What is the technological process of sintering workshop in iron and steel plant?

Sintering is a processing method to provide "concentrate" for blast furnace smelting. Its essence is to prepare all kinds of raw materials (concentrate, mineral powder, fuel, flux, returning ore and iron-containing production waste, etc.). ) mixing and granulating according to a certain proportion to obtain the required sinter.

Sintering process

When preparing inorganic solid compounds by solid-state reaction, the reaction rate is controlled by diffusion process, and high temperature is often needed to make the reaction effective. Other solid compounds are composed of solid phase and liquid phase, which will decompose when melting, so sintering should generally be carried out at a temperature below the melting point of the product to ensure a uniform phase.

But the sintering temperature should not be too low, otherwise the solid-state reaction rate will be too low. In many cases, sintering needs to be carried out in a specific atmosphere or vacuum. It is very important to control the partial pressure of gas phase in the sintering process, especially when the studied system contains valence-changing ions, the partial pressure of gas phase in the solid-state reaction will directly affect the composition and structure of the product.

For example, in the synthesis of copper-based oxide high-temperature superconductors, the oxygen partial pressure must be strictly controlled in the sintering process to ensure that superconducting materials with definite structure, composition and copper state distribution can be obtained.

Before blast furnace ironmaking production, all kinds of powdery iron-containing raw materials are mixed with appropriate amount of fuel and flux, and appropriate amount of water is added. After mixing and granulating, the material undergoes a series of physical and chemical changes on the sintering equipment and is sintered into blocks. Belt exhaust sintering machine is widely used in the production of sinter. It mainly includes the preparation of sintering raw materials, blending, sintering and product treatment.

Extended data

The temperature in the sintering process is called sintering temperature, and the temperature range between sintering temperature and starting overburning temperature is called sintering temperature range. If the sintering temperature and sintering temperature range continue to increase during the sintering process, the green body will begin to deform, soften and burn, which will lead to sintering accidents.

Hazard sources: high temperature, dust, high-speed mechanical rotation, toxic and harmful gases and logistics injuries, aerial work and other hazards;

Accident types: mechanical injury, falling from a height, object strike, lifting injury, burn, electric shock, poisoning and pneumoconiosis;

Cause of the accident: equipment defect, technical process defect, protective device defect, bad working environment, imperfect rules and regulations, and illegal operation.