Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil
The Faina gold deposit, located in the Pitangui Greenstone Belt, NW of the Quadrilátero Ferrífero, Brazil, has produced gold from the oxidized portion of the deposit between June 2010 and June 2013. However, the deeper hypogene (sulfide-rich) section of the deposit has shown lower-than-expected rec...
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Serviço Geológico do Brasil (CPRM)
2025-01-01
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| Series: | Journal of the Geological Survey of Brazil |
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| Online Access: | https://jgsb.sgb.gov.br/index.php/journal/article/view/249 |
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| author | Gabriel Machado da Silva Atlas Vasconcelos Corrêa Neto Mariana Brando Soares Felipe Emerson André Alves Nicollas de Oliveira Ferreira Santos Piero Azevedo Berquó de Sampaio Vitor Diniz Silveira Gabriel Faria Gonçalves |
| author_facet | Gabriel Machado da Silva Atlas Vasconcelos Corrêa Neto Mariana Brando Soares Felipe Emerson André Alves Nicollas de Oliveira Ferreira Santos Piero Azevedo Berquó de Sampaio Vitor Diniz Silveira Gabriel Faria Gonçalves |
| author_sort | Gabriel Machado da Silva |
| collection | DOAJ |
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The Faina gold deposit, located in the Pitangui Greenstone Belt, NW of the Quadrilátero Ferrífero, Brazil, has produced gold from the oxidized portion of the deposit between June 2010 and June 2013. However, the deeper hypogene (sulfide-rich) section of the deposit has shown lower-than-expected recovery rates after direct leaching, leading to the interruption of gold production. This research presents a multi-methodological approach (drill core description, multi-element geochemical analyses and mineral characterization using microscopy and X-ray diffraction) to investigate describe the Faina gold deposit and identify the cause of low recoveries from the hypogene zone. The stratigraphy at Faina consists of a sequence of meta-mafic and meta-sedimentary rocks, with a thick (>40m) saprolite horizon (oxidized portion). Both the meta-mafic rocks and saprolite host gold mineralization, which is identified by distinct geochemical and mineral signatures: 1) Au-As-W in the hypogene zone, with gold associated with sulfides or as disseminations in silicates and 2) Au-As-W in the oxide-rich shallower section with free-milling gold associated with quartz, iron oxide-hydroxides and clay minerals. Geochemical, mineral and textural relationships in the hypogene zone show that submicroscopic gold particles associated with minerals, that consume leaching solution minerals (arsenopyrite, pyrrhotite and berthierite) may cause refractoriness during direct leaching. Separation of gold from these mineral phases, in addition to concentration methods during ore processing may increase gold recovery. The results presented in this research emphasize the importance of a detailed geochemical and mineral characterization to reveal the contrasting mineral and chemical compositions between hypogene and oxidized zone, which may influence gold recovery.
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| format | Article |
| id | doaj-art-2d644253a1884946b96c4d8c0a7fc420 |
| institution | Kabale University |
| issn | 2595-1939 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Serviço Geológico do Brasil (CPRM) |
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| series | Journal of the Geological Survey of Brazil |
| spelling | doaj-art-2d644253a1884946b96c4d8c0a7fc4202025-01-11T11:02:45ZengServiço Geológico do Brasil (CPRM)Journal of the Geological Survey of Brazil2595-19392025-01-018110.29396/jgsb.2025.v8.n1.1Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, BrazilGabriel Machado da Silva0Atlas Vasconcelos Corrêa Neto1Mariana Brando Soares2Felipe Emerson André AlvesNicollas de Oliveira Ferreira Santos3Piero Azevedo Berquó de Sampaio4Vitor Diniz Silveira5Gabriel Faria GonçalvesUFRJ - Universidade Federal do Rio de JaneiroUFRJ - Universidade Federal do Rio de JaneiroUERJ - Universidade Estadual do Rio de JaneiroUFRJ - Universidade Federal do Rio de JaneiroSchool of Earth and Planetary Sciences, Curtin University, Australia; and Earth Evolution and Dynamics Research Center, Qingdao, ChinaJaguar Mining Inc. The Faina gold deposit, located in the Pitangui Greenstone Belt, NW of the Quadrilátero Ferrífero, Brazil, has produced gold from the oxidized portion of the deposit between June 2010 and June 2013. However, the deeper hypogene (sulfide-rich) section of the deposit has shown lower-than-expected recovery rates after direct leaching, leading to the interruption of gold production. This research presents a multi-methodological approach (drill core description, multi-element geochemical analyses and mineral characterization using microscopy and X-ray diffraction) to investigate describe the Faina gold deposit and identify the cause of low recoveries from the hypogene zone. The stratigraphy at Faina consists of a sequence of meta-mafic and meta-sedimentary rocks, with a thick (>40m) saprolite horizon (oxidized portion). Both the meta-mafic rocks and saprolite host gold mineralization, which is identified by distinct geochemical and mineral signatures: 1) Au-As-W in the hypogene zone, with gold associated with sulfides or as disseminations in silicates and 2) Au-As-W in the oxide-rich shallower section with free-milling gold associated with quartz, iron oxide-hydroxides and clay minerals. Geochemical, mineral and textural relationships in the hypogene zone show that submicroscopic gold particles associated with minerals, that consume leaching solution minerals (arsenopyrite, pyrrhotite and berthierite) may cause refractoriness during direct leaching. Separation of gold from these mineral phases, in addition to concentration methods during ore processing may increase gold recovery. The results presented in this research emphasize the importance of a detailed geochemical and mineral characterization to reveal the contrasting mineral and chemical compositions between hypogene and oxidized zone, which may influence gold recovery. https://jgsb.sgb.gov.br/index.php/journal/article/view/249mineral processingPitangui greenstone beltFaina depositGold recoveryQuadrilátero Ferrífero |
| spellingShingle | Gabriel Machado da Silva Atlas Vasconcelos Corrêa Neto Mariana Brando Soares Felipe Emerson André Alves Nicollas de Oliveira Ferreira Santos Piero Azevedo Berquó de Sampaio Vitor Diniz Silveira Gabriel Faria Gonçalves Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil Journal of the Geological Survey of Brazil mineral processing Pitangui greenstone belt Faina deposit Gold recovery Quadrilátero Ferrífero |
| title | Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil |
| title_full | Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil |
| title_fullStr | Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil |
| title_full_unstemmed | Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil |
| title_short | Geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery: A case study of the Faina gold deposit, Pitangui greenstone belt, Brazil |
| title_sort | geochemical and mineralogical differences between supergene and hypogene gold mineralization and influence on gold recovery a case study of the faina gold deposit pitangui greenstone belt brazil |
| topic | mineral processing Pitangui greenstone belt Faina deposit Gold recovery Quadrilátero Ferrífero |
| url | https://jgsb.sgb.gov.br/index.php/journal/article/view/249 |
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