1
25-050
Introduction of a New Environmentally Friendly Acid Mist
Suppressant in Copper Electrowinning—Acorga® EW98
Tim Doubleday
Syensqo, Tempe, AZ
William Szolga Jr
Syensqo, Niagara Falls, Ontario, Canada
Tyler McCallum
Syensqo, Tempe, AZ
Jose Carlos Durazo
Syensqo, Tempe, AZ
Justin Jensen
Syensqo, Tempe, AZ
Luis Moya
Syensqo, Tempe, AZ
ABSTRACT
Sulfuric acid mist is an undesired by-product of the copper
electrowinning process, caused by oxygen evolution at the
anode which entrains droplets of the acidic copper electro-
lyte solution. As the oxygen moves to the surface of the cell,
these droplets become aerosolized resulting in acid mist.
The addition of chemical anti-misting agents to the copper
electrolyte is a common mitigation technique. This paper
details Syensqo’s laboratory development of a new envi-
ronmentally friendly acid mist suppressant, ACORGA ®
EW98. The product exhibits excellent acid mist suppres-
sion and it is fully compatible with the adjacent solvent
extraction process. Lab and pilot test results are reviewed
ahead of future planned industrial trial testing.
INTRODUCTION
Copper electrowinning is an electrochemical reaction
which consists of passing an electrical current through the
electrolyte where copper ions are deposited onto cathodes
as pure copper metal. During this electrochemical reaction,
oxygen is generated at the anode leading to the formation
of sulfuric acid mist. As these tiny droplets rise through
the electrolyte they burst, propelling tiny droplets of acidic
electrolyte into the air.
Acid Mist Challenges and Mitigation in Copper
Electrowinning
The formation of acid mist during the copper electrowin-
ning process has presented several challenges within the
industry. Hazards associated with acid mist include envi-
ronmental concerns, health challenges for employees and
building structural concerns due to corrosion. Several phys-
ical methods to reduce acid mist have been used in indus-
try. Polypropylene balls can be added to the cell surface to
reduce the surface area and minimize the release of acid
mist. Cell hoods can be installed over the electrowinning
cells to contain and direct acid mist to a collection system.
Spray systems can be used to knock down acid mist or ven-
tilation systems may be used to capture and reduce acid
mist from the work area.
Even with these physical controls, acid mist presence
in electrowinning facilities persists and typically require
additional mitigation needs. The addition of chemical
anti-misting agents to the copper electrolyte is a common
mitigation technique, which has historically utilized fluori-
nated surfactants. However, fluorosurfactants are resistant
to degradation and persistent in their environment leading
to long term contamination and health risks. Due to these
challenges, many countries have implemented strict regula-
tions on the use of fluorosurfactants and they are no longer
25-050
Introduction of a New Environmentally Friendly Acid Mist
Suppressant in Copper Electrowinning—Acorga® EW98
Tim Doubleday
Syensqo, Tempe, AZ
William Szolga Jr
Syensqo, Niagara Falls, Ontario, Canada
Tyler McCallum
Syensqo, Tempe, AZ
Jose Carlos Durazo
Syensqo, Tempe, AZ
Justin Jensen
Syensqo, Tempe, AZ
Luis Moya
Syensqo, Tempe, AZ
ABSTRACT
Sulfuric acid mist is an undesired by-product of the copper
electrowinning process, caused by oxygen evolution at the
anode which entrains droplets of the acidic copper electro-
lyte solution. As the oxygen moves to the surface of the cell,
these droplets become aerosolized resulting in acid mist.
The addition of chemical anti-misting agents to the copper
electrolyte is a common mitigation technique. This paper
details Syensqo’s laboratory development of a new envi-
ronmentally friendly acid mist suppressant, ACORGA ®
EW98. The product exhibits excellent acid mist suppres-
sion and it is fully compatible with the adjacent solvent
extraction process. Lab and pilot test results are reviewed
ahead of future planned industrial trial testing.
INTRODUCTION
Copper electrowinning is an electrochemical reaction
which consists of passing an electrical current through the
electrolyte where copper ions are deposited onto cathodes
as pure copper metal. During this electrochemical reaction,
oxygen is generated at the anode leading to the formation
of sulfuric acid mist. As these tiny droplets rise through
the electrolyte they burst, propelling tiny droplets of acidic
electrolyte into the air.
Acid Mist Challenges and Mitigation in Copper
Electrowinning
The formation of acid mist during the copper electrowin-
ning process has presented several challenges within the
industry. Hazards associated with acid mist include envi-
ronmental concerns, health challenges for employees and
building structural concerns due to corrosion. Several phys-
ical methods to reduce acid mist have been used in indus-
try. Polypropylene balls can be added to the cell surface to
reduce the surface area and minimize the release of acid
mist. Cell hoods can be installed over the electrowinning
cells to contain and direct acid mist to a collection system.
Spray systems can be used to knock down acid mist or ven-
tilation systems may be used to capture and reduce acid
mist from the work area.
Even with these physical controls, acid mist presence
in electrowinning facilities persists and typically require
additional mitigation needs. The addition of chemical
anti-misting agents to the copper electrolyte is a common
mitigation technique, which has historically utilized fluori-
nated surfactants. However, fluorosurfactants are resistant
to degradation and persistent in their environment leading
to long term contamination and health risks. Due to these
challenges, many countries have implemented strict regula-
tions on the use of fluorosurfactants and they are no longer