Effect of Hydrogen Addition on Softening and Melting Reduction Behaviors of Ferrous Burden in Gas-Injection Blast Furnac
- PDF / 3,420,085 Bytes
- 11 Pages / 593.972 x 792 pts Page_size
- 116 Downloads / 181 Views
.
INTRODUCTION
THE energy-intensive iron and steel industry is responsible for approximately 6.7 pct of the total anthropogenic CO2 emissions across the world, according to the International Energy Agency.[1] The majority of these emissions (over 70 pct) are produced by iron-making blast furnaces (BFs), which also consume the largest amount of energy in the entire industry.[2] The traditional BF strongly relies on coke, which represents a large part of the production cost. Newly developed BF technologies focus on the utilization of various coke alternatives including natural gas, pulverized coal, plastic waste, biomass, coke oven gas, and other hydrocarbons.[3–12] However, the practical applicability of these materials strongly depends on the distribution of natural resources.[13] In addition, the top gas recycling blast furnace (TGR-BF) has attracted much attention in the recent decades due to its ability to
YANA QIE, QING LYU, XIAOJIE LIU, JIANPEN LI, CHENCHEN LAN, SHUHUI ZHANG, and CHAOJIE YAN are with the College of Metallurgy & Energy, Key Laboratory for Advanced Metallurgy Technology, North China University of Science and Technology, Tangshan 063009, China. Contact e-mail: [email protected] Manuscript submitted July 28, 2017.
METALLURGICAL AND MATERIALS TRANSACTIONS B
decrease both energy consumption and decrease the level of CO2 emissions.[13,14] For example, top gas recycling and tuye`re injection of oxygen were the primary methods used in the ULCOS project.[15] Nonetheless, the cost of CO2 capture in the TGR-BF can be as high as $56/tCO2.[16] Currently, pulverized coal injection (PCI) remains the main technique for decreasing the coke rate,[17] and the highest reported amount of injected coal is equal to approximately 250 kg/tHM (tons of hot metal), which is close to the amount of coke. However, the impact of the coal chemical properties must be also taken into account since they may prevent its complete combustion within the raceway, affect the gas permeability in the shaft, and contaminate the dead man zone, leading to irregular operation of the furnace and decreasing its productivity.[14,18] The gas-injection BF is a new iron-making technology that allows injecting gas into tuye`res and recycling the top gas through a gasifier, which serves as a new gas source and effectively converts CO2 in the BF top gas into CO at a relatively low cost. As compared with the traditional BF with PCI, the gas-injection BF can potentially simplify the iron-making process and recycle the BF top gas, thus decreasing CO2 emissions and increasing the furnace productivity. The utilized process consists of the following steps: BF top gas is injected into the gasifier as the gasifying agent fi coal
gasification occurs in the gasifier fi H2-rich gas is produced fi H2-rich gas is heated using the gas heating device fi the high-temperature gas and hot air are injected into the furnace through the tuye`res (Figure 1). In addition, inferior coal of high-volatile can be utilized in the gas-making process, which not only decreases the depen
Data Loading...
