A Lantern Retort for Small-Scale Gold Extraction

Richard Kwasi Amankwah; Grace Ofori-Sarpong

doi:doi:10.11648/j.ijepp.20140205.13

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A Lantern Retort for Small-Scale Gold Extraction

Richard Kwasi Amankwah, Grace Ofori-Sarpong

Published in International Journal of Environmental Protection and Policy (Volume 2, Issue 5)

Received: 25 August 2014 Accepted: 5 September 2014 Published: 20 September 2014

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Abstract

Two major retorts used in small-scale gold mining operations to reduce mercury emissions, during amalgam distillation are the steel and thermex retorts. Steel retorts are not very popular due to the reported darkening of gold after retorting. In addition, its opaque nature prevents miners from observing the process directly. The Thermex glass retort introduced by the United Nations Industrial Development Organisation (UNIDO) is also not patronised due to the extended heating periods resulting from the low thermal conductivity of glass. This paper describes a new retort, the Lantern retort, a combination of highly conductive steel with transparent glass, and therefore, a potential solution to the above concerns. The Lantern retort has a shorter warm-up and amalgam distillation time, and the rate of heating is 1.81oC/s while that of the Thermex is 1.49oC/s. For an amalgam of mass 20 g, 900 s was required to carry out complete distillation in the Lantern retort as against 2100 s in the Thermex. The height of the distillation column of the Lantern retort required to reduce mercury loss to below 1%, as it is with the Thermex retort, is 2.5 cm. Other advantages of the Lantern retort are that, it is less expensive and can withstand the harsh terrain of small-scale gold mining.

Published in	International Journal of Environmental Protection and Policy (Volume 2, Issue 5)
DOI	10.11648/j.ijepp.20140205.13
Page(s)	161-167
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2014. Published by Science Publishing Group

