3028 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
example, Bhambhani et al. (2023) and Farrokhpay et al.
(2018) found that concentrate grades were drastically lower
when platy clay minerals like talc and mica, respectively,
were present during the flotation of an ore. According to
another recent study by Triffett and Bradshaw (2008), the
surface hydrophobicity of molybdenite particles with a
higher aspect ratio is significantly higher than that of round
particles, which causes them to float more rapidly than par-
ticles with a lower aspect ratio. This, according to the same
authors (Triffett &Bradshaw, 2008), is because hydropho-
bic sulphur species are more concentrated along the basal
planes of the plate-like molybdenite structure.
Platy morphology is a major concern because it is more
commonly found in gangue minerals than valuable min-
erals, which causes significant problems in mineral pro-
cessing operations (Bhambhani et al. 2023 Farrokhpay
et al. 2018 Xia 2017). A difficult platy gangue is talc
(Mg3Si4O10(OH)2), a magnesium silicate mineral that is
frequently encountered in low-grade ore deposits, particu-
larly sulphide-type deposits. Talc, an exceptionally hydro-
phobic mineral, is amenable to flotation concentrates, a
process that reduces the grade of valuable minerals by utilis-
ing its principal surfaces, or basal surfaces, which comprise
approximately 90% of its overall surface area (Nalaskowski
et al. 2007 Tarasevich &Aksenenko 2014). The quantity
of platy talc particles present in a talc ore varies in accor-
dance with the talc’s geographical origin, as noted and
documented by Holland and Murtagh (2000). Therefore,
additional research is needed to determine whether the
flotation behaviour of talc is affected by the amount of
platy particles present. This could potentially provide an
explanation for the divergence in flotation characteristics
among various talcs, and the resulting data could be utilised
to construct predictive models that accurately depict their
flotability.
A major hurdle in gaining understanding of the flota-
tion behaviour of talc through the quantification of its platy
morphology is the need for precise and consistent methods
of characterising its shape. It is common practice to deter-
mine the platy morphology of talc by calculating the aspect
ratio of talc platelets (Forssberg et al., 1988 Hiçyilmaz et
al., 2004 Ulusoy &Kursun, 2011). Th aspect ratio is cal-
culated by dividing the maximum Feret diameter by the
minimum Feret diameter, where Feret diameter is the dis-
tance between two parallel tangents of the particle oriented
at a certain angle (Wiese et al., 2015). Several methods have
been used to calculate the aspect ratio of talc from a 2D
image, which does not accurately represent the platy mor-
phology of talc.
This study used X-ray diffraction (XRD) to determine
the platy morphology of talcs originating from various geo-
graphic locations. The platy morphology, as determined
by XRD, was compared with the results obtained through
image analysis and scanning electron microscopy (SEM).
To investigate the effect of platy morphologies on talc flo-
tability, a flotation test was performed on two different talcs
with varying platy morphologies.
MATERIALS AND METHODS
Materials
Talc lump ores were obtained from mining operation
sites located in India (Table 1(a)) and the United States
(Table 1(b)). The large lump ores were crushed and sieved
through a series of sieves arranged in descending order from
2,000 µm down to 1 mm. Table 2 presents the chemical
analysis of the talc sample determined by X-ray fluores-
cence (XRF). The main chemical constituents of the talcs
were SiO2 of about 57 – 62% and MgO of 26 – 31%.
All instruments used in the current research were located
Table 1. Images of (a) India and (b) United States talc
India (a) USA (b)
example, Bhambhani et al. (2023) and Farrokhpay et al.
(2018) found that concentrate grades were drastically lower
when platy clay minerals like talc and mica, respectively,
were present during the flotation of an ore. According to
another recent study by Triffett and Bradshaw (2008), the
surface hydrophobicity of molybdenite particles with a
higher aspect ratio is significantly higher than that of round
particles, which causes them to float more rapidly than par-
ticles with a lower aspect ratio. This, according to the same
authors (Triffett &Bradshaw, 2008), is because hydropho-
bic sulphur species are more concentrated along the basal
planes of the plate-like molybdenite structure.
Platy morphology is a major concern because it is more
commonly found in gangue minerals than valuable min-
erals, which causes significant problems in mineral pro-
cessing operations (Bhambhani et al. 2023 Farrokhpay
et al. 2018 Xia 2017). A difficult platy gangue is talc
(Mg3Si4O10(OH)2), a magnesium silicate mineral that is
frequently encountered in low-grade ore deposits, particu-
larly sulphide-type deposits. Talc, an exceptionally hydro-
phobic mineral, is amenable to flotation concentrates, a
process that reduces the grade of valuable minerals by utilis-
ing its principal surfaces, or basal surfaces, which comprise
approximately 90% of its overall surface area (Nalaskowski
et al. 2007 Tarasevich &Aksenenko 2014). The quantity
of platy talc particles present in a talc ore varies in accor-
dance with the talc’s geographical origin, as noted and
documented by Holland and Murtagh (2000). Therefore,
additional research is needed to determine whether the
flotation behaviour of talc is affected by the amount of
platy particles present. This could potentially provide an
explanation for the divergence in flotation characteristics
among various talcs, and the resulting data could be utilised
to construct predictive models that accurately depict their
flotability.
A major hurdle in gaining understanding of the flota-
tion behaviour of talc through the quantification of its platy
morphology is the need for precise and consistent methods
of characterising its shape. It is common practice to deter-
mine the platy morphology of talc by calculating the aspect
ratio of talc platelets (Forssberg et al., 1988 Hiçyilmaz et
al., 2004 Ulusoy &Kursun, 2011). Th aspect ratio is cal-
culated by dividing the maximum Feret diameter by the
minimum Feret diameter, where Feret diameter is the dis-
tance between two parallel tangents of the particle oriented
at a certain angle (Wiese et al., 2015). Several methods have
been used to calculate the aspect ratio of talc from a 2D
image, which does not accurately represent the platy mor-
phology of talc.
This study used X-ray diffraction (XRD) to determine
the platy morphology of talcs originating from various geo-
graphic locations. The platy morphology, as determined
by XRD, was compared with the results obtained through
image analysis and scanning electron microscopy (SEM).
To investigate the effect of platy morphologies on talc flo-
tability, a flotation test was performed on two different talcs
with varying platy morphologies.
MATERIALS AND METHODS
Materials
Talc lump ores were obtained from mining operation
sites located in India (Table 1(a)) and the United States
(Table 1(b)). The large lump ores were crushed and sieved
through a series of sieves arranged in descending order from
2,000 µm down to 1 mm. Table 2 presents the chemical
analysis of the talc sample determined by X-ray fluores-
cence (XRF). The main chemical constituents of the talcs
were SiO2 of about 57 – 62% and MgO of 26 – 31%.
All instruments used in the current research were located
Table 1. Images of (a) India and (b) United States talc
India (a) USA (b)