Ironmaking plant dust removal technology

In recent years, with the rapid development of blast furnace ironmaking technology and its continuous advancement towards automation, large-scale and high efficiency, with the goals of low cost, low consumption and low pollution, ironmaking plant dust control has also become a key task in the construction of ecological civilization.

What is blast furnace ironmaking?

Blast furnace ironmaking refers to the production process of smelting pig iron using a blast furnace. The blast furnace is the main body of the process. The iron ore, fuel and solvent loaded from the upper part move downward, and the air-fuel is blown into the lower part for combustion, producing a large amount of high-temperature reducing gas and moving upward; the charge is heated, reduced, melted, and manufactured. A series of physical and chemical processes such as slag, carburization, desulfurization, etc. finally produce liquid slag and pig iron.

Sources of blast furnace ironmaking dust

The main dust in blast furnace ironmaking comes from the taphouse and raw material system.

The pollutants generated by the blast furnace are the smoke and dust generated by the blast furnace when tapping iron and slag, and the smoke and dust generated by high-temperature molten iron and other combustible materials in contact with the slag furnace. For every ton of iron produced by the blast furnace, an average of 2.5 emissions are emitted in the taphouse. tons of smoke and dust, among which the smoke and dust generated by the iron ditch, slag ditch, slag collector, swing nozzle and hot metal tank during normal tapping belong to primary smoke, accounting for 86% of the total smoke.

The smoke generated when the taphole is opened and blocked is secondary smoke, accounting for 14%. The temperature of the smoke in the taphouse is generally 70-200°C. The particle size of soot generally accounts for 50-60% below 10 microns. The content of Fe2O3 in soot is 49.4%, the content of SIO2 is 10.97%, and the carbon content is 15.49%.

The main places where dust is generated in the blast furnace system include the unloading on the trough, the rotation of the belt conveyor, the screening under the trough, the loading of raw and fuel into the feeder, the collecting hopper, etc. The concentration of dust is 5-8g/m³. National standards require that belt conveyors be used above and below the ore trough. All transfer stations, the material receiving opening on the trough and the screening facilities under the trough should be equipped with dust collector purification devices. When a belt conveyor is used to load materials to the furnace top, a separate dust removal device should be installed. , requiring the content of all dust-containing gases emitted after dust removal to be less than 50 mg/m³, and the dust content of the air in the working environment to be reduced to 10 mg/m³.

Dust in the raw material system generally comes from the dust removal from the ore trough in front of the furnace in the ironmaking plant. It mainly includes harmful dust generated during the transfer, unloading, feeding and loading of blast furnace sinter, coke, miscellaneous ore and other raw materials and fuels.

 

furnace dust remove

 

Main dust removal technologies in iron smelting plants

Dust removal at the cast house:

At present, the primary smoke collection and treatment in the tapyard mainly uses dust covers at the parts where smoke is generated, such as tapholes, iron trenches, slag trenches, etc., and then uses fans to remove the smoke, and the smoke enters the bag through the pipe. Use a dust collector or electrostatic precipitator for purification, and the purified gas concentration is less than 50mg/m³.

Secondary dust collector systems generally use the following three types of treatment devices:

1) Natural ventilation air curtain type, that is, the entire roof is regarded as a universal hood with ventilation curtain fans installed around it;
2) Curtain type, there is a ventilation channel composed of movable curtains to pump dust into the dust collector;
3) Set up decentralized collection systems at various dust-generating points at the tapholes, and conduct unified exhaust and dust removal.

Although the treatment technology for dust removal in the cast house is relatively limited due to the high-temperature limit, with the development of the industry and technology, the treatment technology is also constantly improving, mainly focusing on two parts, including the method of cooling and reprocessing this part of dust. It also includes the research and development of high-temperature-resistant treatment materials and products.

At present, in addition to bag dust collectors, cartridge dust collectors are also used in some steel companies. This type of dust collector uses various cylindrical pleated filter materials, which can achieve efficient absorption of dry dust particles, and the dust removal efficiency is much higher than that of traditional bag dust collectors. device, greatly reducing the emission of harmful substances.

Dust removal of the raw material system:

The fundamental measure for dust control in this part of the waste gas is to strictly control the powder content of blast furnace raw materials and fuels, especially the powder content of the sinter.

In addition, airtight covers and exhaust dust removal systems can be set up for equipment with different dust generation points. The airtight covers can be partial airtight covers (such as belt conveyor transfer points), overall airtight covers (such as vibrating screens) or large-capacity airtight covers (such as vibrating screens) according to different situations. For example, at the material pit of the loading trolley), the dust collector can be a bag dust collector, etc.

Dust control in the raw material system generally uses an exhaust hood, a sealing hood or a combination of both to pump the dusty air through the pipe to the dust collector for purification, and the purified flue gas is discharged into the atmosphere through the chimney.

Choose appropriate dust control methods according to different conditions of the factory, so as to meet the new ironmaking plant emission standards and reduce atmospheric pollution.

 

DBM Metallurgical Casting Dust Removal System >>>

Leave a Reply

Your email address will not be published. Required fields are marked *

With machine vision as the core, DBM can provide intelligent equipment R&D, manufacturing, and transformation services such as unmanned factories in the metallurgical industry and other industries, machine vision, and robot application design.

Product category

Customer testimonials

Tell us your needs and a technician will contact you immediately.

Friendship Link

We are committed to becoming a “leader in visual applications”, advocating the core values of “integrity, cooperation, innovation, expertise, and excellence”, taking the road of “technology shaping the brand, innovation leading the industry”, and attaching importance to the investment in scientific research and technology. The research and development of new products and the construction of the team make unremitting efforts for the goal of scientific and technological development.

We have been supplied to world’s top steel manufacturer Arcelormittal, TATA Steel, EZZ steel etc. We do OEM for Concast and Danieli for a long time

Metallurgical Intelligence
Change the way of manufacturing

Save labor, improve working environment, improve efficiency, reduce error rate and save cost!

Металлургический интеллект
Изменить способ производства

Сэкономьте труд, улучшите рабочую среду, повысьте эффективность, уменьшите количество ошибок и снизьте затраты!