Keywords

Small-scale Mining, Gold, Mercury, Amalgamation, Retorting, Lantern Retort

References

[1]	"M. M. Veiga, P. A. Maxson and L. D. Hylander, Origin and consumption of mercury in small-scale gold mining. Journal of Cleaner Production, 2006. Vol. 14 (3-4), pp. 436-447.
[2]	Anon, United Nations Industrial Development Organization. Global Mercury Project Website. http://www.globalmercuryproject.org/.2009. Accessed on Aug/05/2009.
[3]	M. Babut, R. Sekyi, A. Rambaud, M. Potin-Gautier, S. Tellier, W. Bannerman and C. Beinhoff, Improving the environmental management of small-scale gold mining in Ghana: a case study of Dumasi. Journal of Cleaner Production, 2003. Vol. 11 (2), pp. 215-221.
[4]	L. D. Hylander and M.Meili, The Rise and fall of mercury: Converting a resource to refuse after 500 years of mining and pollution. Critical Reviews in Environmental Science and Technology, 2005. Vol. 35 (1), pp. 1-36.
[5]	G. Hilson, C. J. Hilson S. and Pardie, Improving awareness of mercury pollution in small-scale gold mining communities: Challenges and ways forward in rural Ghana, Environmental Research, 2007. Vol. 103 (2), pp. 275-287.
[6]	R. K. Amankwah, M. T. Styles, S. Al Hassan and R. S. Nartey, The application of direct smelting of gold concentrates as an alternative to mercury amalgamation in small-scale gold mining operations. International Journal of Environment and Pollution, 2010. Vol. 41 (3/4), pp. 304-315.
[7]	R. K. Amankwah and C. Anim-Sackey, Strategies for the sustainable development of the small-scale gold and diamond mining industry of Ghana. Resources Policy, 2003. Vol 29 (3-4): pp. 131-138.
[8]	N. Yakovleva, Perspectives on female participation in artisanal and small-scale mining: A case study of Birim North District of Ghana. Resources Policy, 2007. Vol. 32 (1-2), pp. 29-41.
[9]	S. M. Banchirigah, Challenges with eradicating illegal mining in Ghana: A perspective from the grassroots. Resources Policy, 2008. Vol. 33 (1), pp. 29-38.
[10]	G. Hilson, Child Labour in African Artisanal Mining Communities: Experiences from Northern Ghana. Development and Change, 2010. Vol. 41 (3), pp. 445-473.
[11]	G. Drasch, S. Böse-O'Reilly, C. Beinhoff, G. Roider and S. Maydl, The Mt. Diwata study on the Philippines 1999 — assessing mercury intoxication of the population by small-scale gold mining. The Science of the Total Environment, 2001. Vol. 267 (1-3), pp. 151-168.
[12]	J. D. Appleton, T. M. Williams, N. Breward, A. Apostol, J. Miguel and C. Miranda, Mercury contamination associated with artisanal gold mining on the island of Mindanao, the Philippines. The Science of the Total Environment, 1999. Vol. 228 (2-3), pp. 95-109.
[13]	W. Bannerman, M. Potin-Gautier and D. Amouroux, Mercury and arsenic in the gold mining regions of the Ankobra River basin in Ghana. Journal de Physique, 2003. Vol. 107, pp. 107-110.
[14]	J. C. Bonzongo, A. K. Donkor and V. K. Nartey, Environmental impacts of mercury related to artisanal gold mining in Ghana. Journal de Physique IV, 2003. Vol. 107, pp. 217-220.
[15]	P. Tschakert and K. Singha, Contaminated identities: Mercury and marginalization in Ghana's artisanal mining sector. Geoforum, 2007. Vol. 38 (6), pp. 1304-1321.
[16]	G. Hilson and M. J. Clifford, Small-scale gold mining, the environment and human health: an introduction to the Ghana case. International Journal of Environment and Pollution, 2010. Vol. 41 (3-4), pp. 185-194.
[17]	F. K. Nyame, Policy challenges on mercury use in Ghana's artisanal and small-scale mining sector. International Journal of Environment and Pollution, 2010. Vol. 41 (3-4), pp. 202-213.
[18]	P. Tschakert, Mercury in fish: a critical examination of gold mining and human contamination in Ghana. International Journal of Environment and Pollution, 2010. Vol. 41 (3-4), pp. 214-228.
