As an important pillar industry of national economy, iron and steel industry has complicated production process and involves many links. Blast furnace is the core equipment in steelmaking stage, its production flow and technology directly affect the quality and output of steel products. This paper will introduce the production process and technology of the blast furnace of the whole process steel plant in detail, and show it through graphic form to help readers better understand and grasp.

Overview of blast furnace production process

The blast furnace production process mainly includes raw material preparation, furnace cylinder distribution, ignition preheating, wind temperature control, smelting process, iron production and furnace shutdown. Each is described in detail below.

Detailed explanation of blast furnace production process

(1) Raw material preparation

Iron ore preparation: Iron ore is the main raw material for smelting hot metal, and its quality and particle size have an important impact on the smelting effect of blast furnaces. Iron ore needs to be crushed, graded, washed, etc., to ensure that it meets production requirements. The crushed iron ore should meet the particle size requirements to avoid the adverse effect of too large or too small particles on the blast furnace smelting.

Coke preparation: Coke is an important energy and reducing agent for blast furnace smelting, and its quality and quantity directly affect the smelting effect of blast furnace. Coke needs to be carbonized, calcined and mixed to improve its combustion efficiency and temperature in the furnace.

Limestone preparation: Limestone, as a flux, plays a role in reducing the melting point of slag and improving the fluidity of slag during the blast furnace smelting process. Limestone needs to be crushed, screened and other treatment to meet the production requirements.

(2) Furnace cylinder fabric

Furnace cylinder distribution means that the pre-prepared raw materials are put into the furnace chamber in a certain proportion. In the operation of blast furnace, it is necessary to consider the ratio of various raw materials and feeding methods to achieve the best smelting effect. Under normal circumstances, iron ore and coke are mixed in a certain proportion and loaded into the hopper at the upper part of the blast furnace, and then evenly distributed into the furnace cylinder through the distributing device.

(3) Ignition preheating

After the furnace cylinder is distributed, it is necessary to conduct ignition preheating operation. Ignition preheating refers to burning the raw materials in the furnace to gradually increase the temperature in the furnace to the temperature required for smelting. The ignition preheating process usually includes initial ignition, secondary ignition and normal ignition. In the operation of blast furnace, attention should be paid to controlling the ratio of oxygen and fuel for ignition to ensure the normal ignition.

(4) Wind temperature control

After the ignition is preheated, wind temperature control is required. In the blast furnace, energy needs to be provided by combustion, and wind is the key to providing the oxygen required for combustion. In the process of blast furnace operation, it is necessary to control the level of air temperature according to the requirements of smelting conditions. Under normal circumstances, the higher the temperature of the wind, the temperature in the furnace will also increase accordingly. By adjusting the air temperature, the temperature in the blast furnace and the rate of smelting reaction can be controlled.

(5) Smelting process

The smelting process is the core link of blast furnace production and the key step of steel production. In the blast furnace, iron ore is reduced to molten iron through a reduction reaction, and slag is produced. It is necessary to control the temperature, atmosphere, pressure and other parameters in the furnace during the smelting process to ensure the smooth progress of the smelting reaction. In addition, it is necessary to treat the slag to improve the utilization value of the slag.

(6) Iron production

Iron production is the ultimate goal of blast furnace operation and the last link in the smelting process. In the production process, the iron operation needs to be carried out regularly to extract the hot metal in the furnace, and carry out cooling and purification treatment. The iron operation needs to consider factors such as the temperature, speed and cleanliness of the hot metal to ensure the production of steel products that meet the requirements.

(7) Stop the furnace

When the operation cycle of the blast furnace is over or maintenance is required, the furnace shutdown operation is required. Shutdown refers to suspending the smelting process of the blast furnace for cooling, cleaning and maintenance. During the shutdown period, the blast furnace needs to be inspected, maintained and repaired to ensure the normal operation of the blast furnace and extend the service life.

Characteristics of blast furnace production technology

Blast furnace production has the characteristics of high temperature, high pressure and high energy consumption, so it is necessary to strictly control the parameters in the smelting process to ensure the smelting effect and product quality.

Blast furnace production adopts continuous operation mode, which has high production efficiency, but also puts forward higher requirements for equipment maintenance and operation level.

Waste such as slag and waste gas generated in the blast furnace production process needs to be properly disposed of to reduce environmental pollution and waste of resources.