Recent progress in synthesis of composite powders and their applications in low-carbon refractories

Abstract

The development of low-carbon refractories is of great significance, but it is limited by the deteriorated properties that resulted from the decreased graphite content. Incorporating composite powders has proved to be effective in improving the properties of low-carbon refractories. The recent progress in the synthesis of composite powders including modified graphite, nanocarbon-containing composite powders, oxide/non-oxide and non-oxide composite powders and their applications in low-carbon refractories were reviewed, and the future development of composite powder technology was prospected.

Full text

REVIEW
Recent progress in synthesis of composite powders and their
applications in low-carbon refractories
Ji-yuan Luo
1
•Xin-ming Ren
2
•Xiao-chuan Chong
1
•Dong-hai Ding
1
•Bei-yue Ma
2
•Guo-qing Xiao
1
•
Jing-kun Yu
2
Received: 19 February 2022 / Revised: 14 April 2022 / Accepted: 17 April 2022
ÓChina Iron and Steel Research Institute Group 2022
Abstract
The development of low-carbon refractories is of great significance, but it is limited by the deteriorated properties that
resulted from the decreased graphite content. Incorporating composite powders has proved to be effective in improving the
properties of low-carbon refractories. The recent progress in the synthesis of composite powders including modified
graphite, nanocarbon-containing composite powders, oxide/non-oxide and non-oxide composite powders and their
applications in low-carbon refractories were reviewed, and the future development of composite powder technology was
prospected.
Keywords Composite powder Modified graphite Nanocarbon-containing composite powder Oxide/non-oxide 
Non-oxide Low-carbon refractory
1 Introduction
Carbon containing refractories are indispensable in the
metallurgy process of iron and steel owing to their
remarkable thermal shock resistance and slag resistance
[1–4]. Among them, carbon bonded magnesia (MgO–C)
[5–7] and carbon-bonded alumina (Al
2
O
3
–C) refractories
[8–10] are currently widely used. MgO–C refractories are
typically used as the lining materials of converters and
electric arc furnaces as well as the slag lines of steel ladles
[11–14], while Al
2
O
3
–C refractories are dominantly used
to fabricate continuous casting components, such as slide
plates, submerged entry nozzles, long nozzles, and mono-
bloc stoppers [15–17]. Graphite serves usually as the main
carbon source in carbon containing refractories. The
superior performances of carbon containing refractories are
mainly benefited from the unique properties of graphite
including low thermal expansion coefficient, high thermal
conductivity, and poor wettability and low permeability to
molten steel and slags [18–20].
However, high carbon content (about 8–20 wt.%) in
traditional carbon containing refractories is prone to
increase the carbon pick-up in molten steel, which is not
conducive for the production of clean steel. In addition,
fuel consumption per ton steel increases because the heat
loss is increased owing to the high thermal conductivity of
graphite, which can also lead to the deformation of ladle
shells. The sensitivity of graphite to oxidation leaves pores
in refractory bodies accelerating the corrosion of slag as
well as releasing CO
x
greenhouse gases [21]. Hence, to
meet the higher requirement of steel plants to refractories
and save expensive natural graphite sources, it is impera-
tive to develop low-carbon (typically less than 8 wt.%) or
ultra-low-carbon (typically less than 3 wt.%) refractories
[22–24]. However, directly decreasing the graphite usage
usually triggers the deterioration of thermal shock resis-
tance and slag resistance of carbon containing refractories
[25,26]. Hence, much effort has been put in improving the
properties of low-carbon refractories.
Ji-yuan Luo and Xin-ming Ren contributed equally to this work.
&Dong-hai Ding
dingdongxauat@163.com
&Bei-yue Ma
maceramic@126.com
1
College of Materials Science and Engineering, Xi’an
University of Architecture and Technology,
Xi’an 710055, Shaanxi, China
2
School of Metallurgy, Northeastern University,
Shenyang 110819, Liaoning, China
123
J. Iron Steel Res. Int.
https://doi.org/10.1007/s42243-022-00806-3(0123456789().,-volV)(0123456789().,-volV)

The heterogeneity and complexity of refractory matrix
are the main factors affecting the performances of refrac-
tories. Composite powders integrate the advantages of
single component and have lower preparation cost com-
pared to most pure powders [27,28]. A large number of
studies have proved that modifying refractory matrix by
composite powders is an effective way to improve the
properties of refractories [29–31].
The characteristics of composite powders, such as par-
ticle size and distribution, morphology, and bonding of
single element, which are crucial for their function and
stability when being used in refractories, are greatly
affected by the synthesis process. Besides, the synthesis
cost of composite powders should be further decreased for
its wide application in refractories. Therefore, preparing
composite powders with good characteristics by simple and
cost-effective method has also been a hot research area in
recent years. Based on the characteristics of components,
composite powders can be mainly classified into carbon
containing composite powders, oxide/non-oxide composite
powders and non-oxide composite powders. Among them,
carbon containing composite powders can be further clas-
sified into modified graphite and nanocarbon containing
composite powders. This paper systematically reviewed the
status of the synthesis of these composite powders and their
applications in low-carbon refractories.
2 Synthesis of carbon containing composite
powders and their applications
2.1 Graphite modifying
The vulnerability of graphite to oxidation at high temper-
atures as well as its poor dispersibility further deteriorates
the performances of low-carbon refractories [32,33].
