Comparison of Processing Routes for Electric Arc Furnace Dust
The GreeNZinc Process Route
The GreeNZinc Process is an inclusive hazardous waste recycling option allowing EAF Producers to process their own EAF Dust.
The GreeNZinc Process:
- minimizes the logistics of EAF Dust transportation.
- minimizes greenhouse gas emissions by more than 75% compared to Waelz Kiln Process.
- minimizes lead, mercury and particulate emissions.
- recycles EAF Dust high value iron as Liquid Pig Iron (LPI) or Direct Reduced Iron (DRI) units.
- produces a quality, high value Zinc Oxide product.
- requires moderate CAPEX to achieve a superior Zinc Oxide product <US$ 100M
The GreeNZinc Process closes the EAF Dust recycling route and can process the EAF Dust at the Source.
The GreeNZinc Process is able to harness synergies associated with EAF off-gas heat recuperation - thereby significantly reducing greenhouse gas emissions.
The Waelz Kiln Process Route
Current EAF Dust recycling is dominated by third party companies using the Waelz Process - a high-temperature metals recovery process (HTMR) - designated by the EPA as the BEST Demonstrated Available Technology (BDAT) for EAF Dust Management.
Despite BDAT designation the Waelz Kiln Process route:
- produces high greenhouse gas emissions.
- produces lead, mercury and particulate emissions.
- does not recovery heavy metals - producing a low value, low-grade iron-rich clinker used as aggregate.
- produces an initial low grade Crude Zinc Oxide (CZO) which requires additional refining.
- requires large CAPEX to achieve SHG Zinc and Zinc Oxide products > US$ 200M.
The Waelz Process closes the EAF Dust recycling route - but as a stand alone facility - necessitating significant logistics transporting EAF Dust to the processing site.
The coal-based Waelz Process is energy intensive and unable to harness synergies associated with EAF off-gas heat recuperation.