Cradle to Gate
Identity ID
7e01990d-333d-477a-a6d4-db6588d30341
Materials
Associated ID
bf4ad923-6fa5-49b5-aabe-1f366099228e
Included activities starts
Included activities ends
Description
The product represented by this dataset is direct reduced iron, a key intermediate product of the short-process route in steel production. Its production does not rely on coke and blast furnaces and has significant low-carbon potential. The upstream key raw materials are pellets and reducing gas, and downstream it is mainly used in electric arc furnace steelmaking. The core feature of this dataset is its use of a diversified, low-carbon reducing gas system composed of natural gas, coke oven gas, and hydrogen. The system boundary covers the entire process from the entry of pellets and the three gaseous raw materials into the shaft furnace reduction system, through gas treatment, shaft furnace reduction, and product cooling and handling, until the output of qualified DRI product. Specifically, it includes the consumption of all main raw and auxiliary materials (iron ore, the three gases, cooling medium) and energy (electricity and the chemical energy of the fuel gas itself) in the above processes, as well as the waste gas and dust generated in the process. The dataset includes the main raw and auxiliary materials, energy, and waste in the production process; infrastructure such as the manufacturing of production equipment and the construction of plants is not included within the dataset boundary. The data inventory is formed by merging data from multiple sources.
Activity Description
This data set covers the entire process of producing direct reduced iron (DRI) in a shaft furnace starting from pellets and using a mixed reducing gas composed of natural gas, coke oven gas and hydrogen. The main inputs are pellets, natural gas, coke oven gas, hydrogen, cooling gas and electricity; the main outputs are direct reduced iron (DRI) products, as well as processed process waste gas and dust. The main process units include in sequence: preheating and charging of raw materials; mixing, reforming (if necessary) and heating of three reducing gases; countercurrent reduction reaction of mixed reducing gas and iron ore in the shaft furnace; cooling, unloading and subsequent processing (such as hot briquetting) of the reduction products.
Process Description
Direct reduced iron (DRI), also known as sponge iron, is a solid metallic iron product obtained by direct reduction of high-grade iron ore (pellets or lumps) using a gaseous reducing agent in a non-melting state. Its main component is metallic iron (Fe), with a content typically ranging from 85% to 95% (metallization rate), and it contains a certain amount of residual iron oxide and gangue. The carbon content can be regulated over a wide range (0.5%–4%). The product is in the form of a porous solid mass. It is a high-quality raw material for electric furnace steelmaking, particularly suitable for producing high-grade special steel, and can also be used as a coolant or supplementary iron source in blast furnace ironmaking.
Time period
2023
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The core technology of the production process is the gas-based shaft furnace direct reduction process, which is characterized by the use of mixed reducing gas. The process unit is described in detail as follows: First, natural gas, coke oven gas and hydrogen are mixed in a certain proportion, and whether reforming is required is determined based on the composition of the mixed gas (part of the methane or higher-order hydrocarbons is converted into H₂ and CO through catalytic reforming). After the mixed gas is heated to about 850°C~950°C, it is injected from the reduction section in the middle of the shaft furnace, and undergoes a countercurrent reduction reaction with the iron ore (pellets or lumps) moving from top to bottom. The main reducing agents are H₂ and CO. After dust removal, dehydration, and CO₂ removal (such as supporting carbon capture), most of the furnace top gas is recycled together with the supplementary fresh mixed gas. The reduced sponge iron is cooled by cold gas in the lower part of the furnace and then discharged. This technology combines the advantages of multiple gases: hydrogen reduction is fast and clean, and is the key to deep deoxygenation; coke oven gas is rich in H₂ and CO, and contains small amounts of CH₄ and CO₂, which can be used as an effective supplementary reducing gas and carbon source; natural gas is used as a basic reducing gas source and a supplementary carbon source. This multi-gas source mixing technology represents one of the current frontier directions in the transformation of gas-based direct reduction to low-carbon, hydrogen metallurgy. It has the characteristics of flexible raw material adaptability and can gradually increase the proportion of hydrogen to reduce carbon emissions. Currently, this specific mixed gas combination technology is still in the demonstration or specific regional application stage globally (such as utilizing locally enriched coke oven gas resources). It is an important transition and innovative technology between traditional natural gas shaft furnaces and future pure hydrogen shaft furnaces. This data set represents this type of forward-looking mixed gas-based shaft furnace reduction technology.