Modifying graphite with ceramic phases is a useful way to
improve its oxidation resistance and service stability in
low-carbon refractories [34]. Carbides, especially SiC,
have been widely used in carbon containing refractories
serving as raw materials or additives [35–37]. Research
works on synthesizing carbides-coated graphite have been
reported in recent years, which has proved to be an
effective method to improve the oxidation resistance of
graphite [38]. Liao et al. [39] employed silane coupling
agent (SCA) as coating precursors and prepared SiC-coated
expandable graphite. The complexation of SCA with dan-
gling bonds of –OH on expanded graphite resulted in better
covering and dispersion. The SCA coatings were pyrolyzed
at elevated temperature, leading to the formation of SiC
and amorphous SiC
x
O
y
coating on the surface of the
expanded graphite. The oxidation resistance of the expan-
ded graphite was remarkably enhanced owing to the
existence of the composite coatings and the peak temper-
ature was up to 812.1 °C. Liu et al. [40] prepared C–SiC
composite powders by salt-assisted synthesis method with
Si and graphite as raw materials. NaCl and NaF are
adopted as the molten salt medium. The NaCl–NaF molten
salt medium promoted the reaction between the reactants
and stimulated the formation of new phases. In the scan-
ning electron microscopy (SEM) images of the composite
powders shown in Fig. 1a, SiC nano-whiskers with diam-
eter of 10–50 nm can be found densely covering the sur-
face of graphite. The oxidation resistance of the modified
graphite was improved, and the activation energy of oxi-
dation is 226.70 kJ mol
-1
, higher than that of flake gra-
phite (180.98 kJ mol
-1
). Owing to a better protection on
the graphite, higher oxidation resistance was realized in the
low-carbon Al
2
O
3
–C refractories (graphite content 5 wt.%)
containing the C–SiC composite powders. Additionally,
owing to the reaction between the SiC cladding layer and
the slag at high temperature, the viscosity of the slag was
improved, resulting in superior slag resistance. Owing to
lower synthesis temperature, shorter period, and high purity
products with good homogeneity [41,42], molten salt
method is also used to prepare other carbides-coated gra-
phite besides SiC. Li et al. [43,44] prepared Cr
3
C
2
-coated
flake graphite through molten salt method under flowing
argon atmosphere with flake graphite and Cr powders as
the starting materials and NaCl/NaF as the molten salt
medium. When adjusting the reaction temperature to
950 °C and the Cr/C molar ratio to 1/2, a dense Cr
3
C
2
coating on flake graphite is obtained as shown in Fig. 1b.
The incorporation of Cr
3
C
2
-coated flake graphite certainly
improved the oxidation resistance and slag resistance of
low-carbon MgO–C refractories (graphite content 5 wt.%).
Furthermore, the addition of the Cr
3
C
2
-coated flake gra-
phite accelerated the transformation of Mg
2
SiO
4
spherical
grains to columnar particles, which improved the physical
and mechanical properties of the refractory bodies. When
the amount of the composite powders used in the refrac-
tories was 2 wt.%, the low-carbon MgO–C refractories
show optimized cold modulus of rupture (CMOR) and cold
crushing strength (CCS). Some other ceramic phase coat-
ings have also proved to be positive in protecting graphite
from rapid oxidation and are also helpful to improve the
properties of low-carbon refractories. ZrC-coated graphite
[45] (Fig. 1c) was also prepared by molten salt method
with Zr powder and graphite as starting materials. The low-
carbon Al
2
O
3
–C refractories (graphite content 4 wt.%)
containing ZrC-coated graphite exhibited optimized oxi-
dation resistance and slag resistance thanks to the protec-
tion of ZrC to graphite.
Chandra and Sarkar [46,47] fabricated YAG
(Y
3
Al
5
O
12
) hybridized expandable graphite (EG) by
mechanical milling using thermally pre-expanded graphite
J.Y. Luo et al.
123

and YAG powders from chemical precipitation as raw
materials. After mechanical milling, turbostratic disorder
can be observed in the lamellar structure of the expandable
graphite in the hybridized powders. The hybridized powder
was then introduced into Al
2
O
3
–MgO–C refractories
(graphite content 4 wt.%), and the compression strength,
toughness, and intrinsic surface energy of the refractories
were all enhanced, which can contribute to the formation of
well-sintered framework of expandable graphite embedded
polyhedral YAG grains in the refractory matrix, as shown
in Fig. 2.
Although the modified graphite exhibits higher oxida-
tion resistance and hence plays a positive role in improving
the comprehensive properties of low-carbon refractories,
the complexity and cost of the synthesis procedure, the
selection of raw materials, and the stability in character-
istics of the coated graphite are still key factors affecting its
wide application in low-carbon refractories.
2.2 Nanocarbon containing composite powders
A series of research works have proved that substituting
graphite with nanocarbons is beneficial to improve the
performances of low-carbon refractories [48–53]. Owing to
their small particle size, nanocarbons can effectively
improve the density of refractories by filling the pores and
gaps. In addition, nanocarbons, such as nanocarbon black
and artificial expanded graphite, have high deformability
and thus can absorb or relieve the thermal strain energy
stored in refractory bodies [54–56], while carbon nanofi-
bers, carbon nanotubes, and graphene can inhibit the
propagation of microcracks through ‘‘pulling-out,’’
‘‘bridging,’’ and/or ‘‘deflection’’ mechanisms, which are
beneficial to enhance the thermal shock resistance of the
refractories [57–61]. However, the high specific surface
area makes nanocarbons prone to agglomerate and more
sensitive to oxidation than graphite, which greatly affects
Fig. 1 Microstructures of different modified graphite. aSiC whiskers-coated graphite [40]; bCr
3
C
2
-coated graphite [43]; cZrC-coated graphite
[45]
Fig. 2 Expandable graphite embedded polyhedral YAG microstructures in refractory matrix observed by SEM under high resolution [46]
Recent progress in synthesis of composite powders and their applications in low-carbon refractories
123

the service stability of nanocarbons in refractory bodies.
Additionally, high cost is also a crucial issue that inhibits
the application of nanocarbons in low-carbon refractories.
The poor dispersibility as well as oxidation resistance of
nanocarbons can be effectively improved by synthesizing
nanocarbon containing composite powders owing to the
interlocking structure formed between nanocarbons and
other components. The cost of nanocarbon can also be
lowered in this way, and the components in the composite
powders except nanocarbons can also play a positive role
in improving the performance of low-carbon refractories.
The characteristics of the synthesized nanocarbon con-
taining composite powders are greatly affected by synthe-
sis method and raw materials.
Simple and cost-effective synthesis of nanocarbon con-
taining composite powders is one of the important factors
affecting its industrial application, and the selection of
synthesis method also has great influence on the charac-
teristics of the composite powder products. Up to now,
several different nanocomposite powder technologies have
been exploited to synthesize nanocarbon containing com-
posite powders including combustion synthesis and
chemical vapor deposition (CVD), and satisfactory results
were obtained.
