1472 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
across the particle by impact during compression of the
packed bed.
The bottom row of Figure 5 contains particles with
relatively fewer cracks than the top row. Other particles
in the same crushing condition and size fraction showed
similar results. For this HPGR crushing, particles with a
size around 8 mm make good contact with other particles
in the packed bed and form impact cracks at the higher
pressure force of 10N/mm2. The impact cracks provide
access for leaching solution to deeper regions inside the
particles, facilitating better sub-surface fluid transportation
and possibly higher metal recovery. This indicates that the
specific pressure force of HPGR is an important operating
parameter to be adjusted for more internal fractures in
8 mm particles.
15.9 × 12.7 mm Particles
Although the particle in Figure 5 (top left) shows two small
impact cracks in the right region of the volume, most of
the 9.5 × 6.4 mm particles crushed by HPGR at the spe-
cific pressure force of 5 N/mm2 did not have impact cracks.
However, for the size fraction of 15.9 × 12.7 mm, as shown
in Figure 6 (left column), large impact cracks were formed
even at the HPGR pressure of 5 N/mm2. Of course, the 10
N/mm2 particles in this size fraction appear to have
Figure 4. Raw images (top row), 2D segmented images (middle row), and 3D segmented images (bottom
row) of the regular fines, no fines, and double fines 4-inch columns. Color code for middle row: rock,
dark pore, white agglomerated fines, grey. Color code for bottom row: rock, transparent pore, white
agglomerated fines, green
across the particle by impact during compression of the
packed bed.
The bottom row of Figure 5 contains particles with
relatively fewer cracks than the top row. Other particles
in the same crushing condition and size fraction showed
similar results. For this HPGR crushing, particles with a
size around 8 mm make good contact with other particles
in the packed bed and form impact cracks at the higher
pressure force of 10N/mm2. The impact cracks provide
access for leaching solution to deeper regions inside the
particles, facilitating better sub-surface fluid transportation
and possibly higher metal recovery. This indicates that the
specific pressure force of HPGR is an important operating
parameter to be adjusted for more internal fractures in
8 mm particles.
15.9 × 12.7 mm Particles
Although the particle in Figure 5 (top left) shows two small
impact cracks in the right region of the volume, most of
the 9.5 × 6.4 mm particles crushed by HPGR at the spe-
cific pressure force of 5 N/mm2 did not have impact cracks.
However, for the size fraction of 15.9 × 12.7 mm, as shown
in Figure 6 (left column), large impact cracks were formed
even at the HPGR pressure of 5 N/mm2. Of course, the 10
N/mm2 particles in this size fraction appear to have
Figure 4. Raw images (top row), 2D segmented images (middle row), and 3D segmented images (bottom
row) of the regular fines, no fines, and double fines 4-inch columns. Color code for middle row: rock,
dark pore, white agglomerated fines, grey. Color code for bottom row: rock, transparent pore, white
agglomerated fines, green