{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/106080"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/106080","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"The rates of oxidation of galena and sphalerite in acidic ferric chloride solutions","abstract":"When sulfide minerals are exposed to the oxidizing conditions of the earth's surface, their metal ions are released into solution and the S²⁻ is oxidized to either elemental sulfur or sulfate. The experiments described here used a mixed flow reactor system to determine the oxidation rates of galena and sphalerite under conditions similar to that expected in a weathering ore deposit . The specific surface area of the run solids was determined by N₂ BET procedure and the surface textures observed by SEM. The amount of Fe³⁺ converted to Fe²⁺ by the oxidation reaction was determined using an Eh electrode. Solid reaction products include, orthorhombic S(s) and anglesite (PbSO₄) from the galena oxidation and minor orthorhombic S(s) from the sphalerite oxidation. The rate equations describing the 25°C data are: dn<sub>Fe³⁺</sub>/dt = -5.5 ± 1.1 × 10⁻³ (A)(a<sub>Fe³⁺</sub)<sup>1.06 ± 0.16</sup> for galena, and dn<sub>Fe³⁺</sub>/dt = -1.8 ± 0.3 × 10⁻⁶ (A)(a<sub>Fe³⁺</sub>)<sup>0.47 ± 0.08</sup> for sphalerite. Where dn<sub>Fe³⁺</sub>/dt is the rate of reduction of Fe³⁺ (moles sec⁻¹), and A is the surface area of the solid (m²). The calculated E<sub>a</sub> for galena oxidation is 48 kJ mol⁻¹ (25 - 40°C) and is 84 kJ mol⁻¹ (25 -60°C) for sphalerite oxidation. Although galena and sphalerite are both simple, cubic, monosulfides their reaction rate with ferric iron differs by about 2.5 orders of magnitude for m<sub>Fe³⁺</sub> = 10⁻³.","abstract_html":"When sulfide minerals are exposed to the oxidizing conditions of the earth&#x27;s surface, their metal ions are released into solution and the S²⁻ is oxidized to either elemental sulfur or sulfate. The experiments described here used a mixed flow reactor system to determine the oxidation rates of galena and sphalerite under conditions similar to that expected in a weathering ore deposit . The specific surface area of the run solids was determined by N₂ BET procedure and the surface textures observed by SEM. The amount of Fe³⁺ converted to Fe²⁺ by the oxidation reaction was determined using an Eh electrode. Solid reaction products include, orthorhombic S(s) and anglesite (PbSO₄) from the galena oxidation and minor orthorhombic S(s) from the sphalerite oxidation. The rate equations describing the 25°C data are: dn&lt;sub&gt;Fe³⁺&lt;/sub&gt;/dt = -5.5 ± 1.1 × 10⁻³ (A)(a&lt;sub&gt;Fe³⁺&lt;/sub)&lt;sup&gt;1.06 ± 0.16&lt;/sup&gt; for galena, and dn&lt;sub&gt;Fe³⁺&lt;/sub&gt;/dt = -1.8 ± 0.3 × 10⁻⁶ (A)(a&lt;sub&gt;Fe³⁺&lt;/sub&gt;)&lt;sup&gt;0.47 ± 0.08&lt;/sup&gt; for sphalerite. Where dn&lt;sub&gt;Fe³⁺&lt;/sub&gt;/dt is the rate of reduction of Fe³⁺ (moles sec⁻¹), and A is the surface area of the solid (m²). The calculated E&lt;sub&gt;a&lt;/sub&gt; for galena oxidation is 48 kJ mol⁻¹ (25 - 40°C) and is 84 kJ mol⁻¹ (25 -60°C) for sphalerite oxidation. Although galena and sphalerite are both simple, cubic, monosulfides their reaction rate with ferric iron differs by about 2.5 orders of magnitude for m&lt;sub&gt;Fe³⁺&lt;/sub&gt; = 10⁻³.","abstract_has_math":false,"creators":["Chermak, John Alan"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"M.S.","degree_level":"masters","degree_discipline":"Geology","degree_department":"Geology","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1986,"date_issued":"1986","date_published":"1986","updated_at":"2026-07-22T22:18:41Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/106080","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Geology"]},{"key":"dc:creator","label":"Author","values":["Chermak, John