XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2529
that remain free. This makes it necessary to use greater
amounts of copper sulfate, as well as other reagents in order
to activate zinc on the later zinc flotation stage.
Undoubtedly, copper sulfate (CuSO4) has traditionally
been the main zinc activator in the zinc circuit in which
the appropiate amounts used would depend on the type of
sphalerite (zinc sulfide) present in the mineral. For exam-
ple, low-iron sphalerite (zinc sulfide) usually requires high
CuSO4 additions, whereas high iron sphalerite requires low
doses of CuSO4. Nonetheless, the process might require
proper dosis of sodium cyanide to control the iron present,
which makes the recovery stage and control of zinc depres-
sion occasionaly complicated to balanced.
Some types of minerals from the various latitudes of
Peru make it necessary to modify the Zinc depressant to
inhibit the interferents (silicates, carbonates, secondary
copper) that are attached to the zinc sulfides, this modifica-
tions on the depressor can often generate the depression of
other commercially important minerals, failing to promote
the proper recovery of the sulfur. For this reason, we devel-
oped different formulations tailored to the minerals varia-
tions we encounter.
Some minerals may possess high zinc heads, as well as
high lead heads, which means that the depressant requires
fine-tuning and a balanced dosage, so the lead is properly
recovered. On the contrary, with other mineral compo-
sitions, some family of collector´s activates undesirable
minerals which need to be depressed. Our depressor has
a better effect on those minerals and works better when
a selective colector is used with those minerals that need
to be depressed, leaving those that need to be recovered in
a greater proportion. We have found some additives and
selective collectors which may be added to obtain a more
robust depressant when applied to more complex minerals.
THIS IS THE CHEMISTRY OF THE
BRD-400
BRD-400 is presented as an emulsion based on a organic
macromolecules (containing different functional groups)
and other components that reduces the displacement of
zinc sulfides to the concentrate, leaving it free to be acti-
vated and recovered on a later stage.
This reagent spreads the zinc sulphides from the ore by
its dispersing agents, a chelating agent surrounds the sulfide
Zn particles and holds them in solution preventing them
from being floated. Subsequently, in the presence of a zinc
sulphide activator, these sulphides are released to allow their
recovery without altering their quality while maintaining
the most appropriate metallurgic conditions.
BRD-400 is a fully water-soluble reagent so it can
be diluted to any ratio for ease of application, and can be
mixed with any other know depressant. This reagent works
in a wide pH spectrum so it can be adapted to the dif-
ferent minerals and qualities of process water on mining
operations.
METHODS OF ANALYSIS
All tests were carried out in a laboratory flotation cell made
of transparent plastic. The cell volume is 2000cc. In each
test, a sample weight of 1441g (dry weight) and water
content (from the same mine process) of 805cc was used,
obtaining a solids percentage of 48%. The grinding grade
(K80) was 240µm (Table 1).
The grinding time given reached approximately 4.1
minutes. The operation includes a grinding process, con-
ditioning for Rougher Bulk and Rougher Bulk flotation.
The conditioning process for the Rougher Zinc takes place,
followed by the Rougher Zinc Flotation.
The conditions of the flotation equipment were set for
a paddle frequency of 4 paddles per minute. It worked at
110 RPM, with an air dosage of 5L/min at a pressure of
20PSI.
The Reagents used were Lime, ZnSO4, NaCN, PAX,
Foaming Agent, CuSO4, SIPX and BRD-400 manufac-
tured by BioResco S.A.C.
For purposes of comparison, different flotation tests
were carried out: one, according to the mine’s standard pro-
cess with the normal dose of zinc sulfate, and the other,
using the same process where the depressant was replaced
with BRD-400 at a reduced dose (Table 2).
EXPERIMENTAL RESULTS
Figure 2 shows that different proportions of BRD used in
the replacement test providing similar results of iron recov-
ery and mass pull compared to the standard test using zinc
Table 1. Standard Floating Conditions Rougher Scavenger
Standard Floating Conditions Rougher Scavenger Cu
Test
Grind Rougher Cu
D80, μm Lime (g/t) ZnSO4, g/t NaCN, g/t pH PAX, g/t Frother
Standard 240 0,625 100 10 11 20 5
that remain free. This makes it necessary to use greater
amounts of copper sulfate, as well as other reagents in order
to activate zinc on the later zinc flotation stage.
