Ferromanganese Production Research Articles

Duplex Process to Produce Ferromanganese and Direct Reduced Iron by Natural Gas

The application of natural gas instead of solid carbon to produce ferromanganese is a way forward in sustainable development. Mass and energy balances for an integrated duplex process to produce ferromanganese and direct reduced iron (DRI) by natural gas were studied. The process consists of natural gas injection into molten ferromanganese yielding carbon and hydrogen in which the dissolved carbon into the molten metal bath reduces MnO from a coexisting molten slag that is produced from the smelting of manganese ore. Hydrogen and CO gases reduce solid manganese oxides and iron oxides in the Mn ore to MnO and Fe in the ferromanganese reactor burden. A hot gas with a significant amount of CO and H2 leaves the reactor and is upgraded to a rich CO–H2 gas mixture via methane use in a gas reformer. The obtained highly reducing gas is then used to reduce iron ore in a direct reduction reactor for DRI production, while the DRI reactor process gas is partly looped into the gas reformer and the rest is used in an energy recovery unit for electric power generation for the ferromanganese reactor. It is shown that the presented duplex process is more sustainable than the current commercial ferromanganese production process and its application is accompanied by about 50% less electric energy consumption and about 40% less CO2 emission, excluding the source of electricity.

Pretreatment of Manganese Ore for Improved Energy Efficiency and Smelting Furnace Stability

Preheating of feed for smelting in submerged arc furnace (SAF), has shown to have numerous advantages in the ferroalloy industry. In ferrochrome smelting industry for example, preheating the feed before smelting in SAF has shown excellent results in stabilizing SAF smelting operation by removing moisture and volatiles. More importantly, preheating has shown to reduce smelting energy consumption and to increase the smelting furnace capacity. Furthermore, reducing SAF energy consumption has significant benefits in reducing CO2 emissions. However, preheating technology is currently not widely used in ferromanganese production. In ferromanganese production, smelting is mostly done using a mixture of lump and sintered ore as feed to SAF. The behaviour of feed during preheating in separate shaft kiln is still poorly known in smelting. This research is aimed at understanding optimal operating conditions/steps that could be suitable for using preheating technology when lump ore is used in the feed mix. This is also one of the goals of the EU- funded PreMa project.

Extent of Ore Prereduction in Pilot-scale Production of High Carbon Ferromanganese

Three pilot-scale experiments have been conducted at SINTEF/NTNU in a 440 kVA AC electric furnace to demonstrate the process operation, energy requirements and CO2 emissions in the production of high carbon ferromanganese alloys. Comilog, UMK and Nchwaning (Assmang) ores blended with other materials, such as sinter and flux, thus achieving different charge mixtures have been utilized in the experiments. In the prereduction zone, higher manganese oxides in the ore are reduced to MnO through solid-gas exothermic reactions and at a temperature around 800oC, the unwanted endothermic Boudouard reaction is also active. As such, the total coke and energy consumption is highly dependent on if the prereduction occurs by CO gas or solid C. The pilot furnace has been excavated after each experiment and the extent of prereduction of the ore has been investigated by collecting samples from specific regions in the prereduction zone. In addition, material, and energy balance calculations for the three pilot experiments have been calculated using HSC Chemistry software. The HSC material and energy balance calculations have shown that the slag/alloy ratios, metal analyses, carbon consumption and the overall energy consumption are mainly affected by the composition of the charge mixtures. The relationship between the specific carbon consumption, the off-gas CO2/(CO2+CO) ratio and energy consumption to produce 1 tonne of HCFeMn alloy is discussed for the three different pilot-scale scenarios.

