2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 4: Meech Intl. Symp. / Mining Operations

Editors:Kongoli F, Veiga MM, Anderson C
Publisher:Flogen Star OUTREACH
Publication Year:2015
Pages:275 pages
ISBN:978-1-987820-27-0
ISSN:2291-1227 (Metals and Materials Processing in a Clean Environment Series)
CD-SIPS2015_Volume
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    Gold Recovery Study from a Small Scale Mine Tailings from Costa Rica

    Adriana Goncalves1; B. Avelar2; R. Jackson3; D. Ramos4; S. Menezes4; Marcello Veiga5;
    1UBC, Vancouver, Canada; 2FEDERAL UNIVERSITY OF ALFENAS, , Brazil; 3NEWLOX GOLD VENTURES, Vancouver, Canada; 4FEDERAL UNIVERSITY OF OURO PRETO, , Brazil; 5UBC-MINING, Vancouver, Canada;
    Type of Paper: Regular
    Id Paper: 448
    Topic: 4

    Abstract:

    Artisanal Gold Mining (AGM) in 2013 accounted for approximately 12 to 15% of all the gold produced in the world. In many countries, the main method of extraction is whole ore gold amalgamation using mercury in a grinding media. This technique loses to the environment 30 to 50% of the mercury added into the mill and only around 30% of the gold is extracted. This study provides a technical assessment of a tailings deposit from artisanal miners in Costa Rica. About 65,000 tonnes of tailings with 22.73 g Au/tonne is available at the site in which 66% of the gold is below 0.044mm indicating that the majority of the gold particles is fine. With a bench-scale Knelson centrifuge, a tailings sample passing 3 times without grinding resulted in 12% of recovery, 1% mass recovery and grade of 210 g Au/tonne. The GRG (gravity with grinding of the tailings) test resulted in an accumulated recovery of 42%, grade of 50.3 g Au/tonne and mass recovery of 6%. Flotation tests of the gravity separation tailings using Aerofloat 208 obtained gold recovery of 91% with mass recovery of 28%. Although the use of cyanide is not allowed in Costa Rica, the cyanidation of the concentrates with grinding resulted in 87% gold recovery in 12 hours of processing. The idea is to transport the concentrates 200 km to Nicaragua to be leached with cyanide. Furthermore, the data generated have assisted the partner company in the design and deployment of a small scale tailings reprocessing facility with capacity of 80 tpd using an iCON 350 centrifuge and 6 Denver-type mechanical flotation cells. The company's aim is to both reprocess artisanal tailings as well as provide local miners with an alternative to whole ore mercury amalgamation. <br />KEYWORDS: Gold recovery, Artisanal mining, Small-scale processing, Costa Rica

    Keywords:

    Artisanal; Cyanide; Efficiency; Gold; Processing; Recovery; Tailings;

    References:

    [1] Seccatore J. An Estimation of the Artisanal Small - Scale Production of Gold in the World. Report for World Gold Council. Codex Engineering Services: Lungomare, Italy 2012, p. 19 (unpublished).
    [2] UNEP United Nations Environment Programme Global Mercury Assessment. Sources, Emissions, Releases and Environmental Transport, 2013
    [3] Swain EB, Jakus PM, Rice G, Lupi F, Maxson PA, Pacyna JM, Penn A, Spiegel SJ, Veiga MM. Socioeconomic consequences of mercury and pollution. Ambio, 2007; 36 (1): p.45-61
    [4] Veiga MM, Angeloci G; Hitch M; Velasquez-Lopez PC. Processing Centers in Artisanal and Small-Scalle Gold Mining in Ecuador; 2014. Resources Policy, v.38, n.4, p.713-722
    [5] Angeloci- Santos G. Myths and Realities in Artisanal Gold Mining Contamination [MASc thesis]. Vancouver: University of British Columbia, Dept. of Mining Engineering; 2013.
    [6] Meech J. Froth Flotation. [http://www.jmeech.mining.ubc.ca/MINE290/MINE292-Lecture12-15-Froth Flotation-2014.pdf]. Vancouver, 2014 [cited 2014 Nov 5].
    [7] Marsden OJ, House CL. The Chemistry of Gold Extraction. 2nd ed. SME; 2006. p. 428-430.

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    Cite this article as:

    Goncalves A, Avelar B, Jackson R, Ramos D, Menezes S, Veiga M. Gold Recovery Study from a Small Scale Mine Tailings from Costa Rica. In: Kongoli F, Veiga MM, Anderson C, editors. Sustainable Industrial Processing Summit SIPS 2015 Volume 4: Meech Intl. Symp. / Mining Operations. Volume 4. Montreal(Canada): FLOGEN Star Outreach. 2015. p. 133-140.