钢铁
Home
|
About Journal
|
Editorial Board
|
Instruction for Authors
|
Subscriptions
|
Advertisement
|
Contacts Us
|
Chinese
Office Online
Author Center
Peer Review
Editor Work
Office Work
Editor-in-chief
Journal Online
Forthcoming Articles
Current Issue
Archive
Read Articles
Download Articles
Email Alert
Quick Search
Advanced Search
2020 Vol. 55 No. 2
Published: 2020-02-15
Technical Reviews
Raw Material and Ironmaking
Steelmaking
Metal Forming
Materials
Environmental Protection and Energy
Technical Reviews
1
LÜ Xue-wei, YAN Zhi-ming, PANG Zheng-de, BAI Chen-guang, LIANG Dong, XIE Hao
Effect of Al
2
O
3
on physicochemical properties and structure of blast furnace slag: review
With the consumption of high-quality iron ore resources,the grade of iron ore raw used by iron making process gradually decreased. The high aluminum raw materials lead to an increase in the Al
2
O
3
content in the blast furnace slag,which has affected the normal operation of the blast furnace. The review focuses on the effect of Al
2
O
3
on the physicochemical properties and structure of blast furnace slag,which will provide scientific basis and theoretical guidance of blast furnace practice for utilization of high alumina raw materials. In particular,the review begins with an introduction to the effect of Al
2
O
3
content on the free running temperature,viscosity,density,surface tension and desulfurization ability of slag,then discussed the structure of alumino-silicate slag and the role of Al
2
O
3
in the slag structure. The relationship between structure and physicochemical properties is introduced through combing with the slag structure information. The current practices of blast furnace operation with high Al
2
O
3
slag system was discussed, and the possibility of the slag system based on alumino-silicate.
2020 Vol. 55 (2): 1-10 [
Abstract
] (
419
) [
HTML
1KB] [
PDF
1278KB] (
1023
)
11
LAN Peng, TIE Zhan-peng, ZHANG Wei, MIAO Hong-sheng, YAN Qing-zhong, ZHANG Jia-quan
Research progress on spot segregation defects in continuously cast semi-products
More attention from companies and researchers has been paid to the solidification structure and the spot segregation in steel continuous casting, as the demands of high-end users on homogeneity are gradually increasing. Spot segregation, a semi-macroscopic defect of solute inhomogeneity in continuous casting of pipeline steel, gear steel, spring steel, bearing steel, etc, is speckle shape in transverse section and V shape in longitudinal section. It is difficult to remove thoroughly in the following process by diffusion. Spot segregation takes a significant effect on the service property of steel products. The agreement on the formation mechanism of spot segregation during steel continuous casting was totally obtained, however, there is still a difficulty in technology to eliminate it under the present condition. Based on the research achievements in the author′s team and the results in reported literatures, this review illustrated the definition, characteristics, detriment, influencing factors, formation mechanism and control measures of spot segregation. It is expected that it can provide some enlightenments and references for other researchers.
2020 Vol. 55 (2): 11-22 [
Abstract
] (
430
) [
HTML
1KB] [
PDF
9263KB] (
830
)
Raw Material and Ironmaking
23
CHEN Xu-ling, ZHENG Ru-yue, FAN Xiao-hui, GAN Min, HUANG Xiao-xian, JI Zhi-yun
Numerical simulation model of temperature and NO
x
emission in flue gas circulating sintering process
In order to study the influence of flue gas circulation conditions on the thermal state and emission reduction mechanism of the material layer, the heat transfer law of gas-solid and the gas flow mechanics, a numerical simulation model of bed temperature and NO
x
emission of flue gas circulation sintering is established and verified by experiments, which based on the thermodynamics and kinetics of main reactions in flue gas circulating sintering process. The results show that the simulated temperature and gas composition(O
2
、CO、NO)are in good agreement with the experimental values, and the relative error distribution of material layer temperature and NO emission concentration is within ±5%. According to the analysis of simulation model, the main factors affecting the NO emission in flue gas recirculating sintering are the concentration of O
2
and CO. With the decreasing of the concentration of O
2
and the increasing of CO, the reaction rate of fuel N oxidation decreases significantly, the reduction rate of NO-CO increases, and the average emission concentration of NO in flue gas decreases.
