The Waelz Slag from Electric Arc Furnace Dust Processing: Characterization and Magnetic Separation Studies

Area of Science:

• Metallurgical Engineering
• Materials Science
• Environmental Engineering

Background:

• Waelz slag is a significant byproduct of electric arc furnace dust processing.
• This slag contains substantial quantities of iron, zinc, and copper.
• Large volumes (600-800 kg/ton of dust) necessitate efficient valorization strategies.

Purpose of the Study:

• To characterize Waelz slag composition and phase distribution of valuable metals.
• To evaluate the effectiveness of low-intensity wet magnetic separation for iron recovery.
• To understand the influence of slag composition on magnetic separation performance.

Main Methods:

• Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-AES) for elemental analysis.
• X-ray Diffraction (XRD) and Mössbauer spectroscopy for mineralogical characterization.
• Chemical phase analysis and low-intensity wet magnetic separation experiments.

Main Results:

• Waelz slag exhibits complex chemical and mineralogical compositions.
• Iron recovery achieved up to 73% Fe content with 87.2% metallization and 54.8% recovery.
• Copper and zinc did not selectively segregate into magnetic or non-magnetic fractions.
• Slag composition significantly impacts magnetic separation efficiency.

Conclusions:

• Low-intensity wet magnetic separation is a viable method for iron recovery from Waelz slag.
• Complex slag composition presents challenges for selective recovery of all valuable elements.
• Optimized magnetic separation can yield high-grade iron concentrates.