Ferroalloy Production Research Articles

Establishment of Ferroalloy Production Facility - A Feasibility Study

Establishment of Ferroalloy Production Facility - A Feasibility Study

Integrating Process Simulation and Life Cycle Assessment for Enhanced Process Efficiency and Reduced Environmental Impact in Ferromanganese Production

Process simulation was integrated with life cycle assessment to evaluate process efficiency and environmental impact of the production of manganese ferroalloys for various production modes and different ore mineralogies. Utilizing HSC Sim, the model was designed to evaluate the production process with or without a pretreatment step, where results for simulated cases using a four-zone ferromanganese furnace model were exported to openLCA for a complete life cycle assessment. Two main production scenarios were simulated: a closed ferromanganese furnace running on the duplex method and an open furnace running on the discard slag approach. The closed furnace scenario achieved a 17.5% reduction in energy consumption and a 16.2% decrease in direct CO2 emissions with CO-rich off-gas pretreatment. The open furnace scenario showed an 11.2% reduction in energy consumption with thermal solar energy pretreatment but no change in CO2 emissions.

УТИЛИЗАЦИЯ МЕТАЛЛИЧЕСКОГО ПОРОШКА ВЫСОКОУГЛЕРОДИСТОГО ФЕРРОХРОМА МЕТОДОМ САМОРАСПРОСТРАНЯЮЩЕГОСЯ ВЫСОКОТЕМПЕРАТУРНОГО СИНТЕЗА (СВС)

This article discusses the methods of recycling high-carbon ferrochrome metal powder by self-propagating high-temperature synthesis. The article is devoted to the study of aspiration metal dusts formed during the production of ferroalloys. The article analyzes the composition of the source material, its physicochemical properties, and the impact on the testing process. The publication touches upon the relevance of this topic and the advantages of the self-propagating high-temperature synthesis method. Particular attention was paid to comparative analyses of this method from other traditional material processing processes. This article will help to consider the problem of environmental pollution and the impact of traditional metallurgical processes on the ecosystem. The authors also analyze in detail the physical properties of the original powder samples and their combustion temperature mode. The publication shows the process flow charts, laboratory devices, and the type of resulting material. This article provides a detailed analysis of the types of laboratory devices, their physical and mechanical properties. The publication provides a thorough and detailed chemical analysis of the resulting material. In the course of the study, the expected results were obtained, which are presented in the form of tables and a figure. The article consists of an introduction, main part, conclusion, conclusion and list of references.

An Overview of H2 and CH4 as Environmentally Sustainable Alternative Reductants to C for Chromite Smelting

The application of hydrogen (H2) and methane (CH4) as gaseous reductants for pure chromite (FeCr2O4) is reviewed in four theoretical approaches. These approaches are evaluated against the conventional process, where the sole reductant is a solid carbon (C) source. The sustainability is measured by gaseous carbon monoxide (CO(g)) formation, determined by the reaction stoichiometry of each theoretical approach. Decreased CO(g) formation is critical for alleviating the adverse environmental impact of ferroalloy production. The prereduction of FeCr2O4 by H2, followed by reduction by CH4 shows the largest decrease in CO(g) formation, i.e., a 75% decrease, compared to the conventional process. Furthermore, the H2‐based prereduction and CH4‐based primary reduction occur at lower temperatures than C‐based reduction, due to kinetic advantages, and thus decrease energy consumption. The overview discusses the environmental impact of substituting C with H2 and CH4 and briefly discusses how it can be implemented in industry.

Producing a siliceous ferroalloy from a mixture of amorphous rocks

The main silicon-containing component in a charge during ferrosilicon smelting is quartzite. The carbothermic reduction rate of the crystalline structure SiO2 has a limitation associated with a fixed energy reserve of silicon-oxygen bond. The reactive capacity of silica can be increased by using its amorphous form instead of the crystalline SiO2. The amorphous form of silica has a higher dispersion, greater free surface energy, and, consequently, a more active degree of entering into a reaction. Such silica-containing materials include amorphous rocks: diatomite, opoka, tripoli. The article presents the results of experimental studies of electrothermal ferrosilicon production from a mixture of amorphous rocks (tripoli, opoka, diatomite with a mass ratio of 1:1:1).It is established that when smelting the mixture of amorphous rocks containing 77 % SiO2, 7.9 % Al2O3, 5.2 % Σ CaO and MgO, 4 % Σ K2O Na2O, 3.3 % Fe2O3, 1.3 % CaCO3, 0.9 % CaSO4, 0.4 % others, three ferrosilicon grades are formed: FeSi25 (22–29 % Si), FeSi45 (41–47 % Si), FeSi50 (47–52 % Si) with the extraction degree of 70–87.6 % silicon into the alloy. Moreover, the ferrosilicon grade decreases with an increase in steel shavings in the charge from 21.9-31.4 % to 33–35 %. In comparison with ferrosilicon smelting from a standard charge containing quartzite with the crystalline form of SiO2, steel shavings and coke, ferrosilicon production from the mixture of amorphous rocks allows to increase the process rate by 17.5–21.6 %. It is possible to increase the silicon extraction degree into the alloy from 80-85 %–94.5 % if its final stage is carried out in the resistance mode. Widespread occurrence in nature, favorable conditions of occurrence, low cost, high reactive capacity are favorable factors for using amorphous rocks in the production of ferroalloys.

