1964 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
open-pit copper sulfide ore exceeds 0.4%, and P2O5 con-
tent in phosphate rock is higher than 10–12%. Therefore,
the beneficiation process for ultra-low -grade magnetite ore,
requires a very high enrichment ratio to obtain qualified
concentrates, posing significant challenges in development.
China’s reliance on foreign iron ore exceeds 80%. To
enhance self-sufficiency in iron ore, efforts have been made
to develop and utilize this hard to process, low grade iron
ore. However, the majority of mines primarily focus on iron
resource recovery. Currently, the process flow of pre con-
centration, stage grinding and stage magnetic separation
is predominantly utilized to recover magnetite from ultra-
low grade magnetite ores, with this process being relatively
mature (Yuan, 2022 Li et al., 2022 Zhou, 2016) .Only
10% of mines undertake comprehensive phosphorus recov-
ery. Typically, fatty acid collectors are employed for apatite
recovery through direct flotation in iron processing tailings
(Ruan et al.,2019 Muhammad et al., 2022). However,
problems and challenges persist, including difficulty in
achieving standards for phosphate concentrate grade, high
chemical costs, and low recovery rates. The associated low-
grade copper resources are usually not recovered, leading
to a significant amount of resource wastage. In summary,
ultra-low grade magnetite ore resources contain various
valuable components but have extremely low grades. This
necessitates the development of high enrichment ratios
(typically up to 10) and low-cost recycling technologies
that consider both utilization efficiency and economic fac-
tors in the recovery process.
The development of pre concentration technology is
one of the key strategies for reducing the beneficiation costs
of low-grade ores (Ao et al.,2021 Wang et al., 2016 Wang,
2013). This technology is designed to reduce the amount
of subsequent grinding or flotation slurry feed and improve
the grades of flotation feed. By reducing the feed amount
of grinding and flotation, it significantly decreases energy
consumption during milling and reduces reagent consump-
tion during flotation. This paper investigates the process
mineralogy characteristics of the ore, aiming to assess the
feasibility of pre concentration technology based on these
properties. Additionally, it explores recovery technologies
for iron, copper, and phosphorus minerals, tailored to
the specific mineralogical properties of the ore. Given the
relatively low value of copper in the raw ore, it is essen-
tial to ensure that the comprehensive recovery of copper
does not interfere with the primary processes of iron and
phosphorus recovery. Consequently, the focus of copper
flotation recovery technology should prioritize achieving
a qualified copper concentrate rather than maximizing the
recovery rate. Based on the aforementioned research, this
paper proposes the concept of performing the main separa-
tion process under rough grinding conditions, and reduced
feeding quantity by multistage pre concentration to form a
high efficiency and low consumption comprehensive recov-
ery technology that is flexible, and able to fully utilize the
properties of the ore. The findings offer valuable insights for
similar mines seeking to optimize their recovery processes.
MATERIALS AND METHODS
Materials and Reagents
The ultra low grade magnetite ore used for this investiga-
tion was obtained from Hebei province, China. The chemi-
cal composition of the ore is provided in Table 1. As shown
in Table 1, the sample exhibits a TFe content of 14.33%
and an mFe content of 7.26%. Additionally, the sample
contains 2.11% P2O5, 1.48% TiO2, 0.043% Cu, and
0.22% S. Based on the preliminary grade, Fe, P2O5, Cu,
and TiO2 in the mineral sample are potentially suitable for
comprehensive utilization.
In the flotation test, all reagents were industrial prod-
ucts. Collectors JC and JY, synthesized by BGRIMM,
were utilized. Lime served as the pyrite depressant, while
sodium silicate acted as the dispersant. Sodium carbon-
ate was employed to adjust the pulp pH. BK201, a frother
manufactured by BGRIMM, was also used. Tap water was
utilized for all tests.
Magnetic Separation Tests
The magnetic separation tests conducted in this study com-
prised dry pre concentration tests, stage grinding-stage
magnetic separation tests, and wet pre concentration tests.
The ore sample for the dry pre concentration tests was a
crushed raw ore (–3 mm), and the equipment used was a
Table 1. Chemical composition of the ore sample (mass
fraction, %)
Composition
Content
(wt%) Composition
Content
(wt%)
Fe 14.33 mFe 7.26
V
2 O
5 0.104 CaF
2 4.28
SiO2 36.25 TiO2 1.48
Al2O3 8.73 CaO 17.35
MgO 8.21 K
2 O 0.27
P
2 O
5 2.11 S 0.22
Na2O 1.21 Cu 0.043
Zn 0.024 Au* 0.06
Ag* 13.27
*The unit of gold and silver content is grams per ton (g/t).
open-pit copper sulfide ore exceeds 0.4%, and P2O5 con-
tent in phosphate rock is higher than 10–12%. Therefore,
the beneficiation process for ultra-low -grade magnetite ore,
requires a very high enrichment ratio to obtain qualified
concentrates, posing significant challenges in development.