Combustion synthesis, also known as self-propagating
high-temperature synthesis (SHS), is a fast and simple
method to prepare powder materials [62–65]. The energy
consumption of this method is very low because the
propagation of the combustion wave is sustained by the
heat released by the reaction itself [66–68]. Ding et al. [69]
prepared B
4
C/Al
2
O
3
/C nanocomposite powders by com-
bustion synthesis with B
2
O
3
, carbon black, and Al powders
as raw materials. The B
4
C particles in the synthesized
composite powders have good crystallinity and small grain
sizes since there was no time for the B
4
C grains to grow up
during the rapid synthesis process. In addition, the B
4
C
particles were evenly embedded in the Al
2
O
3
matrix, and
the residual nanocarbon black were uniformly distributed
in the powders. Owing to the unique microstructures of the
composite powders, the contact between the uniformly
distributed carbon black and oxygen was isolated by the
B
4
C particles, which improved the oxidation resistance of
low-carbon MgO–C refractories (graphite content 3 wt.%).
Furthermore, the agglomerate structures of the composite
powders and the uniform dispersion of nanocarbon black
resulted in more thermal strain energy consumption and
consequently improved the thermal shock resistance of the
low-carbon MgO–C refractories (Fig. 3).
CNTs/MgO composite powders [70] were also prepared
by a one-step catalytic combustion synthesis method using
magnesium oxalate (MgC
2
O
4
) as the carbon source, mag-
nesium powders as the reductant, and nickel nitrate hex-
ahydrate (Ni(NO
3
)
2
6H
2
O) as the catalyst. The CNTs in the
composite powders exhibit hollow bamboo-like structures
with high aspect ratio, and the growth mechanism follows
the V–L–S mechanism. The synthesized composite pow-
ders were then added into low-carbon Al
2
O
3
–C refractories
(graphite content 2 wt.%). The thermal shock resistance of
the refractories containing 2.5 wt.% CNTs/MgO composite
powders was enhanced remarkably. The residual strength
ratio of the refractory samples after three cycles of thermal
shock test increased 63.9% compared to that of the refer-
ence batch.
Although the composite powders synthesized by com-
bustion synthesis show positive effects on improving the
properties of low-carbon refractories, the rapid and violent
synthesis process increases the inhomogeneity of the
powder products, which may affect the service stability of
composite powders in refractories.
Chemical vapor deposition is a common method to
prepare film or membrane materials for its high controlla-
bility and good designability of the products [71–74].
Recently, CVD method was also used to synthesize
nanocarbon containing composite powders for its conve-
nience in realizing the uniform distribution of nanocarbons
as well as the high controllability in morphologies. Liang
et al. [75] synthesized Al
2
O
3
/multi-walled carbon nanotube
(MWCNT) composite powders by catalytic decomposition
of methane with Fe–Ni/Al
2
O
3
as the catalysts. In the
composite powders, MWCNTs with diameters of about
10–50 nm were deposited on the catalyst and evenly dis-
persed on the surface of Al
2
O
3
particles. The obtained
composite powders and commercial MWCNTs were added
to Al
2
O
3
–C refractories as CNTs sources, respectively. By
comparison, the incorporation of the Al
2
O
3
/MWCNTs
composite powders substantially improved the dispersibil-
ity of MWCNTs in the matrix, which better filled the
interior pores and gaps and achieved higher densification,
fracture properties, thermal shock resistance, and slag
corrosion resistance of the refractory samples. In addition,
superior properties were obtained owing to the in situ
formation of SiC whiskers from the reaction between the
MWCNTs on the surface of Al
2
O
3
grains and the antiox-
idants Si. Moreover, the advantages of CVD method make
it have great potential to modify the interface between
oxides and matrix in low-carbon refractories, which have
considerable effects on the thermal shock resistance of the
low-carbon Al
2
O
3
–C refractories (graphite content 3 wt.%)
owing to interface debonding effects and energy dissipa-
tion mechanisms.
Li et al. [76] synthesized nanocarbons decorated Al
2
O
3
powders through CVD method adopting ethanol as the
carbon source. The content of the catalyst Ni(NO
3
)
2
6H
2
O
affects the morphologies of the nanocarbons: less catalyst
led to the formation of MWCNTs, while higher content of
catalyst is more conducive to the formation of nano-onion-
J.Y. Luo et al.
123

like carbon because of the agglomeration of the catalyst.
The high content of MWCNTs in the composite powders
stimulates the formation of SiC whiskers, which apparently
improved the mechanical properties of the low-carbon
Al
2
O
3
–C refractories (graphite content 2 wt.%). Although
nano-onion-like carbon has little effects on the toughness
of the refractories, the cohesion between the matrix and
Al
2
O
3
particles was reduced, which increased the con-
sumption of the energy stored in the refractory bodies and
hence enhanced the thermal shock resistance (Fig. 4).
Although impressive results have been obtained from
the application of CVD synthesized nanocarbon containing
composite powders in low-carbon refractories, there is still
a long way for its wide application for the high cost as well
as the high precision requirements of this method.
Besides the synthesis method, the carbon sources also
significantly influence the characteristics of the mor-
phologies and distribution of nanocarbons in the composite
powder products. Contributing to the chemical bonding
between metallic oxides and organic carbon, organic acids,
such as magnesium oxalate, magnesium citrate, and cal-
cium citrate, have been explored to synthesize nanocarbon
containing composite powders [77–80]. Ding et al. [81]
prepared multilayer graphene containing MgAl
2
O
4
pow-
ders by sintering magnesium citrate and alumina powders
in carbon embedded condition. The multilayer graphene
pyrolyzed by the methane gas from the decomposition of
magnesium citrate, inside or attached to the surface of the
agglomerated MgAl
2
O
4
grains. The composite powders
remarkably improved the thermal shock resistance of low-
carbon MgO–C (graphite content 3 wt.%) [82] and Al
2
O
3
–
C (graphite content 2 wt.%) [83] refractories because the
microcracks with many branches formed in the agglomer-
ated structures increased the energy dissipation during
thermal shock.
As mentioned above, modified graphite and nanocarbon
containing composite powders can definitely improve the
comprehensive performances of low-carbon refractories.
The unique coating structures between the
graphite/nanocarbons with other components in the com-
posite powders and the interface between these compo-
nents play a key role in improving refractory property,
however, they were seldom reported. Besides, the stability
in the characteristics and function of the composite pow-
ders need to be further investigated.