2020 Vol. 55 (2): 23-30 [
Abstract
] (
353
) [
HTML
1KB] [
PDF
1241KB] (
575
)
31
JIANG Da-jun
Influence of fuel structure on sintering character and comprehensive effect
Both coke and anthracite can be used as sintering fuels in the sintering process, the cost performance of anthracite C is almost double that of C of coke due to price factor, which is conducive to economic sintering. Under the condition of raw material and fuel in Panzhihua Steel Vanadium Co., the system test of fuel structure and proportion was carried out and the test results were comprehensively evaluated. Laboratory tests have shown that "25% coke + 75% coal" had the best overall effect, and the "50% coke +50% coal" was the second, but the ratio of these two structures was better than the use of coke or coal alone. The industrial test showed that the comprehensive effect of "15% Coke +85% Coal" was the best, and the "85% Coke +15% Coal" was the second, the two collocation was better than the use of Coke alone. The test found that the synthetical effect of using coal alone was better than using coke alone, the minerals composition and structure and metallurgical properties of sinter were basically unaffected. After excluding the influence factors of a slightly higher ratio of coal and high gangue content, the obvious economy was still reflected, and the comprehensive effect was not affected. Laboratory flue gas component detection showed that the use of coke or coal alone or both matching, with the change of sintering time, its exhaust gas O
2
, CO, CO
2
content curve shape was highly similar, showing the fuel structure and ratio on the sintering process combustion and action mechanism was same or different little, the difference was that the content of exhaust gas composition had a certain difference but not much, The ratio of combustion efficiency and utilization rate
φ
(CO)/[
φ
(CO)+
φ
(CO
2
)] was similar or had little difference, which indicated that coke and coal can be used interchangeably or in combination to achieve the purpose of economical use of coal.
2020 Vol. 55 (2): 31-41 [
Abstract
] (
419
) [
HTML
1KB] [
PDF
3193KB] (
667
)
42
LU Wei-qiang, ZHANG Jun-jie, DUAN Guo-jian, XU Dong-sheng, PEI Yuan-dong
Practice on solving problem of blast furnace shell rising in Zenith Steel Group Co., Ltd.
The rise of blast furnace shell is a difficult problem faced by some blast furnaces in iron and steel enterprises in recent years, and controlling the rise of blast furnace shell is of great significance to a long life, safe and stable operation of blast furnaces. Aiming at the problem of furnace shell rising in Zenith blast furnace, based on the calculation of pressure vessel blind plate force, combined with long-term analysis and treatment practice, the key reason of furnace shell rising is determined, which is the blind plate force caused by furnace pressure; and five steps of furnace shell rising are given: deformation of furnace bottom plate-deformation of refractory in furnace-crack between refractories-harmful element enrichment along the crevice-furnace shell gradually grows. On this basis, the double bottom slab structure was developed and successfully applied in several blast furnaces of Zenith Iron and Steel Co., Ltd. to solve the problem of furnace shell rising. Finally, the focus of exploring and the reasons for the rise of blast furnace shell should be shifted from raw materials, operation, construction, and refractory materials to the strength of blast furnace bottom plate.