Alan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-10-26T20:10:03Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-10-26T20:10:03Z"]},{"key":"dc:date.issued","label":"Date","values":["1986"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/106080"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["When sulfide minerals are exposed to the oxidizing conditions of the earth's surface, their metal ions are released into solution and the S²⁻ is oxidized to either elemental sulfur or sulfate. The experiments described here used a mixed flow reactor system to determine the oxidation rates of galena and sphalerite under conditions similar to that expected in a weathering ore deposit . The specific surface area of the run solids was determined by N₂ BET procedure and the surface textures observed by SEM. The amount of Fe³⁺ converted to Fe²⁺ by the oxidation reaction was determined using an Eh electrode. Solid reaction products include, orthorhombic S(s) and anglesite (PbSO₄) from the galena oxidation and minor orthorhombic S(s) from the sphalerite oxidation. The rate equations describing the 25°C data are: dn<sub>Fe³⁺</sub>/dt = -5.5 ± 1.1 × 10⁻³ (A)(a<sub>Fe³⁺</sub)<sup>1.06 ± 0.16</sup> for galena, and dn<sub>Fe³⁺</sub>/dt = -1.8 ± 0.3 × 10⁻⁶ (A)(a<sub>Fe³⁺</sub>)<sup>0.47 ± 0.08</sup> for sphalerite. Where dn<sub>Fe³⁺</sub>/dt is the rate of reduction of Fe³⁺ (moles sec⁻¹), and A is the surface area of the solid (m²). The calculated E<sub>a</sub> for galena oxidation is 48 kJ mol⁻¹ (25 - 40°C) and is 84 kJ mol⁻¹ (25 -60°C) for sphalerite oxidation. Although galena and sphalerite are both simple, cubic, monosulfides their reaction rate with ferric iron differs by about 2.5 orders of magnitude for m<sub>Fe³⁺</sub> = 10⁻³."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.S."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The rates of oxidation of galena and sphalerite in acidic ferric chloride solutions"]}]}],"canonical_facts":{"dc:contributor.department":["Geology"],"dc:creator":["Chermak, John Alan"],"dc:date.accessioned":["2021-10-26T20:10:03Z"],"dc:date.available":["2021-10-26T20:10:03Z"],"dc:date.issued":["1986"],"dc:description.abstract":["When sulfide minerals are exposed to the oxidizing conditions of the earth's surface, their metal ions are released into solution and the S²⁻ is oxidized to either elemental sulfur or sulfate. The experiments described here used a mixed flow reactor system to determine the oxidation rates of galena and sphalerite under conditions similar to that expected in a weathering ore deposit . The specific surface area of the run solids was determined by N₂ BET procedure and the surface textures observed by SEM. The amount of Fe³⁺ converted to Fe²⁺ by the oxidation reaction was determined using an Eh electrode. Solid reaction products include, orthorhombic S(s) and anglesite (PbSO₄) from the galena oxidation and minor orthorhombic S(s) from the sphalerite oxidation. The rate equations describing the 25°C data are: dn<sub>Fe³⁺</sub>/dt = -5.5 ± 1.1 × 10⁻³ (A)(a<sub>Fe³⁺</sub)<sup>1.06 ± 0.16</sup> for galena, and dn<sub>Fe³⁺</sub>/dt = -1.8 ± 0.3 × 10⁻⁶ (A)(a<sub>Fe³⁺</sub>)<sup>0.47 ± 0.08</sup> for sphalerite. Where dn<sub>Fe³⁺</sub>/dt is the rate of reduction of Fe³⁺ (moles sec⁻¹), and A is the surface area of the solid (m²). The calculated E<sub>a</sub> for galena oxidation is 48 kJ mol⁻¹ (25 - 40°C) and is 84 kJ mol⁻¹ (25 -60°C) for sphalerite oxidation. Although galena and sphalerite are both simple, cubic, monosulfides their reaction rate with ferric iron differs by about 2.5 orders of magnitude for m<sub>Fe³⁺</sub> = 10⁻³."],"dc:description.degree":["M.S."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/106080"],"dc:language.iso":["en"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["The rates of oxidation of galena and sphalerite in acidic ferric chloride solutions"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["masters"],"thesis:degree_name":["M.S."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:41Z"}