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

Title: Attachment, Coalescence, and Spreading of Carbon Dioxide Nanobubbles at Pyrite Surfaces

Abstract

Recently it was reported that using CO 2 as a flotation gas increases the flotation of auriferous pyrite from high carbonate gold ores of the Carlin Trend. In this regard, the influence of CO 2 on bubble attachment at fresh pyrite surfaces was measured in the absence of collector using an induction timer, and it was found that nitrogen bubble attachment time was significantly reduced from 30 ms to less than 10 ms in CO 2 saturated solutions. Details of CO 2 bubble attachment at a fresh pyrite surface have been examined by AFM measurements and MD simulations, and the results used to describe the subsequent attachment of an N 2 bubble. As found from MD simulations, unlike the attached N 2 bubble, which is stable and has a contact angle of about 90 degrees, the CO 2 bubble attaches, and spreads, wetting the fresh pyrite surface and forming a multi-layer of CO 2 molecules, corresponding to a contact angle of almost 180 degrees. These MDS results are complemented by in-situ AFM images, which show that after attachment, CO 2 nano/micro bubbles spread to form pancake bubbles at the fresh pyrite surface. In summary, it seems that CO 2 bubblesmore » have a propensity to spread, and whether CO 2 exists as layers of CO 2 molecules or as pancake nano/micro bubbles, their presence at the fresh pyrite surface subsequently facilitates film rupture and attachment of millimeter N 2 bubbles, and in this way, improves the flotation of pyrite. The U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences, funded the work performed by L.X.D.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2];  [1]; ORCiD logo [1]
  1. Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 South 1460 East, Rm 412, Salt Lake City, Utah 84112, United States
  2. Chemical and Material Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99353, United States
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1495336
Report Number(s):
PNNL-SA-137798
Journal ID: ISSN 0743-7463
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 34; Journal Issue: 47; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English

Citation Formats

Vaziri Hassas, Behzad, Jin, Jiaqi, Dang, Liem X., Wang, Xuming, and Miller, Jan D. Attachment, Coalescence, and Spreading of Carbon Dioxide Nanobubbles at Pyrite Surfaces. United States: N. p., 2018. Web. doi:10.1021/acs.langmuir.8b02929.
Vaziri Hassas, Behzad, Jin, Jiaqi, Dang, Liem X., Wang, Xuming, & Miller, Jan D. Attachment, Coalescence, and Spreading of Carbon Dioxide Nanobubbles at Pyrite Surfaces. United States. doi:10.1021/acs.langmuir.8b02929.
Vaziri Hassas, Behzad, Jin, Jiaqi, Dang, Liem X., Wang, Xuming, and Miller, Jan D. Mon . "Attachment, Coalescence, and Spreading of Carbon Dioxide Nanobubbles at Pyrite Surfaces". United States. doi:10.1021/acs.langmuir.8b02929.
@article{osti_1495336,
title = {Attachment, Coalescence, and Spreading of Carbon Dioxide Nanobubbles at Pyrite Surfaces},
author = {Vaziri Hassas, Behzad and Jin, Jiaqi and Dang, Liem X. and Wang, Xuming and Miller, Jan D.},
abstractNote = {Recently it was reported that using CO2 as a flotation gas increases the flotation of auriferous pyrite from high carbonate gold ores of the Carlin Trend. In this regard, the influence of CO2 on bubble attachment at fresh pyrite surfaces was measured in the absence of collector using an induction timer, and it was found that nitrogen bubble attachment time was significantly reduced from 30 ms to less than 10 ms in CO2 saturated solutions. Details of CO2 bubble attachment at a fresh pyrite surface have been examined by AFM measurements and MD simulations, and the results used to describe the subsequent attachment of an N2 bubble. As found from MD simulations, unlike the attached N2 bubble, which is stable and has a contact angle of about 90 degrees, the CO2 bubble attaches, and spreads, wetting the fresh pyrite surface and forming a multi-layer of CO2 molecules, corresponding to a contact angle of almost 180 degrees. These MDS results are complemented by in-situ AFM images, which show that after attachment, CO2 nano/micro bubbles spread to form pancake bubbles at the fresh pyrite surface. In summary, it seems that CO2 bubbles have a propensity to spread, and whether CO2 exists as layers of CO2 molecules or as pancake nano/micro bubbles, their presence at the fresh pyrite surface subsequently facilitates film rupture and attachment of millimeter N2 bubbles, and in this way, improves the flotation of pyrite. The U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences, funded the work performed by L.X.D.},
doi = {10.1021/acs.langmuir.8b02929},
journal = {Langmuir},
issn = {0743-7463},
number = 47,
volume = 34,
place = {United States},
year = {2018},
month = {10}
}