Rate of reduction of pyrrhotite in hydrogen

Kor, G. J. W.

doi:10.1007/bf02644099

Cited by 11 publications

(10 citation statements)

References 4 publications

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“…Typically, metallurgical grade ores contain more than 35 pct Mn and literature [8][9][10][11][12][13][14] covers properties of ores with Comilog, CVRD, Groote Eylandt, Wessels and Mamatwan type ores as examples. Several studies [10,11,[15][16][17][18][19][20][21][22] have been conducted on the prereduction of manganese ores by either CO gas or solid carbon.…”

Section: ½8mentioning

confidence: 99%

“…Kor [15] studied the rate of reduction of Mn 3 O 4 by CO and carbonaceous reductants namely; coconut charcoal, coke and pure graphite in the temperature range 900 °C to 1200 °C. The rate of reduction in CO was determined to be fast and the overall rate of reduction by a carbonaceous reductant was influenced by the oxidation of the carbon by CO 2 .…”

Section: ½8mentioning

confidence: 99%

“…The increased extent of prereduction when ores are mixed with solid carbon is due to increased oxidation of C by CO 2 in the presence of coke, thereby increasing the rate of reduction by CO. Gasification of carbon in coke has been previously reported to be catalyzed by Mn 3 O 4 and determines the overall rate of reduction. [15]…”

Section: Extent Of Prereduction Of Manganese Oresmentioning

confidence: 99%

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Prereduction Behavior of Manganese Ores With Solid Carbon and in CO/CO2 Gas Atmosphere

Mukono

Reiersen

Schanche

et al. 2022

Metall Mater Trans B

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The prereduction reactions in the submerged arc furnace (SAF) are highly decisive of the total carbon, and energy consumption of the ferromanganese process. Therefore, understanding the dependency of prereduction behavior on ore characteristics and furnace conditions is of paramount importance. Prereduction behavior of Comilog, Nchwaning and UMK ores with solid carbon was studied in an open 75 kVA induction furnace set up simulating the conditions of an industrial SAF. In addition, the ores were thermogravimetrically studied with non-isothermal heating to 1000 °C in a flowing 70/30 CO/CO2 atmosphere. Gasification of carbon according to Boudouard reaction was considered significant for carbonate ores in induction furnace setup. UMK had a greater extent of prereduction compared to Nchwaning which is low in carbonates and Comilog which is known to have a higher CO reactivity at similar CO contents. TGA rate curves shows that prereduction of UMK ore occurred with two major distinctive steps. The first one was a combination of prereduction reactions and decomposition of carbonates with a peak temperature of 700 °C, and the second peak was the decomposition of calcite at 900 °C. The O/Mn ratio for UMK shows that prereduction is already completed prior to the second decomposition peak at 900 °C. In addition to prereduction reactions, Nchwaning is also characterized by an endothermic step which is decomposition of carbonates at 900 °C. Comilog ore produced the most fines followed by Nchwaning and lastly UMK on decrepitation.

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Section: ½8mentioning

confidence: 99%

Section: ½8mentioning

confidence: 99%

Section: Extent Of Prereduction Of Manganese Oresmentioning

confidence: 99%

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Prereduction Behavior of Manganese Ores With Solid Carbon and in CO/CO2 Gas Atmosphere

Mukono

Reiersen

Schanche

et al. 2022

Metall Mater Trans B

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“…So far, experimental studies [ 26–56 ] and thermodynamic modelings [ 10,13,14 ] of the Fe – N and Mn – N liquid solutions have been performed extensively. The solubility of N in liquid Fe [ 26–48 ] and Mn [ 48–56 ] was measured over wide temperature and pressure ranges.…”

Section: Critical Evaluation and Thermodynamic Optimizationmentioning

confidence: 99%

Thermodynamics of Nitrogen in Molten Fe–Cr–Mn–C–N Alloys

You

Ran

Jiang

et al. 2022

steel research int.

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Thermodynamic behavior of N in the Fe–Cr–Mn–C–N liquid solution is modeled using the Modified Quasichemical Model with consideration of the short‐range ordering. A set of new model parameters for the Fe–Cr–Mn–C–N liquid solution are determined based on a critical evaluation of the available experimental data. The solubility of N in the entire composition range of all binary, ternary, and multicomponent molten alloys within the Fe–Cr–Mn–C–N system is well optimized for various temperatures and N2 pressures. Besides, thermodynamic properties of N in Fe‐based liquid solution affected by the alloying elements are calculated from the developed thermodynamic database. As an application of the database, the N solubility in different steel melts of various conditions is predicted for the process optimization.

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“…The slow kinetics of the second reduction stage was possibly due to its small thermodynamic equilibrium constant (K = 4.2 9 10 À3 at 1173 K [16] ). According to Kor, [22] the slow rate of hydrogen reduction of pyrrhotite at a temperature range of 873 to 1173 K was mainly controlled by the counter-current diffusion of H 2 and H 2 S in the gas-film boundary layer and in the porous iron layer. Figure 8 exhibits the cross section of the reduced product from Test R1, showing the presence of two major phases: alloy and sulfide.…”

Section: Sequential Partial Oxidation-reduction Of Pyrrmentioning

confidence: 99%

Thermal Upgrading of Nickeliferous Pyrrhotite Tailings for the Recovery of Nickel in the Form of Ferronickel Alloy

Liu

Zhang

et al. 2019

Metall Mater Trans B

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Production of ferronickel alloy by thermal treatment of nickeliferous pyrrhotite (Pyrr) tailings was studied by both thermodynamic assessment and experimentation. It was demonstrated that Ni can be extracted from Pyrr by increasing the Fe/S ratio of the material, which was achieved by either partial oxidation of Pyrr followed by H 2 reduction or in situ generation of metallic Fe from the reduction of magnetite by petroleum coke pre-mixed with Pyrr. Examination of the samples produced from thermal treatment at 1173 K demonstrated that both approaches were effective in generating ferronickel, although the size of the particles was suboptimal for subsequent separation. Increasing the ferronickel particle size could be achieved by a smelting step at 1473 K, forming a sulfur-deficient molten matte. Slow cooling of the molten matte resulted in precipitation, settling, and growth of ferronickel alloy particles.

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Rate of reduction of pyrrhotite in hydrogen

Cited by 11 publications

References 4 publications

Prereduction Behavior of Manganese Ores With Solid Carbon and in CO/CO2 Gas Atmosphere

Prereduction Behavior of Manganese Ores With Solid Carbon and in CO/CO2 Gas Atmosphere

Thermodynamics of Nitrogen in Molten Fe–Cr–Mn–C–N Alloys

Thermal Upgrading of Nickeliferous Pyrrhotite Tailings for the Recovery of Nickel in the Form of Ferronickel Alloy

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