3 Synthesis of oxide/non-oxide composite
powders and their applications
It is well known that oxides, such as Al
2
O
3
, ZrO
2
, and
MgO, have excellent resistance to extreme environment,
molten steel, and slags, while non-oxide ceramic phases,
such as AlB
2
, ZrB
2
, and SiC, play a more prominent role in
Fig. 3 Optimized performance of low-carbon MgO–C refractories with combustion synthesized B
4
C/Al
2
O
3
/C composite powders. aOxidation
resistance; bCCS; cCMOR and thermal shock resistance [69]
Fig. 4 Thermal shock resistance of low-carbon Al
2
O
3
–C refractories containing different contents of nanocarbons decorated Al
2
O
3
composite
powders and schematic diagram of effects of powders on propagation behavior of microcracks [76]
Recent progress in synthesis of composite powders and their applications in low-carbon refractories
123

improving the oxidation resistance and the thermal–me-
chanical properties of carbon containing refractories.
Hence, introducing composite powders composed of oxi-
des and non-oxides can integrate the advantages of these
two components and have a synergistic effect on improving
the service performances of low-carbon refractories. AlB
2
is an ideal antioxidant protecting graphite from oxidation at
middle temperatures of about 400–1000 °C. However, the
complexity and high cost of synthesizing pure AlB
2
pow-
ders limit its wide application. To solve this problem,
AlB
2
–Al–Al
2
O
3
[84,85] composite powders were prepared
by combustion synthesis with Al powders and B
2
O
3
as raw
materials. The microstructural evolution during the process
followed a dissolution–precipitation mechanism. The
AlB
2
–Al–Al
2
O
3
composite powders [86] were then intro-
duced into low-carbon MgO–C refractories (graphite con-
tent 3 wt.%) as antioxidants, and their effects on the
oxidation resistance of the refractories were compared with
that of the conventional antioxidants Al/Si and Al powders.
The results showed that the oxidation product of the
composite powders was Mg
3
B
2
O
6
, which melted at
1400 °C and consequently better filled the pores and
blocked the gas channels in the matrix. Hence, the com-
posite powder was superior to Al/Si and Al powders as
antioxidant used in the low-carbon MgO–C refractories.
Although substituting pure powders with composite
powders obtained satisfactory results meanwhile lowering
the production cost, the use of high-purity chemical raw
materials makes the cost of the composite powders still
high. Employing cheap minerals and even some industrial
solid wastes as raw materials to prepare composite powders
is of great potential to further reduce the cost of composite
powders and accelerate its wide application. Based on this
concept, Ma et al. synthesized Al
2
O
3
–SiC composite
powders from pyrophyllite [87], coal ash [88], electroce-
ramics waste [89], and clay [90], respectively. Figure 5
presents the SEM images of these Al
2
O
3
–SiC composite
powders synthesized from different raw materials, and they
are similar in size, all in the micron scale. Furthermore, as
an applicability exploration, the above Al
2
O
3
–SiC
composite powders were introduced into low-carbon
MgO–C refractories (graphite content 4 wt.%), and the
effects on the oxidation resistance and slag resistance were
mainly investigated. As shown in Fig. 6, the oxidation
resistance and slag resistance of the low-carbon MgO–C
samples are improved to a certain extent. The authors
attribute this beneficial effect to the in situ formation of
spinel and forsterite. Specifically, the volume expansion
effect accompanying the formation of spinel and forsterite
effectively filled the pores and gaps of the low-carbon
MgO–C sample; in addition, key properties such as melting
point and viscosity of the slag are changed, thereby
delaying further corrosion of the slag. Furthermore, there
are some easy-to-prepare and low-cost composite powders
that deserve more attention, such as ZrB
2
–SiC (from zircon
and boron oxide) [91], ZrN–SiAlON (from zircon and
bauxite) [92], and SiC–SiAlON (from kyanite tailings)
[93].
4 Synthesis of non-oxide composite
powders and their applications
The combination of different non-oxides, including ZrB
2
,
SiC, ZrN, etc., can also achieve optimized properties of
refractories compared to pure powders. Huang et al. [94]
pre-synthesized Sialon–ZrN composite powders by car-
bothermal reduction method with inexpensive low-grade
bauxite and zirconite as raw materials and introduced the
composite powders into SiC particles to fabricate free-fired
refractories. The resistance of the SiC-based free-fired
refractories to blast furnace slag was improved because the
ZrO
2
from the oxidation of ZrN formed protective phases
with low melting point. ZrB
2
–SiCw (w-whisker) composite
powders were successfully synthesized by Ban et al. [95]
through microwave-assisted carbo/borothermal reduction
method under the protection of argon gas with zircon, boric
acid and activated carbon as raw materials. The composite
powders exhibited low thermal expansion, good oxidation
resistance and poor wettability against slags, and these
Fig. 5 SEM images of Al
2
O
3
–SiC composite powders synthesized from pyrophyllite (1700 °C for 4 h) [87], coal ash (1550 °C for 5 h) [88],
electroceramics waste (1600 °C for 4 h) [89], and clay (600 A for 15 min) [90]
J.Y. Luo et al.
123

characteristics resulted in higher thermal–mechanical
properties and corrosion resistance of the Al
2
O
3
–ZrO
2
–C
refractories (graphite content 2 wt.%) with adding the
ZrB
2
–SiCw composite powders. In addition, some other
non-oxide composite powders with remarkable character-
istics, such as Al
4
Si
2
C
5
powders [96] and ZrB
2
–SiC com-
posite powders [97], were also prepared by researchers
while the study of their effects on the properties of
refractories is still in progress.
Table 1gives a summary of the synthesis methods of
different composite powders and their effects on the
properties of low-carbon refractories.
5 Conclusions
Contemporary research works have proved that the intro-
duction of composite powders including modified graphite,
nanocarbon containing composite powders, oxide/non-ox-
ide and non-oxide composite powders shows positive
effects on the properties of low-carbon refractories. The
insulation from ceramic coatings effectively improves the
oxidation resistance of modified graphite and hence
improves its service stability at high temperatures in low-
carbon refractories. The addition of nanocarbon containing
composite powders achieves a more uniform distribution of
nanocarbons in refractories and consequently results in
superior comprehensive performances. The potential of
oxide/non-oxide and non-oxide composite powders is fur-
ther exploited since they can be prepared from cheap
minerals and industrial wastes.
