1174 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
lead complexes of benzohydroxamic acid), designed using
the theory of self-assembly and molecular regulation at the
mineral flotation interface[7]. The application of Pb-BHA
avoids the demons of fatty acids and water glass, and the
recovery rate of tungsten is greatly improved. Central South
University have also pioneered a advanced atmospheric
flotation technique for both wolframite and scheelite
using Pb-BHA complexes, and this has led to remarkable
advances in tungsten ore processing[8]. In contrast to the
internationally accepted fatty-acid method, flotation with
Pb-BHA has advantage of high selectivity, which effectively
separates scheelite and wolframite from other calcium min-
erals (shown in Figure 1).
And as head grades of tungsten-tin polymetallic ores
have decreased in recent years, so has the separability. This
recent degradation in the separability has presented chal-
lenges in the recovery process. A significant problem has
emerged in the recovery of tungsten due to the relatively
weak collecting performance of Pb-BHA, as highlighted
in recent studies[10]. Furthermore, neither the traditional
fatty acid method nor the more recent Pb-BHA method can
effectively recover cassiterite, resulting in a substantial waste
of tin resources. For instance, the associated tin reserves
in the Shizhuyuan tungsten ore bodies are estimated at
460,000 tons, yet the annual amount of tin discharged to
the tailings pond exceeds 1500 tons[11]. Addressing these
challenges requires innovative collectors and technologies
to improve the recovery of these valuable minerals. Based
on previous studies [12, 13], Pb-BHA has been shown to
adsorb onto scheelite, wolframite, and cassiterite through
the bonding of Pb and O atoms on the mineral surfaces.
However, the recovery of wolframite and cassiterite in prac-
tice is lower than that of scheelite, which needs further
study of the flotation kinetics.
So, in response to the declining performance at the
Shizhuyuan plant, a study was commissioned to investigate
the flotation behaviors and kinetics of scheelite, wolframite,
and cassiterite using Pb-BHA as a collector, with a view
to develop a new, enhanced collector that improves upon
Pb-BHA. The rest of this paper describes that study and
the implementation of the results in the Shizhuyuan plant.
THE IMPLEMENTATION OF THE PB-BHA
PROCESS IN THE SHIZHUYUAN PLANT
The Composition of the Tungsten in the
Shizhuyuan Ore
The Shizhuyuan Mine, located in Chenzhou City, Hunan
Province, China, serves as an example of a complex, poly-
metallic W-Sn ore. The ore from Shizhuyuan contains
0.34% WO3 and 0.12% Sn[6]. The tin exists in the form of
cassiterite. As shown in Table 1, tungsten primarily exists in
the ore as wolframite and scheelite, with only 1.15% occur-
ring as tungstite. The distribution of tungsten between wol-
framite and scheelite is approximately 3:7. The main gangue
minerals include garnet, calcite, fluorite, and quartz, etc.
Implementation of the Original Pb-BHA Tungsten
Process at Shizhuyuan Mine
The original Pb-BHA process for tungsten flotation has rev-
olutionalized the processing of Tungsten in recent years by
economically replacing Petrov’s process. The Pb-BHA pro-
cess represents a notable advancement over Petrov’s process
by eliminating the necessity for environmentally harmful
water glass (Na2SiO3), operating under atmospheric tem-
perature and pressure conditions.
Furthermore, the wastewater from the Pb-BHA pro-
cess, being free of waterglass, is readily re-used in the pro-
cess, leading to another significant benefit. Figure. 1 The room-temperature mixed flotation technique
for both wolframite and scheelite using Pb-BHA [9]
Table 1. Phase analysis of tungsten in Shizhuyuan ore sample, %
Phase Scheelite Wolframite Tungstite Total
WO3 content 0.24 0.095 0.005 0.34
WO
3 distribution rate 70.59 27.94 1.15 100.00

