2404 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
studies have shown they possess attributes in certain sys-
tems that seemingly contradict each other for example,
selective recovery of free Au, Ag and PGM species under
specific conditions, and bulk sulfide flotation including
ubiquitous iron sulfides. From the perspective of Pearson’s
HSAB principle, their propensity to interact with precious
metals (soft acids) can be rationalized via the soft S donor
in their structure on the other hand, their interaction with
species such as pyrite (where Fe2+ is a “harder” borderline
acid) is unexpected and confounding. This is especially
since the ACATCs and ACATUs have been proven to be
strongly selective against pyrite (Basilio, 1989).
In this paper, we discuss preliminary insights from
fundamental and applied studies of the ACADTCs, par-
ticularly with respect to LAB concepts and Pearson’s HSAB
principle. At the experimental level, various substrates
of selected minerals and metals were used for conduct-
ing sessile water drop contact angle measurements, cyclic
voltammetry (CV), and time-of-flight secondary ion mass
spectroscopy (ToF-SIMS). Examples of flotation practice
with the ACADTCs in several ore systems are also provided
to connect findings from the fundamental studies.
EXPERIMENTAL METHODS
A commercial sample containing ~80% butoxycarbonyl
butyl dithiocarbamate (BCBDTC) was used for the studies.
All solutions were made by stirring in nanopure or MilliQ
purified water (deionized, double distilled, 18.2 MΩ·cm)
at room temperature.
Figure 2. Proposed coordination modes of 1:1 and 2:1 metal-ligand complexes of butoxycarbonyl butyl
dithiocarbamate (BCBDTC) with Ag (Note: orientation of the butyl substituents can differ from that
depicted here due to bond rotation)
Figure 3. Structures of a) alkoxycarbonyl alkyl thionocarbamate, b) alkoxycarbonyl alkyl thiourea, and c)
alkoxycarbonyl alkyl dithiocarbamate
studies have shown they possess attributes in certain sys-
tems that seemingly contradict each other for example,
selective recovery of free Au, Ag and PGM species under
specific conditions, and bulk sulfide flotation including
ubiquitous iron sulfides. From the perspective of Pearson’s
HSAB principle, their propensity to interact with precious
metals (soft acids) can be rationalized via the soft S donor
in their structure on the other hand, their interaction with
species such as pyrite (where Fe2+ is a “harder” borderline
acid) is unexpected and confounding. This is especially
since the ACATCs and ACATUs have been proven to be
strongly selective against pyrite (Basilio, 1989).
In this paper, we discuss preliminary insights from
fundamental and applied studies of the ACADTCs, par-
ticularly with respect to LAB concepts and Pearson’s HSAB
principle. At the experimental level, various substrates
of selected minerals and metals were used for conduct-
ing sessile water drop contact angle measurements, cyclic
voltammetry (CV), and time-of-flight secondary ion mass
spectroscopy (ToF-SIMS). Examples of flotation practice
with the ACADTCs in several ore systems are also provided
to connect findings from the fundamental studies.
EXPERIMENTAL METHODS
A commercial sample containing ~80% butoxycarbonyl
butyl dithiocarbamate (BCBDTC) was used for the studies.
All solutions were made by stirring in nanopure or MilliQ
purified water (deionized, double distilled, 18.2 MΩ·cm)
at room temperature.
Figure 2. Proposed coordination modes of 1:1 and 2:1 metal-ligand complexes of butoxycarbonyl butyl
dithiocarbamate (BCBDTC) with Ag (Note: orientation of the butyl substituents can differ from that
depicted here due to bond rotation)
Figure 3. Structures of a) alkoxycarbonyl alkyl thionocarbamate, b) alkoxycarbonyl alkyl thiourea, and c)
alkoxycarbonyl alkyl dithiocarbamate