Recycling of Waste Slag Upon Production of Manganese Ferroalloys

The mineral resources base of manganese ores is sufficiently large in Russia. However, their mining capacity is almost absent. This is due to the low quality of domestic manganese ores and the high content of phosphorus. To date, Russia has been obliged to import the commercial manganese ore, manganese-containing ferroalloys, metallic manganese, and manganese dioxide. To produce the high-carbon ferromanganese the composition of charge was developed. The optimum variant was that where 10–15% of manganese-containing raw materials were changed for waste slag. In this case, the phosphorus content in the high-carbon ferromanganese is lower by approximately 20 rel. % in comparison with the production of ferromanganese only from the manganese-containing raw materials. About 50–60 rel. % of manganese can be extracted from the waste slag of silicon-thermal production. To produce the hot metal, the composition of iron-bearing burden material was developed. The optimum variant was that where 100% of manganese raw materials were changed for the waste slag. In this case, upon production of hot metal, the specific consumptions of manganese raw materials and limestone were decreased by 100 and 20%, respectively. The phosphorus concentration in metal was lower by about 10 rel. % as compared to the production of hot metal only from the manganese raw materials. Up to 55% of manganese can be extracted from the waste slag of silicothermic production, which is irretrievably lost at present.
 Keywords: manganese ferroalloys, manganese-containing raw materials, waste slag, hot metal

High-carbon ferromanganese smelting on high-base slags

The article presents the results of laboratory trials for the smelting of high-carbon ferromanganese on highly-basic slags. Laboratory trials have confirmed that an increase in the basicity of ferromanganese production slags has a positive effect on the reduction of manganese to the metal and a decrease in the concentration of silicon in it. However, the high basicity makes the slag high-melting and tough, leading to large losses of manganese with the slag. The use of on borate fluxes solves this problem by affecting the physical and chemical properties of the final slags, which allows the process to be carried out at high basicities with the achievement of optimal technological indicators. The obtained positive results of laboratory experiments served as the basis for approbation the developed technology on a semi-industrial scale with the smelting of high-carbon ferromanganese by the flux method from the manganese ore of the «Bogach» Deposit. As a result of studying the smelting of carbonaceous ferromanganese in large-scale laboratory conditions, the possibility of converting manganese ores on highly-basic slags with appropriate regulation of the transport properties of slag to a standard metal with high technical and economic indicators was established. The best results are achieved when the CaO/SiO2 ratio in the slag is 1.8 and the boron oxide content in the slag is 0.8%. It is established that under these conditions, the obtained boron-containing highly-basic slags of carbonaceous ferromanganese are not subject to slaking.

An Improved Process for the Production of Low-Carbon Ferromanganese in the Electric Arc Furnace

Low-carbon ferromanganese (LC-FeMn) is an essential ingredient for making high-strength low-alloy steel and stainless steel. The conventional industrial-scale silicothermic method for the production of LC-FeMn comprises several energy intensive complex steps consuming about 2000 kWh/ton. We have attempted an improved silicothermic process, which is based on a single step smelting of optimized charge mix in the electric arc furnace. Thermochemical simulation of the smelting process by FactSage 6.4 showed significant effect of the charge mix basicity (B = CaO/SiO2) on manganese, iron, silicon and phosphorous distribution between the metal and slag. The optimum basicity was found to be 1.5 at the charge mix ratio i.e., Mn ore/lime/SiMn of 1:1:0.6 in the smelting tests. Under optimum conditions, the energy consumption was about 690 kWh/ton. This approach has potential benefits for the ferromanganese industry in terms of simpler and energy efficient process.

Physical and chemical bases of decarburization of high-carbon ferromanganese melt

The aim of the work is to establish physicochemical patterns of behavior of carbon, silicon, manganese when using the method of oxygen purge of high-carbon ferromanganese. Method. The process of blowing red metal to sour is neglected. With the fusion of fused acid, it is more important to oxidize silicon. Its presence in metal is practical in the block of oxidized manganese. Because oxygen is an assimilation gas, the mixing processes of the converter bath components and the reduction of manganese oxides at the metal-slag interface do not develop properly during purging. The smelters of the medium-carbonaceous ferromanganese in the converter are characterized by a stable chemical warehouse and even a higher number of vimogs for this type of alloy. The low concentration of silicon in metal over a number of swimming trunks can be easily shoved with a hat of pre-purge bathtub with sour at the final stage of refining. The behavior of phosphorus in these smelts is not controlled. The content of P2O5 in the final slag is 0.1%. To achieve acceptable concentrations of phosphorus in the metal, it is necessary to use starting materials with a low phosphorus content. Scientific novelty.Taking into consideration the high affinity of silicon for oxygen, the physical and chemical basis for the production of medium-carbon ferromanganese, as well as metallic manganese and low-carbon ferromanganese, is the process of the interaction of manganese oxides of a certain basicity slag melt with silicon dissolved in ferromanganese (manganese), that is, as combined reduction -refining process to produce manganese ferroalloys with a given silicon content standard

