Reducing Regional Haze Emissions

Direct Haze Emissions

In the late 2000s, Cliffs began actively working to reduce emissions which may lead to the formation of regional haze around its operations. The largest contributors were emissions of NOx and SO2 coming from its wholly-owned coal fired plant in Minnesota and its indurating furnaces, a key step in the process of preparing iron ore pellets. 

Our emissions of regional haze pollutants (SO2 & NOx) have been reduced by 43% compared to 2005 with an objective to reduce those emissions by more than 50% by 2022 compared to 2005¹.

These reductions are being accomplished through several steps:

1. Improving process efficiency, using cleaner fuels, and producing lower SO2 emitting pellets.
2. In 2019, Cliffs economically idled its wholly-owned coal-fired power plant, Silver Bay Power, which supplies power to its Northshore Mining operations. Instead, Cliffs will be purchasing power from Minnesota Power’s grid network, which is sourced from a significant portion of renewable sources and has a lower NOx and SO2 emissions profile. This, in turn, will reduce Cliffs’ own emissions. 
3. Cliffs continues to research and develop new indurating furnace burner technologies. In compliance with federal EPA regional haze emissions rules, new low-NOx burner technology has been installed in phases in our eligible indurating furnaces between 2017 and 2021.

Indirect Haze Emissions

Taconite mining, concentrating and pellet production are energy-intensive. We constantly strive to implement energy efficiency projects and reduce the electricity we use. Cliffs purchases the majority of its electricity from providers in Minnesota and Michigan, and through our utility rates, have subsidized efforts to significantly reduce their NOx and SO2 emission. This is through the incorporation of higher percentages of renewable energy and natural gas generation into their portfolio, and through the installation of low-NOx burners, utilization of lower sulfur coals, clean coal technology conversion (e.g., scrubbers, etc.) and retirements of older, coal-fired generating units.

As a significant client, Cliffs has leveraged supplier-customer relationships to help reduce emissions. For example, Cliffs’ involvement in stabilizing the energy supply in Michigan’s Upper Peninsula facilitated the transition of the 350-megawatt coal-fueled Presque Isle Power Plant to new natural gas-generating stations with a combined output capacity of 183 megawatts. The transition, completed in Spring 2019, resulted in 95% reduction in nitrogen dioxide emissions, 99% reduction in sulfur dioxide and mercury emissions, and 45% reduction in particulate emissions.

Cliffs’ electrical power is supplied by sources that have achieved an 89% reduction in SO2 and NOx emissions compared with 2005. Our ongoing efforts are expected to deliver a 97% reduction in SO2 and NOx emissions associated with the electricity we purchase by 2021.