One-step synthesis of composite powders could be the
mainstream in the future. Furthermore, it is of great
importance to clarify the relations among synthesis pro-
cess, interactions between each component, characteristics
and properties of composite powders, their effects on
refractory properties and the function mechanisms. The
interface between each component greatly affects the
properties of composite powders; however, relevant
research works were seldom reported. Besides, the stability
of nanocomposite powders at high temperatures in long-
time service cycles in refractories needs to be further
discussed.
Fig. 6 Oxidation resistance and slag resistance of low-carbon MgO–C samples with Al
2
O
3
–SiC composite powders synthesized from
pyrophyllite (a, 5.0 wt.%) [87], electroceramics waste (b, 0–7.5 wt.%) [89], and clay (c0–7.5 wt.%) [90]
Recent progress in synthesis of composite powders and their applications in low-carbon refractories
123

Table 1 Summary of synthesis of composite powders and their effects on properties of low-carbon refractories
Classification Composite
powders
Raw materials Synthesis
method
Application
(graphite content/
wt.%)
Refractory property
improvement
Mechanism
Graphite
modifying
C–SiC whiskers
[40]
Si, flake graphite,
NaCl/NaF
(molten salt
medium)
Molten salt
method
Al
2
O
3
–C (5) Oxidation resistance,
slag resistance,
CMOR
SiC prevents graphite
from rapid
oxidation; SiC
layers reacting with
slag increase its
viscosity
Cr
3
C
2
-coated
flake graphite
[43]
Cr, C, NaCl/NaF
(molten salt
medium)
Molten salt
method
MgO–C (5) Bulk density,
apparent porosity,
CMOR, CCS, pore
diameter
Formation of
columnar Mg
2
SiO
4
ZrC-coated
graphite [45]
Zr, graphite Molten salt
method
Al
2
O
3
–C (4) Oxidation resistance,
slag resistance
ZrC protects graphite
from rapid oxidation
Nano-YAG
hybridized
expandable
graphite [46]
YAG, EG Mechanical
milling
Al
2
O
3
–MgO–C (4) Compression
strength,
toughness,
intrinsic surface
energy, Weibull
modulus, thermal
shock resistance
(:166.6%)
Well-sintered frame
work of expandable
graphite embedded
polyhedral YAG
grains throughout
matrix
Nanocarbon
containing
B
4
C/Al
2
O
3
/C
[69]
B
2
O
3
, carbon
black, Al
Combustion
synthesis
MgO–C (3) Bulk density,
apparent porosity,
oxidation
resistance, slag
resistance, thermal
shock resistance
(:17.2%)
More uniform B
4
C
better protects
carbon black;
uniform carbon
black consumes
more strain energy
CNTs/MgO [70] Magnesium
oxalate, Mg,
Ni(NO
3
)
2
6H
2
O
Catalytic
combustion
synthesis
Al
2
O
3
–C (2) Thermal shock
resistance
(:63.9%)
Toughening effects of
MWCNTS
Al
2
O
3
/
MWCNTs
[75]
Al
2
O
3
,
Fe(NO
3
)
3
9H
2
O,
Ni(NO
3
)
2
6H
2
O,
methane
Catalytic
deposition
Al
2
O
3
–C (3) Densification,
fracture properties,
slag resistance,
thermal shock
resistance
(:105.4%)
‘‘Bridging’’ and
‘‘pulling out’’ of
uniformly
distributed
MWCNTS
MWCNTs/nano-
onion-like
carbon
decorated
Al
2
O
3
[76]
Reactive alumina,
ethanol,
Ni(NO
3
)
2
6H
2
O
CVD Al
2
O
3
–C (2) CMOR, elastic
modulus, thermal
shock resistance
(:69.4%)
‘‘Bridging’’ and
‘‘pulling out’’ of
MWCNTS,
formation of SiC
whiskers; reduced
cohesion of matrix
and Al
2
O
3
particles
Multilayer
graphene
containing
MgAl
2
O
4
[82,83]
Magnesium
citrate, Al
2
O
3
Protective
sintering
Al
2
O
3
–C (2) Oxidation resistance,
slag resistance,
thermal shock
resistance (:80%,
:57.1%)
Formation of
microcracks with
many branches and
fibrous ceramic
phases; MgAl
2
O
4
increased slag
viscosity
MgO–C (3)
J.Y. Luo et al.
123

Acknowledgements The authors thankfully acknowledge the finan-
cial support of the National Natural Science Foundation of China
(Nos. U20A20239, U1908227, and 51772236) for sponsoring this
work.
References
[1] E.M.M. Ewais, J. Ceram. Soc. Jpn. 112 (2004) 517–532.
[2] X.M. Ren, B.Y. Ma, S.M. Li, H.X. Li, G.Q. Liu, S.X. Zhao,
W.G. Yang, F. Qian, J.K. Yu, J. Aust. Ceram. Soc. 55 (2019)
913–920.
[3] A.P. Luz, R. Saloma
˜o, C.S. Bitencourt, C.G. Renda, A.A. Lucas,
C.G. Aneziris, V.C. Pandolfelli, Open Ceram. 3 (2020) 100025.
[4] S.S. Li, J.H. Liu, J.K. Wang, Q. Zhu, X.W. Zhao, H.J. Zhang,
S.W. Zhang, Int. J. Appl. Ceram. Technol. 15 (2018)
1166–1181.
[5] M. Ludwig, E. S
´nie_
zek, I. Jastrze˛bska, R. Prorok, M. Sułkowski,
C. Goławski, C. Fischer, K. Wojteczko, J. Szczerba, Constr.
Build. Mater. 272 (2021) 121912.
[6] Y. Cheng, T.B. Zhu, Y.W. Li, S.B. Sang, Ceram. Int. 47 (2021)
2538–2546.
[7] X.M. Ren, B.Y. Ma, S.M. Li, H.X. Li, G.Q. Liu, W.G. Yang, F.
Qian, S.X. Zhao, J.K. Yu, J. Iron Steel Res. Int. 28 (2021)
38–45.
