3042 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
INTRODUCTION
Copper, tin and indium are important strategic metals, and
zinc is an important basic metal. Due to the decreasing of
high-quality ore resources, the refractory complex poly-
metallic ore has become the main resource in China. The
super-large and low-grade polymetallic deposit in Dulong,
Wenshan, Yunnan Province in P.R.C. is a typical repre-
sentative of complex polymetallic resources. Its indium
reserves rank first over the world, which account for 36%
of the indium over the world. Its tin reserves rank third
in China, which account for 21.3% tin of China. Its zinc
reserves account for 9.6% of China. The mine has large
reserves, which has multiple co-associated elements such
as indium, zinc, tin, copper, silver, iron and sulfur [1–5] .
However, the useful minerals have fine distribution size
and low grade. Sphalerite is mainly indium-carrying mar-
matite, which has high iron content, high oxidizability, and
greatly changing floatability. Partial sphalerite has similar
floatability to chalcopyrite and pyrrhotite. The floatability
difference among iron sulfide minerals is huge, and cassit-
erite is easy to be over crushed. The separation and recovery
of this ore resource is extremely hard. Therefore, it used
to be called a “refractory ore” resource. Due to the limita-
tion of comprehensive utilization theory, the lack of highly
effective flotation reagents and backward technology, the
efficient utilization of this resource is seriously restricted.
Between 1958 and 1998, only 30% of tin was recovered.
Therefore, it is of great significance to break through the
technical problems of efficient comprehensive utilization of
copper, zinc, tin, indium, sulfur, iron and silver from the
ore resource.
As a consequence, more than 20 years of research work
was carried out aiming at the efficient separation of low-
grade copper-zinc-indium-tin-iron co-associated elements
in complex polymetallic ore in DuLong mine, Yunnan
Province. The mechanism of copper ammonia complex,
precise activation of sphalerite and synchronous depres-
sion of iron sulfide, efficient new flotation reagents, better
recovery of cassiterite, and large-scale utilization of waste
rock were studied. The activation effect of copper ammo-
nia complex by slow-release was discovered. A theoretical
breakthrough was achieved, and a series of high-efficiency
flotation reagents were developed. Five key technologies
were established. By using new flotation reagents and new
technologies, 7 pricing elements such as tin, zinc, indium,
copper, silver, sulfur and iron were efficiently recovered
from the refractory ore in Dulong mine, Yunnan province,
and the annual metal output grows from 115 tons in 1998
to 430,000 tons until now. The achievements of this project
provide 25% of China’s tin concentrate products every year.
EXPERIMENTS
The mineral composition was analyzed by X-Ray Diffraction
(XRD), X-ray fluorescence (XRF), mineral liberation ana-
lyzer (MLA) and chemical multi-element analysis etc. The
laboratory basic test, pilot test and industrial test were
carried out. The flotation tests of single mineral, artificial
mixed ore and actual ore were performed. The flotation
reagents were analytical grade used in the laboratory basic
test, pilot test, and mechanism research. The reagents used
in industrial test were industrial grade. Infrared spectrum
analysis (FT-IR), zeta potential analysis, X-ray photoelec-
tron spectroscopy (XPS) analysis, first-principle calcula-
tion, etc. were used in the mechanism research.
RESULTS AND DISCUSSION
Study on the Acting Mechanism of Copper Ammonia
Complex
Copper sulfate is a common activator for marmatite and
sphalerite, and its mechanism is shown in Equation 1 to
Equation 4. However, there are some problems of it, such
as unstable effective concentration and large consumption
of copper ions under high alkali conditions. In order to
solve the problem, the copper ammonia complex need to be
formed by adding ammonium chloride into the copper sul-
fate system to improve the activation effect. Through single
mineral flotation test and analysis of adsorption capacity,
chemical elements and XPS etc., we found that the behav-
ior of zinc ion dissolution and copper adsorption, activa-
tion products on mineral surface as well as components in
solution had significant changes. The results indicated that
compared with copper sulfate, copper ammonia complex
could store and release copper ions in the flotation process
of complex nonferrous metal ores, and had a slow-release
effect. Its mechanism was shown in Figure 1. In the copper
ammonia system, copper ions could be “stored” in the form
of copper ammonia complexes and hydroxyl copper. When
Cu2+ replaced the zinc ions on the surface of sphalerite, the
sphalerite was activated, and the concentration of Cu2+ in
the solution would be reduced and the component balance
Keywords: Complex polymetallic ore, Flotation, Collector, Depressant, Waste rock
INTRODUCTION
Copper, tin and indium are important strategic metals, and
zinc is an important basic metal. Due to the decreasing of
high-quality ore resources, the refractory complex poly-
metallic ore has become the main resource in China. The
super-large and low-grade polymetallic deposit in Dulong,
Wenshan, Yunnan Province in P.R.C. is a typical repre-
sentative of complex polymetallic resources. Its indium
reserves rank first over the world, which account for 36%
of the indium over the world. Its tin reserves rank third
in China, which account for 21.3% tin of China. Its zinc
reserves account for 9.6% of China. The mine has large
reserves, which has multiple co-associated elements such
as indium, zinc, tin, copper, silver, iron and sulfur [1–5] .
