Kinetics of goldcyanide extraction using ion-exchange resins containing piperazine functionality

Cortina, José Luis; Warshawsky, Abraham; Kahana, Nava; Kampel, V. Ts.; Sampaio, Carlos Hoffmann; Kautzmann, Rubens Müller

doi:10.1016/s1381-5148(02)00180-3

Cited by 60 publications

(26 citation statements)

References 9 publications

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“…For the adsorption on synthetic polymers, the main diffusion resistance is likely to be film or intraparticle diffusion depending on the extend of polymer cross-linking [51]. To assess and differentiate the effect of film and intraparticle diffusion resistances on adsorption kinetics, the Weber-Morris equation, which was derived from Fick's law for adsorbent diffusing in spherical adsorbent particles at a short adsorption time, can be used to establish the relationship between the adsorbent uptake ( ) and the square root of adsorption time ( 1/2 ) [52] as:…”

Section: Weber-morris Equationmentioning

confidence: 99%

Adsorption of pyridine from aqueous solutions by polymeric adsorbents MN 200 and MN 500. Part 2: Kinetics and diffusion analysis

Zhu

Moggridge

D’Agostino

2016

Chemical Engineering Journal

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Telephone: +44 (0)1223 334763Fax: +44 (0)1223 334796 2 AbstractThe adsorption kinetics of pyridine adsorption on Macronet adsorbents MN 200 and MN 500 from aqueous solution was investigated at various initial pyridine concentrations and temperatures. The Weber-Morris plots revealed the influence of both external film diffusion and intraparticle diffusion resistances. The two linear regions in Weber-Morris plots were attributed to macropore and micropore diffusion, which was associated to the bimodal pore size distribution of the adsorbents. New insights into the diffusion mechanisms were highlighted, with the proposed internal film diffusion resistance dominating into the macropore region, whereas homogeneous particle diffusion resistance describes diffusion in the micropore region. The importance of pore and surface diffusion in the micropores was noted in contributing to the observed diffusion kinetics. The pore diffusion coefficient was estimated from PFG (pulsedfield gradient) parameter and molecular diffusion coefficient of pyridine in bulk liquid. A greater contribution of the surface to the overall diffusion kinetics was found for MN 500 as inferred from a proposed calculation method, which agrees with its better adsorption performance. The overall findings highlight the effect of pore structure onto the diffusion mechanisms inside the pores and help to gain a better understanding into the adsorption kinetics of these Macronet adsorbents, which are promising materials for the removal of Nheterocyclic compounds from waste water.

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Section: Weber-morris Equationmentioning

confidence: 99%

Adsorption of pyridine from aqueous solutions by polymeric adsorbents MN 200 and MN 500. Part 2: Kinetics and diffusion analysis

Zhu

Moggridge

D’Agostino

2016

Chemical Engineering Journal

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“…The gold complex NaAu(CN) 2 is then extracted from leach solutions by adsorption onto solid adsorbents such as activated carbon or a synthetic ion exchange resin [7][8][9][10][11]. Activated carbon is the most commonly used adsorbent for gold extraction due to several favourable properties such as high adsorption capacity, good reactivation capabilities, low cost, readily available, high mechanical strength and wear resistance [12].…”

Section: Gold Extraction Process Using Cyanidementioning

confidence: 99%

Review of the Impact on Water Quality and Treatment Options of Cyanide Used in Gold Ore Processing

Nyamunda¹

2017

Water Quality

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Cyanide has been widely used in several industrial applications such as electroplating photography, metal processing, agriculture, food and the production of organic chemicals, plastics, paints and insecticides. The strong affinity of cyanide for metals such as gold and silver makes it suitable for selective leaching of these metals from ores. Cyanide is highly toxic; hence, there is a need to regulate and limit the amount of cyanide that may be discharged into the environment. Technologies focusing on the use of physical, chemical and biological methods have been developed to reduce the concentration of cyanide and cyanide compounds in wastewaters to permissible limits. This chapter reviews the current and emerging technologies for treatment of cyanide from wastewaters generated in gold mining processes.

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“…The organic ion exchange resins are very effective at transferring the radioactive content of a large volume of liquid into a small volume of solid and have proved to be reliable and effective for the control of both the chemistry and radiochemistry of water coolant systems at nuclear power plants and also for processing some liquid radioactive waste. In recent years tremendous work on development of new organic based ion exchangers [7][8][9][10][11][12][13][14][15]. By taking advantage of the fact that, under certain conditions, ion exchange media has a greater affinity for certain ionic species than for others, a separation of these species can be made [16].…”

Section: Introductionmentioning

confidence: 99%

Study on Halide Ions Selectivity of Nuclear Grade Anion Exchange Resin Auchlite ARA-9366

Singare¹,

Patange²

2014

ILCPA

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The selectivity behaviour of nuclear grade anion exchange resin Auchlite ARA-9366 in chloride form towards iodide and bromide ions in the solution was studied. The trend in selectivity of the resin was predicted on the basis of thermodynamics of Clˉ/Iˉ and Clˉ/Brˉ uni-univalent ion exchange reactions. It was observed that the equilibrium constants K values for Clˉ/Iˉ ion exchange reaction were higher than that calculated for Clˉ/Brˉ exchange under identical experimental conditions. Also the enthalpy values for the two uni-univalent ion exchange reactions were calculated as -47.87 and -36.14 kJ/mol respectively. The high K and low enthalpy values obtained for Clˉ/Iˉ ion exchange reaction as compared to that obtained during Clˉ/Brˉ exchange supports higher selectivity of the resin towards iodide ions as compared to that towards bromide ions, when both the ions are present in the same solution.

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Kinetics of goldcyanide extraction using ion-exchange resins containing piperazine functionality

Cited by 60 publications

References 9 publications

Adsorption of pyridine from aqueous solutions by polymeric adsorbents MN 200 and MN 500. Part 2: Kinetics and diffusion analysis

Adsorption of pyridine from aqueous solutions by polymeric adsorbents MN 200 and MN 500. Part 2: Kinetics and diffusion analysis

Review of the Impact on Water Quality and Treatment Options of Cyanide Used in Gold Ore Processing

Study on Halide Ions Selectivity of Nuclear Grade Anion Exchange Resin Auchlite ARA-9366

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