[19]	G. Hilson and R. Vieira, Challenges with minimising mercury pollution in the small-scale gold mining sector: Experiences from the Guianas. International Journal of Environmental Health Research, 2007. Vol. 17 (6), pp. 429-441.
[20]	Anon. Reducing risks from mercury. OPPT Accomplishments Report, http://www.epa.gov/oppt/ar/2007-2009/reducing/mercury.htm. 2014. Accessed: 09/ 02/ 2014.
[21]	A. A. Adimado and D. A. Baah, Mercury in Human blood, Urine, Hair, Nail, and Fish from the Ankobra and Tano river basins in Southwestern Ghana. Bull. Environ. Contam.Toxicol, 2002. Vol. 68, pp. 339-346.
[22]	A. A. Golow and E. A. Adzei, Mercury in surface soil and cassava crop near an alluvial goldmine at Dunkwa-On-Offin, Ghana. Bull. Environ. Contam. Toxicol, 2002. Vol. 69, pp. 228-235.
[23]	R. Eisler, Health risks of gold miners: A synoptic review. Environmental Geochemistry and Health, 2003. Vol. 25, pp. 325-345.
[24]	J. J. Hinton, M. M. Veiga and C. Beinhoff, Women, Mercury, and Artisanal Gold Mining: Risk Communication and Mitigation. J. Phys. IV, 2003. Vol. 107, pp. 617-620.
[25]	T. Iwata, M. Sakamoto, X. Feng, M. Yoshida, X. J. Liu, M. Dakeishi, P. Li, H. Jiang, M. Nakamura and K. Murata, Effects of mercury vapor exposure on neuromotor function in Chinese miners and smelters. Int. Arch Occup Environ Health, 2007. Vol. 80, pp. 381-387.
[26]	R. B. Voegborlo, A. A. Adimado and J. H. Ephraim, Total mercury distribution in different tissues of Frigate Tuna (Auxisthazardthazard) from the Atlantic Coastal waters of Ghana, Gulf of Guinea. Environ. Monit. Assess., 2007. Vol. 132, pp. 503-508.
[27]	R. K. Amankwah and G. Ofori-Sarpong, The lantern retort- A new retort for small-scale gold extraction, In: Proceedings of Precious Metals '10, June 15-16, Falmouth, UK, 2010. pp. 1-14.
[28]	M. T. Styles, R. K. Amankwah, S. Al-Hassan and R. Nartey, The identification and testing of a method for mercury-free gold processing for artisanal and small-scale gold miners in Ghana. Int. J. Environment and Pollution, 2010. Vol. 41 (3/4), pp. 289 –303.
[29]	G. Hilson and A. J. Monhemius, Alternatives to Cyanide in the Gold Mining Industry: What Prospects for the Future? Journal of Cleaner Production, 2006. Vol. 14 (12-13): pp. 1158-1167.
[30]	G. Crispin, Environmental management in small-scale mining in PNG. Journal of Cleaner Production, 2003. Vol. 11 (2), pp. 175-183.
[31]	S. J. Spiegel, O. Savornin and D. Shoko, Mercury reduction in Munhena, Mozambique: Homemade solutions and the social context for change. International Journal of Occupational and Environmental Health, 2006. Vol. 12 (3), pp. 215-221.
[32]	J. B. Jonsson, P. W. U. Appel and R. T. Chibunda, A matter of approach: the retort's potential to reduce mercury consumption within small-scale gold mining settlements in Tanzania. Journal of Cleaner Production, 2009. Vol. 17 (1), pp. 77-86.
[33]	P. C. Velasquez-Lopez, M. M. Veiga and K. Hall, Mercury balance in amalgamation in artisanal and small-scale gold mining: identifying strategies for reducing environmental pollution in Portovelo-Zaruma, Ecuador. Journal of Cleaner Production, 2010. Vol. 18 (3), pp. 226-232.
[34]	D. C. Israel and J. P. Asirot, Mercury Pollution Due to Small-Scale Gold Mining in the Philippines: An Economic Analysis, Philippine Institute for Development Studies, Paper Series No. 2000-06. Draft report, Economy and Environment Program for Southeast Asia. www.pids.gov.ph., 2000. 61 pp
[35]	M. T. Styles, K. P. C. DSouza, S. Al-Hassan, R. K. Amankwah, R. S. Nartey and W. Mutagwaba, Ghana Mining Sector Support Programme Project ACP GH 027, Mercury Abatement Phase 1 Report, 2006. 143 pp. "

