Collectorless flotation of chalcopyrite and sphalerite ores

The flotation of chalcopyrite and sphalerite has been accomplished without the use of collectors. Of the six chalcopyrite ores tested in the present work, some floated well using only a frother, while others required the addition of sodium sulfide, presumably to remove the hydrophilic surface oxidation products. On the other hand, the flotation of sphalerite ores was found to require both sodium sulfide treatment and copper-activation. The ratio of these two reagents was most critical, the optimum Cu²⁺/S²⁻ atomic ratio being approximately 0.17 over a wide range of reagent dosages. Potential measurements taken during both batch and micro-flotation experiments demonstrated that the collectorless flotation of chalcopyrite was possible only in oxidizing conditions, which confirms an earlier finding by Heyes and Trahar (1977). In relation to this phenomenon, three possible mechanisms have been discussed: i) elemental sulfur formed under oxidizing conditions is responsible for the collectorless flotation, ii) polysulfide ions formed during the incipient surface oxidation process render the mineral hydrophobic, and iii) HS⁻ ions, which may render the mineral hydrophilic upon adsorption, are removed from the system under oxidizing conditions. The first mechanism may operate primarily in acidic solutions, while the second mechanism operates in alkaline solutions where elemental sulfur is thermodynamically unstable. The third mechanism is based on the assumption that a clean, unoxidized surface is inherently hydrophobic. Spectroscopic evidence has been presented to support these proposed mechanisms.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mining and Minerals Engineering

Department dc:contributor.department

Mining and Minerals Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1982

Author dc:creator

• Luttrell, Gerald H.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/80213

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/80213