It is really hard to determine the phenomena occurring during aluminum refining process using argon blowing through the liquid metal in industrial conditions. The solution of such problem is physical ...modelling. This kind of modelling gives possibility to determine the level of dispersion of the refining gas in liquid metal. Especially in steel metallurgy RTD (Residence Time Distribution) analysis and visualization process with some colour tracer, which can give extra information about time of mixing are very popularly used. Because the modelling research (especially visualization) is pictorial, the research was conducted to check if it is possible to estimate quantitatively impeller working effectiveness basing on determination of the RTD curves. The examined object was model of URO-200 batch refining reactor. The RTD curves was registered and discussed for three different impellers and four different variants of processing parameters (rotary impeller speed: 300-500 rpm, and gas flow rate: 15-20 l·min–1). Additionally, the process of mixing of the inert gas with water as a modelling agent was enabled to be observed due to introduction of colour tracer (KMnO4). Results obtained from both measuring methods were graphically presented, compared and shortly discussed.
Due to the need to improve the quality of the produced steel, especially its metallurgical purity, attempts are made to use inert gas bubbling curtain in the tundish. The article presents the results ...of the research of metal-slag interaction carried out with the use of the trough-type two-strand tundish water model, made on a reducing scale – 1 : 2,5. The tundish model is built with two gas bubbling curtain. The aim of the research was to determine the optimal value of the flow rate of the blown gas, ensuring the safe course of the process taking into account the secondary contamination of liquid steel with atmospheric gases and endogenous inclusions originating from the slag.
The increase in market demand for small masses of special purpose steel forces its producers to use the technique of continuous casting with a transition zone. The article presents the results of ...model tests of limiting the range of the transition zone as a result of the use of an impact pad and changes in the volume of liquid steel in the tundish. A water physical model of a Continuous Steel Casting (CSC) device equipped with a two-outlets tundish was used for the research. The criterion for assessing the range of the transition zone was the value of the minimum time of complete mixing tome of the tracer in the modeling liquid, determined on the basis of the Residence Time Distribution (RTD) curves. Visualization techniques of the modeling liquid mixing process were used to identify hydrodynamic phenomena.
The article presents the results of the CFD simulation of the method of medium flow and mixing, as well as the movement and removal of solid particles in the model of two-strand tundish as a result ...of installed internal arrangement. Two variants including turbulence inhibitor and impact pad with a ball cutting area were modeled for the tests. CFD simulations are a continuation of previous tests with the use of the physical water model of the continuous steel casting (CSC) device.
One of the primary factors affecting the quality of continuously cast billets is the way the steel flows and mixes in the tundish of Continuous Steel Casting (CSC) machine. This is of particular ...importance in the case of continuous billets. The article presents the results of model tests of identifying the mechanism of liquid steel flow through a tundish under the influence of the applied arrangement of the working space. Two models of turbulence inhibitors and an impact pad with the surface of a sphere segment were used for the research. The tests were carried out with the use of the physical water model of the CSC device, and the obtained results were verified by numerical methods.
The refining process is essential for the removing undesirable hydrogen and harmful impurities from liquid aluminium and its alloys. Physical modelling allows to observe the level of refining gas ...dispersion in the liquid aluminium. Test stand for physical modelling of the barbotage process of aluminum for the bath reactor (URO-200) and continuous reactor (URC-7000) were built. Measurements of the oxygen removal from water were carried out as analogy of the hydrogen desorption process from liquid aluminium. In the research the distilled water saturated with the compressed oxygen was used. The level of water saturation with oxygen and then oxygen desorption from water was reached by means of the dissolved oxygen meter Elmetron CO-401.
This paper presents possibility of removing platinum from the used catalytic converters applying copper as a metal collector in pyrometallurgical methods. The catalytic converter carrier was grinded ...and melted with copper. During the research obtained Cu-Pt alloy was casted as an anode. Such anode was electrically refined in order to recover platinum. Obtained results were discussed.
Purging the liquid steel with inert gases is a commonly used treatment in secondary metallurgy. The main purposes for which this method is used are: homogenization of liquid steel in the entire ...volume of the ladle, improvement of mixing conditions, acceleration of the absorption process of alloy additives and refining of liquid steel from non-metallic inclusions. The basic processing parameters of this treatment are: gas flow rate and the level of gas dispersion in liquid steel. The level of gas dispersion depends on the design and location of the porous plug in the ladle. Therefore, these parameters have a significant impact on the phenomena occurring in the contact zone of liquid steel with slag. Their improper selection may cause secondary contamination of the bath with exogenous inclusions from the slag, or air atmosphere due to discontinuity of the slag and exposure of the excessive surface of the liquid steel free surface. The article presents the results of modelling research of the effect of liquid steel purging with inert gases on phenomena occurring in this zone. The research was carried out using the physical (water) model of steel ladle. As a modelling liquid representing slag, paraffin oil was used, taking into account the conditions of similarity with particular reference to the kinematic viscosity. The results of the conducted research were presented in the form of visualization of phenomena occurring on the surface of the model liquid free surface in the form of photographs. The work is a part of a bigger study concerning modelling of ladle processes.
New technologies and the globalization of the electrical and electronic equipment market cause a continuous increase in the amount of electrical and electronic waste. They constitute one of the waste ...groups that grows the fastest in quantity. The development of the new generation of electrical and electronic devices is much faster than before. Recently attention has been concentrated on hydrometallurgical methods for the recovery of metals from electronic waste. In this article the role of an oxidizing agent, mainly ozone and hydrogen peroxide was presented in hydrometallurgical processes. Leaching process of printed circuits boards (PCBs) from used cell phones was conducted. The experiments were carried out in the presence of sulfuric acid and ozone as an oxidizing agent for various temperatures, acid concentration, ozone concentration. As a result, the concentrations of copper, zinc, iron and aluminum in the obtained solution were measured. The obtained results were compared to results obtained earlier in the presence of hydrogen peroxide as an oxidizing agent and discussed.
The article draws attention to recently conducted research of bacterial leaching of metals from various polymetallic waste. These wastes are the carriers of valuable metals: base metals, precious and ...platinum group metals (e.g. electronic waste, spent catalysts) or rare earth elements.