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1174 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
lead complexes of benzohydroxamic acid), designed using
the theory of self-assembly and molecular regulation at the
mineral flotation interface[7]. The application of Pb-BHA
avoids the demons of fatty acids and water glass, and the
recovery rate of tungsten is greatly improved. Central South
University have also pioneered a advanced atmospheric
flotation technique for both wolframite and scheelite
using Pb-BHA complexes, and this has led to remarkable
advances in tungsten ore processing[8]. In contrast to the
internationally accepted fatty-acid method, flotation with
Pb-BHA has advantage of high selectivity, which effectively
separates scheelite and wolframite from other calcium min-
erals (shown in Figure 1).
And as head grades of tungsten-tin polymetallic ores
have decreased in recent years, so has the separability. This
recent degradation in the separability has presented chal-
lenges in the recovery process. A significant problem has
emerged in the recovery of tungsten due to the relatively
weak collecting performance of Pb-BHA, as highlighted
in recent studies[10]. Furthermore, neither the traditional
fatty acid method nor the more recent Pb-BHA method can
effectively recover cassiterite, resulting in a substantial waste
of tin resources. For instance, the associated tin reserves
in the Shizhuyuan tungsten ore bodies are estimated at
460,000 tons, yet the annual amount of tin discharged to
the tailings pond exceeds 1500 tons[11]. Addressing these
challenges requires innovative collectors and technologies
to improve the recovery of these valuable minerals. Based
on previous studies [12, 13], Pb-BHA has been shown to
adsorb onto scheelite, wolframite, and cassiterite through
the bonding of Pb and O atoms on the mineral surfaces.
However, the recovery of wolframite and cassiterite in prac-
tice is lower than that of scheelite, which needs further
study of the flotation kinetics.
So, in response to the declining performance at the
Shizhuyuan plant, a study was commissioned to investigate
the flotation behaviors and kinetics of scheelite, wolframite,
and cassiterite using Pb-BHA as a collector, with a view
to develop a new, enhanced collector that improves upon
Pb-BHA. The rest of this paper describes that study and
the implementation of the results in the Shizhuyuan plant.
THE IMPLEMENTATION OF THE PB-BHA
PROCESS IN THE SHIZHUYUAN PLANT
The Composition of the Tungsten in the
Shizhuyuan Ore
The Shizhuyuan Mine, located in Chenzhou City, Hunan
Province, China, serves as an example of a complex, poly-
metallic W-Sn ore. The ore from Shizhuyuan contains
0.34% WO3 and 0.12% Sn[6]. The tin exists in the form of
cassiterite. As shown in Table 1, tungsten primarily exists in
the ore as wolframite and scheelite, with only 1.15% occur-
ring as tungstite. The distribution of tungsten between wol-
framite and scheelite is approximately 3:7. The main gangue
minerals include garnet, calcite, fluorite, and quartz, etc.
Implementation of the Original Pb-BHA Tungsten
Process at Shizhuyuan Mine
The original Pb-BHA process for tungsten flotation has rev-
olutionalized the processing of Tungsten in recent years by
economically replacing Petrov’s process. The Pb-BHA pro-
cess represents a notable advancement over Petrov’s process
by eliminating the necessity for environmentally harmful
water glass (Na2SiO3), operating under atmospheric tem-
perature and pressure conditions.
Furthermore, the wastewater from the Pb-BHA pro-
cess, being free of waterglass, is readily re-used in the pro-
cess, leading to another significant benefit. Figure. 1 The room-temperature mixed flotation technique
for both wolframite and scheelite using Pb-BHA [9]
Table 1. Phase analysis of tungsten in Shizhuyuan ore sample, %
Phase Scheelite Wolframite Tungstite Total
WO3 content 0.24 0.095 0.005 0.34
WO
3 distribution rate 70.59 27.94 1.15 100.00