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APA Style

Richard Kwasi Amankwah, Grace Ofori-Sarpong. (2014). A Lantern Retort for Small-Scale Gold Extraction. International Journal of Environmental Protection and Policy, 2(5), 161-167. https://doi.org/10.11648/j.ijepp.20140205.13

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ACS Style

Richard Kwasi Amankwah; Grace Ofori-Sarpong. A Lantern Retort for Small-Scale Gold Extraction. Int. J. Environ. Prot. Policy 2014, 2(5), 161-167. doi: 10.11648/j.ijepp.20140205.13

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AMA Style

Richard Kwasi Amankwah, Grace Ofori-Sarpong. A Lantern Retort for Small-Scale Gold Extraction. Int J Environ Prot Policy. 2014;2(5):161-167. doi: 10.11648/j.ijepp.20140205.13

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@article{10.11648/j.ijepp.20140205.13,
  author = {Richard Kwasi Amankwah and Grace Ofori-Sarpong},
  title = {A Lantern Retort for Small-Scale Gold Extraction},
  journal = {International Journal of Environmental Protection and Policy},
  volume = {2},
  number = {5},
  pages = {161-167},
  doi = {10.11648/j.ijepp.20140205.13},
  url = {https://doi.org/10.11648/j.ijepp.20140205.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijepp.20140205.13},
  abstract = {Two major retorts used in small-scale gold mining operations to reduce mercury emissions, during amalgam distillation are the steel and thermex retorts. Steel retorts are not very popular due to the reported darkening of gold after retorting. In addition, its opaque nature prevents miners from observing the process directly. The Thermex glass retort introduced by the United Nations Industrial Development Organisation (UNIDO) is also not patronised due to the extended heating periods resulting from the low thermal conductivity of glass. This paper describes a new retort, the Lantern retort, a combination of highly conductive steel with transparent glass, and therefore, a potential solution to the above concerns. The Lantern retort has a shorter warm-up and amalgam distillation time, and the rate of heating is 1.81oC/s while that of the Thermex is 1.49oC/s. For an amalgam of mass 20 g, 900 s was required to carry out complete distillation in the Lantern retort as against 2100 s in the Thermex. The height of the distillation column of the Lantern retort required to reduce mercury loss to below 1%, as it is with the Thermex retort, is 2.5 cm. Other advantages of the Lantern retort are that, it is less expensive and can withstand the harsh terrain of small-scale gold mining.},
 year = {2014}
}

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TY  - JOUR
T1  - A Lantern Retort for Small-Scale Gold Extraction
AU  - Richard Kwasi Amankwah
AU  - Grace Ofori-Sarpong
Y1  - 2014/09/20
PY  - 2014
N1  - https://doi.org/10.11648/j.ijepp.20140205.13
DO  - 10.11648/j.ijepp.20140205.13
T2  - International Journal of Environmental Protection and Policy
JF  - International Journal of Environmental Protection and Policy
JO  - International Journal of Environmental Protection and Policy
SP  - 161
EP  - 167
PB  - Science Publishing Group
SN  - 2330-7536
UR  - https://doi.org/10.11648/j.ijepp.20140205.13
AB  - Two major retorts used in small-scale gold mining operations to reduce mercury emissions, during amalgam distillation are the steel and thermex retorts. Steel retorts are not very popular due to the reported darkening of gold after retorting. In addition, its opaque nature prevents miners from observing the process directly. The Thermex glass retort introduced by the United Nations Industrial Development Organisation (UNIDO) is also not patronised due to the extended heating periods resulting from the low thermal conductivity of glass. This paper describes a new retort, the Lantern retort, a combination of highly conductive steel with transparent glass, and therefore, a potential solution to the above concerns. The Lantern retort has a shorter warm-up and amalgam distillation time, and the rate of heating is 1.81oC/s while that of the Thermex is 1.49oC/s. For an amalgam of mass 20 g, 900 s was required to carry out complete distillation in the Lantern retort as against 2100 s in the Thermex. The height of the distillation column of the Lantern retort required to reduce mercury loss to below 1%, as it is with the Thermex retort, is 2.5 cm. Other advantages of the Lantern retort are that, it is less expensive and can withstand the harsh terrain of small-scale gold mining.
VL  - 2
IS  - 5
ER  -

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Author Information

Richard Kwasi Amankwah

Mineral Engineering Department, University of Mines and Technology, Tarkwa, P. O. Box 237, Ghana
Grace Ofori-Sarpong

Mineral Engineering Department, University of Mines and Technology, Tarkwa, P. O. Box 237, Ghana

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Plain Text BibTeX RIS

APA Style

Richard Kwasi Amankwah, Grace Ofori-Sarpong. (2014). A Lantern Retort for Small-Scale Gold Extraction. International Journal of Environmental Protection and Policy, 2(5), 161-167. https://doi.org/10.11648/j.ijepp.20140205.13

