82
J. F. Pusateri et al.
Fig. 5 Waelz kiln oxygen-enrichment schematic
is more tightly targeted near the discharge dam, and (c) process controls and safety
interlocks are more sophisticated and extensive.
Kiln productivity gains of 8–10%, zinc recovery improvement of 1–2%, and nearly
eliminating the use of the natural gas burner have all been realized during proof-ofconcept campaigns at Rockwood in May-September 2019. Optimization and CFD
modeling are in process, along with roll-out to all AZR kilns.
AZR Flame Reactor On-Site EAF Dust Recycling Process
AZR operated its Flame Reactor process on the site of the current Optimus Steel
melt-shop in Beaumont, TX from 1993 to 2008. This natural gas-fired flash-smelting
process operation was shut down due to rising natural gas prices and increasing
Waelz kiln capacity. AZR is re-introducing the process to provide cost-competitive,
on-site EAF dust processing services for operators looking to eliminate dust transport
liabilities.
The Advanced Zinc Recovery (AZR) process utilizes a unique oxy-fuel burner
that generates a high-temperature (> 2000 °C) reducing atmosphere to “flash” smelt
raw EAF dust, separating the volatile metals like zinc from the iron oxides and slagforming compounds, and producing crude zinc oxide (CZO) and granulated iron-rich
slag (IRM).
The AZR process features include:
• Completely enclosed EAF dust receiving, storage and feed systems
• Water-cooled burner, flash-furnace and slag separator modules
• Air-granulated IRM cooling system
• Flash processing residence time of < 0.25 s
• Compact plant footprint of < 4 acres for 60,000 tpy dust capacity
J. F. Pusateri et al.
Fig. 5 Waelz kiln oxygen-enrichment schematic
is more tightly targeted near the discharge dam, and (c) process controls and safety
interlocks are more sophisticated and extensive.
Kiln productivity gains of 8–10%, zinc recovery improvement of 1–2%, and nearly
eliminating the use of the natural gas burner have all been realized during proof-ofconcept campaigns at Rockwood in May-September 2019. Optimization and CFD
modeling are in process, along with roll-out to all AZR kilns.
AZR Flame Reactor On-Site EAF Dust Recycling Process
AZR operated its Flame Reactor process on the site of the current Optimus Steel
melt-shop in Beaumont, TX from 1993 to 2008. This natural gas-fired flash-smelting
process operation was shut down due to rising natural gas prices and increasing
Waelz kiln capacity. AZR is re-introducing the process to provide cost-competitive,
on-site EAF dust processing services for operators looking to eliminate dust transport
liabilities.
The Advanced Zinc Recovery (AZR) process utilizes a unique oxy-fuel burner
that generates a high-temperature (> 2000 °C) reducing atmosphere to “flash” smelt
raw EAF dust, separating the volatile metals like zinc from the iron oxides and slagforming compounds, and producing crude zinc oxide (CZO) and granulated iron-rich
slag (IRM).
The AZR process features include:
• Completely enclosed EAF dust receiving, storage and feed systems
• Water-cooled burner, flash-furnace and slag separator modules
• Air-granulated IRM cooling system
• Flash processing residence time of < 0.25 s
• Compact plant footprint of < 4 acres for 60,000 tpy dust capacity