Application of the submerged nozzles for rotary furnace firing – modeling studies

The temperature distribution in the rotary furnace used in copper metallurgy was modeled based by the numerical calculation method. The CFD (Computational Fluid Dynamics) numerical calculation methods are the effective tools for process optimization (increasing efficiency and improving the economics) due to the rapid ongoing progress in hardware quality as well as the calculation technique itself. The heat exchange model was prepared based on the rotary anode furnace and the converter type rotary furnace. The rotary anode furnace is used to refine the blister copper from the direct-to-blister flash furnace and the converter copper from refining of CuPbFe alloy. The converter was used to reduce the converter slags coming from CuPbFe alloy treatment. The firing process in the anode rotary furnace was modeled to reduce the fuel consumption. The average temperatures of the copper charge and the uniformity of the temperature field for the furnace fired conventionally and using the submerged nozzles was calculated based on the heat exchange model for the anode rotary furnace. Based on the calculations and the analysis it was claimed that using the submerged nozzles together with the gas burner allow reduction of the fuel consumption and improve uniformity of temperature field within the bath. For the converter type furnace, the heat exchange was modeled for the process of converter slag reduction. The temperature distribution in the furnace was modeled particularly focusing on the slag temperature. The analysis also includes the influence of the method of gas supply by changing the number of the nozzles on the reduction process. It was concluded that the nozzles used as the submerged burner allow a higher charge temperature for the same amount of gas. The higher number of the nozzles used in the converter slag reduction process resulted in an increase of temperature of the reduced slag and improved the uniformity of the charge heating.