208 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
minimum operation time of 6-months with the end goal
of proving through sampling and economic analysis that
a larger HPSA unit can eventually replace the current rod
mill. Previous batch unit results defined operating param-
eters for maximum throughput, residence time, and opti-
mal nozzle velocities to maximize grades and recoveries for
downstream processes. This unit is operating off a feed slip
stream, in parallel to the rod mill. Disa will continue to
work towards fully replacing the rod mill with a 250 tph
HPSA unit.
CONTINUOUS TESTING CASE: FILTER
SAND
Filter sand is used in a variety of mining applications
including well water filtration, water reuse, source water fil-
tration, leaching pads, tailings, and many more. Over time,
this filter sand becomes coated with a layer of calcite which
degrades the filtration properties of the sand. Eventually, it
must be discarded and replaced with new, clean sand. This
replacement is both manually laborious and expensive.
In a case study, calcite coated filter sand material was
processed using HPSA technology. This study proved that
HPSA was able to separate the calcite layer from the sand,
regenerating the filtration properties so that it can be re-
used in the filtration process. Material was processed in a
HPSA lab unit, and the post process material was separated
into +105 µm (+140 US mesh) and –105 µm (–140 US
mesh) material. The +105 µm (+140 US mesh) material
was successfully cleaned, replicating the regenerated sand
that could be reused in the filtration system, while the con-
taminants were concentrated in the –105 µm (–140 US
mesh) material. Figure 15 shows the separation of clean and
contaminated material. Figure 16 shows images of the dark
calcite layer breaking off the coarse sand (+105 µm /+140-
mesh) over time. Further XRD analysis was performed
on the feed and 10-minute HPSA samples. The analysis
revealed the quartz content increased from 67% in the feed
to 94% in the product, and the calcite content decreased
from 26% in the feed material to 3% in the product, shown
in Figure 17.
Expanding on the filter sand lab case study, Disa
deployed the Gen B continuous unit to a water treatment
facility for a filter sand regeneration pilot project. The
objective of this pilot was to use HPSA processing to clean
and recycle filter sand to negate the need to fully discharge
and replace contaminated sand.
Contaminated filter sand was size classified over a
6.35 mm (¼ inch) vibratory screen to remove any large
particles that could clog the HPSA system. The under-
sized material was then conveyed into a mix tank where
the slurry was formed. From there, the slurry was pumped
into the HPSA tanks for selective liberation. The HPSA
processed material was then pumped over a vibratory
shaker with a 105 µm (140 US mesh) panel to separate
Figure 14. Gen B installed at a phosphate mill
minimum operation time of 6-months with the end goal
of proving through sampling and economic analysis that
a larger HPSA unit can eventually replace the current rod
mill. Previous batch unit results defined operating param-
eters for maximum throughput, residence time, and opti-
mal nozzle velocities to maximize grades and recoveries for
downstream processes. This unit is operating off a feed slip
stream, in parallel to the rod mill. Disa will continue to
work towards fully replacing the rod mill with a 250 tph
HPSA unit.
CONTINUOUS TESTING CASE: FILTER
SAND
Filter sand is used in a variety of mining applications
including well water filtration, water reuse, source water fil-
tration, leaching pads, tailings, and many more. Over time,
this filter sand becomes coated with a layer of calcite which
degrades the filtration properties of the sand. Eventually, it
must be discarded and replaced with new, clean sand. This
replacement is both manually laborious and expensive.
In a case study, calcite coated filter sand material was
processed using HPSA technology. This study proved that
HPSA was able to separate the calcite layer from the sand,
regenerating the filtration properties so that it can be re-
used in the filtration process. Material was processed in a
HPSA lab unit, and the post process material was separated
into +105 µm (+140 US mesh) and –105 µm (–140 US
mesh) material. The +105 µm (+140 US mesh) material
was successfully cleaned, replicating the regenerated sand
that could be reused in the filtration system, while the con-
taminants were concentrated in the –105 µm (–140 US
mesh) material. Figure 15 shows the separation of clean and
contaminated material. Figure 16 shows images of the dark
calcite layer breaking off the coarse sand (+105 µm /+140-
mesh) over time. Further XRD analysis was performed
on the feed and 10-minute HPSA samples. The analysis
revealed the quartz content increased from 67% in the feed
to 94% in the product, and the calcite content decreased
from 26% in the feed material to 3% in the product, shown
in Figure 17.
Expanding on the filter sand lab case study, Disa
deployed the Gen B continuous unit to a water treatment
facility for a filter sand regeneration pilot project. The
objective of this pilot was to use HPSA processing to clean
and recycle filter sand to negate the need to fully discharge
and replace contaminated sand.
Contaminated filter sand was size classified over a
6.35 mm (¼ inch) vibratory screen to remove any large
particles that could clog the HPSA system. The under-
sized material was then conveyed into a mix tank where
the slurry was formed. From there, the slurry was pumped
into the HPSA tanks for selective liberation. The HPSA
processed material was then pumped over a vibratory
shaker with a 105 µm (140 US mesh) panel to separate
Figure 14. Gen B installed at a phosphate mill