China’s reliance on foreign iron ore exceeds 80%. To
enhance self-sufficiency in iron ore, efforts have been made
to develop and utilize this hard to process, low grade iron
ore. However, the majority of mines primarily focus on iron
resource recovery. Currently, the process flow of pre con-
centration, stage grinding and stage magnetic separation
is predominantly utilized to recover magnetite from ultra-
low grade magnetite ores, with this process being relatively
mature (Yuan, 2022 Li et al., 2022 Zhou, 2016) .Only
10% of mines undertake comprehensive phosphorus recov-
ery. Typically, fatty acid collectors are employed for apatite
recovery through direct flotation in iron processing tailings
(Ruan et al.,2019 Muhammad et al., 2022). However,
problems and challenges persist, including difficulty in
achieving standards for phosphate concentrate grade, high
chemical costs, and low recovery rates. The associated low-
grade copper resources are usually not recovered, leading
to a significant amount of resource wastage. In summary,
ultra-low grade magnetite ore resources contain various
valuable components but have extremely low grades. This
necessitates the development of high enrichment ratios
(typically up to 10) and low-cost recycling technologies
that consider both utilization efficiency and economic fac-
tors in the recovery process.
The development of pre concentration technology is
one of the key strategies for reducing the beneficiation costs
of low-grade ores (Ao et al.,2021 Wang et al., 2016 Wang,
2013). This technology is designed to reduce the amount
of subsequent grinding or flotation slurry feed and improve
the grades of flotation feed. By reducing the feed amount
of grinding and flotation, it significantly decreases energy
consumption during milling and reduces reagent consump-
tion during flotation. This paper investigates the process
mineralogy characteristics of the ore, aiming to assess the
feasibility of pre concentration technology based on these
properties. Additionally, it explores recovery technologies
for iron, copper, and phosphorus minerals, tailored to
the specific mineralogical properties of the ore. Given the
relatively low value of copper in the raw ore, it is essen-
tial to ensure that the comprehensive recovery of copper
does not interfere with the primary processes of iron and
phosphorus recovery. Consequently, the focus of copper
flotation recovery technology should prioritize achieving
a qualified copper concentrate rather than maximizing the
recovery rate. Based on the aforementioned research, this
paper proposes the concept of performing the main separa-
tion process under rough grinding conditions, and reduced
feeding quantity by multistage pre concentration to form a
high efficiency and low consumption comprehensive recov-
ery technology that is flexible, and able to fully utilize the
properties of the ore. The findings offer valuable insights for
similar mines seeking to optimize their recovery processes.
MATERIALS AND METHODS
Materials and Reagents
The ultra low grade magnetite ore used for this investiga-
tion was obtained from Hebei province, China. The chemi-
cal composition of the ore is provided in Table 1. As shown
in Table 1, the sample exhibits a TFe content of 14.33%
and an mFe content of 7.26%. Additionally, the sample
contains 2.11% P2O5, 1.48% TiO2, 0.043% Cu, and
0.22% S. Based on the preliminary grade, Fe, P2O5, Cu,
and TiO2 in the mineral sample are potentially suitable for
comprehensive utilization.
In the flotation test, all reagents were industrial prod-
ucts. Collectors JC and JY, synthesized by BGRIMM,
were utilized. Lime served as the pyrite depressant, while
sodium silicate acted as the dispersant. Sodium carbon-
ate was employed to adjust the pulp pH. BK201, a frother
manufactured by BGRIMM, was also used. Tap water was
utilized for all tests.
Magnetic Separation Tests
The magnetic separation tests conducted in this study com-
prised dry pre concentration tests, stage grinding-stage
magnetic separation tests, and wet pre concentration tests.
The ore sample for the dry pre concentration tests was a
crushed raw ore (–3 mm), and the equipment used was a
Table 1. Chemical composition of the ore sample (mass
fraction, %)
Composition
Content
(wt%) Composition
Content
(wt%)
Fe 14.33 mFe 7.26
V
2 O
5 0.104 CaF
2 4.28
SiO2 36.25 TiO2 1.48
Al2O3 8.73 CaO 17.35
MgO 8.21 K
2 O 0.27
P
2 O
5 2.11 S 0.22
Na2O 1.21 Cu 0.043
Zn 0.024 Au* 0.06
Ag* 13.27
*The unit of gold and silver content is grams per ton (g/t).