Selection of Microorganism for the Bio-Oxidation of a Refractory Gold-Concentrate with Focus on the Behaviour of Antimony Sulphides
| Autor: | Romeu M. N. Giardini, Versiane Albis Leão, Lucas Sanches Magalhães, Michael Leonardo Marques Rodrigues, Liliane Coelho de Carvalho, Suzimara Reis da Silva |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Arsenopyrite Gold cyanidation Chemistry 030106 microbiology chemistry.chemical_element engineering.material Ferrous 03 medical and health sciences 030104 developmental biology Antimony visual_art visual_art.visual_art_medium engineering Pyrite Gold extraction Dissolution Mesophile Nuclear chemistry |
| Zdroj: | The Minerals, Metals & Materials Series ISBN: 9783319950211 |
| DOI: | 10.1007/978-3-319-95022-8_147 |
| Popis: | In the current study, bio-oxidation tests were carried out in shaking flasks with a flotation concentrate containing the sulphides pyrite, arsenopyrite and gudmidite. The tests were performed with mesophilic microorganisms (At. ferrooxidans ) at 30 °C and also with the moderate thermophile S. thermosulfidooxidans, at 50 °C. The effects of (i) previous adaptation of the microorganisms to the concentrate, (ii) ferrous iron concentration and (iii) pulp density (2%, 4% and 6% (w/v)) on the dissolution of the sulphide were studied through arsenic extractions. S. thermosulfidooxidans was more sensitive to the pulp density in comparison to At. ferrooxidans as a reduction in sulphide oxidation was observed with the increase in the solid content to 6%. Therefore, the mesophilic strain was selected for further work, which comprised a rolling bottle experiment at 10% solids. After 40 days of bio-oxidation, the solid material was subjected to cyanidation, which revealed 85% gold extraction as compared to 21% from the original concentrate. The antimony sulphide grains in the bio-oxidized product showed similarity to what was observed in the original sample, suggesting such particles were not susceptible to the bio-oxidation process. |
| Databáze: | OpenAIRE |
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