2020 Vol. 55 (2): 42-47 [
Abstract
] (
500
) [
HTML
1KB] [
PDF
5644KB] (
752
)
Steelmaking
48
WANG Kang, LIU Jian-hui, YANG Shu-feng, LI Jing-she
Evolution of non-metallic inclusions in EAF-LF-VD-CC process of GCr15 bearing steel
To study the evolution of non-metallic inclusions in GCr15 bearing steel.The GCr15 bearing steel produced by EAF-LF-VD-CC process was sampled in various stages in a steel factory. The evolution behavior of inclusions in various processes was systematically analyzed by scanning electron microscopy (SEM-EDS) and ASPEX inclusion quick analysis equipment, which can scan large areas. The result indicates that the main types of inclusions in the refining process of GCr15 bearing steel are MgO-Al
2
O
3
-CaO compound inclusions, MnS inclusions and a small amount of SiO
2
-Al
2
O
3
inclusions, more than 90% of the inclusions distribute in 1-8 μm. With the progress of refining, the number of inclusions decreases gradually, and the number and total area of inclusions decrease to the lowest at the VD soft blowing process. During the refining, the inclusions were gradually transferred to the areas with elevated MgO and CaO content from the initial high Al
2
O
3
(
w
([Al
2
O
3
])>80%) region. After the vacuum condition breaking, the MgO (
w
([MgO])>20%) and CaO (
w
([CaO])>30%) reached the highest. It then moves to the area where the Al
2
O
3
content is elevated, and finally stays in the high Al
2
O
3
(
w
([Al
2
O
3
])>65%) region in the tundish. The main Ds inclusions in steel are MgO-Al
2
O
3
-CaO composite inclusions. The formation and removal of Ds inclusions are random. The VD process has a strong removal effect on Ds inclusions.
2020 Vol. 55 (2): 48-55 [
Abstract
] (
635
) [
HTML
1KB] [
PDF
4095KB] (
768
)
56
LI Yang, CHEN Chang-yong, SUN Meng, QIN Guo-qing, JIANG Zhou-hua
Effect of refractories on inclusions in 95Cr saw wire steel
In order to develop better refractories to improve the purity of saw wire steel, the effects of MgO and MgO-CaO refractories on inclusions in the 95Cr saw wire steel were studied using MoSi
2
furnace in the present experiment. The results indicated that both MgO and MgO-CaO crucibles can control the composition of all of the elements in the steel within the target range and the drop point of inclusion composition within the target low melting point zone. However, compared with the MgO crucible, the MgO-CaO crucible has a better effect in purifying the molten steel, mainly in two aspects. On the one hand, the contents of P, S, [Al]
s
and T[O] in steel are lower. Especially, the
w
([S]) can be reduced to 0.000 6%, the
w
([Al]
s
) to 0.000 3% and the
w
(T[O]) to 0.000 5%. On the other hand, the number of inclusions in steel is less, the size is smaller, and the content of Al
2
O
3
in composite inclusions is lower. Specifically, the proportion of inclusions with an effective diameter of less than 2 μm in steel is 91% after smelting with MgO-CaO crucible, while that of the steel smelted with MgO crucible is only 78%. Moreover, after the MgO-CaO crucible smelting, the mass percent of Al
2
O
3
in complex inclusions in steel is almost less than 10.0%. This is mainly because both MgO and CaO in MgO-CaO refractories can remove P, and CaO also removes S and Al
2
O
3
inclusions in the steel.
2020 Vol. 55 (2): 56-66 [
Abstract
] (
443
) [
HTML
1KB] [
PDF
10439KB] (
573
)
67
LIU Peng, SUI Ya-fei, XU Gang-jun, ZHOU Jun-jun, ZENG Quan-wen
Inclusion generation and control of low carbon steel
High reduction ratio of inclusions in SPHD cold rolling produced by 100 t converter in CSP plant. The main reason for inclusion reduction is that the inclusion removal in steel is not complete. By optimizing the deoxidization process of converter reduce the generation of inclusions, increase the end point temperature of converter, the loss of
Al in LF treatment process is reduced. Recycling refining slag was used for making slag quickly, the
w
((CaO))/
w
(
(
Al
2
O
3
)) was controlled from 1.4 to 1.8, basic 18-25, the white slag time before feeding calcium was maintained for more than 8 minutes, LF furnace sedation time is more than 15 minutes promote the removal of inclusions; Argon blowing in tundish for 2 min and adding calcium silicate powder before pouring to prevent the stopperrising in first casting stages, controlling the constant casting speed, keep tundish steel weight＞20 t to reduce the liquid level fluctuation during casting. Based on the above measures, the SPHD downgrade rate for inclusions decreased from 1.8% to 0.2%.
