scholarly journals Optimized Scheme for Accelerating the Slagging Reaction and Slag–Metal–Gas Emulsification in a Basic Oxygen Furnace

2020 ◽  
Vol 10 (15) ◽  
pp. 5101 ◽  
Author(s):  
Zichao Yin ◽  
Jianfei Lu ◽  
Lin Li ◽  
Tong Wang ◽  
Ronghui Wang ◽  
...  
Keyword(s):  
Fuzzy Control ◽  
Control Method ◽  
Twist Angle ◽  
Critical Factor ◽  
Basic Oxygen Furnace ◽  
Basic Oxygen ◽  
Reference Information ◽  
Stirring Effect ◽  
Key Factor ◽  
Physical And Chemical

Basic oxygen furnace (BOF) steelmaking is widely used in the metallurgy field. The slagging reaction is a necessary process that oxidizes C, Mn, Si, P, S, and other impurities and therefore directly affects the quality of the resultant steel. Relevant research has suggested that intensifying the stirring effect can accelerate the slagging reaction and that the dynamic characteristics of the top blow are the key factor in exploring the related complex physical and chemical phenomena. To address the issue, the standard k-ω turbulence model and level-set method were adopted in the present work and a fluid dynamics model was developed for a BOF. Accordingly, the slag–metal–gas emulsion interaction and stirring effect were investigated, and the interference mechanism of a multi-nozzle supersonic coherent jet was revealed. Finally, a self-adjustment method based on fuzzy control is proposed for the oxygen lance. The results indicate that the transfer efficiency of jet kinetic energy at the gas–liquid interface is the critical factor for the slagging reaction and that multi-nozzle oxygen lances with a certain twisted angle have important advantages with respect to stirring effects and splashing inhibition. The fuzzy control method predicts that the optimal nozzle twist angle is within the range of 7.2° to 7.8°. The results presented herein can provide theoretical support and beneficial reference information for BOF steelmaking.

Steam and Autoclave Treatments on Structure Characteristics of Steel Slag

2011 ◽  
Vol 356-360 ◽  
pp. 1919-1927 ◽  
Author(s):  
Qing Lin Zhao ◽  
Jochen Stark ◽  
Ernst Freyburg ◽  
Ming Kai Zhou
Keyword(s):  
Steel Slag ◽  
Basic Oxygen Furnace ◽  
Free Lime ◽  
Basic Oxygen ◽  
Volume Stability ◽  
Structure Characteristics ◽  
Key Factor ◽  
Electric Arc Furnace Slag ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

Together with the chemical analysis as well as XRD and DTA, effects of steam and autoclave treatments on structure characteristics of basic oxygen furnace slag (BOFS) and electric arc furnace slag (EAFS) are investigated. The results show that steam and autoclave treatments on slag contribute to the conversion of f-CaO and f-MgO to Ca(OH)2 and Mg(OH)2 ,which improve the volume stability of slag by reducing the contents of free lime and periclase, and the autoclave treatment is more effective. Meanwhile, for the utilization of steel slag, the effects on the volume stability by CaO and MgO that were wrapped in eutectic in the crystallite form should be a key factor, besides the contents of f-CaO and coarse periclase crystalline. The thermal reactivity of slag treated by steam and autoclave increased, especially the reactivity of elemental iron and wuestite. The reactivity of EAFS increased more significantly at high temperature due to its higher content of iron.

scholarly journals An Overview of Use of Linz-Donawitz (LD) Steel Slag in Agriculture

2015 ◽  
Vol 10 (3) ◽  
pp. 975-984 ◽  
Author(s):  
Sasmita Chand ◽  
Biswajit Paul ◽  
Manish Kumar
Keyword(s):  
Steel Slag ◽  
Basic Oxygen Furnace ◽  
Vital Role ◽  
Research Progress ◽  
Basic Oxygen ◽  
Prime Concern ◽  
Ld Slag ◽  
Soil Conditioners ◽  
Physical And Chemical ◽  
Disposal Problem

Slag generated from basic oxygen furnace (BOF) or Linz-Donawitz (LD) converter is one of the recyclable wastes in integrated steel plants. This paper deals with the present and possible use of LD slag in agriculture. At present, the amount of slag deposited in storage yard, leading to the occupation of farm land and serious pollution to the environment. Improving the slag utilization is an important way to resolve these problems. The physical and chemical characteristics of steel slag were analyzed and then the research progress of steel slag utilization in agriculture as fertilizer introduced. Due to increasing awareness of the environment, disposal, reuse of wastes without harming the environment has became a prime concern for the industry. The local availability of non conventional sources of plant nutrients and soil conditioners plays a vital role because of the non availability and higher price of environmental fertilizers. Therefore, this waste can be utilized for enhancing yield as well as solving the disposal problem and improve the environment.

