Precipitation of metals by metals (cementation)—kinetics, equilibria

Sędzimir, J.

doi:10.1016/s0304-386x(02)00033-6

Cited by 37 publications

(24 citation statements)

References 2 publications

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“…∆G* = ∆H* -T∆S* (8) where B is the Boltzmann's constant, A is an empirical constant, T is the absolute temperature, R is the gas constant, h is the Plank's constant and e is the electronic charge (e = 2.7183). The values of the thermodynamic parameters are given in Table 7.…”

Section: Thermodynamic Treatment Of the Resultsmentioning

confidence: 99%

“…However, since actual yield and process efficiencies are determined by rate factors, the knowledge of the reaction kinetics is essential for the most economic utilization of the process. Factors affecting these kinetics, such as geometry of the less noble metal surface, temperature, concentration of the metal ions and mode of stirring velocity, have been studied extensively [3][4][5][6][7][8][9][10][11][12][13]. An electrochemical nature of the cementation reaction was recognized and this pictured cementation to occur through shorted electrochemical cells similar to the model proposed for aqueous corrosion.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Taha

2004

Port. Electrochim. Acta

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The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH 3 OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu 2+ ions, temperature and concentration of organic solvent, was investigated. In the case of CH 3 OH, rotating zinc cylinder was used, while in the presence of DMSO stationary zinc sheet and rotating zinc cylinder were used. It was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of DMSO using rotating zinc cylinder > the rate of cementation in the presence of DMSO using stationary zinc sheet; (3) the rate of cementation on zinc cylinder in the presence of DMSO < the rate of cementation in the presence of CH 3 OH. Different reaction conditions, and the physical properties of solutions are studied to obtain dimensionless correlation among all these parameters. Thermodynamic parameters ∆S*, ∆H* and ∆G* were studied.

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Section: Thermodynamic Treatment Of the Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Taha

2004

Port. Electrochim. Acta

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“…Some authors (Stefanowicz et al, 1997;El-Batouti, 2005) suggest attrition to remove the cemented copper from sacrificial metal surface by collisions. Conversely, Sedzimir (2002) suggests that copper growth on less noble metal surface increases the surface of reaction, with subsequent increase of process rate, because no direct contact between copper ions and the less noble metal surface is required to allow copper cementation.…”

Section: Introductionmentioning

confidence: 94%

Recovery of residual copper from low-content tailings derived from waste electrical cable treatment

Anastassakis

Bevilacqua

Lorenzi

2015

International Journal of Mineral Processing

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“…The general reaction for a cementation process is given by [12] mNn ++ nM→nMm ++ mN (1) where N represents the noble metal and M the reductant metal. This process has been applied in metallurgy, to recover metals from dilute leach liquors [13][14][15][16][17][18]. It is also exploited in metal finishing industry to recover noble metals such as copper from some waste solutions, etc.…”

Section: Introductionmentioning

confidence: 99%

Removal of Copper From Wastewater By Cementation From Simulated Leach Liquors

Nassef¹,

El-Taweel²

2015

J Chem Eng Process Technol

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Every year, tons of precious and/or toxic metals are thrown away in industrial liquid effluents and most frequently directly in natural environment. The recovery of those metals in dilute solutions is an everyday problem associating both ecology and economy. Copper is among the most prevalent and valuable metal used by industry. Cementation is one of the most effective and economic techniques for recovering toxic and or valuable metals from industrial waste solution and from leach liquors obtained by leaching low grade copper ore. The present study was carried out to investigate the removal of copper metal ions from synthetic waste water by cementation using a rotating iron cylinder. The study covered the effect of different parameters in batch mode which are: Initial copper concentrations, pH values, rotational speed, and reaction temperature on the rate of cementation. The rate of cementation was found to increase with increasing rotational speed, temperature, and pH till a value of 2.1 and then starts to decrease .On the other hand as the initial copper ions concentration increases from 0.2 to 0.4 M the rate of copper ions removal increase. The rate of copper recovery ranged from 10% to 90% per hour depending on the operating conditions Rates of cementation which can be expressed in terms of the rate of mass transfer were correlated to the controlling parameters by dimensionless equation: Sh=0.18 SC0.33 Re0.961. This equation can be used in the design and operation of high-productivity cementation reactor.

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Precipitation of metals by metals (cementation)—kinetics, equilibria

Cited by 37 publications

References 2 publications

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Recovery of residual copper from low-content tailings derived from waste electrical cable treatment

Removal of Copper From Wastewater By Cementation From Simulated Leach Liquors

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