An alternative low-cost adsorbent for gold recovery from cyanide-leached liquors: Adsorption isotherm and kinetic studies

Adsorption Science and Technology - Tập 37 Số 1-2 - Trang 3-23 - 2019
Refiloe Tsolele1, Fanyana M. Mtunzi1, Michael J. Klink1, Vusumzi Emmanuel Pakade1
1Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa

Tóm tắt

Pristine Macadamia nutshell-based activated carbons were chemically oxidized with different concentrations of H3PO4 and HNO3 to increase their surface adsorption properties and further explore if they could be an attractive alternative low-cost adsorbent for gold recovery from cyanide-leached liquors. The modified activated carbons were labeled MACN20, MACN40 and MACN55 to signify the materials prepared from 20%, 40% and 55% (v/v) HNO3, respectively. Similar nomenclature was followed for H3PO4-modified activated carbons. Brunauer-Emmet-Teller, scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, elemental analysis and X-ray diffraction spectroscopy were used to characterize the prepared activated carbons. The physical properties were attained through determining attrition, ash content, volatile matter and moisture content of all the activated carbons. Various parameters that affect selective adsorption such as the effect of initial concentration, time, agitation speed, interfering species and the dose of the adsorbent were investigated. Optimal parameters for gold ion adsorption were as follows: solution pH, 10; contact time, 6 h; agitation speed, 150 r/min; sorbent amount, 4 g and initial concentration, 5.5 mg/L. The observed selectivity order was not the same for all the adsorbents, but the adsorption of gold was found to be mostly influenced in the presence of nickel and least influenced by copper. MACN55 was found to be the most efficient adsorbent with 74% of gold adsorption from a real-world sample and displayed a similar performance to coconut-based activated carbons.

Từ khóa


Tài liệu tham khảo

10.1016/j.cej.2008.11.035

10.1016/j.cej.2012.01.048

Amor HB, 2013, International Journal of Scientific Research, 4, 309

10.1016/j.desal.2009.10.010

10.4236/ajac.2015.66051

10.1016/j.hydromet.2010.03.016

10.1016/j.egypro.2015.11.556

10.1016/j.jece.2013.12.014

10.1016/j.apsusc.2009.12.109

10.1016/j.jiec.2017.06.036

10.1016/0304-386X(95)00032-C

10.1016/j.apsusc.2015.08.074

10.1007/s11144-015-0889-1

10.1016/j.cej.2010.06.020

Madhavakrishnan S, 2008, Journal of Chemistry, 5, 761, 10.1155/2008/272370

Malik R, 2006, Industrial Journal of Chemical Engineering, 13, 319

10.1016/j.ces.2004.12.049

10.1016/S0304-386X(02)00080-4

10.1016/j.psep.2017.06.007

10.1016/j.hydromet.2013.11.004

10.1016/j.mineng.2013.09.001

10.1016/j.hydromet.2015.08.014

10.1016/j.desal.2006.03.590

10.1016/S0304-386X(02)00062-2

10.17159/0379-4350/2016/v69a22

10.2166/wst.2016.506

10.15261/serdj.19.117

10.1016/j.jaap.2013.10.015

10.1016/j.mineng.2011.09.011

10.1016/j.reffit.2016.11.011

10.1016/j.jtice.2014.09.034

Sayiner B, 2014, Physicochemical Problems of Mineral Processing, 50, 277

Sharifan S (2013) A comparative optimisation study of activated carbon production from hazelnut shells by thermal and microwave heating methods. Ph.D. Thesis, Imperial College London, UK.

Silgado K, 2014, Chemical Engineering Transactions, 37, 721

Soleimani M (2007) Gold adsorption from dilute solutions with carbon adsorbents and modeling of the adsorption system. Ph.D. Thesis, Amirkabir University of Technology, Tehran.

10.1016/j.desal.2010.01.011

10.1016/j.hydromet.2014.05.017

10.1016/j.jhazmat.2006.03.031

10.1016/S0008-6223(97)00073-0

10.1016/j.cherd.2010.06.012

10.1021/la010920a

Vasu AE, 2008, Journal of Chemistry, 5, 814, 10.1155/2008/610503

Vunain E, Kenneth D, Biswick T (2017) Synthesis and characterization of low-cost activated carbon prepared from Malawian baobab fruit shells by H3PO4 activation for removal of Cu(II) ions: Equilibrium and kinetics studies. Applied Water Science 7(8): 4301-4319.

10.1016/S0304-386X(01)00203-1

10.1016/j.apsusc.2014.05.214

10.1016/j.scitotenv.2018.03.091

10.1016/j.jclepro.2017.12.117

10.1016/j.hydromet.2015.04.009

10.1016/j.jcou.2017.05.013

10.1016/S0304-386X(03)00183-X

10.4236/jep.2013.45049

10.1016/j.carbon.2008.11.006