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1173
A New Tungsten Process to Reduce Environmental Impact,
Improve Grade and Recovery and Facilitate Wastewater Reuse
Junhao Fu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Haisheng Han, Wei Sun, Yuehu Hu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Engineering Research Center of Ministry of Education for Carbon Emission Reduction in
Metal Resource Exploitation and Utilization, Central South University, Changsha, China
Stephen Pooley
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Jiangxi Copper Research Division, Nanchang, China
ABSTRACT: A new Tungsten process has been developed to replace Petrov’s process. Based around a novel
collector this process achieves better separation of scheelite and fluorite, improves scheelite grade and recovery,
is much simpler, and the removal of the water glass facilitates straight-forward reuse of the wastewater. And it
works at ambient temperature and pressure.
However, challenges have arisen when implementing this process in Tungsten deposits also containing signifi-
cant tin reserves in the form of cassiterite.
This paper describes how this novel flotation process was developed further to deal with valuable minerals which
are not easily separated from the Tungsten minerals.
INTRODUCTION
Tungsten and tin are strategic mineral resources, and their
continued supply is critical to the long-term development
of the global economy [1, 2]. Currently, there is a scar-
city of high-grade tungsten and tin mineral resources, as
lower-grade and intricate ores emerge as the predominant
resources being developed[3]. In nature, most tin occurs
in the form of cassiterite, with the tungsten-tin ore belt in
the Nanling range belt of China as a prime example[4].
Most tungsten-tin polymetallic ores are dominated by
the recovery of tungsten resources because the grade and
reserves of tungsten are usually higher than tin, and the
floatability of tungsten minerals is better than cassiterite[5].
Tungsten-tin resources usually have a large number of
valuable components, with extremely complex co-occur-
rence relationships and fine particle sizes that pose sig-
nificant challenges to traditional processing techniques[6].
Targeting these complex refractory tungsten-tin polyme-
tallic ores, the mineral processing team at Central South
University has developed a novel and efficient collector
known as the Pb-BHA complex collector (consisting of

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Extracted Text (may have errors)

1173
A New Tungsten Process to Reduce Environmental Impact,
Improve Grade and Recovery and Facilitate Wastewater Reuse
Junhao Fu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Haisheng Han, Wei Sun, Yuehu Hu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Engineering Research Center of Ministry of Education for Carbon Emission Reduction in
Metal Resource Exploitation and Utilization, Central South University, Changsha, China
Stephen Pooley
School of Minerals Processing and Bioengineering, Central South University, Changsha, China
Jiangxi Copper Research Division, Nanchang, China
ABSTRACT: A new Tungsten process has been developed to replace Petrov’s process. Based around a novel
collector this process achieves better separation of scheelite and fluorite, improves scheelite grade and recovery,
is much simpler, and the removal of the water glass facilitates straight-forward reuse of the wastewater. And it
works at ambient temperature and pressure.
However, challenges have arisen when implementing this process in Tungsten deposits also containing signifi-
cant tin reserves in the form of cassiterite.
This paper describes how this novel flotation process was developed further to deal with valuable minerals which
are not easily separated from the Tungsten minerals.
INTRODUCTION
Tungsten and tin are strategic mineral resources, and their
continued supply is critical to the long-term development
of the global economy [1, 2]. Currently, there is a scar-
city of high-grade tungsten and tin mineral resources, as
lower-grade and intricate ores emerge as the predominant
resources being developed[3]. In nature, most tin occurs
in the form of cassiterite, with the tungsten-tin ore belt in
the Nanling range belt of China as a prime example[4].
Most tungsten-tin polymetallic ores are dominated by
the recovery of tungsten resources because the grade and
reserves of tungsten are usually higher than tin, and the
floatability of tungsten minerals is better than cassiterite[5].
Tungsten-tin resources usually have a large number of
valuable components, with extremely complex co-occur-
rence relationships and fine particle sizes that pose sig-
nificant challenges to traditional processing techniques[6].
Targeting these complex refractory tungsten-tin polyme-
tallic ores, the mineral processing team at Central South
University has developed a novel and efficient collector
known as the Pb-BHA complex collector (consisting of

XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1175
This process has now been implemented in 10 sites
in China and Russia with a large plant in Kazakhstan cur-
rently in the design phase.
This original Pb-BHA process was implemented to
recover the Tungsten in the polymetallic ore from the
Shizhuyuan mine in Chenzhou, China. The original
Tungsten flowsheet implemented in the Shizhuyuan plant
employed Pb-BHA as the only collector and Al-Na2SiO3 as
the depressant. This is shown in Figure 2.
Production Performance of the Original Pb-BHA
Process at Shizhuyuan Mine
Following the implementation of the original Pb-BHA
tungsten recovery process at the Shizhuyuan plant, the
performance was monitored closely. The tungsten and tin
recovery is shown in Table 2.
The tungsten recovery in the original process was
70.63% and the WO3 grade of the concentrate is 30.20%.
However, the recovery of tin was not as hoped, and was
as low as 8.83% with a Sn grade is just 1.46%. This needed
to be addressed. As a result, a study was commissioned into
the flotation performance of the ore.
This investigation into the distinct behaviors of schee-
lite and wolframite in the original flotation process involved
analyzing the occurrence of WO3 at different stages, with
the results shown in Figure 3. Through the scavenger
stages, there is a gradual decrease in the WO3 distribution
of scheelite in the tailings, accompanied by a correspond-
ing increase in wolframite. This observation indicates that
the loss of wolframite during the flotation process is greater
than that of scheelite. Additionally, as presented in Table 3,
the WO3 content of the tailings is 0.0965%, and the pro-
portion of tungsten distribution between wolframite and
scheelite has shifted to 6:4 (compared to 3:7 in the feed).
This demonstrates that scheelite is recovered much more
Na2CO3
pH =8.7
Frother
Sulfide tailings
Rougher
Tungsten tailings
Al-Na2SiO3
Cleaner I Scavenger I
Scavenger II
Cleaner II
Al-Na2SiO3
Pb-BHA
WO3-Sn concentrate
Scavenger III
Figure 2. The original Pb-BHA tungsten-tin flotation flowsheet for the Shizhuyuan plant
Table 2. The production index in the original flotation
process
Products
Yield,
%
Grade, %Recovery, %
WO
3 Sn WO
3 Sn
Tungsten
concentrate
0.79 30.20 1.46 70.63 8.83
Tailings 99.21 0.10 0.12 29.37 91.17
Feed 100.00 0.34 0.13 100.00 100.00

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Extracted Text (may have errors)

XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1175
This process has now been implemented in 10 sites
in China and Russia with a large plant in Kazakhstan cur-
rently in the design phase.
This original Pb-BHA process was implemented to
recover the Tungsten in the polymetallic ore from the
Shizhuyuan mine in Chenzhou, China. The original
Tungsten flowsheet implemented in the Shizhuyuan plant
employed Pb-BHA as the only collector and Al-Na2SiO3 as
the depressant. This is shown in Figure 2.
Production Performance of the Original Pb-BHA
Process at Shizhuyuan Mine
Following the implementation of the original Pb-BHA
tungsten recovery process at the Shizhuyuan plant, the
performance was monitored closely. The tungsten and tin
recovery is shown in Table 2.
The tungsten recovery in the original process was
70.63% and the WO3 grade of the concentrate is 30.20%.
However, the recovery of tin was not as hoped, and was
as low as 8.83% with a Sn grade is just 1.46%. This needed
to be addressed. As a result, a study was commissioned into
the flotation performance of the ore.
This investigation into the distinct behaviors of schee-
lite and wolframite in the original flotation process involved
analyzing the occurrence of WO3 at different stages, with
the results shown in Figure 3. Through the scavenger
stages, there is a gradual decrease in the WO3 distribution
of scheelite in the tailings, accompanied by a correspond-
ing increase in wolframite. This observation indicates that
the loss of wolframite during the flotation process is greater
than that of scheelite. Additionally, as presented in Table 3,
the WO3 content of the tailings is 0.0965%, and the pro-
portion of tungsten distribution between wolframite and
scheelite has shifted to 6:4 (compared to 3:7 in the feed).
This demonstrates that scheelite is recovered much more
Na2CO3
pH =8.7
Frother
Sulfide tailings
Rougher
Tungsten tailings
Al-Na2SiO3
Cleaner I Scavenger I
Scavenger II
Cleaner II
Al-Na2SiO3
Pb-BHA
WO3-Sn concentrate
Scavenger III
Figure 2. The original Pb-BHA tungsten-tin flotation flowsheet for the Shizhuyuan plant
Table 2. The production index in the original flotation
process
Products
Yield,
%
Grade, %Recovery, %
WO
3 Sn WO
3 Sn
Tungsten
concentrate
0.79 30.20 1.46 70.63 8.83
Tailings 99.21 0.10 0.12 29.37 91.17
Feed 100.00 0.34 0.13 100.00 100.00