2M sulfuric acid (VI) was used. It was observed that the dust, remaining after leaching, contained platinum in the level of 0.8% and 0.7%, respectively.