Kinetics of pre-reduction of manganese ore by CO

Gao, Yubo; Kim, H G; Sohn, Hong Yong

doi:10.1179/1743285512y.0000000003

Cited by 13 publications

(12 citation statements)

References 13 publications

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“…Previous studies have also observed that Comilog and Nchwaning ore reduce faster in CO-CO 2 atmospheres in smaller particle sizes. [2,16,22] Gao [11] observed no effect by changing the particle size between < 45 to 1000 lm when reducing a precalcined ore in CO-CO 2 atmosphere. This may suggest that the ores have a threshold value at which the kinetics are affected by the particle size.…”

Section: Observationsmentioning

confidence: 99%

“…On the other hand, these semi-oxidized ores often contains significant amount of iron oxides, which may reduce through sequence Fe 2 O 3 -Fe 3 O 4 -FeO-Fe. Several experimental studies have been reported regarding prereduction of manganese ores in CO-CO 2 atmosphere, both in isothermal [2,5,10,11] and non-isothermal [6,[12][13][14][15][16] temperature regimes. Non-isothermal studies have commonly been used to simulate the industrial furnace conditions, i.e.…”

Section: Introductionmentioning

confidence: 99%

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Reduction of Manganese Ores in CO-CO2 Atmospheres

Larssen

Senk

Tangstad

2020

Metall Mater Trans B

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The reduction of higher manganese oxides to MnO in the prereduction zone of a ferromanganese furnace is largely decisive for the overall energy efficiency and climate gas emissions for the overall production process. Kinetics of the gas-solid reaction between the ore and CO(g) in the ascending furnace gas is dependent on the ore characteristics. The aim of this study was to elucidate the reduction steps during prereduction of two commercial manganese ores, Comilog and Nchwaning, in CO-CO2 atmosphere. Ore samples in various size fractions were exposed to isothermal and non-isothermal temperature regimes in various gas atmospheres utilizing a thermogravimetric furnace. Samples were characterized by titration, XRF, XRD, and SEM analyses. Comilog is a high oxygen ore, where the majority of the ore is constituted by various tetravalent manganese minerals. When heated in reducing atmosphere, MnO2-oxides were reduced to MnO in a single step at temperatures below 550 °C. The rate was dependent on the particle size and CO-concentration. When the temperature reached 550 °C, any present MnO2 rapidly decomposed to Mn2O3, which further continued to reduce to MnO. Nchwaning ore was found to be mainly constituted by Mn2O3-oxides, calcite and hematite. Manganese- and iron-oxides were found to reduce at similar temperature ranges, however the manganese oxide reduction was initiated prior to the iron oxides in smaller particle sizes (< 4 mm). Trivalent manganese oxides reduced to MnO in a single step, and the reduction of iron oxides subsided with the formation of wüstite. Carbonates decomposed at temperature range 800 °C to 1000 °C. Both ores obtained a promoted reaction rate with decreasing particle size and increased pctCO in CO-CO2 atmosphere.

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Section: Observationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reduction of Manganese Ores in CO-CO2 Atmospheres

Larssen

Senk

Tangstad

2020

Metall Mater Trans B

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“…8). In addition, according to the reports [33,34], it is the chemical reaction that controls the reduction of iron ore pellet at the temperature range of 550 °C to 750 °C. Therefore, reduction rates of reactions (1) -(3) are improved by the high temperature.…”

Section: Influences Of Carburizing Temperaturementioning

confidence: 99%

Preparation and recovery of iron carbide from pyrite cinder using carburization-magnetic separation technology

Chen

Gou

et al. 2018

J min metall B Metall

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A new technique with carburization followed by magnetic separation is presented for the preparation of high-grade iron carbide from pyrite cinder to promote the high value-added utilization of pyrite cinder. The effects of carburizing temperature, carburizing time and Na 2 SO 4 dosage on carburized pellets were investigated, and the effects of Na 2 SO 4 dosage and grinding fineness on magnetic concentrate were carried out. The optimized process parameters were proposed as follows: carburizing at 650 °C for 180 minutes in CO-CO 2-H 2 gas mixtures, Na 2 SO 4 dosage of 9%, magnetic field intensity of 130 mT, and grinding fineness of 92.25% powder passing 0.025mm. The iron content, total carbon content, total iron and carbon content of magnetic concentrate were 82.62%, 5.60%, and 88.22%, respectively. The recovery rate of iron reached 88.67%. The behaviors and mechanisms of carburization, separation, and Na 2 SO 4 , were ascertained with optical microscopy, X-ray powder diffraction (XRD), and scanning electron microscope (SEM).

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“…Manganese has been a critical element for the production of steels, batteries, fertilizer, non-ferrous alloys, catalysts, and pigment, etc. [1][2][3] Driven by the high crude steel production rate of China, global manganese resources have been mostly consumed by the country [4,5] for the production of manganese ferroalloy, which is produced by smelting with submerged electric arc furnaces (SAF) at a high energy cost [6][7][8][9]. Cheap and high-grade manganese ores have become scarce due to its continuous consumption.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Selective Chlorination and Carbothermic Reduction of High-Iron Manganese Ore for the Recovery of Manganese Chloride and Metallic Iron

Cui

Cong

et al. 2019

Metals

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Metallurgical processing of low-grade manganese ore with high iron content is gaining increasing attention due to the gradual depletion of high-grade Mn ores, amid the difficulties in its efficient extraction for both Mn and Fe values in an environmentally-friendly manner. Attempting to tackle the difficulties, this paper describes an innovative process for selectively chlorinating and reducing the high-Fe manganese ore in a simultaneous manner, aiming to produce water-soluble MnCl2 and metallic Fe. After pre-mixing with carbonaceous reductant, CaCl2 and MgCl2 as the chlorinating agent, the Mn ore was heated at 1000 °C. As much as 89.4% Mn can be chlorinated in its water-soluble form, with dissolution of only 3.0% Fe. The presence of CaCl2 during carbothermic reduction resulted in significant promotion in both the Fe reduction rate and formation of large metallic Fe particles due to the segregation effect, facilitating subsequent separation. Selective Mn chlorination by MgCl2 took place with or without the involvement of SiO2, forming MgSiO4 or MgO, respectively.

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Kinetics of pre-reduction of manganese ore by CO

Cited by 13 publications

References 13 publications

Reduction of Manganese Ores in CO-CO2 Atmospheres

Reduction of Manganese Ores in CO-CO2 Atmospheres

Preparation and recovery of iron carbide from pyrite cinder using carburization-magnetic separation technology

Simultaneous Selective Chlorination and Carbothermic Reduction of High-Iron Manganese Ore for the Recovery of Manganese Chloride and Metallic Iron

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