2490 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
It was observed that the collectors preferentially che-
misorbed on the Pt and As atoms and formed stable six-
membered Pt and four-membered As complexes, as shown
in Figure 4 and 5, respectively. Interestingly, it was noted
that for SDTBAT adsorption, the N atom also formed
bonds with As atom for sperrylite (Figure 4a and 4b. The
SDTBAT was observed to bond in a monodentate mode
for platarsite under neutral condition (see Figure 5a), while
the acidic condition did not form any bond with the sur-
face as shown in Figure 5b. This suggested that platarsite is
less reactive towards the collectors and could interact with
the collectors through van der Waals forces.
The adsorption energies and the calculated bond
length for NBX, NBDTC and DTBAT collectors both
in neutral and acidic condition are presented in Table 3.
The SDTBAT appeared to form three bonds with sper-
rylite surface, while the HNBDTC form only two bonds
with the surface (Figure 4). The bond lengths of Pt1–S1
=2.417 Å, and a larger Pt2–S2 =2.501 Å and As1–N1 =
2.007 Å for dry sperrylite surface were obtained. It was also
noted that the SDTBAT had a larger Pt2–S2 bond (2.485
Å) and Pt1–S1 bond (2.444 Å) and As1–N1 bond (2.015
Å) on hydrated sperrylite surface. The HNBDTC resulted
in a larger bond length of 2.580 Å (Pt2–S2) and 2.440 Å
(Pt1–S1) on dry sperrylite surface, while the hydrated sur-
face resulted in a bond length of 2.447 Å (Pt2–S2) and
2.435 Å (Pt1–S1) under acidic condition. The SDTBAT
on dry platarsite surface resulted in a bond length of 2.441
Figure 5. Adsorption structures on dry platarsite (100) surface: (a) neutral SDTBAT adsorptions, and (b) acidic HDTBAT
adsorptions
Table 3. The adsorption (kJ·mol–1), and bond lengths (Å) of NBX, NBDTC and DTBAT adsorption on sperrylite and
platarsite (100) surface.
Model Molecule Conditions Eads.
Bond Lengths
Pt1–S1 Pt2–S2 As1–N1
PtAs2 SDTBAT Neutral Dry –382.04 2.417 2.501 2.007
SDTBAT Neutral Hydrated –370.04 2.444 2.485 2.015
HNBDTC Acidic Dry –162.17 2.440 2.580 N/A
HNBDTC Acidic Hydrated –186.31 2.435 2.447 N/A
PtAsS SDTBAT Neutral Dry –298.01 N/A 2.441 N/A
SDTBAT Acidic Dry –113.02 N/A N/A N/A
It was observed that the collectors preferentially che-
misorbed on the Pt and As atoms and formed stable six-
membered Pt and four-membered As complexes, as shown
in Figure 4 and 5, respectively. Interestingly, it was noted
that for SDTBAT adsorption, the N atom also formed
bonds with As atom for sperrylite (Figure 4a and 4b. The
SDTBAT was observed to bond in a monodentate mode
for platarsite under neutral condition (see Figure 5a), while
the acidic condition did not form any bond with the sur-
face as shown in Figure 5b. This suggested that platarsite is
less reactive towards the collectors and could interact with
the collectors through van der Waals forces.
The adsorption energies and the calculated bond
length for NBX, NBDTC and DTBAT collectors both
in neutral and acidic condition are presented in Table 3.
The SDTBAT appeared to form three bonds with sper-
rylite surface, while the HNBDTC form only two bonds
with the surface (Figure 4). The bond lengths of Pt1–S1
=2.417 Å, and a larger Pt2–S2 =2.501 Å and As1–N1 =
2.007 Å for dry sperrylite surface were obtained. It was also
noted that the SDTBAT had a larger Pt2–S2 bond (2.485
Å) and Pt1–S1 bond (2.444 Å) and As1–N1 bond (2.015
Å) on hydrated sperrylite surface. The HNBDTC resulted
in a larger bond length of 2.580 Å (Pt2–S2) and 2.440 Å
(Pt1–S1) on dry sperrylite surface, while the hydrated sur-
face resulted in a bond length of 2.447 Å (Pt2–S2) and
2.435 Å (Pt1–S1) under acidic condition. The SDTBAT
on dry platarsite surface resulted in a bond length of 2.441
Figure 5. Adsorption structures on dry platarsite (100) surface: (a) neutral SDTBAT adsorptions, and (b) acidic HDTBAT
adsorptions
Table 3. The adsorption (kJ·mol–1), and bond lengths (Å) of NBX, NBDTC and DTBAT adsorption on sperrylite and
platarsite (100) surface.
Model Molecule Conditions Eads.
Bond Lengths
Pt1–S1 Pt2–S2 As1–N1
PtAs2 SDTBAT Neutral Dry –382.04 2.417 2.501 2.007
SDTBAT Neutral Hydrated –370.04 2.444 2.485 2.015
HNBDTC Acidic Dry –162.17 2.440 2.580 N/A
HNBDTC Acidic Hydrated –186.31 2.435 2.447 N/A
PtAsS SDTBAT Neutral Dry –298.01 N/A 2.441 N/A
SDTBAT Acidic Dry –113.02 N/A N/A N/A
