XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 205
of a traditional ball mill. These larger flakes hold a higher
value in niche markets, which can increase the total value
per ton of the final product. Figure 10 shows Backscatter
Electron Images of graphite flakes resulting from the two
processes to illustrate the improved size retention resulting
from HPSA. For the customer, switching to HPSA would
create an estimated annual OPEX and total CAPEX savings
equal to $13M and $15M, respectively.
Test results indicate that HPSA can more effectively
liberate graphite from the gangue materials while preserv-
ing flake size, as opposed to traditional grinding methods.
Batch Testing Case: Rare Earths
In a Rare Earth Element (REE) application, HPSA dem-
onstrated a more efficient size separation using the base
mineral orthoclase to liberate the target minerals: mona-
zite, cerite, bastnasite, and rhodochrosite. It is noted that
two target minerals (bastnasite and monazite) have a Mohs
hardness of 4.5 and 5, respectively whereas, the base min-
eral (orthoclase) has a Mohs hardness of 6. Figure 12 shows
that HPSA processing improved concentration of the Total
Rare Earth Elements (TREEs) in the fine fraction from
29.0% in the feed, to 95% in the post HPSA product.
Figure 12 displays the MLA of the feed material and
post-HPSA samples. Pre-HPSA, the REE bearing bast-
nasite and monazite are associated with the host mineral
orthoclase. Images of the post HPSA material clearly show
that the bastnasite and monazite have been liberated from
the orthoclase. The results demonstrate how the unique
application of energy provided by HPSA leads to selective
liberation of softer minerals.
Batch Testing Case: Copper
HPSA was benchmarked against a rod mill for a regrind cir-
cuit processing ore containing copper. The objective of this
case study was to quantify the selective liberation capability
of HPSA relative to the traditional size-reduction focused
liberation technology of a rod mill.
In one case study, in a comparison to the rod mill,
HPSA increased copper recovery by 22% for the –74 µm
Figure 10. (top right) Graphite Flake Product from ball mill processing, (others) Graphite flakes
produced via HPSA processing indicating graphite flake size retention with HPSA Processing
of a traditional ball mill. These larger flakes hold a higher
value in niche markets, which can increase the total value
per ton of the final product. Figure 10 shows Backscatter
Electron Images of graphite flakes resulting from the two
processes to illustrate the improved size retention resulting
from HPSA. For the customer, switching to HPSA would
create an estimated annual OPEX and total CAPEX savings
equal to $13M and $15M, respectively.
Test results indicate that HPSA can more effectively
liberate graphite from the gangue materials while preserv-
ing flake size, as opposed to traditional grinding methods.
Batch Testing Case: Rare Earths
In a Rare Earth Element (REE) application, HPSA dem-
onstrated a more efficient size separation using the base
mineral orthoclase to liberate the target minerals: mona-
zite, cerite, bastnasite, and rhodochrosite. It is noted that
two target minerals (bastnasite and monazite) have a Mohs
hardness of 4.5 and 5, respectively whereas, the base min-
eral (orthoclase) has a Mohs hardness of 6. Figure 12 shows
that HPSA processing improved concentration of the Total
Rare Earth Elements (TREEs) in the fine fraction from
29.0% in the feed, to 95% in the post HPSA product.
Figure 12 displays the MLA of the feed material and
post-HPSA samples. Pre-HPSA, the REE bearing bast-
nasite and monazite are associated with the host mineral
orthoclase. Images of the post HPSA material clearly show
that the bastnasite and monazite have been liberated from
the orthoclase. The results demonstrate how the unique
application of energy provided by HPSA leads to selective
liberation of softer minerals.
Batch Testing Case: Copper
HPSA was benchmarked against a rod mill for a regrind cir-
cuit processing ore containing copper. The objective of this
case study was to quantify the selective liberation capability
of HPSA relative to the traditional size-reduction focused
liberation technology of a rod mill.
In one case study, in a comparison to the rod mill,
HPSA increased copper recovery by 22% for the –74 µm
Figure 10. (top right) Graphite Flake Product from ball mill processing, (others) Graphite flakes
produced via HPSA processing indicating graphite flake size retention with HPSA Processing