3086
Inhibitory Effects of Metabisulfite and Dextrin Combination on
Pyrite Flotation: Enhancing Separation Efficiency in the Presence
of Potassium Amyl Xanthate
Mario Corona-Arroyo, Karen Solorzano, Christina Echeveste,
Mercedes Salazar-Hernandez, Israel López-Báez
Mining, Metallurgical and Geological Engineering Department, Engineering Division, Universidad de Guanajuato
ABSTRACT: The depressive effect of metabisulfite and dextrin, both individually and in combination, on
pyrite in the presence and absence of amyl xanthate has been investigated. This research focused on analyzing
the contact angle and microflotation. The experiments were conducted at a pH of 8, aiming to minimize
lime consumption. The results showed that the combination of metabisulfite (MBS) and dextrin (DX) more
effectively reduced the flotation and contact angle of pyrite compared to their separate effects. Furthermore,
an increase in the depression of pyrite was observed when metabisulfite was applied in conjunction with the
pulp aeration.
INTRODUCTION
Pyrite (FeS2), one of the most abundant sulfides in the
Earth’s crust, is often found in association with valu-
able minerals such as galena, coal, gold, sphalerite, and
chalcopyrite (Mu et al., 2016a). Despite its relatively low
economic importance, pyrite is commonly suppressed in
flotation processes and treated as waste. However, this pro-
cess can be challenging due to pyrite’s tendency to float
alongside minerals like chalcopyrite, galena, and sphalerite,
which can reduce the quality of the concentrate by decreas-
ing the concentration of base metals. Therefore, efficient
elimination of pyrite is crucial in the processing of sulfide
minerals. The selectivity issues in its differential flotation
primarily arise from the electrochemical behavior of pyrite
and the mineral textures present in the processed deposits.
Today, a variety of methods have been developed to
separate copper, lead, and zinc minerals from pyrite. The
flotation of sulfides with pyrite depression in an alka-
line medium is commonly used. The search for selective
depressants that effectively inhibit the flotation of pyrite
without affecting valuable minerals has become a criti-
cal goal. Recently, pyrite control has become increasingly
important in various mining units in states such as Hidalgo,
Zacatecas, Durango, and San Luís Potosí from México. A
factor associated with this challenge is the increase in head
grades, which typically ranges between 1 and 5%, although
recently Fe head grades over 10% have been reported. In
certain cases, extremely fine grinding is required to achieve
adequate liberation, generally less than 70%, although a
particle size less than 75 micrometers is usually sufficient.
To date, the inorganic reagents commonly used for
the flotation of copper sulfide minerals through pyrite
depression include lime, potassium dichromate, potassium
permanganate, hydrogen peroxide, calcium hypochlo-
rite, among others (Khoso et al., 2019). In lead flotation,
various chemical schemes are employed for Pb-Fe separa-
tion, including the use of NaCN and lime. Although these
reagents are highly efficient in pyrite depression during
Inhibitory Effects of Metabisulfite and Dextrin Combination on
Pyrite Flotation: Enhancing Separation Efficiency in the Presence
of Potassium Amyl Xanthate
Mario Corona-Arroyo, Karen Solorzano, Christina Echeveste,
Mercedes Salazar-Hernandez, Israel López-Báez
Mining, Metallurgical and Geological Engineering Department, Engineering Division, Universidad de Guanajuato
ABSTRACT: The depressive effect of metabisulfite and dextrin, both individually and in combination, on
pyrite in the presence and absence of amyl xanthate has been investigated. This research focused on analyzing
the contact angle and microflotation. The experiments were conducted at a pH of 8, aiming to minimize
lime consumption. The results showed that the combination of metabisulfite (MBS) and dextrin (DX) more
effectively reduced the flotation and contact angle of pyrite compared to their separate effects. Furthermore,
an increase in the depression of pyrite was observed when metabisulfite was applied in conjunction with the
pulp aeration.
INTRODUCTION
Pyrite (FeS2), one of the most abundant sulfides in the
Earth’s crust, is often found in association with valu-
able minerals such as galena, coal, gold, sphalerite, and
chalcopyrite (Mu et al., 2016a). Despite its relatively low
economic importance, pyrite is commonly suppressed in
flotation processes and treated as waste. However, this pro-
cess can be challenging due to pyrite’s tendency to float
alongside minerals like chalcopyrite, galena, and sphalerite,
which can reduce the quality of the concentrate by decreas-
ing the concentration of base metals. Therefore, efficient
elimination of pyrite is crucial in the processing of sulfide
minerals. The selectivity issues in its differential flotation
primarily arise from the electrochemical behavior of pyrite
and the mineral textures present in the processed deposits.
Today, a variety of methods have been developed to
separate copper, lead, and zinc minerals from pyrite. The
flotation of sulfides with pyrite depression in an alka-
line medium is commonly used. The search for selective
depressants that effectively inhibit the flotation of pyrite
without affecting valuable minerals has become a criti-
cal goal. Recently, pyrite control has become increasingly
important in various mining units in states such as Hidalgo,
Zacatecas, Durango, and San Luís Potosí from México. A
factor associated with this challenge is the increase in head
grades, which typically ranges between 1 and 5%, although
recently Fe head grades over 10% have been reported. In
certain cases, extremely fine grinding is required to achieve
adequate liberation, generally less than 70%, although a
particle size less than 75 micrometers is usually sufficient.
To date, the inorganic reagents commonly used for
the flotation of copper sulfide minerals through pyrite
depression include lime, potassium dichromate, potassium
permanganate, hydrogen peroxide, calcium hypochlo-
rite, among others (Khoso et al., 2019). In lead flotation,
various chemical schemes are employed for Pb-Fe separa-
tion, including the use of NaCN and lime. Although these
reagents are highly efficient in pyrite depression during