[8] X.W. Wei, A. Yehorov, E. Storti, S. Dudczig, O. Fabrichnaya,
C.G. Aneziris, O. Volkova, Adv. Eng. Mater. 24 (2022)
2100718.
[9] C. Atzenhofer, S. Gschiel, H. Harmuth, J. Eur. Ceram. Soc. 37
(2017) 1805–1810.
[10] J.F. Chen, L.G. Chen, Y.W. Wei, N. Li, S.W. Zhang, Corros.
Sci. 143 (2018) 166–176.
[11] Q. Gu, G.Q. Liu, H.X. Li, Q.L. Jia, F. Zhao, X.H. Liu, Ceram.
Int. 45 (2019) 24768–24776.
[12] J.F. Chen, N. Li, J. Huba
´lkova
´, C.G. Aneziris, J. Eur. Ceram.
Soc. 38 (2018) 3387–3394.
[13] R. Sarkar, B.P. Nash, H.Y. Sohn, J. Eur. Ceram. Soc. 40 (2020)
529–531.
[14] Q. Gu, T. Ma, F. Zhao, Q.L. Jia, X.H. Liu, G.Q. Liu, H.X. Li, J.
Alloy. Compd. 847 (2020) 156339.
[15] J. Zhang, X.C. Li, W. Gong, P.A. Chen, B.Q. Zhu, J. Eur.
Ceram. Soc. 39 (2019) 2739–2747.
[16] Z. Chen, W. Yan, S. Schaffo
¨ner, Y.W. Li, N. Li, J. Alloy.
Compd. 862 (2021) 158036.
Table 1 (continued)
Classification Composite
powders
Raw materials Synthesis
method
Application
(graphite content/
wt.%)
Refractory property
improvement
Mechanism
Oxide/non-
oxide
integrate
ZrO
2
–SiC [98] Zircon, carbon
black
Carbothermal
reduction
Al
2
O
3
–C (15) Bulk density,
crushing strength,
thermal shock
resistance (:702%)
Phase transformation
of ZrO
2
AlB
2
–Al–Al
2
O
3
[86]
Al, B
2
O
3
Combustion
synthesis
MgO–C (3) Oxidation resistance Mg
3
B
2
O
6
formed and
melted at 1400 °C,
filling pores and
blocking gas
channels
Al
2
O
3
–SiC [87] Pyrophyllite,
natural graphite
Carbothermal
reduction
MgO–C (4) Slag resistance Increase in slag
viscosity and
formation of
MgAl
2
O
4
Al
2
O
3
–SiC [89] Electroceramics
waste, carbon
black
Carbothermal
reduction
MgO–C (4) CCS, thermal shock
resistance
(:17.18%),
oxidation
resistance, slag
resistance
Formation of spinel-
and forsterite-
containing dense
protective layer
Al
2
O
3
–SiC [90] Clay, carbon black Electromagnetic
induction
heating
MgO–C (4) Apparent porosity,
CCS, thermal
shock resistance
(:15.01%),
oxidation
resistance
Volume expansion
caused by in situ
formation of spinel
and forsterite
ZrB
2
–SiCw [95] Zircon, boric acid
and activated
carbon
Carbo/
borothermal
reduction
Al
2
O
3
–ZrO
2
–C (2) Corrosion resistance,
cold modulus of
rupture, hot
modulus of
rupture, thermal
shock resistance
(:65%–85%)
Low expansion
coefficient, good
conductivity, and
poor wettability to
slags of ZrB
2
–SiCw
Recent progress in synthesis of composite powders and their applications in low-carbon refractories
123

[17] C.F. Yin, X.C. Li, P.A. Chen, B.Q. Zhu, Ceram. Int. 45 (2019)
7427–7436.
[18] M.Q. Liu, J.T. Huang, Q.M. Xiong, S.Q. Wang. Z. Chen, X.B.
Li, Q.W. Liu, S.W. Zhang, Nanomaterials 9 (2019) 1242.
[19] X.L. Shang, X.Y. Tian, H.X. Li, X.F. Wang, G.Q. Liu, W.G.
Yang, J. Chin. Ceram. Soc. 47 (2019) 412–418.
[20] S.S. Li, J.H. Liu, J.K. Wang, L. Han, H.J. Zhang, S.W. Zhang,
Ceram. Int. 44 (2018) 12940–12947.
[21] J.T. Huang, M.Q. Liu, Z.H. Sun, X.L. Hou, X.B. Li, Z. Chen,
Z.H. Hu, J.T. Ma, Z.J. Feng, Rare Metal Mater. Eng. 49 (2020)
682–687.
[22] X.M. Ren, B.Y. Ma, H. Liu, Z.F. Wang, C.J. Deng, G.Q. Liu,
J.K. Yu, J. Eur. Ceram. Soc. 42 (2022) 3986–3995.
[23] T.B. Zhu, Y.W. Li, S.B. Sang, S.L. Jin, J. Ceram. Sci. Technol. 7
(2016) 127–134.
[24] G.F. Liu, N. Liao, M. Nath, Y.W. Li, S.B. Sang, J. Eur. Ceram.
Soc. 41 (2021) 2948–2957.
[25] Y. Chen, C.J. Deng, X. Wang, C. Yu, J. Ding, H.X. Zhu, J. Eur.
Ceram. Soc. 41 (2021) 963–977.
[26] Z. Gao, B.Y. Ma, J. Iron Steel Res. 33 (2021) 353–362.
[27] J.Y. Luo, G.Q. Xiao, D.H. Ding, X.C. Chong, J.C. Ren, B. Bai,
Ceram. Int. 47 (2021) 29607–29619.
[28] Q.L. Chen, T.B. Zhu, Y.W. Li, Y. Cheng, N. Liao, L.P. Pan, X.
Liang, Q.H. Wang, S.B. Sang, Ceram. Int. 47 (2021)
20178–20186.
[29] H. Xu, X.T. Wang, Z.F. Wang, Y. Ma, H. Liu, Y.L. Wang, J.
Alloy. Compd. 766 (2018) 759–768.
[30] C. Yu, K.R. Cheng, J. Ding, C.J. Deng, Z.L. Xue, X.X. Wu,
H.X. Zhu, Ceram. Int. 43 (2017) 11415–11420.
[31] H.X. Li, J.K. Yu, K. Hiragushi, China’s Refract. 9 (2000) No.2,
3–6.