2020 Vol. 55 (2): 67-74 [
Abstract
] (
589
) [
HTML
1KB] [
PDF
6074KB] (
749
)
75
DONG Wen-liang, PAN Hong-wei, LUO Lei, JI Chen-xi, LI Hai-bo, TIAN Zhi-hong
Phosphorous distribution in dephosphorization slag
The morphology and composition of three different dephosphorization converter slags were compared and the effect of basicity and TFe on the phosphorous distribution in slag different phases was discussed. For the slag with a high FeO content and low basicity, the slag existed as a liquid state in the oxygen blowing process, then the high FeO structure of which the P
2
O
5
mass percent was about 6.5% and the CaO-SiO
2
-(FeO) phase were formed under the air cooling condition. For the slag with a medium FeO content and low basicity, the slag existed as a liquid state during the high temperature and the precipitation phases were not much different under the sampling air cooling condition. When the basicity of the slag is moderate and the TFe content is suitable, the slag is in a solid-liquid coexisting zone at the high temperature, 2CaO·SiO
2
-3CaO·P
2
O
5
solid solution was formed and the mass percent of P
2
O
5
in the solid solution was as high as 30%-40%. In the process of dephosphorization, the proportion of 2CaO·SiO
2
in the dephosphorization slag should be increased, and 2CaO·SiO
2
-3CaO·P
2
O
5
was formed to reduce the activity of P
2
O
5
in the liquid phase slag, which made a contribution to the dephosphorization efficiency.
2020 Vol. 55 (2): 75-81 [
Abstract
] (
353
) [
HTML
1KB] [
PDF
8012KB] (
605
)
Metal Forming
82
XIAO Hong, XU Zi-an, ZHANG Chun-jie
Incremental solution of internal stress in coiling process of cold rolled strip
The coiling process of strip steel produces internal stress in the coil due to the action of tension. The magnitude and distribution of the internal stress directly affect the occurrence of defects such as the coil collapse and the convexity after rolling. Considering the difference of the radial and circumferential elastic modulus of the coil and the nonlinearity of the radial elastic modulus,based on the plane axisymmetric elastic theory to deduce the incremental solution equation of the internal stress in the coiling process,introducing the corresponding boundary conditions,the article obtains the equations of radial stress increment and displacement increment for each layer of strip in coil with arbitrary number of coiling layers. The effect of strip thickness and coiling tension and unwinding on the drum pressure and stress distribution in the coil is studied based on the incremental solution method. The results are compared with the experimental results, and the correctness of the proposed method is verified.
2020 Vol. 55 (2): 82-87 [
Abstract
] (
361
) [
HTML
1KB] [
PDF
1066KB] (
925
)
Materials
88
AI Ke-nan, ZHANG Pan-pan, ZHAO Meng-hao, LI Cheng-liang, ZHANG Zhi-ming, FU Jian-xun
Analysis of formation mechanism of surface crack of 1215 free-cutting steel during drawing
Surface crack is a common defect of 1215 free cutting steel. In order to explore the cause of surface crack in drawing process of 1215 free cutting steel,the surface crack regions of 1215 free-cutting steel were analyzed and characterized by non-aqueous solution electrolysis,optical microscope and scanning electron microscope. The reason for the surface crack of 1215 free-cutting steel during drawing was studied. The results show that large-sized manganese sulfide inclusions were found at the end of the crack propagation of the sample cross section. There are large-sized manganese sulfide inclusions and slag particles on the inner wall of the crack. It is speculated from the results that slag particles in steel is the main cause of crack initiation, and large-sized manganese sulfide inclusions are the cause of crack propagation. According to the mechanism of crack initiation and propagation,this paper proposes to control the initiation and propagation of cracks by increasing the alkalinity and reduction of the slag and accurately controlling the oxygen content of the refining station.
