Hot Metal Charging Research Articles

Mathematical modelling and techno-economic analysis of electric arc furnace steelmaking process with hot metal charging in China

Mathematical modelling and techno-economic analysis of electric arc furnace steelmaking process with hot metal charging in China

Analysis and optimisation on the energy consumption of electric arc furnace steelmaking

ABSTRACT To clarify the influence factors and optimization direction of energy consumption of EAF steelmaking, this study established a complete mass and energy balance model, comprising infiltrated air and off-gas flowrate measurement model and radiative and convective heat loss model, to forecast power and oxygen consumption. The influence of power supply, oxygen supply, carbon injection, infiltrated air, and hot metal charging on the power consumption of EAF is discussed. The results show that optimizing production parameters will effectively reduce power consumption, especially improve the infiltrated air flowrate when there are sufficient combustible gases, which is conducive to energy conservation and emission reduction. Additionally, due to the intensive energy and carbon input in the upstream process of hot metal production, the energy consumption and carbon emissions of hot metal charging EAF are much higher than those of 100% scrap charging EAF.

An energy optimization study of the electric arc furnace from the steelmaking process with hot metal charging

A study of energy optimization derived from simulation software has been done for the high-intensity energy of an Electric Arc Furnace (EAF), hot metal charging within the cooler duct dedusting system. The present work aims to develop a dynamic model of the EAF operation based on mass and energy balances integrated with simulation of the dedusting system with hot metal charging system using MATLAB® and Computational Fluid Dynamics (CFD). The effect of various percentages of hot metal charging on EAF performance and the dedusting system was simulated and validated from the real EAF data plant from one of the steel manufacturer companies in Indonesia. Three cases for the EAF with various hot metal (HM), sponge iron, and scrap iron charging compositions and four cases for the EAF with post-combustion CO have been developed. Careful observation shows that the electric arc power consumption can be reduced down to 72.9 MWh from 87.4 MWh (ca. 16% more efficient) while at the same time increasing the HM charging temperature at the endpoint of the duct dedusting system up to 900°C from 540°C (app. 65% higher). Additionally, advanced simulation of an EAF with post-combustion CO shows that power consumption can be decreased to 59.9 MWh (ca. 30% more efficient).

Effect of hot metal charging on economic and environmental indices of electric arc furnace steelmaking in China

Hot metal (HM) charging electric arc furnaces (EAF) with good production indices and economic benefits have been widely used in China. In this study, the economic and environmental indices of EAF were analyzed based on a mechanistic process model, and the energy consumption, carbon emissions, and production costs with different hot metal ratios (HMRs) were obtained. There are strong correlations between HMR and the energy consumption, carbon emissions, and production costs of EAF. The Pareto optimal solution for the current state is 50% HMR-EAF, which produces carbon emissions of 1402.68 kg-CO2/t and a production cost of 3609.40 CNY/t. Considering the current situation in China, this process is more in line with the need to coordinate the economic and environmental indices of steel plants compared to direct reduced iron (DRI)-EAF, scrap-EAF, and blast furnace-basic oxygen furnace (BF-BOF) processes. Moreover, it has the potential to be more easily realized and promoted.

Novel concept of recycling sludge and dust to BOF converter through dispersed in-situ phase induced by composite ball explosive reaction

Recycling of iron and steelmaking dusts is a key issue in environmental protection efforts and to ensure efficient utilization. In this investigation, we developed a novel recovery process that uses a dispersed in-situ phase induced by an explosive reaction of composite balls of iron and steelmaking dusts. We designed and prepared composite balls for this function using a laboratory model batch-type balling disc (at 12 r/min) and optimized the feeding modes in 180-t and 260-t basic oxygen furnace (BOF) converters. The results indicate that feeding composite balls into BOF converters is an effective novel technology for recovering iron and steelmaking dusts. The period after hot metal charging and prior to the oxygen-blowing process is the most reasonable time to feed composite balls. Composite ball treatment is not appropriate for steel production with sulfur requirements lower than 80 ppm. The maximum composite ball feeding amount is 40 kg/t and the iron yield rate is better than 95%. Compared with the conventional recycling process of sludge and dust, this novel technology is more convenient and efficient, saving up to 309 RMB per ton of steel. Further investigation of this novel recycling technology is merited.

Smelting Period Shortening Practices in Process of Electric Arc Furnace Steelmaking

From a global point of view, advocating EAF steelmaking means reducing the consumption of resources like iron ores, coke, water and so on and on the same time cutting down the emission of carbon dioxide and residue, which is good for the environment and corresponding to Sustainable Development Strategy. We hold that considering the shortage of electric power and scrap steel in our country, the application direction of EAF steelmaking should be manufacture of quality steel with high additional value and reducing operation cost by shortening smelting period. This paper, aimed at NISCO, GISE-ZIS and AISG who take shortening smelting period as the core subject, hot metal charging technology in EAF and coherent oxygen lance technology as effective technical measures, optimizing process flow, improving product quality and reducing operation cost as purpose; investigates their experience in developing modern EAF steelmaking technology.

Refractory products of the BKO company for lining hot-metal charging ladles and hot-metal-car ladles

This article describes the range of carbon-bearing products made by the Borovichi Refractories Combine to line hot-metal charging ladles and hot-metal-car ladles. The specifications of the products are presented along with results from their use in ladle linings.

EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime

A new electric arc furnace (EAF) steelmaking process with increasing hot metal charging ratio and improving slagging regime simultaneously was developed and applied in a 50 t electric arc furnace for more than a year at No.1 Steelmaking Plant of Shanxi Taigang Stainless Corporation Limited. The essential fact of the new EAF steelmaking process was to charge hot metal in two portions or steps: firstly, 35wt%-40wt% hot metal was pretreated by blowing oxygen in a specially designed reactor for decarburization and improving hot metal temperature and melting premelted slag; secondly, 30wt% hot metal was charged into EAF with high basicity refining slags from ladle furnace (LF)-vacuum degassing furnace (VD) refining process. The results show that the hot metal charging ratio can reach to about 65wt%-70wt% for the new EAF steelmaking process; meanwhile, the tap-to-tap time of a 50 t EAF can shorten by 5-10 min, the electricity consumption can decrease by 35-50 kW·h/t, the lime consumption can reduce by 10.5 kg/t of molten steel, and the content of harmful heavy metals in molten steel can be easily controlled to less than the upper limits of aimed steel specification or grade compared with the traditional EAF steelmaking process. In addition, the dephosphorization ability shows a slight strengthening, however, a small degree of lessening for desulphurization ability is observed for the new EAF steelmaking process, but the weakness of desulphurization ability cannot become an obstacle to its further application since a stronger desulphurization ability can be achieved during secondary refining of LF coupled with VD after EAF steelmaking process.

Process and practice of reducing the Cr loss during EAF with De-P hot metal charging for melting stainless steel

Based on practice, the main factors affecting the process of EAF with De-P HM charging have been theoretically analyzed, such as using oxygen, the material charging and making slag. Based on the process features of EAF with De-P HM charging, EAF productivity increase was achieved with application of the integrated control theory on EAF process in Baosteel Stainless Steel Branch.

AUMENTO DAS PLANTAS CONSTEEL® NO MUNDO: FLEXIBILIDADE PARA A CARGA CONTÍNUA DE GUSA LÍQUIDO E SUCATA NO FORNO ELÉTRICO A ARCO AGORA NA SIDERURGIA BRASILEIRA

This paper describes the latest big Consteel® applications around the world and the perspectives of utilization of this recognized technology on the recovery of the growth of the Brazilian Steel Industry, with particular attention to the utilization of hot metal as main part of the charging mix. The Consteel® EAF process represents the extension of the advantages of continuous charge feeding and melting process – typical of EAFs charged with 100% DRI – to the charging of scrap. This with the additional benefit of an “environmentally friendly” preheating of the charge help the reducing energy requirements of the process. Moreover the possibility of injecting oxygen for 100% of the power-on time makes the Consteel® process the best option for taking most of the advantages coming from hot metal charging in an EAF. Process details and technological peculiarities of this particular type of operation are described

Cables with a steel core for hot-metal charging cranes

Cables with a steel core 42 mm in diameter are used on hot-metal charging cranes. Heat is released as molten pig iron is poured into the converter, and the resulting superheated gases and flames (whose temperature sometimes reach 1300°C) act on the surrounding production equipment, building structures, and cables. An analysis of defects in the steel cables of such cranes has shown an increase in the incidence of rejection of these cables for technological and design-related reasons. The main reasons for the failure of cables in inspections are loss of cross section, extrusion of the strands, and curvature. The use of cables with a spring-type core makes it possible to lengthen their service life and make the formation of the defects just mentioned less likely. Cables of this type are more flexible, which improves their performance on blocks and drums. The spring-type core ensures that the cable will remain intact during service and that the lubricant will be evenly distributed among the strands.

Process and Practice of EAF with De-P Hot Metal Charging for Melting Stainless Steel

The article introduce the process of Electric Arc Furnace with Dephosphorized hot metal charging for melting stainless steel in Baosteel stainless steel Branch. Based on the practice of production, The main factors affecting the process of EAF with De-P HM charging are theoretically analyzed, such as using oxygen, the material charging and making slag. The optimization of hot metal charging can advance the use of chemical and physical energy, reduce the consumption of power. The optimization of using oxygen can increase the use of chemical energy. The optimization of material charging can reduce the oxidation of Cr. Making foamy slag can advance the transformer capacity and the use of power. Based on the character of the process EAF with De-P HM charging for Melting Stainless Steel, EAF productivity increased were reached with application of integrated control theory on EAF process in Baosteel stainless steel branch.

EAF technology evolution by continuous charging

Recent developments in electric arc furnace (EAF) based meltshop operation are reviewed, including the Consteel system which facilitates continuous scrap charging and preheating completed by hot metal charging. The benefits offered by these developments are quantified, backed by operational performance results from several facilities. The future will see increasing use of EAFs to produce high quality steels, often in innovative operational combinations alongside the blast furnace route.

Changing paradigm of metal separation technology for steel production

Near future technological development of ironmaking and steelmaking has been discussed with emphasis placed on ecological processes, products and systems for sustaining resources circulatory society. Measures to reduce CO2 emission and energy consumption are considered in terms of optimization of blast furnace operation, new ironmaking routes, processing of scrap, electric arc furnace operation with hot metal charging, refining technology for high performance steels, and waste processing using steelmaking‐related technologies.

Economical method of repairing the bridge of a hot-metal charging crane

Economical method of repairing the bridge of a hot-metal charging crane