XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2399
of MgCO3 and can facilitate gangue mineral suppression
in a flotation systems. CO2 gas bubbles enhanced pent-
landite recovery through improving their hydrophobicity,
aggregation, and floatability. Through the complexation
of Mg2+ on serpentine’s surface by the phosphate group in
STPP, heterogeneous agglomeration was limited, thereby
reversing the electrostatic attraction between serpentine
and pentlandite to electrostatic repulsion. This resulted in
serpentine suppression by 5% (the highest among all cases)
and subsequent improved pentlandite recovery. In general,
a good agreement between zeta potential measurements,
micro-flotation tests and XPS analyses was established for
all cases.
Thus, researchers can leverage information from this
study to advance CO2 flotation studies where CO2 is
specifically used as a flotation gas. This study also provides
a proof of concept that CO2 can be utilized in mineral pro-
cessing operations serving both to improve recovery of valu-
able minerals and to simultaneously store carbon as mineral
carbonates, thereby introducing a strong decarbonization
strategy. Removing divalent cations from process waters in
the mineral processing operations through precipitation
or complexation reactions, will reduce water viscosity and
decrease the need for water treatment. In addition to that,
it greatly reduces the need to draw process water from fresh
water sources which further strengthens sustainability.
Due to the fact that STPP was the most significant ser-
pentine depressant and the use of CO2 as a flotation gas
showed the most significant improvement in pentlandite
recovery, further studies can explore combination of both
Figure 12. Schematic representation of fine mineral aggregation due to enhanced hydrophobic interactions with CO
2 bubbles
Figure 13. Schematic representation of the role of STPP in the serpentine-pentlandite system
of MgCO3 and can facilitate gangue mineral suppression
in a flotation systems. CO2 gas bubbles enhanced pent-
landite recovery through improving their hydrophobicity,
aggregation, and floatability. Through the complexation
of Mg2+ on serpentine’s surface by the phosphate group in
STPP, heterogeneous agglomeration was limited, thereby
reversing the electrostatic attraction between serpentine
and pentlandite to electrostatic repulsion. This resulted in
serpentine suppression by 5% (the highest among all cases)
and subsequent improved pentlandite recovery. In general,
a good agreement between zeta potential measurements,
micro-flotation tests and XPS analyses was established for
all cases.
Thus, researchers can leverage information from this
study to advance CO2 flotation studies where CO2 is
specifically used as a flotation gas. This study also provides
a proof of concept that CO2 can be utilized in mineral pro-
cessing operations serving both to improve recovery of valu-
able minerals and to simultaneously store carbon as mineral
carbonates, thereby introducing a strong decarbonization
strategy. Removing divalent cations from process waters in
the mineral processing operations through precipitation
or complexation reactions, will reduce water viscosity and
decrease the need for water treatment. In addition to that,
it greatly reduces the need to draw process water from fresh
water sources which further strengthens sustainability.
Due to the fact that STPP was the most significant ser-
pentine depressant and the use of CO2 as a flotation gas
showed the most significant improvement in pentlandite
recovery, further studies can explore combination of both
Figure 12. Schematic representation of fine mineral aggregation due to enhanced hydrophobic interactions with CO
2 bubbles
Figure 13. Schematic representation of the role of STPP in the serpentine-pentlandite system