Cleaner steel production can drive global economic growth, improving quality of life without compromising human health and the environment. This will be particularly important in China and developing countries, who are increasing steel production to meet demands associated with growing population, incomes and urbanization.

China’s pollution problems are well documented, with implications for environmental and human health impacts worldwide. Its iron and steel industry has been identified as the largest contributing industrial source of pollutants. It is also a significant contributor of dioxins (PCDD/Fs), persistent organic pollutants that can cause cancer, reproductive and developmental problems.

In light of these trends, China is implementing regulatory policies to curb pollution. In July 2018, it released the Blue Sky Action Plan, targeting reductions in PM2.5, VOCs, NOx and greenhouse gases. For the Chinese iron and steel industry, this signifies capacity reductions, and industry consolidation that will phase out small mills and rely more on large blast furnaces.

It may also result in the increased sourcing of higher-grade raw material inputs to reduce pollution impacts per ton of steel production. Research and regulatory studies have demonstrated emissions improvements that Chinese mills will experience by switching from use of sinter to iron ore pellets.

Steelmaking Process

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The results of one study (Wu et al. 2015), captured in the chart below, show the estimated ranges of pollutants emitted by Chinese mills through the use of sinter versus the use of pellets. The range of emissions from pellets is consistently lower than that of sinter.

  • Up to 38% improvement in SO2 emissions
  • Up to 77% improvement in NOx emissions
  • Up to 81% improvement in PM2.5 emissions
  • Up to over 80% improvement in TSP emissions
Emissions Factor Rangers

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Moreover, the same study found that dioxin emissions and non-methane volatile organic compounds (NMVOC) were non-detectable in the pelleting process, whereas the dioxin emissions factor could exceed 1000 ng I-TEQ per ton from sintering and the NMVOC was estimated at 0.219 kg per ton.

A study by the Intergovernmental Panel on Climate Change also suggests that CO2 emissions per ton could improve by 85% through using pellets over sinter.

Shifting towards use of pellets as iron feedstock is necessary should Chinese steel mills wish to achieve environmental improvements that make their performance comparable to American counterparts. In 2009, the Alliance for American Manufacturing (AAM) published a report that compared emissions per ton of steel produced in the U.S. and China.

  • Chinese SO2 emissions were over 400% higher per ton of steel as compared to emissions in the U.S.
  • Chinese NOx emissions were ~190% larger per ton of steel as compared to emissions in the U.S.
  • Chinese PM emissions were more than 1800% larger per ton of steel as compared to emissions in the U.S.
Emissions per Ton

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While the scale of environmental benefits achievable in China remains uncertain due to limited data availability, the positive impacts of switching feedstock are well documented and there is a strong basis for structural change in the Chinese steel industry.

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