The coal injection system is an important part of the ironmaking production process. Coal powder smelting has the advantages of significantly reducing coke ratio, improving economic benefits, and reducing environmental pollution. Currently, coal injection technology is developing towards high injection rate and dense phase transportation. Under the premise of high injection rate and dense phase transportation, how to stably, evenly, and accurately adjust the coal powder injection rate and increase the coal coke ratio is to maintain furnace stability and ensure smooth operation of the furnace, One of the basic prerequisites for achieving a better smelting state of the blast furnace.

In July 2020, our company collaborated with Xinda Iron and Steel to complete the blind spot fluidized side discharge process transformation project (blast furnace coal injection process optimization transformation project), which has been successfully put into operation in the No. 2 furnace of the Ironmaking Plant. It is understood that since its operation for one month, the coal output of the 2 # blast furnace has been evenly and continuously fluctuating, and the nitrogen and air consumption has shown a significant downward trend compared to the past. The hourly coal injection rate has increased from 28 tons to 34 tons, and there has been a peak of 38 tons/hour. This project not only effectively reduces the coke ratio, but also alleviates the current tight fuel supply situation, and can save 5.1 million yuan in total annual costs for ironmaking.

Recently, the 5 # blast furnace also passed the acceptance inspection. This project mainly renovates the fluidized bed at the bottom of the spray tank. The self-developed fluidized bed is made of high-tech and high-performance stainless steel sintered wire mesh, which is characterized by high mixing resistance, tensile corrosion, high mechanical strength, high rigidity, long service life, high accuracy of hole tracking, uniform airflow distribution, and small loss of positive force. After the transformation, the fluidization effect is good, the coke ratio is significantly reduced, and the furnace condition is stable and smooth. This has found a new way for energy conservation and consumption reduction in ironmaking, and has great promotion value.

The successful operation of the blind spot fluidized side discharge project (blast furnace coal injection process optimization and transformation project) is an important equipment transformation project implemented by Xinda Steel in the ironmaking field and a key energy-saving transformation project that is fully promoted. It has also made our company a huge success in the optimization and improvement of blast furnace coal injection process, becoming a leader in this field. The subsequent 6 # blast furnace renovation is ongoing.