Copper reduction represents one of the steps in the process of fire refining of blister copper. Process of copper reduction with natural gas as performed in the anode furnace was modeled. Numerical analysis was conducted using the IPSA (Inter- Phase-Slip Algorithm) module of PHOENICS package and standard turbulent model k - ε. The model takes into account the liquid phase - slag and phase of natural gas which is supplied through the tuyere from the bottom of the charge. Calculations were made for two different diameters of tuyeres for supply of reducer. Based on the calculations and analysis, it was found out that the gas flow which causes strong movement in the bath guarantees homogeneous composition of the liquid copper in each process stage. Application of a tuyere with a larger diameter results in a greater intensity of the reduction process and better use of the reducer.
W artykule omówiono rezultaty obliczeń procesu bezpośredniego dopalania gazów po redukcji miedzi w piecu anodowym PAO. Do symulacji wykorzystano oprogramowanie numeryczne CFD openFOAM w wersji 1.7.0. Skład atmosfery gazowej porównano dla pieca bez wprowadzonego układu dopalającego oraz po modyfikacji poprzez doprowadzenie lancy dopalającej w przestrzeń gazową pieca. Rezultaty przeprowadzonych obliczeń wskazują zmniejszenie udziału tlenku węgla w wyniku wprowadzenia dyszy dopalającej o ok. 50 % objętościowych. Modelowanie numeryczne umożliwia wcześniejsze ustalenie miejsca i sposobu doprowadzenia strumienia utleniacza bez negatywnego wpływu na przebieg procesu redukcji.
EN
In modern metallurgical processes should be taken into account factors related to the negative impact of installation on the environment. Often, reducing the environmental impacts of lead to additional effects deteriorating the performance of the system. Proper modification of processes with high energy intensity in a small impact on improving the technology while allowing the energy intensity indicators. Formed in the process of reduction of gaseous pollutants such as carbon monoxide are a valuable component of the fumes. Skilful carry them through chemical conversion into substances with less negative impact on the environment to avoid rapid wear of the combustion installation sequence. In the presented paper was analyzed the impact of application of the internal combustion using oxygen nozzle on the concentration of this com-pound in the area of the PAO anode furnace. The study was conducted by numerical calculations using the procedures and computational fluid dynamics and software openFOAM in version 1.7.0. The composition of gaseous atmosphere was compared to the furnace not equipped with an afterburning of carbon monoxide and after modification by bringing the flow of oxygen by afterburning lance. Figure l and Table l presents the main assumptions for the numerical calculations and construction equipment. CFD modeling included a gas space in the furnace above liquid material input. In the calculations was used a global model of afterburning of CH4 and CO with adopted intermediate compounds using the Jones-Lindstedt mechanism. Simulation was based on the substantial streams introduced into the furnace (Table 3) and the atmospheric composition of gases from the raised-bed reactor (Table 4). Distribution of afterburning nozzle has to respect the conditions and limitations of the processes carried out in the device. Mainly it was not to interfere in the reducing zone of gases layer above the liquid bath. For the assumed state of operation, it was found that the nozzle reduces the volume fraction of carbon monoxide in the exhaust gases leaving the furnace chamber with 8+12 % to about 5 %, so it is possible to reduce the volume fraction of the component an average of 50 %. It was found that the axis of the nozzle flowing stream of oxygen maximum reacts to a length of 3 m along the axis from the front burner, which translates to about 1.03 meters. above the roof of the furnace. This distance indicates that the gas dynamics of the main stream of afterburning does not interact directly with the surface of molten metal. Modelling also showed that after the introduction of the nozzle directly over the entire bath, the gas mixture has reductive nature what indicating no impairment reductive atmosphere above the bath.
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