1
25-066
Optimizing the Impacts of Organic and Surfactants on the
Suppression of Sulfuric Acid Mist in Electrowinning System
Ellen Amoako Afful
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
Ashish Kakoria
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
Michael Moats
Department of Materials Science and Engineering,
Missouri University of Science and Technology
Guang Xu
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
ABSTRACT
Electrowinning and solvent extraction are crucial steps in
the production of high-purity copper. However, safety con-
cerns have been raised regarding the acid mist generated
from the electrowinning process. The mist generated results
in health risks to workers and damage to machinery and
infrastructure. Currently, chemicals and pellets are used to
control acid mist. However, the effectiveness of these con-
trols may vary depending on the type of organic solvent
used in the solvent extraction process, which can influence
the generation of acid mist. This study aims to evaluate the
impacts of organic solvents and surfactants on acid mist
suppression. In this study, an electrolyte is contacted with
organic solvents to simulate the solvent extraction. The
electrolyte is dosed with 20 mg/L of surfactant at each
contact. Acid mist testing is performed on the electrolyte
separated from the organic phase at the end of the solvent
extraction step. The mist collected is analyzed to determine
the level of acid mist generated. The results of this study
indicate that organic solvents and surfactants showed sig-
nificant acid mist suppression, but with somewhat different
suppression efficiencies. After first contact, Licorice and the
organic, for instance, showed a suppression efficiency of up
to 69.7% but its efficiency gradually decreased as the num-
ber of contacts increased.
INTRODUCTION
Electrowinning and solvent extraction are essential in the
hydrometallurgical process used to extract leachable copper
from secondary sulfides and highly from low-grade chal-
copyrite. This method is highly effective and widely used
for producing significant quantities of high-purity copper
at a cost-effective rate. Its importance lies in its ability to
achieve large-scale production while producing copper with
no impure substances. Therefore, it has become a corner-
stone of modern metal refining processes[1]. The process
of electrowinning copper ions has been a crucial aspect of
copper production and supply since its development in the
late 19th century. Despite advancements in the technology
involved in copper electrowinning, the fundamental equip-
ment and principles have remained unchanged since its
development [2].
In this process, copper oxide ore is crushed and stored
at a heap leach pad where dilute sulfuric acid is sprinkled.
The leach solution containing copper ions, sulfuric acid
(dilute) and other impurities is collected into a tank that
goes through a solvent extraction process. During this pro-
cess, copper ions are transferred from the low-concentra-
tion leach solution into an organic solvent, which is then
extracted using a strong sulfuric acid solution to be finally
extracted as copper metal during the electrowinning pro-
cess. While this method is effective, the electrowinning
process causes adverse environmental impacts by generat-
ing corrosive sulfuric acid mist. Workers in copper electro-
winning plants are particularly vulnerable to exposure to
this mist through inhalation, skin contact, and ingestion.
Exposure to more than 1 mg/m3 per a 10 hour work shift
to sulfuric acid mist can lead to various health problems,
25-066
Optimizing the Impacts of Organic and Surfactants on the
Suppression of Sulfuric Acid Mist in Electrowinning System
Ellen Amoako Afful
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
Ashish Kakoria
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
Michael Moats
Department of Materials Science and Engineering,
Missouri University of Science and Technology
Guang Xu
Department of Mining and Explosives Engineering,
Missouri University of Science and Technology
ABSTRACT
Electrowinning and solvent extraction are crucial steps in
the production of high-purity copper. However, safety con-
cerns have been raised regarding the acid mist generated
from the electrowinning process. The mist generated results
in health risks to workers and damage to machinery and
infrastructure. Currently, chemicals and pellets are used to
control acid mist. However, the effectiveness of these con-
trols may vary depending on the type of organic solvent
used in the solvent extraction process, which can influence
the generation of acid mist. This study aims to evaluate the
impacts of organic solvents and surfactants on acid mist
suppression. In this study, an electrolyte is contacted with
organic solvents to simulate the solvent extraction. The
electrolyte is dosed with 20 mg/L of surfactant at each
contact. Acid mist testing is performed on the electrolyte
separated from the organic phase at the end of the solvent
extraction step. The mist collected is analyzed to determine
the level of acid mist generated. The results of this study
indicate that organic solvents and surfactants showed sig-
nificant acid mist suppression, but with somewhat different
suppression efficiencies. After first contact, Licorice and the
organic, for instance, showed a suppression efficiency of up
to 69.7% but its efficiency gradually decreased as the num-
ber of contacts increased.
INTRODUCTION
Electrowinning and solvent extraction are essential in the
hydrometallurgical process used to extract leachable copper
from secondary sulfides and highly from low-grade chal-
copyrite. This method is highly effective and widely used
for producing significant quantities of high-purity copper
at a cost-effective rate. Its importance lies in its ability to
achieve large-scale production while producing copper with
no impure substances. Therefore, it has become a corner-
stone of modern metal refining processes[1]. The process
of electrowinning copper ions has been a crucial aspect of
copper production and supply since its development in the
late 19th century. Despite advancements in the technology
involved in copper electrowinning, the fundamental equip-
ment and principles have remained unchanged since its
development [2].
In this process, copper oxide ore is crushed and stored
at a heap leach pad where dilute sulfuric acid is sprinkled.
The leach solution containing copper ions, sulfuric acid
(dilute) and other impurities is collected into a tank that
goes through a solvent extraction process. During this pro-
cess, copper ions are transferred from the low-concentra-
tion leach solution into an organic solvent, which is then
extracted using a strong sulfuric acid solution to be finally
extracted as copper metal during the electrowinning pro-
cess. While this method is effective, the electrowinning
process causes adverse environmental impacts by generat-
ing corrosive sulfuric acid mist. Workers in copper electro-
winning plants are particularly vulnerable to exposure to
this mist through inhalation, skin contact, and ingestion.
Exposure to more than 1 mg/m3 per a 10 hour work shift
to sulfuric acid mist can lead to various health problems,