Mariola Saternus

Vapour Treatment Method Against Other Pyro-and Hydrometallurgical Processes Applied to Recover Platinum From Used Auto Catalytic Converters

Today more and more cars are produced every year. All of them have to be equipped with catalytic converters, the main role of which is to obtain substances harmless to the environment instead of exhausted gases. Catalytic converters contain platinum group metals (PGM) especially platinum, palladium and rhodium. The price of these metals and their increasing demand are the reasons why today it is necessary to recycle used auto catalytic converters. There are many available methods of recovering PGM metals from them, especially platinum. These methods used mainly hydrometallurgical processes; however pyrometallurgical ones become more and more popular. The article presents results of the research mainly concerning pyrometallurgical processes. Two groups of research were carried out. In the first one different metals such as lead, magnesium and copper were used as a metal collector. During the tests, platinum went to those metals forming an alloy. In other research metal vapours were blown through catalytic converter carrier (grinded or whole). In the tests metals such as calcium, magnesium, cadmium and zinc were applied. As a result white or grey powder (metal plus platinum) was obtained. The tables present results of the research. Processing parameters and conclusions are also shown. To compare efficiency of pyrometallurgical and hydrometallurgical methods catalytic converter carrier and samples of copper with platinum obtained from pyrometallurgical method were solved in aqua regia, mixture of aqua regia and fluoric acid.

Numerical and Physical Modelling of Aluminium Barbotage Process

Today the aluminium refining process, especially barbotage is one of the most essential necessary technological stages in obtaining aluminium. It gives possibility to remove undesirable hydrogen and non-metallic and metallic inclusions from aluminium. Phenomena that take place during the barbotage process are rather complicated, but the knowledge about their character enables to optimize and control this process. Modelling research is used to outline these phenomena. Physical and mathematical modelling can be applied in carrying out aluminium barbotage process. Mathematical modelling uses numerical methods to solve the system of differential equations. The paper presents results of physical and numerical modelling of the refining process taking place in the continuous reactor URC-7000. Physical modelling was carried out for the different flow rate of refining gas (argon). It was in the range between 2 to 25 dm3/min. Numerical calculation was done using commercial program in Computational Fluid Dynamics (CFD). Model Volume of Fluid (VOF) was applied in modelling the multiphase flow. Obtained results were compared in order to verify the numerical settings and correctness of the choice.

Bayern`s Method of Al2O3 Production – Possibilities of Red Mud Disposal and Utilization

Bayern`s method is the first stage of obtaining primary aluminium. The product of this process is alumina. The paper presents how much alumina was produced in the last couple of years and who were its leading producers. As the main ore for alumina production is bauxite; it was necessary to describe its characteristics: chemical composition and types of bauxites. Short description of the method (digestion, precipitation and calcination) was presented. During this process a lot of pollution is usually emitted to the atmosphere, but mostly a lot of red mud is generated. This is the main waste of the process, which at the same time is very harmful to the environment. The ways red mud is disposed or utilized were reviewed. Two kinds of red mud disposal are known: wet and dry disposal. Both were characterized and their advantages and disadvantages were outlined. The possibilities of red mud utilization were shown. The focus was put on iron recovery or recovery of compounds such as Al2O3 or TiO2. The use of red mud in building materials was discussed. Radioactivity of such materials was also analyzed. Possibility of red mud utilization as a pigment and radiopaque material was also mentioned.

Physical Modelling of Metallurgical Processes

Today physical modelling is a commonly used tool in modelling metallurgical processes. It can be applied both in steel metallurgy and non-ferrous metals metallurgy processes. It gives the opportunity to determine the hydrodynamic conditions of the processes. Although, the flow of mass and gas is not totally presented by such modelling, this kind of research is very often and willingly used. That is because it is really difficult to conduct experimental research in industrial conditions. Typically water is used as a modelling agent, so the physical modelling is not as expensive as the one carried out in industrial conditions. To obtain representative research from physical modelling the physical models have to be built according to the strict rules coming from the theory of similarity. The results obtained from the experimental test on the physical model, after verification, can be transferred to the real conditions. The article shows the obatined results coming from physical modelling of the steel production process. In the Institute of Metals Technologies of Silesian University of Technology the appropriate test stand was built to simulate the steel flow and mixing in the ladle. The visualization results have been presented. To simulate processing condition during aluminium refining additional test stand was also built. The exemplary results have been shown for different flow rate of gas, rotary impeller speed and different shapes of impellers. All presented results have been discussed and presented for the perspectives of further research.