Phase Relations in Ferromanganese Production During Prereduction: South African Ores

In the steel industry, ferromanganese is an important additive. During the production of ferromanganese the ore goes through prereduction and reduction. The prereduction step is very important, as the degree of reduction during ferromanganese is important. Although many investigations have been conducted on different manganese ores, the current study investigated different phases that formed during prereduction when South African ore was used. The ore was mixed with carbon in excess as the reducing agent, and no fluxes were added while CO gas was blown in the furnace. The temperature was varied from 1000°C to 1200°C with 100°C interval. For each temperature, the time varied from 30 min to 90 min with 30 min interval. The ore to carbon ratio was 4:1. After the experiments, the resulting products were subjected to chemical and phase analysis using XRD, XRF and SEM.

Development of the organization of rational schemes for the use of technogenic waste in the processes of off-treatment of steel intermediate

The results of the experimental verification of the efficiency of complex out-of-furnace treatment of low carbon steel using a test mixture based on man-made waste, which is fed partly to the melting unit at the end of the oxidation period of melting and partly by pouring under a stream of liquid metal. is the use of slag-forming materials obtained by joint heat treatment of mixtures of components containing the above mentioned oxides and carbonaceous material of vegetable origin. Their weight ratio in the initial mixture is determined by the purpose and properties of the finished product. The positive technological effects that are achieved by applying the developed method of after-treatment will in future provide favorable conditions for the effective conduct of microalloying, modification, vacuuming and stable casting of low-quality and ultra-low carbon steel. A slight decrease in the temperature of the steel intermediate in the implementation of the method is about 10 - 15 ° C, which is easily compensated for the installation of the ladle, and a slight increase in electricity consumption is compensated by the effects achieved in the processing of low-carbon steel intermediate. Obtaining a higher degree of desulfurization and deoxidation of steel, as well as reducing the contamination of Al2O3 steel and improving the ecological purity of the process can be achieved by reducing the composition of the SHS used in the first stage of processing, the amount of slag aluminothermal production of ferromanganese and complete exclusion of melting, melting weight ratios of powdered waste production of lime, aluminum-thermal slag production of ferromanganese, sludge neutralization of electrocorundum and carbide cr emnia.

Coke and coal as reductants in manganese ore smelting: An experiment

Abstract The effect of coke and bituminous coal on the reduction of medium-grade manganese ore in ferromanganese production was investigated. Charges of 30 kg medium grade manganese ore, 12 kg limestone and varied amounts of coke and coal were smelted in a Submerged Electric Arc Furnace (SAF) at temperatures of 1300°C to 1500°C. The composition of the ferromanganese and the slag were determined by X-Ray Fluorescence. It was found that using coke as a single reductant resulted in a 96% yield of ferromanganese which was higher than by using coal either as a single reductant or in a mixture of coal and coke. It was also found that using coke as a single reductant resulted in the lowest specific energy consumption. Using coal as reductant produced ferromanganese containing high sulfur and phosphorus.

A new method of manganese alloys obtaining

High cost of the ferromanganese production by traditional methods resulted in searching of new technologies for its production. The main objective of the study was to establish the technological parameters of a new process for the ferromanganese production by using ITmk3 process elements in laboratory conditions. The studies were carried out in the “Nabertherm” chamber furnace, which allows for simulate the temperature and time parameters of ITmk3 process elements in a rotary hearth furnace.The charge for ferromanganese obtaining consisted of manganese ore from the Zhayremsk deposit (Kazakhstan) and non-scarce coal, the consumption of which provided close to stoichiometric one in carbon for the direct reduction of manganese and iron from the correspondent oxides. The composition of the ore gangue and coalash provided a mixture with a slag melting point below 1400 °C.The maximum yield of ferroalloy and the conversion of manganese into the ferroalloy from the burden was achieved at a temperature and duration of thermal treatment of 1500 °C and 10 min, respectively. Information obtained during the study may be used for large-scale testing in a commercially size rotary hearth furnace.