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ACS Style

Richard Kwasi Amankwah; Grace Ofori-Sarpong. A Lantern Retort for Small-Scale Gold Extraction. Int. J. Environ. Prot. Policy 2014, 2(5), 161-167. doi: 10.11648/j.ijepp.20140205.13

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AMA Style

Richard Kwasi Amankwah, Grace Ofori-Sarpong. A Lantern Retort for Small-Scale Gold Extraction. Int J Environ Prot Policy. 2014;2(5):161-167. doi: 10.11648/j.ijepp.20140205.13

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@article{10.11648/j.ijepp.20140205.13,
  author = {Richard Kwasi Amankwah and Grace Ofori-Sarpong},
  title = {A Lantern Retort for Small-Scale Gold Extraction},
  journal = {International Journal of Environmental Protection and Policy},
  volume = {2},
  number = {5},
  pages = {161-167},
  doi = {10.11648/j.ijepp.20140205.13},
  url = {https://doi.org/10.11648/j.ijepp.20140205.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijepp.20140205.13},
  abstract = {Two major retorts used in small-scale gold mining operations to reduce mercury emissions, during amalgam distillation are the steel and thermex retorts. Steel retorts are not very popular due to the reported darkening of gold after retorting. In addition, its opaque nature prevents miners from observing the process directly. The Thermex glass retort introduced by the United Nations Industrial Development Organisation (UNIDO) is also not patronised due to the extended heating periods resulting from the low thermal conductivity of glass. This paper describes a new retort, the Lantern retort, a combination of highly conductive steel with transparent glass, and therefore, a potential solution to the above concerns. The Lantern retort has a shorter warm-up and amalgam distillation time, and the rate of heating is 1.81oC/s while that of the Thermex is 1.49oC/s. For an amalgam of mass 20 g, 900 s was required to carry out complete distillation in the Lantern retort as against 2100 s in the Thermex. The height of the distillation column of the Lantern retort required to reduce mercury loss to below 1%, as it is with the Thermex retort, is 2.5 cm. Other advantages of the Lantern retort are that, it is less expensive and can withstand the harsh terrain of small-scale gold mining.},
 year = {2014}
}

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TY  - JOUR
T1  - A Lantern Retort for Small-Scale Gold Extraction
AU  - Richard Kwasi Amankwah
AU  - Grace Ofori-Sarpong
Y1  - 2014/09/20
PY  - 2014
N1  - https://doi.org/10.11648/j.ijepp.20140205.13
DO  - 10.11648/j.ijepp.20140205.13
T2  - International Journal of Environmental Protection and Policy
JF  - International Journal of Environmental Protection and Policy
JO  - International Journal of Environmental Protection and Policy
SP  - 161
EP  - 167
PB  - Science Publishing Group
SN  - 2330-7536
UR  - https://doi.org/10.11648/j.ijepp.20140205.13
AB  - Two major retorts used in small-scale gold mining operations to reduce mercury emissions, during amalgam distillation are the steel and thermex retorts. Steel retorts are not very popular due to the reported darkening of gold after retorting. In addition, its opaque nature prevents miners from observing the process directly. The Thermex glass retort introduced by the United Nations Industrial Development Organisation (UNIDO) is also not patronised due to the extended heating periods resulting from the low thermal conductivity of glass. This paper describes a new retort, the Lantern retort, a combination of highly conductive steel with transparent glass, and therefore, a potential solution to the above concerns. The Lantern retort has a shorter warm-up and amalgam distillation time, and the rate of heating is 1.81oC/s while that of the Thermex is 1.49oC/s. For an amalgam of mass 20 g, 900 s was required to carry out complete distillation in the Lantern retort as against 2100 s in the Thermex. The height of the distillation column of the Lantern retort required to reduce mercury loss to below 1%, as it is with the Thermex retort, is 2.5 cm. Other advantages of the Lantern retort are that, it is less expensive and can withstand the harsh terrain of small-scale gold mining.
VL  - 2
IS  - 5
ER  -

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