XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3127
factors such as grinding fineness, collector types, rougher
pH value, and reagent dosage on copper and molybdenum
recovery rates. Ultimately, a flotation process and efficient
collector suitable for this type of ore are identified.
MATERIALS AND METHODS
Materials and Reagents
This study mainly focuses on actual copper molybdenum
ores obtained from northern Chile, but also uses chalcopy-
rite samples for micro-flotation tests.
The chemical composition of the actual ore is listed in
Table 1. And Table 1 shows that this ore sample consists
1.01% Cu and 0.0064% Mo. Process mineralogy of ore
samples suggests that the copper bearing minerals include
chalcopyrite (CuFeS2), bornite (Cu5FeS4), and chalcoc-
ite (Cu2S). Chalcopyrite (CuFeS2) is the primary copper
minerals found in the ore sample. And molybdenum metal
mainly exists as molybdenite .
The samples of chalcopyrite (97.2% purity) with par-
ticle size fractions of –74 +38 μm were used for micro-
flotation tests .
In the flotation test, all the reagents were industrial
products. Isobutyl xanthate(SIBX), PJ053, BK901B, Z200
and BK386 were used as collectors, of which BK901B and
BK386 were synthesized by BGRIMM. Lime was used
to adjust pH values and depress sulfur. Sodium hydrosul-
fide (NaSH) was used as an activator.BK233 is a frother
produced by BGRIMM. In the micro-flotation tests, the
frother terpene alcohol is chemically pure. The tap water
was used for all actual ore flotation tests. The water used in
the single mineral tests is distilled water.
Micro-Flotation Tests
The micro-flotation test was carried out by using an XFG
flotation machine with a fixed speed of 1300 r/min and a
flotation cell volume of 40 mL. Before conducting the test,
2.0 g of chalcopyrite was pretreated in an ultrasonic bath
for 3 min, after that, the samples were transferred into the
flotation cell and the collector was added. After stirring for
2 min, the frother was added. After stirring for another 2
min, a micro-flotation test was performed for 5 min. The
concentrates (froth products) and tailings were collected to
be dried and weighed.
Flotation Tests
The flotation tests were conducted using an XFG series
flotation machine (Jilin Prospecting Machinery Factory,
China) equipped with plexiglass flotation cells of various
volumes to accommodate different flotation operations.
The flotation feed was crushed, then rotary-split into 1 kg
portions, and subsequently wet grinded to achieve a 50%
solids content with specific grinding fineness in a mild steel
ball mill. The resulting slurry was transferred to a 3-litre
flotation cell for roughing, and the pulp concentration
was adjusted to 27%. Multiple flotation cells with differ-
ent volumes were used for cleaning and scavenging for
cleaning. The impeller speed was set to 1750 rpm before
reagent addition and flotation. After the flotation process,
the products were collected, dried, and weighed. Finally,
the recovery rate was calculated based on the dry weights
and grades of the products.
RESULTS AND DISCUSSION
Effect of Grinding Fineness on Roughing
Based on preliminary exploratory tests, the bulk flotation
process was determined and several condition flotation tests
were carried out. Under the rougher flotation conditions of
lime dosage of 300 g/t, Z200 dosage of 32 g/t, SIBX dos-
age of 7 g/t and BK233 dosage of 35 g/t, the effects of the
grinding size on the recoveries and grades of Cu and Mo
in the rougher concentrates were studied. The results are
shown in Figure 1.
As shown in Figure 1, as the mass ratio of particles
passing through 74 μm increases, the recoveries of Cu and
Mo also tend to increase accordingly. When the particle
size distribution exceeds 70% passing through 74 μm, the
increasing trend of Cu and Mo recoveries gradually slows
down. Therefore, the influence of other factors was exam-
ined in the condition where the grinding fineness is –74 μm
accounting for 70%.
Table 1. Chemical composition of the actual ore sample
(mass fraction, %)
Composition Content (wt%)
Cu 1.01
Mo 0.0064
S 1.8
Fe 2.52
Au* 0.08
Ag* 18.3
SiO2 66.58
CaO 0.32
MgO 1.35
Al2O3 16.99
K2O 3.29
Na
2 O 2.62
*The unit of silver content is grams per ton (g/t).
factors such as grinding fineness, collector types, rougher
pH value, and reagent dosage on copper and molybdenum
recovery rates. Ultimately, a flotation process and efficient
collector suitable for this type of ore are identified.
