skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994

Abstract

The major objectives of this work are (1) to determine the Eh-pH conditions under which pyrite is stable, (2) to determine the mechanism of the initial stages of pyrite oxidation and (3) to determine if the semi-conducting properties of pyrite effects its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that pyrite assumes a unique potential referred to as the ``stable potential`` at the instance it is fractured and that this potential is several hundred millivolts more negative than the steady state mixed potential of pyrite. It has also been shown that by holding the potential of pyrite at its stable potential during fracture, pyrite undergoes neither oxidation nor reduction. It has also been found that fresh pyrite surfaces created by fracture in an electrochemical begin to oxidize at potentials that are about 200 mV moremore » negative than the potentials reported in the literature for pyrite oxidation. This is attributed to the fact that most work on pyrite has employed polished electrodes that have pre-existing oxidation products on the surface. The existence of a pH dependent stable potential for freshly fractured pyrite electrodes was based on studies conducted mainly on pyrite from Peru.« less

Authors:
;
Publication Date:
Research Org.:
Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mining and Minerals Engineering
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
106671
Report Number(s):
DOE/PC/92547-T8
ON: DE95017746
DOE Contract Number:  
FG22-92PC92547
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1994]
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 40 CHEMISTRY; COAL; DESULFURIZATION; PYRITE; OXIDATION; FLOTATION; ELECTROCHEMISTRY; ELECTRODES; VOLTAMETRY; PROGRESS REPORT

Citation Formats

Yoon, R H, and Richardson, P E. Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994. United States: N. p., 1994. Web. doi:10.2172/106671.
Yoon, R H, & Richardson, P E. Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994. United States. https://doi.org/10.2172/106671
Yoon, R H, and Richardson, P E. 1994. "Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994". United States. https://doi.org/10.2172/106671. https://www.osti.gov/servlets/purl/106671.
@article{osti_106671,
title = {Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994},
author = {Yoon, R H and Richardson, P E},
abstractNote = {The major objectives of this work are (1) to determine the Eh-pH conditions under which pyrite is stable, (2) to determine the mechanism of the initial stages of pyrite oxidation and (3) to determine if the semi-conducting properties of pyrite effects its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that pyrite assumes a unique potential referred to as the ``stable potential`` at the instance it is fractured and that this potential is several hundred millivolts more negative than the steady state mixed potential of pyrite. It has also been shown that by holding the potential of pyrite at its stable potential during fracture, pyrite undergoes neither oxidation nor reduction. It has also been found that fresh pyrite surfaces created by fracture in an electrochemical begin to oxidize at potentials that are about 200 mV more negative than the potentials reported in the literature for pyrite oxidation. This is attributed to the fact that most work on pyrite has employed polished electrodes that have pre-existing oxidation products on the surface. The existence of a pH dependent stable potential for freshly fractured pyrite electrodes was based on studies conducted mainly on pyrite from Peru.},
doi = {10.2172/106671},
url = {https://www.osti.gov/biblio/106671}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Dec 31 00:00:00 EST 1994},
month = {Sat Dec 31 00:00:00 EST 1994}
}