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A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore

There is an abundant availability of zinc sulphide (sphalerite) ore (160 million tons at 7.40 % Zn) at Gamsberg, Northern Cape in South Africa. The ore body is South Africa’s greatest unexploited base metal resource. Regardless of its size, the low zinc and high manganese content of the sphalerite c...

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Main Author: Dlamini, Zethu
Other Authors: Petersen, Jochen
Format: Thesis
Language:English
Published: Centre for Bioprocess Engineering Research 2015
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access_status_str Open Access
author Dlamini, Zethu
author2 Petersen, Jochen
author_browse Dlamini, Zethu
Petersen, Jochen
author_facet Petersen, Jochen
Dlamini, Zethu
author_sort Dlamini, Zethu
collection Thesis
description There is an abundant availability of zinc sulphide (sphalerite) ore (160 million tons at 7.40 % Zn) at Gamsberg, Northern Cape in South Africa. The ore body is South Africa’s greatest unexploited base metal resource. Regardless of its size, the low zinc and high manganese content of the sphalerite combined with the low zinc price prohibits the development of the deposit. Sphalerite is the most common zinc mineral, hence 95 % of the world’s zinc production is from this mineral. Sphalerite is currently processed by crushing-milling-flotation, followed by the roast-leach-electrowinning (RLE) process. This route has major detrimental impacts on the environment, it produces SO2, and cannot treat ores of low grade or higher complexity. Therefore, alternative processes are being sought in order to circumvent the RLE process. This study compares three different process routes in the context of processing ore from the Gamsberg deposit for refining 3.4 million tpa ore in order to produce special high grade (SHG) zinc (>99.995% Zn). These routes include heap leaching and refining locally (route 1), preparing a flotation concentrate and refining it locally (route 2) and lastly, preparing a flotation concentrate and shipping it for toll refining in Europe (route 3). Zinc heap leaching has not yet been commercialised due to the absence of solvent extraction reagents which can selectively extract zinc from a low tenor acidic pregnant leach solution without incorporating the neutralization stage. Therefore, route 1 has higher risk as compared to the other routes. A desktop model which provides a comparison of capital cost, operating cost, NPV, IRR and PVR has been developed. Parameters such as average zinc grade, process recovery and zinc price are provided as inputs. The effects of fluctuations in important parameters such as working capital, and zinc price on NPV are assessed using Matlab.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:33:21.255Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2015
publishDateRange 2015
publishDateSort 2015
publisher Centre for Bioprocess Engineering Research
publisherStr Centre for Bioprocess Engineering Research
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/13677 A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore Dlamini, Zethu Petersen, Jochen Bioprocess Engineering There is an abundant availability of zinc sulphide (sphalerite) ore (160 million tons at 7.40 % Zn) at Gamsberg, Northern Cape in South Africa. The ore body is South Africa’s greatest unexploited base metal resource. Regardless of its size, the low zinc and high manganese content of the sphalerite combined with the low zinc price prohibits the development of the deposit. Sphalerite is the most common zinc mineral, hence 95 % of the world’s zinc production is from this mineral. Sphalerite is currently processed by crushing-milling-flotation, followed by the roast-leach-electrowinning (RLE) process. This route has major detrimental impacts on the environment, it produces SO2, and cannot treat ores of low grade or higher complexity. Therefore, alternative processes are being sought in order to circumvent the RLE process. This study compares three different process routes in the context of processing ore from the Gamsberg deposit for refining 3.4 million tpa ore in order to produce special high grade (SHG) zinc (>99.995% Zn). These routes include heap leaching and refining locally (route 1), preparing a flotation concentrate and refining it locally (route 2) and lastly, preparing a flotation concentrate and shipping it for toll refining in Europe (route 3). Zinc heap leaching has not yet been commercialised due to the absence of solvent extraction reagents which can selectively extract zinc from a low tenor acidic pregnant leach solution without incorporating the neutralization stage. Therefore, route 1 has higher risk as compared to the other routes. A desktop model which provides a comparison of capital cost, operating cost, NPV, IRR and PVR has been developed. Parameters such as average zinc grade, process recovery and zinc price are provided as inputs. The effects of fluctuations in important parameters such as working capital, and zinc price on NPV are assessed using Matlab. 2015-08-10T06:43:01Z 2015-08-10T06:43:01Z 2015 Master Thesis Masters MSc (Eng) http://hdl.handle.net/11427/13677 eng application/pdf Centre for Bioprocess Engineering Research Faculty of Engineering and the Built Environment University of Cape Town
spellingShingle Bioprocess Engineering
Dlamini, Zethu
A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
thesis_degree_str Master's
title A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
title_full A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
title_fullStr A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
title_full_unstemmed A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
title_short A techno-economic comparison of three process routes for the treatment of Gamsberg zinc ore
title_sort techno economic comparison of three process routes for the treatment of gamsberg zinc ore
topic Bioprocess Engineering
url http://hdl.handle.net/11427/13677
work_keys_str_mv AT dlaminizethu atechnoeconomiccomparisonofthreeprocessroutesforthetreatmentofgamsbergzincore
AT dlaminizethu technoeconomiccomparisonofthreeprocessroutesforthetreatmentofgamsbergzincore