Eco-friendly low-carbon manganese ferroalloy production for cleaner steel technologies

Global steel production, a major contributor to anthropogenic carbon dioxide, heavily relies on manganese, a key ingredient that significantly impacts the carbon footprint during the production of high-carbon ferromanganese. A single-step generation of low-carbon ferromanganese (LC-FeMn) from manganese ore in an electric arc furnace (EAF) was investigated. The theoretical and experimental investigations helped to balance the required and supplied energy. The process sustainability was predicted based on the enthalpy of the reaction. Pre-reduction of manganese ore decreased energy consumption in the smelting process and saved raw materials costs. The simulation studies revealed a significant effect of lime and silica on the slag-metal equilibrium. It further confirmed the best-reducing condition with the basicity 1.5–1.77 by smelting tests in EAF. Experimental results showed an optimal charge mixture comprising appropriate ratios of ore:SiMn:lime ratio, producing a standard-grade product. Simultaneous melting and smelting sensibly used the exothermic heat, consuming 410–880 kWh/ton, much lower than the international benchmark, i.e. approximately 2000 kWh/ton. The characterization of resulting slags corroborated the advantages of the manganese ore pre-reduction on the energy and reductant consumption, alloy grade, and slag characteristics. The present study's findings can potentially contribute to the ongoing low-carbon initiatives of steel.

THEORETICAL AND EXPERIMENTAL MODELING OF THE PROCESS OF MELTING COMPLEX ALLOYED STEELS (Fe-Si-Al-Mn)

In the practice of complex theoretical research of multicomponent systems, the so-called thermodynamic-diagram method of analysis is known, which significantly simplifies the study of phase transformations in multicomponent systems by dividing them into thermodynamically stable elementary partial subsystems of equal dimensionality as the main ones. Thermodynamic-diagram analysis combines the thermodynamic assessment of chemical interactions between components in the studied system with a geometric diagram. Such a combination, as studies of the physicochemical principles of refractories and ferroalloys production have shown, proves to be productive in interpreting chemical interactions in complex systems.

Feasibility of Biochar from Seaweed for Ferroalloy Production

Biochar from seaweed, specifically sugar kelp, cultivated on the Norwegian coastline has been investigated as a possible biocarbon source for the metal industry to reduce the dependency on terrestrial biomass. Pre-processing of the biomass prior to pyrolysis is needed to reduce the water and ash content and was performed by water and acid washing followed by drying. The three types of biochar were obtained after pyrolysis at a temperature of 550 °C. Characterization of the three batches of biochars showed that pre-processing of the seaweed as was done during the water and acid washing, plays an important role on the removal of ash content. Due to the enormous amount of woody biomass needed for example in the ferroalloy industry to replace fossil coal, replacing only parts of the woody biomass with kelp biochar could have a significant impact. Water washing combined with acid washing had the best results considering the ash and fixed carbon contents. Microstructural analysis of the seaweed biochars showed a very porous material with the crystal structure resembling that of charcoal, albeit a lower degree of crystallinity.Graphical

Development of a new laboratory-scale reduction facility for the hydrogen plasma smelting reduction of iron ore based on a multi-electrode arc furnace concept

