2
concentrate grades are not considered within the financial
evaluation for the Santo Domingo project (NI 43-101
Technical Report, 2024).
EXPERIMENTAL
Davis Tube Tests
Bench-scale magnetic separation tests were conducted
using a Davis Tube Test in the early stages of the Santo
Domingo project and form the basis of the geological block
model’s, in combination with magnetic susceptibility read-
ings completed throughout the deposits, to determine iron
concentrate grade and mass recovery (Figure 1). The assays
from the Davis Tube Tests provided valuable information
for the initial stages of the project with respect to plant
design and continue providing relevant information as a
link between laboratory and pilot testwork programs to the
forecast model.
Laboratory and Pilot Low Intensity Magnetic
Separation Testwork
Low Intensity Magnetic Separation testwork at laboratory
and pilot plant scale was completed for the Santo Domingo
project using composite and variability samples – covering
the main mineralized geological units considered for the
life of mine – and have been used as the primary basis of the
iron concentration plant design.
Initially laboratory scale LIMS testwork was carried
out using mainly annual composites or geological domains
as identified at the time, and direct seawater considered to
be the main source of water make-up. This definition was
modified during 2018 to use desalinated seawater, mainly
due to difficulties in achieving the required levels of chlo-
ride in the final iron concentrate (NI 43-101 Technical
Report, 2020). Laboratory testwork described here used
desalinated seawater as per the current definition of the
Santo Domingo project.
In 2019, laboratory scale iron separation testwork
using desalinated seawater and tailings from bench-scale
sulfide rougher flotation tests, conducted using a com-
posite sample representing the first 5 years of operation,
was completed (Figure 2). The test procedure simulated
the iron concentration circuit established at the time, spe-
cifically rougher magnetic separation (considered at 1,000
Gauss), followed by regrind targeting a P80 of 40 microns
and three cleaning stages (at 750 Gauss). The results of the
circuit produced an iron concentrate grade of 65.1% Fe
at 18.44% mass recovery to the final concentrate from a
feed iron grade of 28.4% Fe (SGS, 2020). Complementary
testwork was also completed during the program, with no
future relevance for the design.
In 2020 a pilot flotation testwork program using
desalinated seawater was completed, generating sufficient
rougher flotation tailings for the first magnetic separation
pilot plant. The pilot used an industrial diameter 48 in
(1.2 m) magnetic drum separator (Figure 3) and followed
Figure 1. Davis Tube Test on Santo Domingo project sample
Figure 2. Low intensity magnetic separator drum used for
the Santo Domingo project
concentrate grades are not considered within the financial
evaluation for the Santo Domingo project (NI 43-101
Technical Report, 2024).
EXPERIMENTAL
Davis Tube Tests
Bench-scale magnetic separation tests were conducted
using a Davis Tube Test in the early stages of the Santo
Domingo project and form the basis of the geological block
model’s, in combination with magnetic susceptibility read-
ings completed throughout the deposits, to determine iron
concentrate grade and mass recovery (Figure 1). The assays
from the Davis Tube Tests provided valuable information
for the initial stages of the project with respect to plant
design and continue providing relevant information as a
link between laboratory and pilot testwork programs to the
forecast model.
Laboratory and Pilot Low Intensity Magnetic
Separation Testwork
Low Intensity Magnetic Separation testwork at laboratory
and pilot plant scale was completed for the Santo Domingo
project using composite and variability samples – covering
the main mineralized geological units considered for the
life of mine – and have been used as the primary basis of the
iron concentration plant design.
Initially laboratory scale LIMS testwork was carried
out using mainly annual composites or geological domains
as identified at the time, and direct seawater considered to
be the main source of water make-up. This definition was
modified during 2018 to use desalinated seawater, mainly
due to difficulties in achieving the required levels of chlo-
ride in the final iron concentrate (NI 43-101 Technical
Report, 2020). Laboratory testwork described here used
desalinated seawater as per the current definition of the
Santo Domingo project.
In 2019, laboratory scale iron separation testwork
using desalinated seawater and tailings from bench-scale
sulfide rougher flotation tests, conducted using a com-
posite sample representing the first 5 years of operation,
was completed (Figure 2). The test procedure simulated
the iron concentration circuit established at the time, spe-
cifically rougher magnetic separation (considered at 1,000
Gauss), followed by regrind targeting a P80 of 40 microns
and three cleaning stages (at 750 Gauss). The results of the
circuit produced an iron concentrate grade of 65.1% Fe
at 18.44% mass recovery to the final concentrate from a
feed iron grade of 28.4% Fe (SGS, 2020). Complementary
testwork was also completed during the program, with no
future relevance for the design.
In 2020 a pilot flotation testwork program using
desalinated seawater was completed, generating sufficient
rougher flotation tailings for the first magnetic separation
pilot plant. The pilot used an industrial diameter 48 in
(1.2 m) magnetic drum separator (Figure 3) and followed
Figure 1. Davis Tube Test on Santo Domingo project sample
Figure 2. Low intensity magnetic separator drum used for
the Santo Domingo project