Abstract:The sources of steel slag,chemical composition,mineral composition,expansive pulverization and some other properties of steel slag are reviewed in this paper.In addition,various slag treatment processes are introduced as well.On this basis,the research and utilization state of converter slag at home and abroad is described.According to the shortcomings of steel slag treatment in our country,it is pointed out that the new technology of steel slag treatment with pressure heat tightness is expected to solve the problems of steel slag stability,grindability and other aspects.

Abstract:The boiling point of sulfur dioxide under normal pressure is-10℃,which is not significantly different from room temperature.Therefore,sulfur dioxide can be liquefied and separated through refrigeration to achieve the goal of reducing air pollution.The chimney flue gas generally has a high temperature,and the cooled cold air can be used as a low-temperature source to exchange heat with the high-temperature flue gas,forming a circulating cooling system and reducing the energy consumption of the refrigeration device.Comparing the refrigeration desulfurization process with the traditional baking soda dry desulfurization process,it is found through calculation that baking soda dry desulfurization is suitable for high-temperature flue gas and low sulfur content situations,while the refrigeration desulfurization process has obvious advantages in low flue gas temperature and high sulfur content situations.

Abstract:In order to meet the needs of high quality,low consumption and emission reduction in sintering production,a series of technical measures for improving quality and reducing consumption of 2 × 380 m2 sintering machine were adopted in masteel.Through continuous optimization of thick bed sintering production economic potential,the application and innovation management of many new energy-saving technologies,such as upgrading of ignition furnace,changing belt cooler into ring cooler,air leakage treatment of sintering machine,frequency conversion technology of large fan,etc.,the quality of sinter and energy saving have been improved remarkably,and the process energy consumption has been reduced from 55 kgce/t to 47 kgce/t.At the same time,the paper puts forward the improvement direction of the problems existing in the current high efficiency and low consumption production of 2 × 380 m2 sintering machine,so as to further promote the sustainable development of energy saving and emission reduction.

Abstract:As the CC and heating technologies were not changed,the influence was done over CC overheat temperature on the bearing steel GCr15 band structure adopting 2 spheroidized technology.It was found that the band structure grade of the spheroidized was the least which the test results were the grade 2.5,2.0,1.0 when the overheat temperature of CC was more than 30℃,the band structure grade of the spheroidized was the highest which the test results were the grade 3.5,3.0,2.5 when the overheat temperature of CC was between 22℃and 30℃and the band structure grade of the spheroidized was the second which the test results were the grade 3.5,2.5 when the overheat temperature of CC was less than 22℃.So the advice was put forward that the overheat temperature of CC was best controlled between 30℃and 40℃to production bearing steel GCr15 when the band structure grade was wanted for the smaller controlled.

Abstract:In order to solve the problem of nitrogen increase in the refining process,small-grained limestone is added to the ladle slag layer in advance,and the CO2 bubbles generated by decomposition are used to form a sealed isolation layer to reduce nitrogen increase.After the implementation,the nitrogen addition rate of the LF refining process was reduced from the original average of 4.55×10-6 to 3.25×10-6,and the proportion of≤5×10-6 of nitrogen was increased from 88.3%to 95.0%,which achieved significant control effects,thereby reducing the cost per ton of steel and improving the quality of molten steel.

Abstract:This article explores the significant impact of steel throwing speed on throwing distance and its application significance in hot rolling projects.Based on the process layout of APM company,it has been determined that under the condition of a friction coefficient of 0.25,a reasonable steel throwing speed of 4 m/s should be selected to achieve a balance between production efficiency and product quality,and effectively control costs.Research has found that a reasonable throwing distance is crucial for the stability and efficient operation of the rolling process,while also helping to shorten the length of the rolling line and control investment within a reasonable range.This study provides empirical evidence for optimizing the steel throwing process,and looking forward to the future,more factors need to be comprehensively considered to further explore the potential of the steel throwing process.

Abstract:Experiments on abrasion resistance,thermal explosion,and calcination at different temperatures were conducted on limestone with similar chemical compositions but different grain sizes.The results showed that the larger the grain size of the limestone,the worse its abrasion resistance,the more severe the explosion at high temperatures,and the slower the calcination decomposition rate.At higher temperatures,the decomposition rate of limestone with different grain sizes was faster,and the larger the grain size,the narrower the temperature range for producing higher-quality lime.This experiment provides guidance and recommendations for selecting limestone in the lime calcination process.