Steel production accounts for a significant share of industrial CO2 emissions. The HPSR process is a possible alternative to reduce these emissions massively if not completely negate them. In principle, Fe-ore is reduced at high temperatures in the plasma of a DC electric arc. hydrogen reacts with the oxidic melt at the gas-liquid interface. Various concepts for the hydrogen plasma reduction of iron ore have been investigated, but the process technology has not yet surpassed the demonstration scale (TRL5). Experimental setups for charging masses from a few grams to a few hundred kilograms have been realized. Further investigations on the process stability and the reaction kinetics are still necessary. An improved laboratory-scale furnace concept shall provide the basis for the fundamental research. An existing laboratory facility is the starting point for designing and constructing the new plasma furnace. There are several problems with this experimental setup. Mainly, the reactor’s dimensions and power supply limitations restrict the arc’s length. The first leads to problems with excessive refractory wear, while the latter limits the variation of process parameters. Strong cooling when using Fe crucibles and the unstable nature of the arc complicate the process control. A promising concept to deal with the problem of arc stability is the use of multiple electrodes in a direct current arc furnace. Together with an optimized furnace geometry, new potential for further investigations can open. Using a multi-cathode furnace is also promising to further explore ferroalloy production via hydrogen plasma reduction. An electric arc furnace was designed based on the requirements for the planned plasma reduction facility. The energy requirement was based on assumptions for heat transfer from the arc to the melt, walls, and lid and continuous transfer through the individual furnace parts. Considerations of power supply, hearth dimensions, refractory design, controlled gas atmosphere, and the implementation of auxiliary equipment were central to creating an ideal basis for various experimental setups.

MULTIFACTOR ANALYSIS OF THE EFFICIENCY OF THE FERROALLOY PROCESS

Ore-reducing ferroalloy processes must be considered as a relationship of parameters and characteristics of subsystems and elements. The maximum energy capacity of the furnace and its productivity is achieved both due to the design parameters of the bath, the short network, the power of the furnace transformer, the diameter of the self-ignition electrodes, as well as the electrotechnological and thermophysical properties of the initial charge materials, ore-slag melt and final ferroalloy. The amount of carbon is one of the most significant technological parameters of the carbon reduction process for the production of manganese ferroalloys. In the work, the most significant final indicators are adopted and their correlation with electrical characteristics and technological parameters is determined.

PRODUCTION OF SPECIAL COKE FROM LOW-CAKING COALS USED IN THE FERROALLOY INDUSTRY

This article draws attention to the importance of effective control of the composition and properties of the charge in the production of ferroalloys. The main focus is on carbon reducing agents, which play a key role in this process. The problem of the shortage of special coke in Kazakhstan is considered and solutions are proposed – the using of substandard raw materials for the production of reducing agents. In particular, the possibility of using coal from the Zhalyn deposit in a mixture with coal from the Shubarkol deposit is being considered. Researches of differential thermal analysis (DTA) of coals Shubarkol (100 %), Zhalyn (100 %), as well as in a mixture in a ratio of 50:50 % are presented. The detailed characteristic expressed by endothermic and exothermic peaks allows us to fully study the physico-chemical processes occurring as a result of thermal exposure. The conducted studies show that the obtained special coke in a ratio of 50:50% has good performance for reducing agents used in the electrothermy of ferroalloy production. In conclusion, it is emphasized that the use of coal fines helps to reduce the accumulation of coal «wastes», which has a positive effect on the environment. This shows the importance of further research in this area to optimize the ferroalloy production process. Keywords: coals, reducing agent, special coke, coke, production of ferroalloys, low-caking coals, non-caking coals, Zhalyn.

Application of hydrogen in production of ferroalloys

Application of hydrogen in production of ferroalloys

Complex microwave processing of high-ash brown coal in relation to the energy and metallurgical industries

Relevance. The need of the Tomsk region for valuable energy resources obtained from local low-grade resources to develop iron ore deposits available in the region and cover energy needs. Aim. To study gaseous and solid products obtained from low-grade brown coal of the Talovsky deposit (Tomsk region) under microwave pyrolysis conditions in relation to the energy and metallurgical industries. Objects. Brown coal of the Talovsky deposit (Tomsk region). Methods. Certified SS methods to determine thermal characteristics and elemental composition of coal organic and mineral parts, the "transmission-reflection" method for measuring imaginary (ε'') and real (ε') components of the complex dielectric permittivity, physical experiment, gas analysis, Brunauer–Emmett–Teller method for measuring texture characteristics. Results. Brown coal of the Talovsky deposit has high values of moisture and ash contents for operating conditions, which leads to a low calorific value. Such characteristics make it possible to classify coal as a low-grade fuel, which indicates the inexpediency of its use as a raw material for the energy and metallurgical industries. Thermal processing by means of microwave pyrolysis makes it possible to obtain a high-calorie (heat of combustion over 21 MJ/m3) and environmentally friendly (hydrogen content over 29%) gaseous fuel from the low-grade brown coal of the Talovsky deposit. The resulting solid carbonaceous residue has an ash content of over 48%, which required its chemical treatment in a solution of HF and HCl. As a result of the solid carbonaceous residue treatment, its ash content decreased by more than 38%, the sulfur content – by more than 1.5 times. According to its characteristics, the resulting product corresponds to the currently available carbonaceous products – semi-coke, coke and carbon reducing agent for ferroalloy production.

