What adsorbents does Steel Plant need

In the steel production, adsorbents are widely used, mainly for waste gas treatment and other processes. Adsorbents can effectively remove harmful substances and improve the cleanliness of the production environment. Below, we will make a detailed introduction to several commonly used adsorbents and their applications in steel production.

1、What is an adsorbent? Why is it so important in steel production?

Adsorbent is a solid material which can selectively aggregate specific substances (adsorbates) on its surface or pores through physical or chemical reactions. In the complex environment of high temperature, dust, and harmful gases in the steel industry, adsorbents are mainly used for:

* Purification and Separation: Removing impurities and harmful components from raw gas and liquid.

* Environmental production: Treat waste gas and wastewater generated during sintering, coking, ironmaking, and steelmaking processes to achieve standard emissions.

*Quality improvement: Remove harmful elements from the molten steel during the smelting process to improve the purity of the steel.

2、Types and application scenarios of adsorbents in the steel industry:

# Activated Carbon

Activated carbon is one of the most commonly used adsorbents in steel plant, with a developed pore structure and a huge specific surface area. It mainly relies on physical adsorption and can adsorb various harmful gases and impurities. In the treatment of steel plant exhaust gas, activated carbon is mainly used to adsorb harmful substances such as SO2 and CO2 in the flue gas, reduce the concentration of exhaust gas emissions, and meet environmental protection requirements.

The main purpose is to remove pollutants such as sulfur dioxide and heavy metals from flue gas, which is the core material for achieving ultra-low emissions.

# Activated alumina

Activated alumina is usually chosen as spherical, with high mechanical strength, good thermal stability, and extremely strong affinity for moisture. In the process of steel production, the main appliction are as follows:

*Gas drying: Used for deep drying of process gases such as compressed air, oxygen production systems, and blast furnace blowing to protect subsequent equipment from moisture corrosion.

*Fluoride removal: It is more widely used in the electrolytic aluminum industry, but it is also used in gas protection for certain special steel grades.

# Molecular sieve

Molecular sieves have a uniform microporous structure and are adsorbents with specific pore sizes that can selectively adsorb molecules based on their size. In steel plant, molecular sieve 13x are mainly used for gas separation and purification, such as separating oxygen, nitrogen, etc. from air. In addition, molecular sieves can also be used to remove impurities such as water and carbon dioxide, and improve gas quality.

*Deep drying and purification: Used for separating and purifying oxygen, nitrogen, hydrogen, CO gases, etc., removing trace amounts of water and CO2 from them.

*PSA oxygen/nitrogen production: used as the core adsorbent in pressure swing adsorption units, providing gas for steelmaking and blast furnace enrichment injection.

# Silica gel

Silca gel is an inorganic polymer material with strong adsorption properties. The moisture absorption capacity is slightly lower than molecular sieve zeolite, but silica gel has a cost advantage. In steel plant water treatment, silica gel is mainly used to remove harmful substances such as heavy metal ions and suspended solids in water, and improve water quality cleanliness. Meanwhile, silica gel can also be used for drying and moisture prevention, ensuring the normal operation of production equipment.

In summary, adsorbents play an important role in the production process of steel production, effectively removing harmful substances and improving the cleanliness of the production environment. Activated carbon, molecular sieve, activated alumina and silica gel are several commonly used adsorbents in steel production, each with their own advantages in different application scenarios. With the continuous improvement of environmental protection requirements, the application of adsorbents will become more widespread, providing strong support for the green development of steel mills.