MnO reduction in high carbon ferromanganese production: practice and theory

ABSTRACTThe SAF (submerged arc furnace) process is most widely used for industrial production of high carbon ferromanganese. Most plants use ore feed in the form of lump ore (−75 mm +6 mm), but long term supply is limited, and large quantities of ore fines are generated in ore mineral processing. Therefore development of alternative processes using ore fines (−10 mm) is important. The AlloyStream process is one such process developed to use a feed material mixture of fine ore, coal and flux. This process development provided a unique opportunity to correlate MnO reduction process theory to pilot plant production practice represented in minerlogical observations from furnace heap samples.

Phase identification of individual crystalline particles by combining EDX and EBSD: application to workplace aerosols.

This paper discusses the combined use of electron backscatter diffraction (EBSD) and energy dispersive X-ray microanalysis (EDX) to identify unknown phases in particulate matter from different workplace aerosols. Particles of α-silicon carbide (α-SiC), manganese oxide (MnO) and α-quartz (α-SiO2) were used to test the method. Phase identification of spherical manganese oxide particles from ferromanganese production, with diameter less than 200nm, was unambiguous, and phases of both MnO and Mn3O4 were identified in the same agglomerate. The same phases were identified by selected area electron diffraction (SAED) in transmission electron microscopy (TEM). The method was also used to identify the phases of different SiC fibres, and both β-SiC and α-SiC fibres were found. Our results clearly demonstrate that EBSD combined with EDX can be successfully applied to the characterisation of workplace aerosols. Graphical abstract Secondary electron image of an agglomerate of manganese oxide particles collected at a ferromanganese smelter (a). EDX spectrum of the particle highlighted by an arrow (b). Indexed patterns after dynamic background subtraction from three particles shown with numbers in a

The ferromanganese production using Indonesian low-grade manganese ore using charcoal and palm kernel shell as reductant in mini electric arc furnace

The series of ferromanganese production have been conducted using charcoal and palm kernel shell as a reducing agent to replace of cokes. The experiment was preceded by the characterization of raw materials. Manganese ore and limestone were analyzed using XRF and XRD. Charcoal and palm kernel shells were analyzed proximate to determine its carbon content. Based on the analysis of raw materials then calculated mass balance to determine the raw material requirements for each experiment. The variations are the use of reductant ratio (1, 1.5 and 2.1 stoichiometric ratio). Products and slag are analyzed using OES and AAS to determine its chemical composition. The results showed that the use of palm kernel shell as a reductant better than charcoal for all use ratio (1, 1.5 or 2.1 stoichiometric ratio). The highest percentage of manganese extraction using palm kernel shells as a reducing agent is 49.91% (75.58% Mn, 15.75% Fe, 2.12% C, 5.23% Si, 0.08% P) with the product of FeMn is 6,6 kg. The highest percentage of manganese extraction using charcoal as reductant is 44.16% (72.35% Mn, 18.44% Fe, 1.93% C, 5.69% Si, 0.02% P) with the product of FeMn is 6,1 kg. The results showed that palm kernel shell and charcoal could potentially be used as a reductant in the production ferromanganese.

Ferromanganese production from the mixture of medium-grade and low-grade Indonesian manganese ore

In this present work, the ferromanganese was produced by mixing two different grades of Indonesian manganese ore. The possibility of mixing medium-grade manganese ore (27.77 Mn–4.44 Fe–14.7 Si) and low-grade manganese ore (16.39 Mn–19.22 Fe–20.23 Si) to produce ferromanganese was investigated clearly. The 30 Kg of manganese ore mixture was smelting by using sub-merged arc furnace (SAF). The composition of manganese ore mixture in percent weight to produce ferromanganese was 100–0, 75–25, 50–50, 25–75, and 0–100 for medium-grade and low-grade manganese ore, respectively. These ores were smelted together with stoichiometry cokes. Limestone was added in this smelting process to obtain 0.75 of basicity in this smelting process. The chemical composition of ferromanganese was analyzed with X-Ray Fluorescence (XRF). From the smelting process, the ferromanganese with 31.13 Mn–59.84 Fe–7.84 Si and 75.19 Mn–20.17 Fe–3.27 Si were resulted from 100% of low-grade and medium-grade manganese ore, respectively. The Mn-content in ferromanganese and the yield of ferromanganese production were decreased with the increasing of low-grade manganese ore in the mixture of low-grade and medium-grade manganese ore smelting process.

