Abstract：The paper introduces and interprets the content of the Emission Standard of Air
P o l l u t a n t s f o r L i m e a n d C a l c i u m C a r b i d e I n d u s t r y （ G B 4 1 6 1 8 — 2 0 2 2 ） a n d a n a l y z e s i t s
i mp l e m e n t a t i o n s t a t u s. Th i s n a t i o n a l s t a n d a r d s p e c i f i e s t h e e m i ss i o n r e q u i r e m e n t s f o r t h e industries，but does not specify special emission limits, and the limits are relatively lax.
However，it combines the current situation of air pollutant treatment and the development
characteristics and status of the lime industry in China, and reflects the concerns of the industry，
which can thus provide feasible guidance. Enterprises in lime industry should effectively implement
this standard，comprehensively utilize source control and end-of-pipe treatment methods, put
emphasis on the adoption of collaborative technologies for pollution control and carbon reduction，
and take carbon emission management as a key task in the future. This is the approach for them
to achieving synergistic efficiency in reducing pollutant emissions and carbon emissions，and
realizing a comprehensive green transformation of the lime industry as soon as possible.

This paper introduces the ASC (Al2O3-SiC-C) hot metal runner castables prepared with
brown corundum, activated alumina，cement，silica powder and spherical asphalt as the main raw
materials. The effects of different antioxidants on the properties of the castables were studied. The
results indicate that: DT1400N has a better effect on oxidation resistance and high-temperature
bending strength than that of the boron carbide powder，the effect of boron carbide powder is better
than that of the silicon carbide powder，and the effect of silicon carbide powder is better than that of
325-mesh metal silica powder and 200-mesh metal powder. For bending and compressive strength at
ambient temperature，the effects of silicon carbide powder，boron carbide powder，and DT1400N
are equivalent，but the effects of 325-mesh metal silica powder and 200-mesh metal silica powder are
slightly worse. For bending and compressive strength at medium to high temperature，because of better
antioxidant ability，the weight of the body is reduced due to oxidation porosity. The effect of DT1400N
is better than that of boron carbide powder，the effect of boron carbide powder is better than that of
silicon carbide powder，and the effect of silicon carbide micro powder is better than that of metal silica
powder. According to the experimental research results，the hot metal runner castables with the addition
of DT1400N has the best effect.

To investigate the feasibility of producing Ti-based aluminate cement from ferrotitanium
slag, a solid metallurgical waste，experiments were conducted using ferrotitanium slag and calcium
oxide as raw materials. Through the experiments，the proportions of three different groups of
cement raw materials are determined with three aluminate alkalinity coefficients of 0.7，0.8 and
0.9. The corresponding Ti-based aluminate cement samples were prepared by firing in an electric
furnace at 1 350 ℃ for 30 min，and the micro-structure，phase composition，setting time and
bond strength of the samples are tested and analyzed. The results show that with the decrease
of the proportion of ferrotitanium slag, the content of Al2O3 gradually decreases，the content of
CaO gradually increases，the CA phase of the synthesized Ti-based aluminate cement gradually
increases，the CA2 phase gradually decreases，the setting time gradually shortens，and the
flexural strength and compressive strength at the 1st day and the 3rd day gradually increase.

Zirconia ladle filter sand was prepared using zircon sand，chromite，and quartz sand as
the main raw materials. The sand meets the requirements for high alloy steel smelting in EAF ladle.
The influence of quartz sand content on its composition，structure，and properties has been studied.
The research results indicate that after high-temperature heat treatment，the linear change rate of
the sample gradually increases with the increase of the content of quartz sand，the apparent porosity
significantly decreases，and the bulk density first decreases and then increases. The particles in
each sample are mainly in point contact，forming generating a low melting phase dominated by
K2O-Al2O3-SiO2-FeO. Meanwhile，the high-temperature compressive strength slightly increases，
and the thickness of the sintered layer increases，promoting the sintering of the ladle filter sand.
For ladles for the smelting of high alloy steel grades in Baosteel's EAF（with an alloy content
of Cr + Ni + Mo ≥ 8%），the zirconia ladle filter sand has been applied to replace the chrome
ladle filter sand. Currently，it has been stably used for 9 months（a total of 210 heats），and the
automatic opening rate of the ladle has significantly improved，increasing from 85.0% to 97.2%.

Abstract：Tabular corundum particles and fused spinel particles as aggregates，tabular corundum
fine powder，sintered or fused spinel fine powder，and reactive α-Al2O3 micro powder as the
matrix, and high-purity calcium aluminate cement as the binder，are cast with vibration，and then
calcined to 1 550 ℃ to prepare corundum spinel samples. The effects of chemical composition，
phase composition and particle size distribution of sintered spinel fine powder and fused spinel
fine powder from different suppliers on the microstructure，permanent linear change rate after
sintering，apparent porosity，bulk density，flexural strengths at room temperature and high
temperature and compressive strength at normal temperature of corundum spinel castables are
studied.

The paper analyzes the dust emission characteristics of the TSR lime kiln during the pressure
relief process，identifices the main reason for dust pollution lies in the initial shock wave caused by
high pressure，which prevents the flue gas from directly going to the bag filter. The paper clarifies
the characteristics of the formation，propagation, and evolution behavior of the initial shock wave，
compares the attenuation effects of extending the length of the straight pipe，providing more bends，
and installing a flare structure and pressure relief chamber on the shock wave pressure, and proposes a
direct-connection bag filter technology for flexible pressure relief based on a block pressure relief valve.
The initial shock wave pressure of the exhausted flue gas is reduced from 8 kPa to 1 kPa，making the
flue gas go directly to the bag filter. The environmental dust pollution has been significantly improved.
In addition，a fan-shaped plug anti-settling technology based on a three-way internal rotary valve is
proposed in response to the problem of dust settling in the valve body and pipeline system.

