Abstract:This paper mainly introduces the design development and application practice of composite bricks for hole parts of hot blast furnaces at home and abroad,analyzes the advantages and disadvantages of the design mode of composite bricks for hot blast furnaces from the perspective of production,processing and design of refractory products,and analyzes the production and processing technology of composite bricks for composite bricks,in order to solve the practical production and application problems of composite bricks for hot blast furnaces.

Abstract:In this paper,the web crack problem of beam blank caster is studied.Firstly,the causes of web cracks were analyzed,including the influence of molten steel composition,pouring temperature,cooling system and other factors,and then a series of measures to control web cracks were put forward from the perspective of process optimization,such as optimizing molten steel composition,accurately controlling pouring temperature,adjusting cooling intensity and cooling uniformity,etc.,and the effectiveness of these measures was verified by comparing with the actual production data.The research results are of great significance for improving the quality of the special shape continuous casting and reducing the rejection rate.

Abstract:During the ball drawing process of GCR15 wire revealed cracks and decarburization in Metallographic examination,the cause of wire drawing fracture can be identified on studing conventional spheroidization annealing and isothermal spheroidization annealing.The results show that GCr15 steel spheroidized processd by heating at 790℃,then at 720℃for 5～6 h and cooling to 650℃is the best annealing,and the mechanical properties reach the usage requirements.There aren't non-metallic inclusions and coarse carbide particles by the scanning electron microscopy and energy spectrum analysis on fatigue failure specimens.Isothermal spheroidization annealing has better matrix structure and control effect on decarbonization than conventional annealing.Scanning electron microscopy observation reveals that the carbide particles are spherical and dispersed after isothermal spheroidization annealing,poor carbides spheroidization are the main reason for the fracture during drawing process by conventional spheroidization annealing.

Abstract:The main reasons of upwarping defect in the production process of hot-rolled strip steel are analyzed and summarized in this article.This paper describes the influence of the immersion depth of the crystallizer nozzle,the structure of the mold nozzle,the casting speed,the billet heating,the surface condition of rough rolling rolls and quality of finish rolling plate on the occurrence of warping.Combined with strip steel production,the production measures for controlling upwarping defect in steelmaking and rolling production processes are described.

Abstract:A large amount of flake graphite is produced as a byproduct in the steel smelting process.The graphite from the desulfurization slag of molten iron can be extracted as a primary graphite product through flotation.This article takes the desulfurization slag of molten iron as the research object,uses XRD and SEM to characterize and analyze the graphite morphology in the desulfurization slag of molten iron,and compares it with the natural graphite morphology.The study found that the graphite in the desulfurization slag of molten iron contains more large flake graphite(+0.15 mm).The microstructure of graphite in iron desulfurization slag is basically consistent with natural graphite.Some parts of graphite in iron desulfurization slag may have defects,pits,claw cracks,etc.During the formation process,some parts of graphite come into contact with slag iron,which affects the surface morphology of graphite and forms different structural defects.

Abstract:The chemical composition,non-metallic inclusions and metallographic structure of 440 MPa low-alloy steel plate were analyzed by means of spectral inspection,metallographic observation,scanning electron microscopy and energy spectrum examination,and the specific reasons for the post-fracture delamination phenomenon in the transverse tensile fracture were analyzed.The results show that there are MnS,Al2O3 inclusions and pearlite bands in the steel matrix,and the plastic inclusions have obvious splitting effect on the steel matrix.The band structure induced by alloying element segregation induces microcracks,and the interaction and joint action of the two destroy the continuity of the base metal matrix,which is the key factor leading to the lamination of the fracture.By strengthening the pretreatment of molten iron raw materials,the purity of liquid steel is improved,and the content of harmful elements such as phosphorus and sulfur is strictly controlled.The form of sulfide inclusions is changed by means of calcium treatment,and the content of Al2O3 inclusions is reduced.Low superheat casting is adopted in the continuous casting process and the process of controlled rolling and cooling is combined to obtain the expected metallurgical structure.It can significantly reduce the occurrence rate of such defects.

Abstract:This paper proposes an analytical method for testing the gold content in rough silver using ICP spectroscopy.The effects of analytical lines,instrument power,gas flow,titration acidity,residual silver content,and coexisting elements on the detection results were examined in detail.The results show that the gold analytical line should be selected as 242.7 nm,the instrument power should be 1 150 W,the gas flow should be 0.50 L/min,the titration acidity(hydrochloric acid)should be 10%,and the residual silver content should be≤20 mg/L.When there are 11 interfering elements(copper,iron,lead,bismuth,antimony,selenium,tellurium,platinum,tin,zinc,and palladium)in the solution with a concentration of 100 μg each and the concentrations of each interfering element are 100 μg,200 μg,and 300 μg,there is no significant effect on the determination of 100 μg gold;when the concentrations of each interfering element are 500 μg,1 000 μg,and 1 500 μg,there is no significant effect on the determination of 500 μg gold.The recovery rate of the method is 97.55%-103.67%,and the relative standard deviation of repeatability is 1.18%-2.76%.It has good accuracy and precision.