However, the useful minerals have fine distribution size
and low grade. Sphalerite is mainly indium-carrying mar-
matite, which has high iron content, high oxidizability, and
greatly changing floatability. Partial sphalerite has similar
floatability to chalcopyrite and pyrrhotite. The floatability
difference among iron sulfide minerals is huge, and cassit-
erite is easy to be over crushed. The separation and recovery
of this ore resource is extremely hard. Therefore, it used
to be called a “refractory ore” resource. Due to the limita-
tion of comprehensive utilization theory, the lack of highly
effective flotation reagents and backward technology, the
efficient utilization of this resource is seriously restricted.
Between 1958 and 1998, only 30% of tin was recovered.
Therefore, it is of great significance to break through the
technical problems of efficient comprehensive utilization of
copper, zinc, tin, indium, sulfur, iron and silver from the
ore resource.
As a consequence, more than 20 years of research work
was carried out aiming at the efficient separation of low-
grade copper-zinc-indium-tin-iron co-associated elements
in complex polymetallic ore in DuLong mine, Yunnan
Province. The mechanism of copper ammonia complex,
precise activation of sphalerite and synchronous depres-
sion of iron sulfide, efficient new flotation reagents, better
recovery of cassiterite, and large-scale utilization of waste
rock were studied. The activation effect of copper ammo-
nia complex by slow-release was discovered. A theoretical
breakthrough was achieved, and a series of high-efficiency
flotation reagents were developed. Five key technologies
were established. By using new flotation reagents and new
technologies, 7 pricing elements such as tin, zinc, indium,
copper, silver, sulfur and iron were efficiently recovered
from the refractory ore in Dulong mine, Yunnan province,
and the annual metal output grows from 115 tons in 1998
to 430,000 tons until now. The achievements of this project
provide 25% of China’s tin concentrate products every year.
EXPERIMENTS
The mineral composition was analyzed by X-Ray Diffraction
(XRD), X-ray fluorescence (XRF), mineral liberation ana-
lyzer (MLA) and chemical multi-element analysis etc. The
laboratory basic test, pilot test and industrial test were
carried out. The flotation tests of single mineral, artificial
mixed ore and actual ore were performed. The flotation
reagents were analytical grade used in the laboratory basic
test, pilot test, and mechanism research. The reagents used
in industrial test were industrial grade. Infrared spectrum
analysis (FT-IR), zeta potential analysis, X-ray photoelec-
tron spectroscopy (XPS) analysis, first-principle calcula-
tion, etc. were used in the mechanism research.
RESULTS AND DISCUSSION
Study on the Acting Mechanism of Copper Ammonia
Complex
Copper sulfate is a common activator for marmatite and
sphalerite, and its mechanism is shown in Equation 1 to
Equation 4. However, there are some problems of it, such
as unstable effective concentration and large consumption
of copper ions under high alkali conditions. In order to
solve the problem, the copper ammonia complex need to be
formed by adding ammonium chloride into the copper sul-
fate system to improve the activation effect. Through single
mineral flotation test and analysis of adsorption capacity,
chemical elements and XPS etc., we found that the behav-
ior of zinc ion dissolution and copper adsorption, activa-
tion products on mineral surface as well as components in
solution had significant changes. The results indicated that
compared with copper sulfate, copper ammonia complex
could store and release copper ions in the flotation process
of complex nonferrous metal ores, and had a slow-release
effect. Its mechanism was shown in Figure 1. In the copper
ammonia system, copper ions could be “stored” in the form
of copper ammonia complexes and hydroxyl copper. When
Cu2+ replaced the zinc ions on the surface of sphalerite, the
sphalerite was activated, and the concentration of Cu2+ in
the solution would be reduced and the component balance
Keywords: Complex polymetallic ore, Flotation, Collector, Depressant, Waste rock