High activity lime plays an important role in energy conservation and emission
reduction，as well as in peak carbon emissions and carbon neutrality. Since the current active lime
has been found difficult to meet the requirements，increasingly more importance is being attached
to the production technology of high activity lime. This paper analyzes the characteristics of the
limestones from the Wuhai Hainan Mining Company of Baotou Steel Group and researches the
process technology for preparing high activity lime. The research results show that the limestones
from the mining company mainly include calcite，dolomite，quartz and iron minerals，and their
decomposition characteristics are greatly related to their particle size. This type of limestone can be
used to calcine highly active lime，especially，the limestones with a particle size of 0.125 ～ 0.63
mm at a calcination temperature of 1 000 ～ 1 050 ℃ for 30 ～ 40 minutes. The highly active lime
calcined under those conditions features fine grains，multiple pores，and high activity.

Abstract：In this paper, calcination experiments of limestones from three sources were carried
out，their micro-structures analyzed. Then，the obtained activated lime was used for converter
dephosphorization experiments. The experimental results show that: 1）The grades and grain
sizes of limestones from the three sources are different，the limestone No. 1 has a higher impurity
content；limestone No. 3 has the largest grain size，No. 2 the second，while limestone No. 1 has
the minimum among the three；2）the higher the grade and the larger the grain size of limestone，
the higher the activity of the calcined lime is and the less residue is left after hydrolysis reaction —
the results indicate that the residue of lime No. 3 is 96.1 g less than that of lime No. 1；3）the lime
with a high impurity content and low activity affects the slagging and dephosphorization rate of the
converter - the dephosphorization rate of lime No. 3 is 9.8% higher than that of No. 1 on average.

Abstract：Clay bonded silicon carbide products are prepared with silicon carbide and silica
powder as the main raw materials and clay as the binder. The influence of different moulding
pressures（100 MPa，150 MPa，180 MPa，200 MPa，and 230 MPa）and particle grading on
the microstructure and properties of silicon carbide products are studied. The results show that
when 17% silicon carbide fine powder is added，the bulk density value is 2.42 g/cm3，and the
room temperature compressive strength and flexural strength are 83.46 MPa and 17.4 MPa，
respectively； meanwhile，the oxidation resistance has been further improved. When the molding
pressure is 230 MPa，the mechanical properties and oxidation resistance of the pressed samples
reach their maximum values.

With the continuous improvement of the service life of the continuous casting tundish,
the requirements for the service life of the down nozzle of the tundish are also increasing. The
quick-change submerged entry nozzle can achieve continuous pouring and quick replacement of
the nozzle，and it is widely used due to its convenience and low production costs. However, when
replacing the nozzle，skulling is prone to occurrence between the upper and lower plates，leading
to oxygen absorption on the nozzle plate surface, oxidation of the liquid steel，and even serious
breakout accidents caused by the penetration of liquid steel from the plate surface. The paper
specifically analyzes the reasons for the skulling on the surface of the submerged entry nozzle and
proposes specific solutions，which have achieved good results through practical applications.

The paper analyzes the problems occurred on the stopper rod during casting of a slab CCM in
a particular steel plant，and clarifies that the falling off of the rod head and the breakage of the rod body
during the casting are the main causes for the stoppage of the CCM，which seriously affects the normal
production. With the study on the breakage of the stopper rod，it is believed that there are problems in
the design，construction，baking，and use of the stopper rod. By optimizing the material of the stopper
rod，the shape design，the installation method，and the operations during the casting，the problem of
breakage has been effectively improved，making the use of the stopper rod more stable.

Using tabular corundum，sintered mullite and flake graphite as the main raw materials, and
thermosetting phenolic resin as the binder，a comparative study is conducted on the effect of aluminum
silicon alloy powder on the performance of the lower nozzle for ladle by adding metal aluminum powder
and metal silicon powder versus adding aluminum silicon alloy powder. The results show that the addition
of aluminum silicon alloy powder can reduce the bulk density of the sample，increase the porosity，and
significantly enhance the medium temperature and high temperature strength of the sample. Meanwhile,
the thermal shock resistance is also significantly improved. The addition of aluminum silicon alloy powder
is superior to the composite addition of metal aluminum powder and metal silicon powder.

The paper studies the effect of adding rare earth yttrium oxide on the properties of
Al2O3-SiC-C bricks. The results show that the addition of rare earth yttrium oxide can promote
the sintering of Al2O3-SiC-C brick samples，and the bulk density, apparent porosity，and
cold compressive strength of the samples are significantly improved. Under high temperature
conditions，rare earth yttrium oxide can make the sample,s structure denser，resulting in a
significant improvement in the bending resistance at high temperature. After adding yttrium oxide，
the thermal shock resistance and slag resistance of the samples are also significantly improved.

The paper introduces the structural characteristics of the refractory bricks of doubleshaft
kilns，shows the test and analysis results of their burnt bricks and lances and then，as a
result，unveils and addresses the reasons for the burnout. The double-shaft kilns after improvement
run smoothly and meet the production requirements.