3551
Conversion of Siliceous Tailings to Permeable Bricks—
Optimization of Pore Structure
Li Yong, Zhao Qingchao, Li Weiguang, Zhu Yangge, Li Xueliang, Tang Peiyao
State Key Laboratory of Mineral Processing, BGRIMM Technology Group, Beijing, China
ABSTRACT: Tailings are a kind of solid waste that needs to be treated, whereas low activity is a challenge for
its utilization. Herein, we proposed a new strategy for utilizing tailings to prepare permeable bricks. The process
involves in combining gold tailings (GT) and diamond tailings (DT) with kaolin to prepare recycled aggregates,
and then wrapping them with binders via pressing and sintering to prepare permeable bricks. The effects of
molding pressure, sintering temperature, and sintering time on the performance of permeable bricks were
systematically studied. The phase composition, microstructure, and pore structure distribution of permeable
bricks were analyzed using XRD, SEM, and industrial CT. The results showed that the splitting tensile strength
and permeability coefficient of permeable bricks are negatively correlated. Under the optimal process conditions,
the splitting tensile strength and permeability coefficient of the prepared permeable bricks reached 3.65MPa
and 1.89×10–2cm/s, respectively, meeting the requirements of Chinese standards. The primary mineral phases of
tailings-based permeable brick were quartz, albite, and amorphous fractions. The total pore volume accounted
for 11.07% of the sample volume, of which the connected pores and closed pores account for 10.62% and
0.45% of the total sample volume, respectively. The well-developed pore structure and connectivity enhanced
the water permeability and strength of tailings-based permeable brick. This research demonstrated the feasibility
of preparing permeable bricks by using fine tailings and provided a new strategy for the high-value utilization
of solid waste.
Keywords: Tailings Permeable bricks Recycled aggregate Pore structure
INTRODUCTION
With the continuous development and utilization of global
mineral resources, the quality of mineral resources con-
tinues to decline[Wang et al., 2020], and the difficulty of
mineral resources development and utilization has further
increased[Li et al., 2022]. In addition, the massive dis-
charge and accumulation of tailings and the potential envi-
ronmental pollution have seriously constrained the rapid
growth of the mining sector[Tao et al., 2023]. Gold tailings
(GT) and Diamond tailings (DT) are the by-products of the
development and utilization of gold and diamond mineral
resources, respectively. At present, the primary treatment
method is to pile up tailings storage, which not only occu-
pies a large amount of land but also poses a severe environ-
mental risk. In addition, the construction and maintenance
of the tailings storage will also be costly[Han et al., 2023].
In 2021, China’s gold tailings production amounted to
more than 160 million tonnes, and the accumulated stock-
pile amounted to more than 2.23 billion tonnes. Whereas,
its comprehensive utilization rate is only 26%[Niyonzima
Conversion of Siliceous Tailings to Permeable Bricks—
Optimization of Pore Structure
Li Yong, Zhao Qingchao, Li Weiguang, Zhu Yangge, Li Xueliang, Tang Peiyao
State Key Laboratory of Mineral Processing, BGRIMM Technology Group, Beijing, China
ABSTRACT: Tailings are a kind of solid waste that needs to be treated, whereas low activity is a challenge for
its utilization. Herein, we proposed a new strategy for utilizing tailings to prepare permeable bricks. The process
involves in combining gold tailings (GT) and diamond tailings (DT) with kaolin to prepare recycled aggregates,
and then wrapping them with binders via pressing and sintering to prepare permeable bricks. The effects of
molding pressure, sintering temperature, and sintering time on the performance of permeable bricks were
systematically studied. The phase composition, microstructure, and pore structure distribution of permeable
bricks were analyzed using XRD, SEM, and industrial CT. The results showed that the splitting tensile strength
and permeability coefficient of permeable bricks are negatively correlated. Under the optimal process conditions,
the splitting tensile strength and permeability coefficient of the prepared permeable bricks reached 3.65MPa
and 1.89×10–2cm/s, respectively, meeting the requirements of Chinese standards. The primary mineral phases of
tailings-based permeable brick were quartz, albite, and amorphous fractions. The total pore volume accounted
for 11.07% of the sample volume, of which the connected pores and closed pores account for 10.62% and
0.45% of the total sample volume, respectively. The well-developed pore structure and connectivity enhanced
the water permeability and strength of tailings-based permeable brick. This research demonstrated the feasibility
of preparing permeable bricks by using fine tailings and provided a new strategy for the high-value utilization
of solid waste.
Keywords: Tailings Permeable bricks Recycled aggregate Pore structure
INTRODUCTION
With the continuous development and utilization of global
mineral resources, the quality of mineral resources con-
tinues to decline[Wang et al., 2020], and the difficulty of
mineral resources development and utilization has further
increased[Li et al., 2022]. In addition, the massive dis-
charge and accumulation of tailings and the potential envi-
ronmental pollution have seriously constrained the rapid
growth of the mining sector[Tao et al., 2023]. Gold tailings
(GT) and Diamond tailings (DT) are the by-products of the
development and utilization of gold and diamond mineral
resources, respectively. At present, the primary treatment
method is to pile up tailings storage, which not only occu-
pies a large amount of land but also poses a severe environ-
mental risk. In addition, the construction and maintenance
of the tailings storage will also be costly[Han et al., 2023].
In 2021, China’s gold tailings production amounted to
more than 160 million tonnes, and the accumulated stock-
pile amounted to more than 2.23 billion tonnes. Whereas,
its comprehensive utilization rate is only 26%[Niyonzima