Undoubtedly, copper sulfate (CuSO4) has traditionally
been the main zinc activator in the zinc circuit in which
the appropiate amounts used would depend on the type of
sphalerite (zinc sulfide) present in the mineral. For exam-
ple, low-iron sphalerite (zinc sulfide) usually requires high
CuSO4 additions, whereas high iron sphalerite requires low
doses of CuSO4. Nonetheless, the process might require
proper dosis of sodium cyanide to control the iron present,
which makes the recovery stage and control of zinc depres-
sion occasionaly complicated to balanced.
Some types of minerals from the various latitudes of
Peru make it necessary to modify the Zinc depressant to
inhibit the interferents (silicates, carbonates, secondary
copper) that are attached to the zinc sulfides, this modifica-
tions on the depressor can often generate the depression of
other commercially important minerals, failing to promote
the proper recovery of the sulfur. For this reason, we devel-
oped different formulations tailored to the minerals varia-
tions we encounter.
Some minerals may possess high zinc heads, as well as
high lead heads, which means that the depressant requires
fine-tuning and a balanced dosage, so the lead is properly
recovered. On the contrary, with other mineral compo-
sitions, some family of collector´s activates undesirable
minerals which need to be depressed. Our depressor has
a better effect on those minerals and works better when
a selective colector is used with those minerals that need
to be depressed, leaving those that need to be recovered in
a greater proportion. We have found some additives and
selective collectors which may be added to obtain a more
robust depressant when applied to more complex minerals.
THIS IS THE CHEMISTRY OF THE
BRD-400
BRD-400 is presented as an emulsion based on a organic
macromolecules (containing different functional groups)
and other components that reduces the displacement of
zinc sulfides to the concentrate, leaving it free to be acti-
vated and recovered on a later stage.
This reagent spreads the zinc sulphides from the ore by
its dispersing agents, a chelating agent surrounds the sulfide
Zn particles and holds them in solution preventing them
from being floated. Subsequently, in the presence of a zinc
sulphide activator, these sulphides are released to allow their
recovery without altering their quality while maintaining
the most appropriate metallurgic conditions.
BRD-400 is a fully water-soluble reagent so it can
be diluted to any ratio for ease of application, and can be
mixed with any other know depressant. This reagent works
in a wide pH spectrum so it can be adapted to the dif-
ferent minerals and qualities of process water on mining
operations.
METHODS OF ANALYSIS
All tests were carried out in a laboratory flotation cell made
of transparent plastic. The cell volume is 2000cc. In each
test, a sample weight of 1441g (dry weight) and water
content (from the same mine process) of 805cc was used,
obtaining a solids percentage of 48%. The grinding grade
(K80) was 240µm (Table 1).
The grinding time given reached approximately 4.1
minutes. The operation includes a grinding process, con-
ditioning for Rougher Bulk and Rougher Bulk flotation.
The conditioning process for the Rougher Zinc takes place,
followed by the Rougher Zinc Flotation.
The conditions of the flotation equipment were set for
a paddle frequency of 4 paddles per minute. It worked at
110 RPM, with an air dosage of 5L/min at a pressure of
20PSI.
The Reagents used were Lime, ZnSO4, NaCN, PAX,
Foaming Agent, CuSO4, SIPX and BRD-400 manufac-
tured by BioResco S.A.C.
For purposes of comparison, different flotation tests
were carried out: one, according to the mine’s standard pro-
cess with the normal dose of zinc sulfate, and the other,
using the same process where the depressant was replaced
with BRD-400 at a reduced dose (Table 2).
EXPERIMENTAL RESULTS
Figure 2 shows that different proportions of BRD used in
the replacement test providing similar results of iron recov-
ery and mass pull compared to the standard test using zinc
Table 1. Standard Floating Conditions Rougher Scavenger
Standard Floating Conditions Rougher Scavenger Cu
Test
Grind Rougher Cu
D80, μm Lime (g/t) ZnSO4, g/t NaCN, g/t pH PAX, g/t Frother
Standard 240 0,625 100 10 11 20 5