Abstract:This article deeply explores the hazards of zinc in blast furnaces and various measures to improve the zinc removal rate of blast furnaces.The circulation and accumulation of zinc in blast furnaces can have many adverse effects on gas utilization,coke quality,lining structure,and charge performance.Through the analysis of zinc discharge pathways,a series of comprehensive measures have been proposed,including raw material control,improvement of blast furnace operation system,slag management,adjustment of iron tapping frequency,gas ash treatment,and monitoring and analysis.The aim is to reduce the enrichment of zinc in the blast furnace,improve its production efficiency and lifespan,and provide useful reference and guidance for steel enterprises'blast furnace iron-making production.

Abstract:This study focuses on the profound impact of increasing the ratio of sintered ore on the smooth operation,trend,and process operation of blast furnaces.Through in-depth analysis of permeability,characteristics of soft melt zone,thermal regime,reduction process,and various process operation links,combined with a large amount of actual production data and case analysis,the aim is to provide comprehensive and in-depth theoretical basis and practical guidance for steel enterprises to optimize furnace burden structure,improve blast furnace production efficiency and economic benefits.

Abstract:According to the requirements of lightweight,high bearing capacity and long service life proposed by the quality upgrade of steel formwork for building concrete construction,the composition system design of medium carbon,low silicon and medium manganese,plus niobium and titanium micro-alloy is adopted,and the solid solution strengthening of carbon and manganese elements and the precipitation and precipitation strengthening of niobium and titanium elements are fully utilized.The cold-rolled steel strip for the manufacture of building support formwork has been successfully developed by combining the whole process of protective pouring technology,controlled rolling and cooling and cover annealing technology.The obtained annealed steel strip structure is ferritic+point spherical free cementite,yield strength is more than 345 MPa,tensile strength is more than 470 MPa,elongation after breaking is more than 16%,the product on the basis of ensuring strength and toughness,has a good elongation,fully meet the bending and strength requirements of steel formwork manufacturing.The mass preparation of cold-rolled steel strips for high-performance building support structures is realized,which meets the needs of customized services of users,and has strong industrial practice and promotion value.

Abstract:There are many ladle baking positions in a steel enterprise,and at the same time,it is basically a single point control,without accurate measurement and accurate control system.In view of this situation,this project can realize the ladle baking process in different states automatically according to the baking process curve,and the accurate control and measurement of ladle baking gas in a certain enterprise by upgrading and reforming the ladle baking PLC automatic control system.The gas consumption is effectively reduced by nearly 30%,and the ladle baking control and data in the steelmaking workshop are connected through Ethernet after the transformation and upgrading,and the remote control and energy consumption data detection of ladle baking are realized.This paper has certain reference significance for the development of ladle baking technology in the steel industry.

Abstract:The high scrap ratio in the long process of iron and steel enterprises to reduce carbon emissions and improve economic benefits has a certain significance,scrap preheating as an important method to improve the scrap ratio,scrap high efficiency,low carbon baking technology has become more and more the focus of the industry.In this paper,the influence of different scrap preheating temperatures on the improvement of scrap ratio is calculated.Meanwhile,the scrap preheating test based on the efficient utilization of scrap preheating exhaust gas proves that the preheating efficiency of scrap can be effectively improved by recycling exhaust heat from regenerative bricks,which provides a certain reference value for the subsequent development of efficient and low-carbon scrap preheating devices in iron and steel enterprises.

Abstract:The black line defect at the edge of wide and thick plates,also known as"edge straight cracking",is closely related to factors such as the state of the casting slab corner and rolling process.It usually appears in different forms such as wider single strips or thinner multiple"wire drawing"strips.It is a common problem faced by medium and thick plate production enterprises in the industry.Constructing a finite element calculation model for thermal/mechanical coupling in the rolling process,studying the temperature field and metal flow deformation law of casting slabs with different narrow surface slab structures during the rolling process.By reserving a widening amount on the narrow surface of the casting billet,the widening amount in the middle of the narrow surface during the rolling process is equivalent to the widening amount on the upper and lower surfaces in the last pass,in order to achieve the goal of controlling the distribution range of black lines.After on-site implementation verification,the new mould has achieved significant results in improving the black line defects of wide and thick plates,and the distance between the black line and the side edge of the steel plate can be reduced by 10 mm.

Abstract:Metallurgicalferricdust was fused by NaOH and dissolved in water.Fluorine in the sample was effectively melted out.The pH of the solution was adjusted by hydrochloric acid(1+1)and NaOH solution with alizarin red S solution as the indicator.Then the pH of the solution was adjusted between 5 and 6 by adding sodium citrate buffer solution.The potential value was measured with the fluoride ion selective electrode to calculate the content of fluorine in the sample.The results indicate that the relative standard deviations(RSD,n=8)of measured results were less than 3.00%and the recoveries were between 95%-110%.

