Research And Practice On Converter Negative Energy Steelmaking At Steel-making Plant, Kunsteel

The energy conservation and environmental protection effects very important functions for sustainable development of iron and steel industry in 21st century. The core concepts of negative energy steelmaking (NES) are to solve the series problems concerning with the recovery and effective utilization of converter gas and steam. Directed towards how to realize NES at converter steelmaking section, recourse to the theoretical achievement and practical experience of NES in iron and steel industry at home and abroad, NES has been firstly achieved at converter section, steelmaking plant, Kunming Iron and Steel Company (KISC). Which not only created much more economic returns, social efficiency and environmental benefits for KISC, but also laid a solid foundation for carrying out NES at all steelmaking sections in next stage.Beginning with the analysis of the key technologies of realizing converter NES and the situation of energy consumption and recovery at converter section of KISC, this research project focuses on improving converter gas and steam recovery, which dominates the energy recovery constitution, and on reducing the coke oven gas (COG) and oxygen consumption, which governs the energy consumption composition. Directing to the problems concerning with the recovery and effective utilization of converter gas and steam, various factors influencing converter gas and steam recovery have been analyzed in great depth. Countermeasures such as optimizing smelting process, completing the software and hardware facilities, improving recovery methods and operation, elevating raw materials quality, etc. have been taken, at the same time coupled with both technological and administrative means of energy conservation, with improvement of gas pipeline network arrangement. The ultimate objectives are to fully and rationally utilize converter gas, and reduce COG consumption. Based on the theoretical research and the production practice, NES has finally been achieved at converter section, steelmaking plant, KISC, notable economic, social and environmental benefits have thereby been produced.The NES practice at KISC started in 2006. The average converter process energy consumption indicator was steadily decreased, which were-0.538,-4.024,-5.39kgce/t in 2007, 2008,2009 respectively. By 2009, the converter gas recovery of steelmaking plant was by and large in a stable state. Substantial development has been made of converter gas recovery since then. The gas recovery level is largely in a leading position in same type domestic steel plants. On the basis of three years of research and practice, remarkable effects of economic, social and environmental benefits have been achieved. Taking the energy consumption indicator of steelmaking plant in 2009 as the base number, a profit of RMB 29.89 Yuan per ton product was obtained. With total output 3,265,800 tons, the direct economic benefit was RMB 97.6148 million Yuan. Meanwhile, the main technical and economic indicators of the steelmaking plant have steadily promoted. The specific indicators of ferrous charges consumption, the amount of gas recovery, oxygen consumption, slag charges consumption and converter process energy consumption have all been improved.