2020 Vol. 55 (2): 88-94 [
Abstract
] (
363
) [
HTML
1KB] [
PDF
8264KB] (
481
)
95
LI Dong-hui, XIAO Mao-guo, SUN Hao, HE Wen-chao, ZHANG Xu, LI Shao-hong
Effects of deep cryogenic treatment on microstructure and thermal stability of H13 steel
In order to study the effect of deep cryogenic treatment on the thermal stability and microstructure evolution of H13 hot work mold steel,the thermal stability and microstructure evolution of H13 hot work mold steel treated by different heat treatment processes were characterized by Rockwell hardness tester,X-ray diffractometer,scanning electron microscope and transmission electron microscope. The results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite,which resulted in the hardness of the tested steel subjected to deep cryogenic treatment is higher than that of the quenched tested steel. In addition,after deep cryogenic treatment,the hardness of the tested steel during tempering at 540 ℃ for 20 h is higher than that of the conventional heat treatment tested steel,and the cryogenically treated tested steel has better thermal stability too. Compared with the conventional heat-treatment tested steel,the deep cryogenic treatment promotes the segregation of carbon atoms in the steel and precipitates as carbides during the tempering process,thus the carbon content in the martensite matrix after tempering of the cryogenically treated tested steel is less than the conventional heat treatment. Moreover,the results of transmission electron microscopy showed that a large number of dispersed nano-scale M
23
C
6
carbides precipitated during the tempering process of the tested steel. After a long time of tempering,the carbide coarsening caused the hardness of the tested steel to decrease with the increase of tempering time.
2020 Vol. 55 (2): 95-102 [
Abstract
] (
423
) [
HTML
1KB] [
PDF
14878KB] (
519
)
103
DUAN He, SHAN Yi-yin, YANG Ke, SHI Xian-bo, YAN Wei, REN Yi
Experimental on process, microstructure and mechanical properties of X80 high strength pipeline steel for low temperature
As the pipeline extends to low temperature areas,higher requirements are imposed on the low temperature performance of the pipeline. In order to break through the bottleneck of the strength and toughness balance of high strength pipeline steel laid in the low-temperature region,it is necessary to optimize the microstructure and the thermal mechanical controlled process (TMCP) of the commercial available pipeline steel. In order to study the relationship between the TMCP parameters and the complex microstructure to guide the actual rolling process,the Gleeble thermal simulator was used to observe the different microstructures by changing the cooling rate,finishing rolling temperature,finishing cooling temperature and relaxed time,and then,the change rule in the different microstructures was analyzed. The results showed that with increase of the cooling rate,the volume percent of polygonal (quasi-polygonal) ferrite decreased but that of the bainitic ferrite increased. With increase of the finishing rolling temperature,the grains were coarsening but the fraction of acicular ferrite was basically unchanged. When the finishing cooling temperature was raised to 550 ℃,severely coarsened microstructure was emerged and a large number of MA islands with sharp-angled shape which are harmful to the low temperature toughness appeared. When the relaxed time was prolonged,the grain size and the volume percent of polygonal ferrite were both gradually increased. Based on the results on properties,a microstructure composed of fine quasi-polygonal ferrite (PF),granular bainite (GB) and a small amount of bainitic ferrite (BF) (QF+GB accounted for more than 90%) was designed for the X80 pipeline steel used in extremely-cold region. In this microstructure,the percentage of high angle grain boundaries was more than 50%. Finally,the industrial TMCP parameters such as finishing rolling temperature,finishing cooling temperature and cooling rate were optimized to be 750 ℃,480 ℃ and 20 ℃/s,respectively,which made the X80 pipeline steel with excellent low temperature impact toughness,satisfying the requirements of comprehensive properties,especially in the extremely-cold region.