Abstract:In order to improve the accuracy of predicting the inlet pressure of the sintering plant,the least squares support vector machine is applied for prediction.The prediction model is improved by adding complementary set empirical mode decomposition and Markov chain method.The main inlet pressure time series is decomposed into different components through complementary set empirical mode decomposition.These components are used as model inputs and trained using LSSVM models to obtain initial predicted values.Then,based on Markov chain theory,an error state transition matrix is established to obtain the corrected error,which is combined with the initial predicted values to obtain the final predicted value.The improved algorithm model has higher prediction accuracy than the LSSVM algorithm,which verifies the effectiveness of the model.

Abstract:As an important basic processing raw material,the current information identification and recognition of special-shaped continuous casting billets are relatively backward due to their own morphology,structure,and stacking method.With the development of equipment technology and the organic integration with process requirements,the development and application of equipment systems for identifying and recognizing special-shaped continuous casting steel billets are carried out through mature industrial robot technology and machine image recognition algorithm models.This solves the problem of inaccurate manual identification and information tracking,and is an important technical means to achieve quality traceability of special-shaped continuous casting steel billets.This article introduces the development and application of an equipment system for identifying and identifying special-shaped continuous casting steel billets in a domestic steelmaking plant.After the system was put into use,its application met on-site requirements and improved the quality traceability and control level of special-shaped billets.

Abstract:Aiming at the high incidence of fire cutting crack in die steel,the characteristics and mechanism of fire cutting crack were analyzed according to the actual process parameters.It is determined that hydrogen stress,thermal stress and structure stress are the causes of fire crack.The stress of steel plate was alleviated by four controls:stacking and cooling to 150℃before the slab was put into the furnace,the heating time of slab was extended to 400 min,stacking and cooling to 250℃after the steel plate was rolled off the line,and stacking and cooling to 100℃after the steel plate was cut.The crack rate of steel plate was reduced from 80%to 10.4%.

Abstract:The complex corrosive environment in underground coal mines seriously threatens the safety and service life of equipment,and traditional high-strength steel is difficult to meet the demands.This paper aims at the characteristics of weak alkalinity and high mineralization degree of mine water in coal mines.Through systematic analysis of the corrosion mechanism,the design and preparation of 550 MPa corrosion-resistant high-strength steel with a thin specification of 10-25 mm are carried out.When designing the composition,mechanical,welding and corrosion resistance properties are taken into account,and the online quenching+medium-temperature tempering process is adopted.Experiments show that the produced Q550D corrosion-resistant high-strength steel has an average yield strength of≥570 MPa,an average tensile strength of ≥ 650 MPa,an average elongation after fracture of ≥18％,and an average longitudinal impact energy of≥150 J at-20℃.It has excellent mechanical properties.Its average corrosion rate is only two-thirds of that of traditional Q550D steel,and its corrosion resistance is 1.5 times higher.The research results provide high-quality steel for coal mine engineering and have an improving effect on ensuring safe production and reducing costs.

Abstract:The current LF refining endpoint temperature prediction is mainly based on the heat balance of the LF refining process,which is achieved through existing empirical judgment,theoretical analysis,big data regression,and other methods.However,it does not fully consider factors such as the temperature drop of different ladle conditions and the waiting time after the ladle leaves the station.On the basis of fully considering the significant influencing factors in the LF refining station,this paper focuses on the actual situation and conducts regression analysis on different types of ladle conditions and production organization modes.Real time temperature prediction models and endpoint temperature prediction models for the LF refining process are constructed,and verified online in different steel mills at 4 × 120 t and 4 × 210 t,with the deviation between predicted temperature and measured temperature fully meeting normal actual production,providing accurate guidance for temperature control in the LF refining process.

Abstract:In the process of iron ore sintering and blending optimization in steel production,fluctuations in iron ore supply and prices result in a wide variety of raw materials and complex blending ratios.This complexity transforms the optimization problem from linear to nonlinear.Traditional linear programming methods struggle to effectively handle these nonlinear issues,leading to low computational efficiency and difficulty in obtaining global optimal solutions.To address these challenges,this study proposes a solution based on a locally linear iterative method.By introducing slack variables and numerical differentiation,nonlinear constraints are transformed into linear forms,and iterative approximations gradually converge to the optimal solution,significantly improving computational efficiency and stability.Focusing on minimizing sintering production costs,the system integrates technologies such as MATLAB and MySQL to construct a sintering ore blending optimization model.Practical applications demonstrate that the model can generate global optimal solutions within 10 seconds while satisfying complex constraints,reducing the production cost per ton of sintered ore by 5.8 Yuan.This approach delivers substantial economic benefits to enterprises.