Synthesis and characterisation of alites from reduced basic oxygen furnace slags

2021 ◽  
Vol 147 ◽  
pp. 106518
Author(s):  
Katharina Schraut ◽  
Burkart Adamczyk ◽  
Christian Adam ◽  
Dietmar Stephan ◽  
Birgit Meng ◽  
...  
Keyword(s):  
Basic Oxygen Furnace ◽  
Basic Oxygen

scholarly journals Time-Dependent Strength Behavior, Expansion, Microstructural Properties, and Environmental Impact of Basic Oxygen Furnace Slag-Treated Marine-Dredged Clay in South Korea

2021 ◽  
Vol 13 (9) ◽  
pp. 5026
Author(s):  
Gyeong-o Kang ◽  
Jung-goo Kang ◽  
Jin-young Kim ◽  
Young-sang Kim
Keyword(s):  
Particle Size ◽  
Environmental Impact ◽  
South Korea ◽  
Mechanical Characteristics ◽  
Basic Oxygen Furnace ◽  
Microstructural Properties ◽  
Compression Tests ◽  
Basic Oxygen ◽  
Strength Behavior ◽  
Bof Slag

The aim of this study was to investigate the mechanical characteristics, microstructural properties, and environmental impact of basic oxygen furnace (BOF) slag-treated clay in South Korea. Mechanical characteristics were determined via the expansion, vane shear, and unconfined compression tests according to various curing times. Scanning electron microscopy was conducted to analyze microstructural properties. Furthermore, environmental impacts were evaluated by the leaching test and pH measurements. According to the results, at the early curing stage (within 15 h), the free lime (F-CaO) content of the BOF slag is a significant factor for developing the strength of the adopted sample. However, the particle size of the BOF slag influences the increase in the strength at subsequent curing times. It was inferred that the strength behavior of the sample exhibits three phases depending on various incremental strength ratios. The expansion magnitude of the adopted samples is influenced by the F-CaO content and also the particle size of the BOF slag. Regarding the microstructural properties, the presence of reticulation structures in the amorphous gels with intergrowths of rod-like ettringite formation was verified inside the sample. Finally, the pH values and heavy metal leachates of the samples were determined within the compatible ranges of the threshold effect levels in the marine sediments of the marine environment standard of the Republic of Korea.

scholarly journals Component Modification of Basic Oxygen Furnace Slag with C4AF as Target Mineral and Application

2021 ◽  
Vol 13 (12) ◽  
pp. 6536
Author(s):  
Yanrong Zhao ◽  
Pengliang Sun ◽  
Ping Chen ◽  
Xiaomin Guan ◽  
Yuanhao Wang ◽  
...  
Keyword(s):  
Intermediate Phase ◽  
Raw Materials ◽  
Activity Index ◽  
Basic Oxygen Furnace ◽  
Hydration Products ◽  
Basic Oxygen ◽  
Bof Slag ◽  
Mineral Compositions ◽  
Slag Component ◽  
Basic Oxygen Furnace Slag

In this paper, a new method of basic oxygen furnace (BOF) slag component modification with a regulator was studied. The main mineral was designed as C4AF, C2S and C3S in modified BOF slag, and the batching method, mineral compositions, hydration rate, activation index and capability of resisting sulfate corrode also were studied. XRD, BEI and EDS were used to characterize the mineral formation, and SEM was used to study the morphology of hydration products. The results show that most inert phase in BOF slag can be converted into active minerals of C4AF and C2S through reasonable batching calculation and the amount of regulating agent. The formation of C4AF and C2S in modified BOF slag is better, and a small amount of MgO is embedded in the white intermediate phase, but C3S is not detected. With the increase in the CaO/SiO2 ratio in raw materials, the CaO/SiO2 ratio of calcium silicate minerals in modified BOF slag increases, the contents of f-CaO are less than 1.0%, and the activity index improves. Compared with the BOF slag, the activity index and exothermic rate of modified BOF slag improved obviously, and the activity index of 90 days is close to 100%. With the increase in modified BOF slag B cement, the flexural strength decrease; however, the capability of resisting sulfate corrode is improved due to the constant formation of a short rod-like shape ettringite in Na2SO4 solution and the improvement of the structure densification of the hydration products.

scholarly journals Research and application of smart streetlamp based on fuzzy control method

2021 ◽  
Vol 183 ◽  
pp. 341-348
Author(s):  
Maohua Ai ◽  
Pengju Wang ◽  
Wei Ma
Keyword(s):  
Fuzzy Control ◽  
Control Method
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