[32] M. Raju, S.C. K, T. Mahata, D. Sarkar, H.S. Maiti, J. Eur.
Ceram. Soc. 42 (2022) 1804–1814.
[33] X.F. Xu, T.B. Zhu, Y.W. Li, Y.J. Dai, M. Nath, Y.C. Ye, N.Y.
Hu, Y.J. Li, X.Y. Wang, J. Eur. Ceram. Soc. 42 (2022) 672–681.
[34] X. Xu, Y. Li, Q. Wang, S. Sang, L. Pan, J. Ceram. Sci. Technol.
8 (2017) 455–462.
[35] C. Atzenhofer, H. Harmuth, J. Eur. Ceram. Soc. 41 (2021)
7330–7338.
[36] J.L. Xiao, J.F. Chen, Y.W. Wei, Y. Zhang, S.W. Zhang, N. Li,
Ceram. Int. 45 (2019) 21099–21107.
[37] Y. Zhang, J.F. Chen, N. Li, Y.W. Wei, B.Q. Han, Y.P. Cao, G.Q.
Li, Ceram. Int. 44 (2018) 16435–16442.
[38] J.K. Ye, S.W. Zhang, W.E. Lee, J. Eur. Ceram. Soc. 33 (2013)
2023–2029.
[39] N. Liao, Y.W. Li, J.B. Shan, T.B. Zhu, S.B. Sang, D.C. Jia,
Ceram. Int. 44 (2018) 3319–3325.
[40] Z.L. Liu, C.J. Deng, C. Yu, X. Wang, J. Ding, H.X. Zhu, Ceram.
Int. 44 (2018) 13944–13950.
[41] J.H. Liu, Z. Huang, C.G. Huo, F.L. Li, H.J. Zhang, S.W. Zhang,
J. Am. Ceram. Soc. 99 (2016) 2895–2898.
[42] Z.T. Liu, J.K. Xu, X.Q. Xi, J. Zhou, J. Eur. Ceram. Soc. 42
(2022) 1302–1310.
[43] W. Li, X. Wang, C.J. Deng, C. Yu, J. Ding, H.X. Zhu, Adv.
Powder Technol. 32 (2021) 2566–2576.
[44] W. Li, C.J. Deng, C. Yang, X. Wang, C. Yu, Z. Ding, H.X. Zhu,
Ceram. Int. 48 (2022) 15227–15235.
[45] X. Wang, Y. Chen, C. Yu, J. Ding, D. Guo, C.J. Deng, H.X. Zhu,
J. Alloy. Compd. 788 (2019) 739–747.
[46] K.S. Chandra, D. Sarkar, J. Eur. Ceram. Soc. 41 (2021)
3782–3797.
[47] K.S. Chandra, D. Sarkar, Mater. Sci. Eng. A 803 (2021) 140502.
[48] T.B. Zhu, Y.W. Li, S.B. Sang, Z.P. Xie, Ceram. Int. 42 (2016)
18833–18843.
[49] T.B. Zhu, Y.W. Li, S.B. Sang, S.L. Jin, Y.B. Li, L. Zhao, X.
Liang, Ceram. Int. 40 (2014) 4333–4340.
[50] M. Bag, S. Adak, R. Sarkar, Ceram. Int. 38 (2012) 2339–2346.
[51] M. Bag, S. Adak, R. Sarkar, Ceram. Int. 38 (2012) 4909–4914.
[52] V. Pilli, R. Sarkar, J. Alloy. Compd. 781 (2019) 149–158.
[53] V. Roungos, C.G. Aneziris, Ceram. Int. 38 (2012) 919–927.
[54] H.B. Fan, Y.W. Li, S.B. Sang, Mater. Sci. Eng. A 528 (2011)
3177–3185.
[55] V. Pilli, R. Sarkar, J. Alloy. Compd. 735 (2018) 1730–1736.
[56] S. Behera, R. Sarkar, Int. J. Appl. Ceram. Technol. 11 (2014)
968–976.
[57] T.B. Zhu, Y.W. Li, S.L. Jin, S.B. Sang, N. Liao, Ceram. Int. 41
(2015) 3541–3548.
[58] S. Darban, M.G. Kakroudi, M.B. Vandchali, N.P. Vafa, F.
Rezaei, V. Charkhesht, Ceram. Int. 46 (2020) 20954–20962.
[59] N. Liao, Y.W. Li, S.L. Jin, S.B. Sang, H. Harmuth, J. Eur.
Ceram. Soc. 36 (2016) 867–874.
[60] Q.H. Wang, Y.W. Li, M. Luo, S.B. Sang, T.B. Zhu, L. Zhao,
Ceram. Int. 40 (2014) 163–172.
[61] M. Bach, P. Gehre, H. Biermann, C.G. Aneziris, Ceram. Int. 46
(2020) 12574–12583.
[62] K.C. Patil, S.T. Aruna, T. Mimani, Curr. Opin. Solid State
Mater. Sci. 6 (2002) 507–512.
[63] G.H. Liu, K.X. Chen, J.T. Li, Scripta Mater. 157 (2018)
167–173.
[64] B.H. Wang, M.J. Leonardi, W. Huang, Y. Chen, L. Zeng, B.J.
Eckstein, T.J. Marks, A. Facchetti, Adv. Electron. Mater. 5
(2019) 1900540.
[65] M. Zahiri, M. Shafiee Afarani, A.M. Arabi, Appl. Phys. A 124
(2018) 663.
[66] I.V. Iatsyuk, Y.S. Pogozhev, E.A. Levashov, A.V. Novikov,
N.A. Kochetov, D.Y. Kovalev, J. Eur. Ceram. Soc. 38 (2018)
2792–2801.
[67] N. Lu, G. He, J.X. Liu, G.H. Liu, J.T. Li, Ceram. Int. 44 (2018)
2463–2469.
[68] M. Akhlaghi, S.A. Tayebifard, E. Salahi, M. Shahedi Asl, G.
Schmidt, Ceram. Int. 44 (2018) 9671–9678.
[69] D.H. Ding, X.C. Chong, G.Q. Xiao, L.H. Lv, C.K. Lei, J.Y. Luo,
Y.F. Zang, Ceram. Int. 45 (2019) 16433–16441.
