2
well. Since marcasite lead and copper ores are believed to
be most challenging to process, the system can then help
expand other ore resources like high iron high zinc ores and
copper ore resources.
Chemical reagents play dominant roles in flotation and
can be implemented at a lower cost comparing to upgrad-
ing process equipment and production infrastructures. It
became apparent that first and foremost an effective iron
depressant must be found to depress marcasite, and for that
matter pyrite as well. Through searching this iron depres-
sant, a new 2nd modern flotation reagent system could be
established which would complement and enhance the cur-
rent century old and proven bulk reagents. The 2nd reagent
system at minimum would consist of one collector and
one depressant for each lead, zinc, and copper circuit. Doe
Run therefore started working with Solvay to screen its vast
commercial reagents to identify these reagents for compre-
hensive plant trial to build the 2nd Solvay modern reagent
system and placed it in DCS for automatic intelligent con-
trol. In 2022, a hybrid reagent system was designed for and
deployed at Buick Mill, consisting of highly targeted, selec-
tive collectors and depressants for each stage of the process.
The most vital of these reagents is a powerful and selective
iron depressant which can suppress marcasite and pyrite
as well. With traditional reagents alone, it is very difficult
to control where marcasite will go in the flotation circuit,
making the production of saleable concentrates difficult or
impossible while it is present. While most of the iron-bear-
ing gangue processed at Buick Mill is pyrite, there are large
reserves of ores with considerable lead and copper content
which are rich in marcasite as well. Thus, the addition of an
iron depressant which can reject marcasite from the process
enables the economical processing of marcasite ores with a
considerable amount of additional ore value.
Expert control is another proven low-cost approach
especially for Buick mill previously without advanced pro-
cess control (APC) beyond DCS. With foresight a few years
prior, Doe Run already piloted 2 VisioFroth ™ cameras on
the zinc rougher line at its Brushy Creek mill. Around the
time Buick mill started seeking fundamental solutions to
process marcasite high lead high copper ores in early 2022,
Doe Run implemented VisoFrothTM cameras first at the
zinc rougher and cleaner lines at Buick mill, even if still at a
deep learning curve, and immediately after early success, at
copper rougher and cleaner lines as well. So, VisioFroth ™
and OCS-4D© that powers and controls VisioFroth ™ were
vigorously examined and OCS-4D© was chosen as a great
platform to develop into intelligent digital expert flotation
control system.
Advanced data analytics plays an ever more essential
role in mill optimization and can be at a very low cost.
Doe Run was implementing PI System across all its mills
at the time, very timely providing vast mill data including
bulk and new reagents, the quantitative VisioFroth ™ bub-
ble characteristics and online XRF assays for all lead, zinc,
and copper circuits. Buick mill started very comprehensive
advanced mill data modeling that contributed to develop-
ing effective expert flotation that overtook and automati-
cally run the entire zinc and copper flotation circuits and
2nd modern reagent system in late 2022, a breakthrough.
Buick then installed cameras on lead rougher and cleaner
lines and expert controlled the entire flotation plant of all
three lead, zinc, and copper circuits in May 2023, auto-
matically removing froth to reach target rougher and final
concentrate grades even with rapidly varying ore lead, zinc
and copper grades.
Doe Run and Buick mill collaborated very closely with
Metso to develop a comprehensive and ever-expanding
enterprise mill expert control and operating system, rightly
named Digital One on the production line that includes
and utilizes DCS, VisioFroth ™, XRF, modern and bulk
regents, air and MIBC, no limits once inside DCS. Buick
mill with Digital One expert control has processed over
200,000 tons of marcasite lead and copper ores and made
salable concentrates and strives to expand ore resources and
create significant value.
Buick mill extensively examined and investigated
various mill control methods and philosophies, including
but are not limited to Digital Twin, AI, Advanced Process
Control (APC) and Model Prediction Control (MPC).
APPLICATIONS OF VISIOFROTH™
Buick Mill adopted and applied VisioFroth ™ gradually
with milestones achieved in several phases, a profound
operational culture change. First, operators could see and
started as a reference to use the velocity of froth moving
out of flotation cells, visually and intuitively instead of
using other references or non-visual froth depth in DCS.
This was a “sea change” and a major milestone. Second,
operators could manually input froth velocity setpoint and
VisioFroth ™ reached the setpoint and operators would
adjust the velocity manually and frequently from time to
time, the “cruise control.” Third, VisioFroth ™ took over
and adjusted froth velocity to reach the target rougher and
final concentrate grades, completing the “culture change”
for the operators.