Abstract:Due to the instability of traditional rubber dynamic and static sealing technology,the air leakage rate of Taiyuan Iron and Steel's 320m?blast ring cooler reaches 40%to 45%.This renovation project consists of a transmission device,a rotating body assembly,a cover assembly,a discharge area exhaust hood,a pressure rail,a support roller,a side stop roller,a discharge safety device,a sealing device,a feeding funnel,a cooling blower(including motor and muffler),and a circular belt conveyor.After the renovation of the ring cooler,the air leakage rate of the ring cooler was reduced to below 3%,the power consumption of the ton sintering ore fan was significantly reduced,and the inlet air temperature of the chimney was significantly increased by about 100℃.

Abstract:Based on the analysis of the current energy consumption situation in the cold rolling mill,and in view of the problems and deficiencies in energy management,by analyzing the impact of gas and electricity consumption in the energy structure,a series of measures have been taken,such as optimizing process parameters,implementing management and technical energy conservation and consumption reduction,and conducting energy efficiency benchmarking.Through the application and implementation of extreme energy efficiency energy management,the optimal energy cost has been achieved,promoting the sustainable development of energy conservation and consumption reduction in the cold rolling mill.

Abstract:In order to improve the comprehensive utilization value of steel slag tailings in steel plant disposal and achieve solid waste resource utilization,a sintering production experiment was carried out based on the sintering raw materials and steel slag characteristics of Quanzhou Mingguang Iron and Steel.The physical and chemical indicators of the sintered ore were measured and studied,and the utilization effect of steel slag tailings was analyzed.The results showed that the proportion of steel slag tailings was 1.555%,and the process and cost indicators changed.The sintering utilization coefficient and low-temperature reduction pulverization performance of sintered ore were improved,and the solid consumption decreased;The TFe of sintered ore decreased by 0.347%,CaO increased by 0.206%,SiO2 increased by 0.112%,MgO content increased by 0.094%,P content increased by 0.013%.The cost of sintered ore decreased by 13.24 Yuan/t,and the cost per ton of iron decreased by 7.04 Yuan/t.From May to August,Quanzhou Mingguang sintering used 13 000 tons of tailings,with a ratio of 1.05%.The grade of sintered ore decreased by 0.237%,and the grade entering the furnace decreased by 0.2%,offsetting the consumption of imported ore and lime powder.The cost of sintered ore entering the furnace decreased by 7.68 Yuan/t,and the cost of iron per ton decreased by 2.92 Yuan.

Abstract:The converter slag treatment technology was optimized in Shiheng special steel making plant to adapt to the progress of steel-making technology.The plant has made a comprehensive and systematic improvement on the treatment process of hot stewed steel slag under pressure.A separate jaw crusher has been added between the 2#and 3#belts to solve the problem of repeated recycling of large steel slag;The simultaneous treatment of converter slag and refining slag was realized,and the content of free CaO in slag was reduced to less than 2%,and the particle size of steel slag was reduced to less than 10 mm.In addition,the innovative application of wet variable flow dedusting and ultra-low emission integrated tower technology effectively reduced the floor area by 30%,and the water consumption was reduced from 0.3 m3/t slag to 0.12 m3/t slag.At the same time,ensure that the dust concentration in the flue gas emission is controlled within 5 mg/m3.Through the wet electrostatic precipitator technology,the dusty steam produced by the stewing residue was successfully digested,and the discharge of dusty steam was completely eliminated.At the same time,the dust removal pipeline is equipped with an automatic flushing device,which effectively avoids the hardening problem of the pipeline,so as to realize a clean,environmental friendly,efficient and energy-saving slag treatment process.

Abstract:Germanium is a critical strategic metal in the high-tech field.Owing to its resource scarcity and the increasingly prominent supply-demand contradiction,the recovery of germanium from germanium-containing wastewater has become a research hotspot.This technology bears triple values of resource recycling,environmental protection and economic benefits,which is in line with the concept of circular economy.This paper reviews the traditional recovery methods including precipitation and reduction methods,as well as the emerging technologies such as solvent extraction,ion exchange and membrane separation.The principles,application effects and inherent limitations of these methods are analyzed,and the key influencing factors(wastewater impurities,pH value and temperature)and the differences in technical economic costs are also discussed.Future research should focus on developing multi-technology composite processes,optimizing operation parameters and exploring new materials,so as to achieve high-efficiency,economical and eco-friendly germanium recovery,and further alleviate resource shortage and support the sustainable development of related industries.

Abstract:A large amount of waste heat is generated during industrial production processes(such as the high-temperature red coke from coke ovens in coking plants),which boasts great potential for recovery and utilization.Iodine compounds,characterized by large inter-nuclear distances and weak intermolecular forces,can be pyrolyzed at relatively low temperatures.Therefore,iodine and its compounds can be applied in waste heat recovery.By decomposing iodine compounds with the abundant high-temperature waste heat produced in industrial production,it is possible to design chemical processes that convert the thermal energy of industrial high-temperature waste heat into the chemical energy of specific substances.This paper discusses and analyzes the role and application of iodine in waste heat recovery in aspects such as hydrogen production via water pyrolysis,ammonia synthesis under mild conditions,and flue gas desulfurization.