Energy-saving ferroalloy production

In the laboratory, ore–coal blends consisting of small components (ore, coal, and flux) are prepared. If the coal consumption in the reduction of metals is standardized, ferroalloys with moderate iron content may be obtained; the carbon content in the alloys may be adjusted within the range 0.80–1.5%. This fundamentally new technology for the production of ferrochrome and ferromanganese permits the replacement of electric power by fuel. That considerably reduces production costs, while improving alloy quality and reducing the environmental impact of the process.

Dissolution Kinetics of Iron from Low-Grade Mn Ore and Optimization Using Response Surface Methodology

In this study an attempt has been made to increase Mn/Fe ratio in dump Manganese ore fines so that it can be used for the production of ferromanganese. For this purpose non-coking coal was used as reductant and dilute hydrochloric acid as leaching medium for the roasted ore. The effects of acid strength, leaching time, leaching temperature, stirring speed, ore particle size and pulp density have been studied. The dissolution of iron follows the kinetic model 1 − 2x/3 − (1 − x)2/3 = kdt. Thus product layer diffusion is the controlling mechanism and the activation energy has been determined to be 26.23 kJ/mol at 40–95 °C. Another set of experiments have been conducted according to 23 full factorial design, and regression equation for iron dissolution has been developed.

Improved manganese extraction in the production of manganese ferroalloys

In the production of manganese ferroalloys from ore, about 50% of the manganese in the ore is lost. The manganese lost with the enrichment-slag tailings may be returned to the production of manganese ferroalloys by dithionate method of enrichment of the slurries. A technology is developed for the production of high-carbon ferromanganese from concentrate obtained by the chemical enrichment of tailings slurries. Low-phosphorus Mn slag is used in the production of ferrosilicomanganese and refined manganese ferroalloys. A method is described for alloying hot metal with manganese from slag during the production of lowand medium-carbon ferromanganese. Processes are developed for the production of medium-carbon ferromanganese by mixing ore–limestone melt with high-carbon ferromanganese and removing the phosphorus from Mn-bearing melts by bubbling with CO. The degree of phosphorus removal (70–90%) depends on the bubbling time. By means of improved production of manganese ferroalloys and extraction of manganese from slag and slurries, the manganese extraction may be significantly increased.

Dissipation of Electrical Energy in Submerged Arc Furnaces Producing Silicomanganese and High-Carbon Ferromanganese

Submerged-arc furnace technology is applied in the primary production of ferroalloys. Electrical energy is dissipated to the process via a combination of arcing and resistive heating. In processes where a crater forms between the charge zone and the reaction zone, electrical energy is dissipated mainly through arcing, e.g., in coke-bed based processes, through resistive heating. Plant-based measurements from a device called “Arcmon” indicated that in silicomanganese (SiMn) production, at times up to 15% of the electrical energy used is transferred by arcing, 30% in high-carbon ferromanganese (HCFeMn) production, compared with 5% in ferrochromium and 60% in ferrosilicon production. On average, the arcing is much less at 3% in SiMn and 5% in HCFeMn production.

Effect of slag basicity in ferromanganese production using medium-grade manganese ore from East Java-Indonesia

ABSTRACTFerromanganese is one of the most important alloying elements in steel industries. In this work, the production of ferromanganese was carried out using three-phase submerged mini electric arc furnace. The effect of slag basicity due to the addition of a various amount of limestone as fluxing agent on this smelting process was investigated. The chemical composition of ferromanganese and slag was analysed with X-ray fluorescence. From this experiment, the optimum slag basicity was 0.8 that produced 8.2 kg of ferromanganese with 78.1% Mn, 12.7% Fe, and 8.9% Si. It resulted from 30 kg of manganese ore, 7.5 kg of cokes, and 12 kg of limestone.