Ефективність використання коксу із заданими значеннями питомого електричного опору

DOI: 10.31081/1681-309X-2024-0-2-28-32 Specialty161, 051. U.D.C. 661.66.2:537.311/.312 EFFICIENCY OF COKE UTILISATION WITH SPECIFIED VALUES OF ELECTRICAL RESISTIVITY © V.V. Vladymirenko, N.M. Dyakova (National Technical University "Kharkiv Polytechnic Institute", 2, Kyrpychova str., Kharkiv, 61002, Ukraine), I.V. Shulga, Ph.D. in Technical Sciences, (State Enterprise “Ukrainian State Research Institute for Carbochemistry (UKHIN)”, 7 Vesnina str., Kharkiv, 61023, Ukraine) The article shows that ensuring the specified values of coke resistivity for different directions of its use allows achieving a positive effect in metallurgical production. It is noted that the resistivity of coke for modern blast furnaces using pulverised coal should be minimal. This is ensured by the proper final coking temperature, which makes it possible to obtain coke with the required level of readiness – the final temperature should be at least 1100 оС. This reduces not only the specific electrical resistance of coke, but also its reactivity. The post-reaction strength of the coke is also significantly increased. This makes it possible to reduce coke consumption for pig iron production and increase the productivity of blast furnaces. As a result, it can be achieved the generation of an additional profit of UAH 377.20 per ton of coke. The resistivity of ferroalloy coke, unlike blast furnace coke, should be as high as possible, which will increase the amount of heat generated in the electric circuit of ferroalloy furnaces and used for endothermic reduction reactions. Therefore, lower coke readiness and lower final coking temperatures are sufficient to produce ferroalloy coke. The use of such coke makes it possible to increase the productivity of electric furnaces for smelting ferroalloys and reduce the consumption of raw materials and electricity. According to the results presented in this article, the additional profit is 4741.37 UAH per ton of coke. The weighted average efficiency of the use of coke with given values of resistivity in the national economy, determined by the volume of coke use in various industries, is 464.48 UAH per ton of coke. Keywords: coal coke, electrical resistivity, post-reaction strength, blast furnace production, ferroalloy production, economic efficiency. Corresponding author I.V. Shulga, e-mail: ko@ukhin.org.ua

Method to predict alloy yield based on multiple raw material conditions and a PSO-LSTM network

The production of ferroalloys accounts for a large proportion of the total energy consumption of the steelmaking industry. Accurately predicting alloy element yields is the key to reducing alloy waste, but there are significant differences in alloy yield under different conditions using ferroalloy raw materials during steelmaking. Therefore, this paper proposes a multi-model alloy element yield prediction method based on a particle swarm optimization (PSO) hyperparameter-optimized long short-term memory (LSTM) network and raw material condition classification. The accuracy of the PSO-LSTM prediction model was verified through simulations and was significantly higher than that of other network models when using the same raw material conditions. The average absolute error of predictions using raw materials with a low drum index was 0.4485, and it was 0.6162 under a high drum index, which was significantly lower than that (0.7077) under the condition without classification. This demonstrates the rationality of classifying working conditions according to the raw material conditions of ferroalloys. In addition, this paper combines the prediction model with a linear programming algorithm to develop a ferroalloy operating system and uses it in a steel plant to guide workers to complete an alloying operation. After four months of industrial testing, the internal control rate of finished steel composition increased from 91–94 % to 95–98 %. According to statistical analysis, the optimized HRB400E threaded steel consumed 1.23 kg less silicon-manganese per ton of steel, reduced the cost of steel alloy per ton by 8.6 yuan, and significantly reduced the waste of ferroalloys during steelmaking.

The Choice of Binder for the Production of Briquettes from Highly Dispersed Dust of Ferroalloy Production

Based on the information analysis, the briquetting process is defined as the optimal way to dispose of highly dispersed dust (HDD) of ferroalloy production. Initial studies have been conducted on the choice of a binder for briquetting (HDD). The obtained results showed the possibility of utilization of highly dispersed dust of Kazakhstan content by briquetting. As a binder, liquid glass and caustic soda were used in an amount of 10% by weight each. To ensure the necessary mechanical strength of briquettes, the pressing pressure below 40 kN seems impractical.