Abstract:Aiming at the problems existing in iron and steel enterprises,such as low turnover efficiency of hot metal ladles,large temperature drop at the iron-steel interface,and insufficient process coordination,the Gangcheng Base of Shandong Iron and Steel Co.,Ltd.has constructed a full-process technical system of"turnover optimization-interface management and control-collaboration upgrade"through phased technical research.Industrial practice from 2 022 to 2 024 shows that the comprehensive turnover times of hot metal ladles have increased from 2.3 times to 3.4 times,the comprehensive temperature drop of the whole process has decreased from 197℃to 128℃,and the comprehensive hot metal charging temperature has increased from 1301℃to 1365℃.

Abstract:This article focuses on the application and innovation of intelligent magnetic separation technology for palletizing machines in steel production.Through in-depth analysis of the problem of the palletizing machine in the wide and thick plate heat treatment production line of a certain steel plant,intelligent magnetic separation technology for the palletizing machine has been developed.This technology effectively solves many problems of traditional palletizing machines,significantly improves lifting accuracy,efficiency,and safety,promotes the development of steel production towards intelligence,and provides important support for technological progress and industrial upgrading in related fields.

Abstract:During the manufacturing process of components in a home appliance factory,a chromium free passivation hot-dip galvanized product from a certain steel factory experienced paint detachment during the hundred grid test after powder spraying,which seriously affected its use.After analysis,the problem of paint detachment is caused by damage to the surface film of chromium free passivation galvanized sheet and a decrease in powder adhesion.Through on-site research and laboratory analysis,the following conclusions can be drawn:The longer the degreasing time,the longer the silane treatment time,the more severe the damage to the chromium free passivation film,and the larger the paint removal area.The higher the drying temperature,the more severe the damage to the chromium free passivation film and the larger the paint removal area.The longer the drying time,the more severe the damage to the chromium free passivation film and the larger the paint removal area.This problem was solved by shortening the degreasing time,silane treatment time,and drying time.

Abstract:The primary methods for determining trace alloying elements in micro alloy steel reference materials include Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES),Inductively Coupled Plasma Mass Spectrometry(ICP-MS),and spectrophotometry.This study systematically evaluates the methodological performance of these three approaches,focusing on the principles of quantification,precision and accuracy,detection limits,and interference element analysis.The findings provide technical support for optimizing detection methods used in the certification of microalloyed steel reference materials,offering significant practical value for enhancing the quality control of metallurgical products.

Abstract:The magnetic roasting,as an innovative beneficiation approach,has gained significant research attention due to its ability to substantially improve both the grade and recovery rate of iron concentrates.This paper presents a systematic review of magnetic roasting technologies,including circulating fluidized bed and suspension roasting,as well as examines their advancements in industrial applications.Among these,suspension magnetic roasting stands out as an advanced process with strong developmental potential.Its precise control over particle suspension and reaction uniformity lends it broad prospects for future utilization.

Abstract:To address the cracking issue during the bending process of 355 MPa grade steel strip,multiple technical methods including metallographic structure observation,scanning electron microscopy characterization,and mechanical property testing were employed to systematically investigate the core causes of the cracking failure.The test results indicated that the main structure of the steel strip was pearlite and ferrite,with a small amount of bainite,and the grain size was approximately grade 10 with uniform distribution.The mechanical property indicators met the standards but were on the high side.After the steel strip was slit,burrs were found on the edges.If the bending radius was too small during bending,it would cause significant stress concentration on the edges,and the outer layer metal deformation would exceed the plastic limit,which was the main cause of cracking.In addition,the steel strip surface was covered with iron oxide scale,and there was slight pearlite segregation in the core,further increasing the cracking sensitivity.In response to the causes,it is recommended to strictly control the segregation of the cast billet,optimize the surface cleaning process,and improve the edge cutting accuracy.

Abstract:To clarify the effect law and regulation path of sulfur content on the Z-direction tensile properties of steel plates,mechanical property tests,metallographic observations and SEM analyses were adopted to explore the influence mechanism of sulfur content changes on the Z-direction properties of steel plates.The results show that sulfur content is the core factor regulating the Z-direction cross-sectional reduction rate of steel plates,and has a weak influence on the strength index.When the sulfur content was increased from 0.005%to 0.015%,the Z-direction reduction of area dropped sharply from 45%to 30%,a decrease of 33%,while the tensile strength and yield strength only decreased by 4%and 3%respectively.Microscopic analysis confirmed that under high-sulfur conditions,the number of long strip MnS inclusions in steel significantly increased,with the average length-to-diameter ratio rising from 3 to 12.Inclusions are prone to stress concentration under Z-direction stress,inducing intergranular fracture and accelerating crack propagation,thereby deteriorating Z-direction toughness.By implementing the pre-desulfurization of molten iron and the refining process outside the furnace,the sulfur content can be controlled below 0.010%.Combined with Mn/Ca alloying treatment to optimize the morphology of inclusions,the Z-direction reduction of area can be increased to over 48%.