2020 Vol. 55 (2): 103-111 [
Abstract
] (
317
) [
HTML
1KB] [
PDF
10431KB] (
562
)
112
MA Xiao-cong, AN Zi-jun, CHEN Lei, MEI Rui-xue, HAO Shuo, PENG Cheng
Influence of loading direction on tensile properties of a TRIP-assisted duplex stainless steel sheet
To clarify the effect of loading direction on the tensile properties of a TRIP-assisted duplex stainless steel sheet,the tensile deformation behavior of the test sheet at loading directions of 0°,45°and 90° with rolling direction (RD) were investigated by tensile test. Microstructural characteristics,especially the kinetics of strain-induced martensitic transformation (SIMT) were comparatively analyzed through EBSD,TEM,XRD,etc. The results showed that the tensile properties exhibited a strong anisotropy. The tensile strength and the ductility increased in the order of 0°,45°and 90°,but the yield strength was not sensitive to the loading direction. Microstructural analysis showed that the SIMT occurred in the metastable austenite which caused the transformation induced plasticity (TRIP) with a mechanisms of γ→ε→α
'
. Loading at the loading direction of 0° was in favor of TRIP,while the SIMT was suppressed at the loading direction of 90° due to the strain partitioning between austenite and ferrite. Moreover,the quantitative models of the kinetics of SIMT at different loading directions were established,respectively,whereby the content of strain-induced martensite at different deformation stages could be predicted.
2020 Vol. 55 (2): 112-118 [
Abstract
] (
354
) [
HTML
1KB] [
PDF
4748KB] (
717
)
119
FANG Xu-dong, BAO Han-sheng, LI Yang, XU Fang-hong, XIA Yan
Development of model heat resisting seamless tube C-HRA-5 for ultra-supercritical power plant boilerand
In order to meet the requirements of superheater and reheater boilers in 630-650 ℃ ultra-supercritical power plants,The C-HRA-5 stainless steel seamless steel pipe was prepared according to the process of "EAF+AOD (or VIM+ESR)+diameter forging+extrusion+cold rolling" through the technical research of composition design,smelting,cold and hot deformation and heat treatment and breaking through the bottleneck of key technology. The products are characterized by precise chemical composition control,low volume percent of non-metallic inclusions,pure steel,good surface quality,uniform structure and excellent performance. Its chemical composition,grain size,micro-structure,mechanical properties at room temperature,high temperature tensile properties,high temperature durability and other performance indicators meet the requirements of ASME SA-213 standard,and its steam oxidation resistance and welding performance are excellent. Its physical quality has reached the international advanced level,and has been evaluated by Shanghai Boiler Works,Ltd,Dongfang Boiler Group Co.,Ltd.,Harbin Boiler Co.,Ltd.,Shanghai Power Equipment Research Institute and CISRI. The product has been appraised and certified by the National Technical Committee for Standardization of Boiler and Pressure Vessel,and has taken the lead in formulating relevant group standards. It can be used in superheater,reheater and other parts of ultra (ultra) critical boiler,as well as pressure structure parts under similar conditions.
2020 Vol. 55 (2): 119-130 [
Abstract
] (
341
) [
HTML
1KB] [
PDF
11582KB] (
660
)
131
HUI Ya-jun, WU Ke-min, XU Ke-hao, XIAO Bao-liang, LINGHU Ke-zhi, LIU Kun
Development of 500 MPa grade high ductility square tube steel and its work hardening behavior
In order to develop a 500 MPa grade high ductility square tube steel that meets the requirements of secondary processing,the microstructure,properties,strengthening mechanism and work hardening mechanism of 500 MPa grade high ductility square tube steel were investigated by utilizing optical microscope(OM),scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results show that the microstructures of the two tested steels are composed of ferrite and a small amount of pearlite. Compared with the high C-high Mn-Nb microalloyed test steel,the size of ferrite and pearlite is finer,the size of the second phase precipitates is larger,and the density of dislocation is similar. The mechanical properties of the tested steels are similar before forming,except for the yield ratio of the low C-low Mn-Nb and Ti microalloyed test steel is higher. The low C-low Mn-Nb and Ti microalloyed test steel has a significantly work hardening effect after forming,the yield strength and tensile strength increased by 45 and 26 MPa,respectively,while the elongation decreased by 6.0%. The yield strength and tensile strength of the high C-high Mn-Nb microalloyed test steel increased by 22 MPa and 10 MPa,respectively,and the elongation decreased by 4.0%. The grain refinement strengthening is the most important strengthening modes,the grain refinement strengthening accounts for 52.9%-61.8%,the solid solution strengthening is the second main strengthening mechanism,the solid strengthening accounts for 17.2% to 25.3%,while the precipitation strengthening and dislocation strengthening contributes little to the yield strength. The dislocation strengthening increased to 82 MPa of the low C-low Mn-Nb and Ti microalloyed test steel after forming,which is higher than that of the high C-high Mn-Nb microalloyed test steel. Hence,the high C-high Mn-Nb microalloyed test steel is more suitable for the preparation of high ductility automotive square tube in view of the comprehensive mechanical properties as compared to the other one.
