8 Environmental Impacts of Steel Production

The most widely used building and engineering material in the world is steel. The building and infrastructure sectors consume somewhat more than half of all steel produced. This begs the question: are there environmental impacts of steel production?

Steel will most likely be utilized extensively in a variety of structures, including street furniture, multi-story buildings, homes, and bridges, both in the structural fabric and in the individual parts.

The value of steel around the globe is enormous. Steel accounts for around 95% of all metals produced and has a significant impact on economies and society in ways other than just financial gain. It is a vital raw material for a vast range of goods and uses due to its adaptability, strength, and practicality.

What is steel?

We should first review the definition of steel before examining its effects on the environment. To put it simply, steel is an alloy consisting primarily of iron, carbon, and manganese, along with trace amounts of silicon, sulphur, and oxygen.

This alloy contains 2% and 1% of carbon and manganese, respectively. However, low, medium, and high-carbon steels are created, and commercial-quality steels usually have significantly lower concentrations of these components.

Steel’s strength and hardness are derived from carbon, which also makes the material more brittle and less workable. Therefore, ensuring that steel is of the proper grade for its intended use requires careful control of the carbon content. The majority of steel has 0.35% carbon, while very few have 1.85%.

The steel can be given the appropriate performance qualities by adding further ingredients to this mixture. For instance, adding chromium results in the production of stainless steel.

Environmental Impacts of Steel Production

The process of turning iron ore into steel begins with mining, or, to put it simply, this is the first stage in the process. The process of blasting, etc., with coal is highly polluting. It releases several pollutants, including PM, fugitive dust, and sulphur oxides.

  • Coke Oven
  • Blast Furnace
  • Carbon Dioxide
  • Nitrogen Oxides
  • Sulphur Dioxide
  • Dust
  • Organic Pollutants
  • Water

1. Coke Oven

Coal Tar, VOCs, arsenic, beryllium, chromium, and other materials are among the pollutants released from coal-fired ovens. They are poisonous and possibly even cancerous.

2. Blast Furnace

The iron ore is melted to produce liquid iron in the blast furnace. The Basic Oxygen Method is the name of this technique. Pig iron, also known as crude iron, is produced in the furnace by feeding a mixture of metallic ore, coke, and fluxing agents like limestone. Pig iron is then processed into steel.

The EAF (Electric Arc Furnace) technology is an alternative that melts scrap steel at high temperatures rather than pig iron. Both processes result in the production of pollutants like hydrocarbons, carbon monoxide, PM, NO2, and SO2.

3. Carbon Dioxide

Carbon dioxide (CO2) is the quantitatively greatest airborne emission from steel facilities. Variations in the amount of steel produced from ore have an impact on carbon dioxide emissions since blast furnaces and sponge iron plants reduce iron ore, which is the primary source of emissions.

The use of fossil fuels in furnaces for heat treatment and reheating, for example, produces emissions as well.

About half of the energy used by the steel industry overall comes from coal used as a reducing agent in blast furnaces and sponge iron plants (process coal plus other energy kinds). Approximately 90% of the carbon dioxide emissions from the steel sector come from coal.

4. Nitrogen Oxides

Nitrogen oxide (NOx) emissions occur mostly in coking plants, electric arc furnaces, reheating and heat treatment furnaces, nitric acid pickling, and transportation.

Because of the high temperatures required in the iron and steel industries, it is difficult to prevent the generation of nitrogen oxides during fuel combustion processes because nitrogen is present in the air.

5. Sulphur Dioxide

Sulfur dioxide (SO2) emissions are closely linked to the burning of oil, primarily in coke manufacturing and reheating furnaces.

6. Dust

Most steel industry operations result in the formation of dust, particularly those involving blast furnaces and coking facilities. The development of ventilation systems, filters, and dedusting technologies has led to a significant reduction in dust emissions.

Generally speaking, installed filters can eliminate more than 99 percent of the dust particles that are present in the extracted furnace gases.

The dust’s metallic content—zinc, nickel, chromium, and molybdenum—is removed, handled, and essentially recycled, turning it into a valuable byproduct.

Actual and specific dust emissions have decreased by around 80% since 1992. Studies conducted over several decades on moss have shown that metal emissions have decreased in tandem with dust, primarily.

Within the steel sector, dust emissions are no longer considered to be a significant environmental concern. It should be noted that modern purifying technology is expensive and energy-intensive, including dust handling.

7. Organic Pollutants

The primary source of hydrocarbon emissions is the application of solvents in procedures like painting and cleaning. The furnaces used in the production process to melt scrap metal are the primary source of hydrocarbon emissions. Hydrocarbon emissions from melting furnaces may be linked to changes in the furnace’s processing parameters as well as, most likely, the makeup of the scrap.

When paired with filters, efficient dust separation and temperature management of flue gases can reduce certain pollutants, such as dioxins, which are mostly attached to dust particles. However, as the steel factories’ 2005 measurement results show, it is extremely difficult to assess dioxin emissions.

8. Water

The primary use of water is in cooling procedures. Process water is used as a lubricant, for cleaning, pickling, and cleansing process gases. Water used for sanitation is also used in smaller quantities.

Where seawater is accessible, heat exchangers use it mostly for indirect cooling. This indicates that an increase in temperature of no more than a few degrees will not have an impact on the water when it is released again. In other instances, cooling techniques employ surface water from lakes and watercourses.

Surface water is also commonly used as process water in steel factories; following cleaning processes like sedimentation and oil water separation, it can attain a recycling rate exceeding 90%. In addition to being used for sanitation, municipal water is also used in modest amounts for process water.


Many steel businesses currently do not adhere to best practices when it comes to addressing the environmental impact of steel manufacturing and the problem of emissions. Swift and major action is required to comply with regulations and reduce air pollution caused by the steel industry.

One method of reducing industrial pollution is to use carbon capture and sequestration (CCS), which removes carbon dioxide from industrial plants at the source. However, CCS is an expensive and energy-intensive process that may also be highly damaging.

According to studies, burning coal, etc., might raise emissions by 25% when CCS is used. The only viable option is a low-cost, highly efficient method of covering vast regions.


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A passion-driven environmentalist by heart. Lead content writer at EnvironmentGo.
I strive to educate the public about the environment and its problems.
It has always been about nature, we ought to protect not destroy.

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