Investigation of the beneficiation of refractory ferromanganese ores “Zhomart” deposits

In order to provide ferroalloy production with high-quality raw materials, the need to develop technologies for processing of low-grade manganese and ferromanganese ores is becoming increasingly important. In view of the change in the quality characteristics of ores, the decrease in manganese content and the ability to beneficiation by traditional methods, it is necessary to consider new approaches and technological solutions. The article presents data from a study on the beneficiation of refractory iron-manganese ore from the Zhomart deposit. The mineralogy, physical and mechanical properties, and granulometric composition of the ore were determined. The results of a study on gravitational beneficiation using a laboratory pulsator with a pneumatic drive and a laboratory 2-chamber diaphragm jigging machine and magnetic beneficiation of ore with a high-intensity magnetic field are presented. Iron-containing concentrate (Fe-45% and Mn-6.5% is mainly represented by hematite mixed with non-metallic minerals quartz and calcite) and iron-manganese concentrate (Mn-21.7% and Fe-21.1% in the form of hematite, Brownite and pyrolusite, also mixed with quartz and calcite). The concentrates are not suitable for smelting manganese-containing ferroalloys but can be used in the process of electrothermal beneficiation with selective carbothermal reduction of iron in an ore-thermal furnace. The smelting products can be manganese cast iron and iron-free, low-phosphorus limiting manganese slag with a high ratio of manganese to iron.

Temperature and frequency dependencies of the permittivities of ferroalloys and reaction mixtures

Ferroalloys, such as ferrochromium, ferromanganese and ferrosilicon are pyrometallurgically produced in energy intensive submerged arc furnaces. In turn, these materials can be used as reagents in a number of pyrometallurgical processes, where the energy requirements are typically supplied by electricity or by the combustion of hydrocarbons. Presently, there are significant incentives to develop more efficient processes, which utilize renewable energy. The electricity from these renewable sources can be converted into electromagnetic radiation, such as microwaves, which in turn can be used as a thermal energy source. The amount of energy absorbed from the electromagnetic field and the amount converted into heat are determined by the real and the imaginary permittivities, respectively. These permittivity results are needed for process development, in particular for numerical modelling. In this research, the permittivities of selected ferroalloys and reaction mixtures were determined as a function of temperature and frequency using the cavity perturbation technique. Also, the limitations of the cavity perturbation technique for these types of measurements are highlighted. In order to interpret the permittivity changes for the reaction mixtures, HSC Chemistry®7.1 was utilized to model the compositional changes as a function of temperature. The results indicate that microwaves are a potential heating source for ferroalloy production and also in processes which utilize ferroalloys as a reagent.

The Possibility of Obtaining Mangano Ferro Silico Chromium from Dusts of Silicon and Chromium Ferroalloys Production Using High-Ash Coal

The Possibility of Obtaining Mangano Ferro Silico Chromium from Dusts of Silicon and Chromium Ferroalloys Production Using High-Ash Coal

Methods and installations for utilization of fine screenings of ferroalloys

To date, the production of such ferroalloys as ferrosilicon, ferromanganese, ferosilicomanganese, high-carbon ferrochrome amounts to thousands of tons per year. Preparation of the ferroalloy for sale involves crushing the ferroalloy ingot to the commercial fraction, as a result of which there are dust-like screenings, which are further stored in warehouses and harm the environment. The existing sieving is a finished product, which in composition is close to the final fraction, the size of which is 10-250 mm. To apply sieving in steel production technology, it must be re-melted and cast into an ingot. The resulting ingot is repeatedly crushed until a commercial fraction is obtained. The main problem is the remelting of the dropout, since various difficulties arise due to its size and electrophysical properties. This article presents methods and installations for remelting sieving ferroalloys of various brands, as well as their comparison, disadvantages and advantages. The article describes plasma, induction crucible, as well as dual DC and AC installations designed for remelting sieving of various ferroalloys with a fraction less than 10 mm. The disadvantages and advantages of each method and remelting installation are described. Various experimental data obtained during the melting of ferroalloys sieving in the described installations are presented. Based on the data described in the article, as well as relying on other conclusions, in conclusion, a method of remelting with the removal of ferroalloys was proposed, including the advantages of existing ones, as well as excluding their disadvantages.