Aiming at hard-to-reuse gasification
fine slag, a new process of
treating gasification fine slag by classification was presented. The
screening treatment was carried out based on ensuring the original
particle size composition of fine slag, and it was divided into six
particle size ranges as follows: +0.5, 0.3–0.5, 0.125–0.3,
0.074–0.125, 0.045–0.074, and −0.045 mm. The
physical properties of different size range samples were examined
by elemental analysis, X-ray diffraction, X-ray fluorescence, cold
field emission scanning electron microscopy, and energy-dispersive
spectrometry. The results showed that the carbon content of the median
section (0.125–0.3 mm) fine slag had significant improvement
compared with the other section fine slag. The carbon distribution
of the +0.125 mm fine slag was concentrated, while the carbon distribution
of −0.125 mm was dispersed and closely mixed with minerals.
The content of trace elements Cr, Mn, Ni, V, Cd, Pb, and Mo was determined
by inductively coupled plasma–mass spectrometry, and the correlation
between minerals and trace elements of different particle size-graded
fine slag was evaluated by Pearson correlation analysis. The results
suggested that high vaporization temperature and metallic oxide forms
of trace elements had a strong correlation with feldspar.