Using Physical Modeling to Optimize the Aluminium Refining Process

Abstract

Concern for the environment and rational management of resources requires the development of recoverable methods of obtaining metallic materials. This also applies to the production of aluminium and its alloys. The quality requirements of the market drive aluminium producers to use effective refining methods, and one of the most commonly used is blowing an inert gas into liquid aluminium via a rotating impeller. The efficiency and cost of this treatment depends largely on the application of the correct ratios between the basic parameters of the process, which are the flow rate of the inert gas, the speed of the rotor and the duration of the process. Determining these ratios in production conditions is expensive and difficult. This article presents the results of research aimed at determining the optimal ratio of the inert gas flow rate to the rotary impeller speed, using physical modeling techniques for the rotor as used in industrial conditions. The tests were carried out for rotary impeller speeds from 150 to 550 rpm and gas flow rates of 12, 17 and 22 dm3/min. The research was carried out on a 1:1 scale physical model, and the results, in the form of visualization of the degree of gas-bubble dispersion, were assessed on the basis of the five typical dispersion patterns. The removal of oxygen from water was carried out analogously to the process of removing hydrogen from aluminium. The curves of the rate of oxygen removal from the model liquid were determined, showing the course of oxygen reduction during refining with the same inert gas flows and rotor speeds mentioned above.

Comparison of Degassing Efficiency on a Foundry Degassing Unit Using Different Rotor Types

“…To a certain extent, these findings are confirmed by the results of [41][42][43], where the authors performed physical modelling of the aluminium melt refining process with various flow rates of the refining gas and rotor revolutions. As shown by the results, the oxygen content in the water decreases with increasing gas flow only up to a certain value.…”

“…Physical modelling was carried out as part of research focused on optimization of the refining technology used at the foundry MOTOR JIKOV Slévárna a.s. with the aim to improve the aluminium casting quality [12,42,45]. Several rotors of different shapes were studied during the modelling process.…”

Assessment of refining efficiency during the refining cycle in a foundry degassing unit in industrial conditions

“…The aim of the experiments was to verify the technological parameters of the rotors, designed on the basis of physical modelling and the operational experience of technologists from MOTOR JIKOV Slévárna a.s. (Die-casting division). As part of physical modelling 22 , a number of variants of technological parameters were proposed and tested, which fell within a relatively wide range. Due to the time-consuming nature of conducting operational tests, only those variants whose application in operational conditions is realistic were selected.…”

“…In highly stirred reactors, the behaviour and mechanism of gas bubbles as well as the hydrodynamic field are complicated 21 . The hydrodynamic field is characterized by turbulence and an uneven rate of energy dissipation and the presence of vortices moving in different directions 22 . This means that the bubbles in such systems are exposed to various internal and external forces that lead to their rupture 23 .…”

The Benefits of Using an Advanced Material for Production of Spherical Impact Pad for Tundish

“…These formulations exhibited increased resistance to corrosion induced by cast steel. [5][6][7][8]. IPC TECAST BPV CST was made, which is a new advanced technology of cement-free castables bound with a binder based on the sol-gel method [1][2][3].…”