2020 Vol. 55 (2): 131-138 [
Abstract
] (
280
) [
HTML
1KB] [
PDF
10899KB] (
509
)
Environmental Protection and Energy
139
ZHANG Jun, YAN Ding-liu, WAN Xin-yu, GAO Jian-jun
Comparative test on different dry granulation methods of blast furnace slag
In order to improve the dry granulation effect of blast furnace slag,and determine an appropriate granulation process,the characteristics and mechanism of different granulation methods were compared by means of dry granulation tests of the blast furnace slag. The results show that the form of granulated slag particles changes to needle-like and filamentous with the increasing of the air flow rate,and the traditional air-blow quenching technique cannot obtain the ideal granulation particles in size and form. In addition,adopting the air-water mixing quenching method can improve the granulation effect under a relatively small air volume,and the filamentous slag can be avoided,which can be regarded as the development direction of the air-blow quenching method. The mechanical granulation effect is better than that of air-blow quenching,and the optimal granulation as well as vitrification effect can be obtained in the combination of mechanical and air-blow quenching granulation.
2020 Vol. 55 (2): 139-143 [
Abstract
] (
391
) [
HTML
1KB] [
PDF
9421KB] (
473
)
144
ZHOU Mao-jun, ZHANG Dai-hua
Technology integration and practice of ultra-low emission of sintering flue gas in Baosteel
In order to meet the ultra-low emission standard of iron and steel industry,based on the source control and emission reduction technology,the sintering process of Baosteel adopts two co-purification processes,including four-electric field electrostatic precipitation and two-level activated carbon adsorption method,and four-electric field electrostatic precipitation and CFB desulfurization plus SCR denitrification method. The equipment,emission reduction effect and operation cost of the two processes are systematically analyzed. The results show that SO
2
emission concentration of both processes can lower than 20 mg/m
3
(standard state), and can be potential to meet NO
x
ultra-low emission limits lower than 50 mg/m
3
(standard state),but it is difficult to reach the requirement that the emission limits of particulate matter lower than 10 mg/m
3
(standard state). The by-product recovery rate of two-level activated carbon adsorption is high. While the synergistic purification process will produce a large amount of desulfurization ash,resulting in extra disposal. In terms of investment and comprehensive cost,the two-level activated carbon adsorption method is higher than the synergistic purification method,but if depreciation operation cost and direct cost are not considered,the result is just opposite. The energy consumption of the converted ton sinter of the synergistic purification method is significantly higher than that of the two-level activated carbon secondary adsorption method. Based on the analysis of environmental protection tax amount,the unit pollution equivalent removal and emission cost,producing and environmental protection facilities should be considered as a whole cooperate.
2020 Vol. 55 (2): 144-151 [
Abstract
] (
341
) [
HTML
1KB] [
PDF
1280KB] (
817
)
钢铁
News
·
·
·
·
·
More
Author Center
Instruction for Authors
Template
Copyright Agreement
Links
·
Links
More
Copyright © IRON AND STEEL
Supported by: Beijing Magtech
