Abstract:
This study investigates the effectiveness of various beneficiation methods for recovering
chromium from refined ferrochrome slag. Dry magnetic separation at different field intensities (0.45 T and 0.8 T) showed that selective extraction of metallic chromium (Crmet) is
more efficient at 0.45 T, achieving a recovery rate of up to 90.05%. Pneumatic separation
using SEPAIR technology demonstrated promising results, especially for wide particle size
fractions (0–20 mm), where chromium recovery reached 40.32% due to density differences
between slag particles and metallic inclusions. Enrichment on a shaking table proved to
be the most selective method, producing a concentrate with 29.9% Cr and 90.7% recovery,
although the yield was low (3.8%). SEM-EDX and SEM-BSE analyses confirmed the heterogeneous phase composition of slag grains, revealing chromium–iron alloys embedded
in oxide matrices. Based on laboratory experiments and material characterization, it is
concluded that magnetic separation can be used for preliminary concentration, pneumatic
classification is effective for processing bulk slag with economic potential, and gravity
concentration on shaking tables is suitable for producing high-grade concentrates. The
resulting tailings, low in chromium, are suitable for reuse in the production of building
materials after carbonation treatment.