[70] G.D. Li, D.H. Ding, G.Q. Xiao, E.D. Jin, J.Y. Luo, C.K. Lei,
Ceram. Int. 48 (2022) 10601–10612.
[71] B. Deng, Z.F. Liu, H.L. Peng, Adv. Mater. 31 (2019) 1800996.
[72] H.M. Park, J.Y. Lee, K.Y. Jee, S.I. Nakao, Y.T. Lee, Sep. Purif.
Technol. 254 (2021) 117642.
[73] A. Baux, S. Jacques, A. Allemand, G.L. Vignoles, P. David, T.
Piquero, M.P. Stempin, G. Chollon, J. Eur. Ceram. Soc. 41
(2021) 3274–3284.
[74] F. Ye, Q. Song, Z.C. Zhang, W. Li, S.Y. Zhang, X.W. Yin, Y.Z.
Zhou, H.W. Tao, Y.S. Liu, L.F. Cheng, L.T. Zhang, H.J. Li,
Adv. Funct. Mater. 28 (2018) 1707205.
[75] F. Liang, N. Li, B.K. Liu, Z.Y. He, Metall. Mater. Trans. B 47
(2016) 1661–1668.
[76] Y.W. Li, J.B. Shan, N. Liao, S.B. Sang, D.C. Jia, J. Eur. Ceram.
Soc. 38 (2018) 3379–3386.
[77] L.H. Lv, G.Q. Xiao, D.H. Ding, Y. Ren, S.L. Yang, P. Yang, X.
Hou, Int. J. Appl. Ceram. Technol. 16 (2019) 1253–1263.
[78] A. Huczko, M. Kurcz, A. Da˛browska, M. Bystrzejewski, P.
Strachowski, S. Dyjak, R. Bhatta, B. Pokhrel, B.P. Kafle, D.
Subedi, Phys. Status Solidi B 253 (2016) 2486–2491.
[79] Y.Q. Zhu, H.T. Yi, X.Y. Chen, Z.H. Xiao, Ind. Eng. Chem. Res.
54 (2015) 4956–4964.
[80] R. Sun, C.W. Tai, M. Strømme, O. Cheung, ACS Appl. Nano
Mater. 2 (2019) 778–789.
[81] D.H. Ding, L.H. Lv, G.Q. Xiao, Y. Ren, S.L. Yang, P. Yang, X.
Hou, Ceram. Int. 45 (2019) 6209–6215.
[82] D.H. Ding, L.H. Lv, G.Q. Xiao, J.Y. Luo, C.K. Lei, Y. Ren, S.L.
Yang, P. Yang, X. Hou, Int. J. Appl. Ceram. Technol. 17 (2020)
645–656.
J.Y. Luo et al.
123

[83] L.H. Lv, G.Q. Xiao, D.H. Ding, Ceram. Int. 47 (2021)
20169–20177.
[84] P. Yang, G.Q. Xiao, D.H. Ding, Y. Ren, Z.W. Zhang, S.L. Yang,
W. Zhang, Refract. Ind. Ceram. 60 (2019) 46–54.
[85] P. Yang, G.Q. Xiao, D.H. Ding, Y. Ren, S.L. Yang, L.H. Lv, X.
Hou, Mater. Res. Express. 5 (2018) 055029.
[86] P. Yang, G.Q. Xiao, D.H. Ding, Y. Ren, S.L. Yang, L.H. Lv, X.
Hou, Y.Q. Gao, Ceram. Int. 48 (2022) 1375–1381.
[87] B.Y. Ma, Q. Zhu, Y. Sun, J.K. Yu, Y. Li, J. Mater. Sci. Technol.
26 (2010) 715–720.
[88] B.Y. Ma, X.M. Ren, Y. Yin, L. Yuan, Z. Zhang, Z.Q. Li, G.Q.
Li, Q. Zhu, J.K. Yu, Ceram. Int. 43 (2017) 11830–11837.
[89] B.Y. Ma, X.M. Ren, Z. Gao, J.L. Tian, Z.H. Jiang, W.Y. Zan,
J.K. Yu, F. Qian, Y.N. Cao, G.F. Fu, Int. J. Appl. Ceram.
Technol. 19 (2022) 1265–1273.
[90] B.Y. Ma, X.M. Ren, Z. Gao, F. Qian, Z.Y. Liu, G.Q. Liu, J.K.
Yu, G.F. Fu, J. Iron Steel Res. Int. (2021) https://doi.org/10.
1007/s42243-021-00653-8.
[91] X.G. Deng, S. Du, H.J. Zhang, F.L. Li, J.K. Wang, W.G. Zhao,
F. Liang, Z. Huang, S.W. Zhang, Ceram. Int. 41 (2015)
14419–14426.
[92] Z.J. Zhang, X.W. Wu, H. Zhao, J. Liu, H. Porwal, Z.H. Huang,
Y.G. Liu, M.H. Fang, X. Min, Adv. Appl. Ceram. 116 (2017)
151–157.
[93] X. Min, M.H. Fang, Z.H. Huang, G.F. Jin, Y.G. Liu, C. Tang,
X.W. Wu, H.X. Zhang, Z.X. Guo, JOM 67 (2015) 1379–1384.
[94] J.T. Huang, Z.H. Huang, Y.G. Liu, M.H. Fang, H.T. Liu, X.W.
Cao, X.C. Li, M.Y. Yin, R.L. Wen, H. Tang, Ceram. Int. 40
(2014) 9763–9773.
[95] J.J. Ban, C.J. Zhou, L. Feng, Q.L. Jia, X.H. Liu, J.H. Hu, Ceram.
Int. 46 (2020) 9817–9825.
[96] C. Yu, C.J. Deng, H.X. Zhu, Z.L. Xue, J. Ding, S.M. Zhou, Adv.
Powder Technol. 28 (2017) 177–184.
[97] F.L. Li, C. Tan, J.H. Liu, J.K. Wang, Q.L. Jia, H.J. Zhang, S.W.
Zhang, Ceram. Int. 45 (2019) 9611–9617.
[98] B.Y. Ma, J.K. Yu, Trans. Nonferrous Met. Soc. China 17 (2007)
996–1000.
Recent progress in synthesis of composite powders and their applications in low-carbon refractories
123