Refining Combined Burner (RCB) Injection Technology for EAF

Key processes in the electric arc furnace include scrap (DRI) melting, refining and stirring the steel, and foaming slag formation. The Refining Combined Burner (RCB) injection technology, developed by Primetals Technologies, was designed to integrate these functions into a single tool. The latest injection technologies for oxygen, natural gas, and nitrogen are positioned close to the steel bath, enhancing the efficiency and safety of electric arc furnaces. The RCB technology supports the necessary processes for Quantum EAF, Ultimate EAF, and Standard EAF, and is also available as a standalone product.

The Refining Combined Burner (RCB) Injection technology is integrated into the water-cooled side wall, eliminating the need to open the slag door for injection purposes. This design minimizes energy losses and enhances process safety. The refining combined burner system operates in four distinct modes. In low fire mode during charging, the device is protected from slag and steel splashes. Burner mode supplies up to 3.5 MW of chemical energy in addition to electrical energy. This mode features a swirl nozzle that optimally mixes gas and oxygen, resulting in a stable flame with an ideal shape.

Lancing mode utilizes a supersonic O₂ stream to decarbonize the steel bath while binding unwanted tramp elements. For stainless steel production, a supersonic N₂ stream is used. The RCB's supersonic oxygen stream, surrounded by a protective flame, maintains a laminar flow to enhance efficiency and reduce splashes. Multi-point supersonic oxygen injection ensures strong bath stirring, promoting compositional and temperature homogeneity. Lastly, the combined use of RCB O₂ lancing and a separate carbon lance helps to build up foaming slag. This leads to increased metallic yield and protects panels and refractory from higher heat loads. The RCB Injection Technology is part of the automated steel production strategy by Primetals Technologies, with RCBs controlled via L1/L2 programs. Currently in development, the RCB burner mode will soon be ready for hydrogen and hydrogen/natural gas mixes.

Benefits of the electric arc furnace Refining Combined Burner (RCB) Injection Technology

• Additional injection system using chemical energy via side wall with closed slag door
• Oxygen, gas, and carbon injection technology close to the steel bath
• Preheating of scrap during melting
• Oxygen injection for decarburization
• Optimized flame shaping with swirl mix technology
• Improved efficiency of thermal and metallurgical processes
• Increase in productivity of up to 6%
• 15% decrease in electrical energy consumption
• 10% decrease in oxygen consumption
• 10% shorter tap-to-tap times