MATERIALS AND METHODS
Materials and Reagents
This study mainly focuses on actual copper molybdenum
ores obtained from northern Chile, but also uses chalcopy-
rite samples for micro-flotation tests.
The chemical composition of the actual ore is listed in
Table 1. And Table 1 shows that this ore sample consists
1.01% Cu and 0.0064% Mo. Process mineralogy of ore
samples suggests that the copper bearing minerals include
chalcopyrite (CuFeS2), bornite (Cu5FeS4), and chalcoc-
ite (Cu2S). Chalcopyrite (CuFeS2) is the primary copper
minerals found in the ore sample. And molybdenum metal
mainly exists as molybdenite .
The samples of chalcopyrite (97.2% purity) with par-
ticle size fractions of –74 +38 μm were used for micro-
flotation tests .
In the flotation test, all the reagents were industrial
products. Isobutyl xanthate(SIBX), PJ053, BK901B, Z200
and BK386 were used as collectors, of which BK901B and
BK386 were synthesized by BGRIMM. Lime was used
to adjust pH values and depress sulfur. Sodium hydrosul-
fide (NaSH) was used as an activator.BK233 is a frother
produced by BGRIMM. In the micro-flotation tests, the
frother terpene alcohol is chemically pure. The tap water
was used for all actual ore flotation tests. The water used in
the single mineral tests is distilled water.
Micro-Flotation Tests
The micro-flotation test was carried out by using an XFG
flotation machine with a fixed speed of 1300 r/min and a
flotation cell volume of 40 mL. Before conducting the test,
2.0 g of chalcopyrite was pretreated in an ultrasonic bath
for 3 min, after that, the samples were transferred into the
flotation cell and the collector was added. After stirring for
2 min, the frother was added. After stirring for another 2
min, a micro-flotation test was performed for 5 min. The
concentrates (froth products) and tailings were collected to
be dried and weighed.
Flotation Tests
The flotation tests were conducted using an XFG series
flotation machine (Jilin Prospecting Machinery Factory,
China) equipped with plexiglass flotation cells of various
volumes to accommodate different flotation operations.
The flotation feed was crushed, then rotary-split into 1 kg
portions, and subsequently wet grinded to achieve a 50%
solids content with specific grinding fineness in a mild steel
ball mill. The resulting slurry was transferred to a 3-litre
flotation cell for roughing, and the pulp concentration
was adjusted to 27%. Multiple flotation cells with differ-
ent volumes were used for cleaning and scavenging for
cleaning. The impeller speed was set to 1750 rpm before
reagent addition and flotation. After the flotation process,
the products were collected, dried, and weighed. Finally,
the recovery rate was calculated based on the dry weights
and grades of the products.
RESULTS AND DISCUSSION
Effect of Grinding Fineness on Roughing
Based on preliminary exploratory tests, the bulk flotation
process was determined and several condition flotation tests
were carried out. Under the rougher flotation conditions of
lime dosage of 300 g/t, Z200 dosage of 32 g/t, SIBX dos-
age of 7 g/t and BK233 dosage of 35 g/t, the effects of the
grinding size on the recoveries and grades of Cu and Mo
in the rougher concentrates were studied. The results are
shown in Figure 1.
As shown in Figure 1, as the mass ratio of particles
passing through 74 μm increases, the recoveries of Cu and
Mo also tend to increase accordingly. When the particle
size distribution exceeds 70% passing through 74 μm, the
increasing trend of Cu and Mo recoveries gradually slows
down. Therefore, the influence of other factors was exam-
ined in the condition where the grinding fineness is –74 μm
accounting for 70%.
Table 1. Chemical composition of the actual ore sample
(mass fraction, %)
Composition Content (wt%)
Cu 1.01
Mo 0.0064
S 1.8
Fe 2.52
Au* 0.08
Ag* 18.3
SiO2 66.58
CaO 0.32
MgO 1.35
Al2O3 16.99
K2O 3.29
Na
2 O 2.62
*The unit of silver content is grams per ton (g/t).