Selective Recovery Of Copper From Solutions After Bioleaching Electronic Waste

Abstract Research on selective extraction of copper from solution after bioleaching grounded printed circuit boards (PCBs) using LIX 860N-IC were conducted. The effect of LIX 860N-IC concentration, phase ratio and influence of initial pH value of aqueous phase on the extraction of copper and iron was examined. It was found that the extraction rate of copper increases with the LIX 860N-IC concentration. Best results of Cu extraction (98 %) were achieved with extractant concentration of 5 % and pH 1.9. Higher pH value of aqueous phase (pH=2.4) is conducive to the simultaneous effect of Fe co-extraction.

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

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.

Corrosion Resistance of ZnAlMg Alloys for Batch Hot Dip Galvanizing

In the paper the results of corrosion resistance tests on ZnAlMg alloys used as batch hot dip galvanizing baths are presented. The tests were carried out on ZnAl alloys with 7 wt.% Al with the addition of 3 wt.% and 6 wt.% Mg. Corrosion resistance of tested alloys was compared with corrosion resistance of the traditional zinc bath alloy. Corrosion resistance of the alloys was defined by comparative methods in two standard corrosion tests in neutral salt spray and in moist atmosphere containing SO2. Electrochemical parameters of the corrosion process were determined on the basis of potentiodynamic tests. It was determined that the alloy of ZnAl7 has better corrosion resistance than the corrosion resistance of the alloy of a traditional zinc bath and that the addition of Mg to the alloy increases the corrosion resistance.

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

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.

Hydrodynamics of the Aluminium Barbotage Process Conducted in a Continuous Reactor

Today aluminium obtained from ores (primary) and from scrap (secondary) need to be refined. During this process harmful impurities such as hydrogen, sodium, lithium, oxides, borides or carbides can be removed. There are many different ways of aluminium refining process. The most popular seem to be barbotage that means blowing through aluminium many tiny gas bubbles of refining gas. Reactors applying this methods have been working all over the word. They are of different types: bath and continuous, using ceramic porous plugs, special kinds of nozzles or rotary impeller for generating small gas bubbles. At present reactors for continuous refining have become the most popular. In Poland typical representative of such reactors is URC-7000 reactor. The phenomena occurring during this process are rather complicated. Therefore to know them better the modelling research is applied, especially physical modelling. The paper presents the results of such a research. The tests were carried out in the test stand for modelling the babotage process in the URC-7000 reactor. The different modelling agents were tested (water, glycerin and mixture of water and glycerine). The density and viscosity of water and glycerin mixture were determined. Modelling tests were conducted for four different flow rates of refining gas: 6, 10, 15 and 20 dm3/min. Results were registered by digital camera. Pictures for different modelling agents were juxtaposed and discussed.

Numerical and Physical Modelling of Aluminium Refining Process Conducted in URO-200 Reactor

At present both primary and secondary aluminium needs to be refined before further treatment. This can be done by barbotage process, so blowing small bubbles of inert gas into liquid metal. This way harmful impurities especially hydrogen can be removed. Barbotage is very complex taking into consideration hydrodynamics of this process. Therefore modelling research is carried out to get to know the phenomena that take place during the process better. Two different modelling research can be applied: physical and numerical. Physical modelling gives possibility to determine the level of gas dispersion in the liquid metal. Whereas, numerical modelling shows the velocity field distribution, turbulent intensity and volume fraction of gas. The paper presents results of physical and numerical modelling of the refining process taking place in the bath reactor URO-200. Physical modelling was carried out for three different flow rate of refining gas: 5, 10 and 15 dm3/min and three different rotary impeller speeds: 0, 300, 500 rpm Commercial program in Computational Fluid Dynamics was used for numerical calculation. Model VOF (Volume of Fluid) was applied for modelling the multiphase flow. Obtained results were compared in order to verify the numerical settings and correctness of the choice.