Lime-enhanced carbon monoxide reduction of cuprous sulfide

Mohan, M.; Mankhand, T R; Prasad, P. M.

doi:10.1007/bf02672889

Cited by 11 publications

(13 citation statements)

References 12 publications

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“…In accordance with Eq. [6], the observed linear relation supports rate control by pore diffusion in the last stage.…”

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratesupporting

confidence: 73%

“…However, in either stage, rate control by the interfacial reaction or by pore diffusion can be ascertained by the fulfillment of the criterion X CuFeS 2 a1=z 0 1 , for a given t and the other variables, following Eqs. [6] and [7]. This means that the X CuFeS 2 vs t plot for a smaller z 0 1 should lie above that for a greater z 0 1 , which is observed in Figure 12.…”

Section: Effect Of Bed Heightmentioning

confidence: 68%

“…[6]. Because the values of t on the x-axis, in Figure 10, are measured from t = 0, while the last stage of reduction spans over the duration t = 60 to 120 minutes, it will be appropriate to check for the linearity of the plot X 2 CuFeS 2 at t ¼ 120 minutes ð Þ ÀX 2 CuFeS 2 ðat t ¼ 60 minutesÞ vs x H 2 in À x H 2eq , consistent with Eq.…”

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratementioning

confidence: 96%

“…To find the rate-controlling step and the associated activation energy, the effects of different variables on the kinetics of hydrogen reduction of chalcopyrite concentrate will be considered and analyzed using Eqs. [5], [6], and [7], subsequently. with the hydrogen flow rate of 300 mL min À1 .…”

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratementioning

confidence: 99%

“…To overcome this barrier, lime, which is a suitable material to fix the produced hydrogen sulfide gas in the form of solid calcium sulfide, has been successfully used by many researchers. [2][3][4][5][6] However, the addition of lime, which is a strongly hygroscopic material, introduces handling problem and imposes an additional task of separating the solid waste of calcium sulfide from the produced metal. Still another simple method to overcome the thermodynamic barrier is to accept the poor utilization of the reducing gas and use sufficiently large quantity of it.…”

Section: Introductionmentioning

confidence: 99%

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Kinetics of Hydrogen Reduction of Chalcopyrite Concentrate

Chatterjee

Ghosh

2015

Metall Mater Trans B

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A Ghatshila chalcopyrite concentrate (average particle size, 50 lm) containing primarily CuFeS 2 and SiO 2 (Cu 16 pct) was reduced by a stream of hydrogen in a thermogravimetric analyzer (TGA) at selected temperatures [1173 K to 1323 K (900°C to 1050°C)], hydrogen flow rates, partial pressures of hydrogen (0.33 9 101.3 to 101.3 kPa), and sample bed heights. The product was a mixture of Cu (26 pct), SiO 2 , CuFeO 2 , and Fe. The rate equations for the three typical controlling mechanisms, namely, gas film diffusion (mass transfer), pore diffusion, and interfacial reaction, have been derived for the system geometry under study and applied to identify the rate-controlling steps. The first stage of the reduction, which extended up to the first 13 minutes, was rate controlled by the interfacial reaction. The last stage, which spanned over the last 60 to 120 minutes and accounted for a small percentage of reduction, was controlled by pore diffusion through the built-up Cu (and Fe) layer. The activation energy in the first stage was 101 kJ mol À1 and that in the second stage was 76 kJ mol À1 . Subsequent acid leaching with 1 M HCl solution of the reduction product removed all soluble species, leaving a Cu (53.3 pct) + SiO 2 mixture, with a small concentration (2.7 pct) of Cu 2 O in it. This result compares well with the predicted final mixture of Cu (59 pct)-SiO 2 based on a mass balance on the starting concentrate. A follow-up heating at 1523 K (1250°C) produced a sintered Cu-SiO 2 composite with spherical copper particles of 400 lm diameter embedded in a silica matrix. Elemental chemical analyses were carried out by energy-dispersive X-ray spectroscopy/atomic absorption spectroscopy. The phase identification and microstructural characterization of CuSiO 2 mixtures were carried out by X-ray powder diffraction and optical microscopy.

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“…In accordance with Eq. [6], the observed linear relation supports rate control by pore diffusion in the last stage.…”

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratesupporting

confidence: 73%

Section: Effect Of Bed Heightmentioning

confidence: 68%

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratementioning

confidence: 96%

Section: B Hydrogen Reduction Of the Chalcopyrite Concentratementioning

confidence: 99%