Bacterially catalyzed reductive dissolution of manganese for the liberation of silver from refractory ore

Persistent Link:
http://hdl.handle.net/10150/277986
Title:
Bacterially catalyzed reductive dissolution of manganese for the liberation of silver from refractory ore
Author:
Upp Oden, Karen Lee, 1959-
Issue Date:
1991
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This research focuses on the development of a biological treatment process to enhance silver recovery from a low grade, silver-bearing manganese ore. These manganese oxide ores have been classified as refractory and thereby characterized noncommercial for the recovery and production of silver by conventional methods. A species of Bacillus polymyxa, which was isolated from the Crystal Hill Mine in southern Colorado, facilitated the reductive dissolution of manganese dioxide. Insoluble Mn(IV) was reduced to soluble Mn(II), and silver ions contained within the manganese oxide lattice were released and/or exposed, making them amenable to cyanide extraction. A direct relationship was observed between the biological transformation of Mn(IV) to a lower valence and increased silver recovery following cyanidation. Batch studies, with ore passing minus 10 mesh (0.14 inch diameter), had silver recoveries that were twice the amount extracted by chemical treatment alone over a 120-hour period. However, rates of reductive dissolution diminished significantly as ore particle size increased and specific surface area decreased.
Type:
text; Thesis-Reproduction (electronic)
Keywords:
Biology, Microbiology.; Engineering, Civil.; Engineering, Metallurgy.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College
Degree Grantor:
University of Arizona
Advisor:
Arnold, Robert G.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleBacterially catalyzed reductive dissolution of manganese for the liberation of silver from refractory oreen_US
dc.creatorUpp Oden, Karen Lee, 1959-en_US
dc.contributor.authorUpp Oden, Karen Lee, 1959-en_US
dc.date.issued1991en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis research focuses on the development of a biological treatment process to enhance silver recovery from a low grade, silver-bearing manganese ore. These manganese oxide ores have been classified as refractory and thereby characterized noncommercial for the recovery and production of silver by conventional methods. A species of Bacillus polymyxa, which was isolated from the Crystal Hill Mine in southern Colorado, facilitated the reductive dissolution of manganese dioxide. Insoluble Mn(IV) was reduced to soluble Mn(II), and silver ions contained within the manganese oxide lattice were released and/or exposed, making them amenable to cyanide extraction. A direct relationship was observed between the biological transformation of Mn(IV) to a lower valence and increased silver recovery following cyanidation. Batch studies, with ore passing minus 10 mesh (0.14 inch diameter), had silver recoveries that were twice the amount extracted by chemical treatment alone over a 120-hour period. However, rates of reductive dissolution diminished significantly as ore particle size increased and specific surface area decreased.en_US
dc.typetexten_US
dc.typeThesis-Reproduction (electronic)en_US
dc.subjectBiology, Microbiology.en_US
dc.subjectEngineering, Civil.en_US
dc.subjectEngineering, Metallurgy.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorArnold, Robert G.en_US
dc.identifier.proquest1346128en_US
dc.identifier.bibrecord.b27179308en_US
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