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Cleaner than city air


thyssenkrupp starts operation of the world’s biggest fabric filter for the sintering process

The start-up of the world’s biggest and most advanced fabric filter for sinter production is a big step forward for the environment.
The start-up of the world’s biggest and most advanced fabric filter for sinter production is a big step forward for the environment.

Dust has no chance

Why would a steel producer need more than 44,000 extremely fine filter bags, each almost three meters long and with a total fabric area of 45,000 square meters? To filter out almost 100 percent of the dust generated during the production of sinter and thus improve the environmental situation in Duisburg. From commodity to high-tech: Sinter is used in the production of all steel products. The new fabric filter at thyssenkrupp Steel Europe is not only the biggest in the world, it is also the most efficient, capturing even the finest particulates. Its construction was a project of superlatives.

“That was a real mammoth project”

He’s not easily impressed: After all, processing enormous volumes of raw materials is part of his daily work. But looking at the gigantic pipe sections for the stack – almost too big to be transported by ship – and the vast amounts of filters, cables and motors used in the fabric filter, even Carsten Rokitt was lost for words – almost. Watch this video to see what Rokitt, who is head of burden preparation, has to say about the fabric filter and environmental protection.

The area of all cloth filters corresponds to 45,000 square meters of the size of seven soccer fields.
The area of all cloth filters corresponds to 45,000 square meters of the size of seven soccer fields.

The fabric filter effect

Modern electrostatic precipitators are already very good at filtering out sinter dust. But thyssenkrupp set itself the goal of going beyond official requirements and setting a new standard for reducing air pollution. The new fabric filter achieves this using tens of thousands of fine fabric bags which capture even very fine dust. Unbelievably, the air that comes out at the end of the process is cleaner than the air most of us breathe every day in big cities.

The sinter plant filter unit in numbers

How it works

The waste air from the sinter plant is first cleaned by electrostatic precipitators that capture the greater part of the dust. But that still leaves a much bigger challenge: tiny dust particulates. To remove them, the waste air is fed through 44,000 extremely fine filter bags, each almost three meters long. The total fabric area of over 45,000 square meters is enough to clean up to 1.3 million cubic meters of waste air an hour, removing the residual dust almost entirely.

To make the sinter cake requires hot air
To make the sinter cake requires hot air.

What we need sinter for

Steel is made from various raw materials, mainly iron ore and coke. The sinter plant is one of the first steps in steel production. Here, iron ore fines are mixed with coke and other materials such as lime, heated to a temperature of 1,200 degrees and baked together. The resultant “sinter cake” is then broken into lumps and cooled, ready for the next step in the steel production process: the blast furnace. To make the sinter cake requires hot air, which after the process is laden with dust. Conventional electrostatic precipitators collect most of this dust, but now thyssenkrupp’s new fabric filter, the biggest of its kind in the world, captures even the tiniest dust particles.

Construction phase

Start of construction on the world’s biggest fabric filter for sinter production

Start of construction on the world’s biggest fabric filter for sinter production

The official starting signal for construction of the world’s biggest fabric filter for the sintering process was given in November 2015 – a big step toward further improving the quality of air in Duisburg and protecting the environment. The huge components for the stack were almost too big to be transported even by ship …

Stack construction

Stack construction

… because the pipe sections for the gigantic 400 metric ton stack only just fitted beneath some of the bridges on the route. The blue-striped stack was assembled on site using a special crane. For the four segments, each 27 meters long and almost six meters in diameter, the 70-meter crane boom had to be additionally lengthened.

Environmental protection and sustainability

Environmental protection and sustainability

A 3D visualization of the new fabric filter. Emissions are reduced to such an extent that they are below the statutory limits for air pollution. The world’s biggest and most advanced sinter dust filter was officially started up in spring 2017 – another big step forward for the environment in the Duisburg region.

  • 150

    employees involved

  • 51 million euro

    investment

  • 19 months

    construction phase

Pollution control that sets global standards

For Dr. Wolfgang Volkhausen, protecting the environment does not stop at the steel mill gate. The team leader for emissions control at thyssenkrupp is responsible for ensuring that official air pollution limits are met. Dr. Volkhausen is also member of a European community in which environmental experts such as him can swap ideas and experiences. As a result, thyssenkrupp operates one of the world’s cleanest iron and steel mills on its almost 10 square kilometer site in the north of Duisburg. The expertise of our environmental experts is in demand worldwide.

ThyssenKrupp Contact

Business Area Steel Europe

Erik Walner

Media Relations

Telephone: +49 203 52 45130

Fax: +49 203 52 25707

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