The expert control system at Buick Mill is built on top
of the VisioFroth ™ technology. By expanding on capabili-
ties and scope of the VisioFroth ™ system, integrating it
well. Since marcasite lead and copper ores are believed to
be most challenging to process, the system can then help
expand other ore resources like high iron high zinc ores and
copper ore resources.
Chemical reagents play dominant roles in flotation and
can be implemented at a lower cost comparing to upgrad-
ing process equipment and production infrastructures. It
became apparent that first and foremost an effective iron
depressant must be found to depress marcasite, and for that
matter pyrite as well. Through searching this iron depres-
sant, a new 2nd modern flotation reagent system could be
established which would complement and enhance the cur-
rent century old and proven bulk reagents. The 2nd reagent
system at minimum would consist of one collector and
one depressant for each lead, zinc, and copper circuit. Doe
Run therefore started working with Solvay to screen its vast
commercial reagents to identify these reagents for compre-
hensive plant trial to build the 2nd Solvay modern reagent
system and placed it in DCS for automatic intelligent con-
trol. In 2022, a hybrid reagent system was designed for and
deployed at Buick Mill, consisting of highly targeted, selec-
tive collectors and depressants for each stage of the process.
The most vital of these reagents is a powerful and selective
iron depressant which can suppress marcasite and pyrite
as well. With traditional reagents alone, it is very difficult
to control where marcasite will go in the flotation circuit,
making the production of saleable concentrates difficult or
impossible while it is present. While most of the iron-bear-
ing gangue processed at Buick Mill is pyrite, there are large
reserves of ores with considerable lead and copper content
which are rich in marcasite as well. Thus, the addition of an
iron depressant which can reject marcasite from the process
enables the economical processing of marcasite ores with a
considerable amount of additional ore value.
Expert control is another proven low-cost approach
especially for Buick mill previously without advanced pro-
cess control (APC) beyond DCS. With foresight a few years
prior, Doe Run already piloted 2 VisioFroth ™ cameras on
the zinc rougher line at its Brushy Creek mill. Around the
time Buick mill started seeking fundamental solutions to
process marcasite high lead high copper ores in early 2022,
Doe Run implemented VisoFrothTM cameras first at the
zinc rougher and cleaner lines at Buick mill, even if still at a
deep learning curve, and immediately after early success, at
copper rougher and cleaner lines as well. So, VisioFroth ™
and OCS-4D© that powers and controls VisioFroth ™ were
vigorously examined and OCS-4D© was chosen as a great
platform to develop into intelligent digital expert flotation
control system.
Advanced data analytics plays an ever more essential
role in mill optimization and can be at a very low cost.
Doe Run was implementing PI System across all its mills
at the time, very timely providing vast mill data including
bulk and new reagents, the quantitative VisioFroth ™ bub-
ble characteristics and online XRF assays for all lead, zinc,
and copper circuits. Buick mill started very comprehensive
advanced mill data modeling that contributed to develop-
ing effective expert flotation that overtook and automati-
cally run the entire zinc and copper flotation circuits and
2nd modern reagent system in late 2022, a breakthrough.
Buick then installed cameras on lead rougher and cleaner
lines and expert controlled the entire flotation plant of all
three lead, zinc, and copper circuits in May 2023, auto-
matically removing froth to reach target rougher and final
concentrate grades even with rapidly varying ore lead, zinc
and copper grades.
Doe Run and Buick mill collaborated very closely with
Metso to develop a comprehensive and ever-expanding
enterprise mill expert control and operating system, rightly
named Digital One on the production line that includes
and utilizes DCS, VisioFroth ™, XRF, modern and bulk
regents, air and MIBC, no limits once inside DCS. Buick
mill with Digital One expert control has processed over
200,000 tons of marcasite lead and copper ores and made
salable concentrates and strives to expand ore resources and
create significant value.
Buick mill extensively examined and investigated
various mill control methods and philosophies, including
but are not limited to Digital Twin, AI, Advanced Process
Control (APC) and Model Prediction Control (MPC).
APPLICATIONS OF VISIOFROTH™
Buick Mill adopted and applied VisioFroth ™ gradually
with milestones achieved in several phases, a profound
operational culture change. First, operators could see and
started as a reference to use the velocity of froth moving
out of flotation cells, visually and intuitively instead of
using other references or non-visual froth depth in DCS.
This was a “sea change” and a major milestone. Second,
operators could manually input froth velocity setpoint and
VisioFroth ™ reached the setpoint and operators would
adjust the velocity manually and frequently from time to
time, the “cruise control.” Third, VisioFroth ™ took over
and adjusted froth velocity to reach the target rougher and
final concentrate grades, completing the “culture change”
for the operators.
The expert control system at Buick Mill is built on top
of the VisioFroth ™ technology. By expanding on capabili-
ties and scope of the VisioFroth ™ system, integrating it