3588 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
increase in flotation cell sizes with the latest designs reach-
ing up to 660 m3 cells rougher cells. Rougher flotation has
been dominated with self aspirated and forced air machines
whilst the cleaner circuits have seen the inclusion of differ-
ent cell technologies such as the Staged Flotation Reactor
(SFR), Direct Flotation Reactor (DFR), Column Cells and
Jameson Cells. Concentrate dewatering has not changed
significantly over time with a combination of thickeners
and pressure filter presses but the tailings side has seen pro-
gressive advancement of higher underflow densities with
hi-density thickeners and even paste thickening in some
instances. Moving forward it is expected to see some addi-
tional concentrator circuit variations including some spe-
cialty applications with Autogenous mills, High Pressure
Grinding Rolls (HPGR) and stirred mill technology and
considerations for dry grinding involving Vertical Roller
Mills (VRM’s). There are one or two disruptive technolo-
gies in the copper recovery space that may influence the
circuit design and these are expected to be in demonstra-
tion scale this year.
This paper describes industry experience in the design
and layout of the concentrators including crushing, grind-
ing, flotation and dewatering stages for concentrates and
tailings. The paper includes specific examples from some of
the most successfully executed modern day concentrators.
HISTORICAL DEVELOPMENTS
Bechtel’s first venture into minerals projects was cited with
the Castledome and Morenci copper projects in 1942 dur-
ing World War II. The work was performed by the Power
and Industrial group out of San Francisco. During the rest
of the 1940s there were a few US projects for steel mills and
a Saudi Arabia cement plant.
During the 1950s was Bechtel’s first real entry to the
minerals side with iron ore development in Venezuela then
laterite nickel processing in Oregon for Hanna Mining
(later opening the doors for Cerro Matoso in Colombia).
The 1950s also saw expansion into multiple iron ore pro-
cessing plants (concentrators and pelletizing) in the USA
and Canada as well as exposure to coke calcining, zirco-
nium, titanium and our first alumina plant and first alu-
minium smelter (both USA). The work in this period was
still performed by Bechtel Power and Industrial.
This spectrum of commodities continued through the
1960s, though more internationally, and with the addition
of lead, zinc and uranium, then copper for El Teniente in
Chile and Palabora Mining in South Africa. In the mid
1960s, Mining &Metals (M&M) split from Power and
Industrial to form a separate Bechtel Division, based in San
Francisco, California, USA.The primary commodities fla-
vor through the 1970s continued with iron ore, steel, lat-
erite nickel but also included the milestone copper project
of Bougainville in Papua New Guinea and several uranium
facilities and bulk materials handling projects.
By the early 1980s, M&M was operating within the
Civil and Minerals unit, still based in San Francisco, and
this continued until the commodities market recovered
from the lows of that cycle. In the 1990s M&M completed
a number of signature copper concentrators including
Asarco Ray and the Kennecott Copperton Concentrator
amongst others. In recent times Quebrada Blanca II, Las
Bambas, Antapaccay and OGP1 projects were completed.
CONCENTRATOR TRACK RECORD
Copper was the product of the first mining project that
Bechtel undertook, at the Morenci Mining facility for
Phelps Dodge in the early 1940s. Bechtel’s past copper min-
ing and processing successes include Palabora in Southern
Africa Antamina, Los Pelambres, Collahuasi, Candelaria,
and Escondida Concentrators in Latin America Kennecott
and Ray Concentrator in North America and Olympic
Dam, Freeport, Ok Tedi, and Cadia Hills in the Asia-
Pacific Region.
Bechtel has built a significant portion of copper con-
centrators and is one of the leading designer and installer of
autogenous and semi-autogenous grinding mills.
The following Table 1, Table 2 and Table 3 provides a
list of the key copper projects completed and the timeline
together with the execution approach.
As expected and due to declining ore grades the con-
centrator project sizes have increased over time. Many of
Bechtel’s projects are based on studies conducted in the
early stages of project development. Bechtel has also con-
duct modernization and de-bottlenecking studies of exist-
ing facilities. Feasibility studies typically progress from
conceptual and pre-feasibility through detailed feasibility
studies used for financial analysis. In many of the develop-
ment projects the optimization and trade-off studies have
been an essential part of the studies and these studies can
continue through basic and detail engineering as opportu-
nities are recognized to improve the economics and tech-
nology of a project.
Table 2 and Table 3 indicates the SAG and Ball Mills
sizes hat Bechtel has been designed and constructed.
Note: Svedala is now Metso-Outotec and Fuller is FLSmidth
The following are some examples of some of the proj-
ects listed.
increase in flotation cell sizes with the latest designs reach-
ing up to 660 m3 cells rougher cells. Rougher flotation has
been dominated with self aspirated and forced air machines
whilst the cleaner circuits have seen the inclusion of differ-
ent cell technologies such as the Staged Flotation Reactor
(SFR), Direct Flotation Reactor (DFR), Column Cells and
Jameson Cells. Concentrate dewatering has not changed
significantly over time with a combination of thickeners
and pressure filter presses but the tailings side has seen pro-
gressive advancement of higher underflow densities with
hi-density thickeners and even paste thickening in some
instances. Moving forward it is expected to see some addi-
tional concentrator circuit variations including some spe-
cialty applications with Autogenous mills, High Pressure
Grinding Rolls (HPGR) and stirred mill technology and
considerations for dry grinding involving Vertical Roller
Mills (VRM’s). There are one or two disruptive technolo-
gies in the copper recovery space that may influence the
circuit design and these are expected to be in demonstra-
tion scale this year.
This paper describes industry experience in the design
and layout of the concentrators including crushing, grind-
ing, flotation and dewatering stages for concentrates and
tailings. The paper includes specific examples from some of
the most successfully executed modern day concentrators.
HISTORICAL DEVELOPMENTS
Bechtel’s first venture into minerals projects was cited with
the Castledome and Morenci copper projects in 1942 dur-
ing World War II. The work was performed by the Power
and Industrial group out of San Francisco. During the rest
of the 1940s there were a few US projects for steel mills and
a Saudi Arabia cement plant.
During the 1950s was Bechtel’s first real entry to the
minerals side with iron ore development in Venezuela then
laterite nickel processing in Oregon for Hanna Mining
(later opening the doors for Cerro Matoso in Colombia).
The 1950s also saw expansion into multiple iron ore pro-
cessing plants (concentrators and pelletizing) in the USA
and Canada as well as exposure to coke calcining, zirco-
nium, titanium and our first alumina plant and first alu-
minium smelter (both USA). The work in this period was
still performed by Bechtel Power and Industrial.
This spectrum of commodities continued through the
1960s, though more internationally, and with the addition
of lead, zinc and uranium, then copper for El Teniente in
Chile and Palabora Mining in South Africa. In the mid
1960s, Mining &Metals (M&M) split from Power and
Industrial to form a separate Bechtel Division, based in San
Francisco, California, USA.The primary commodities fla-
vor through the 1970s continued with iron ore, steel, lat-
erite nickel but also included the milestone copper project
of Bougainville in Papua New Guinea and several uranium
facilities and bulk materials handling projects.
By the early 1980s, M&M was operating within the
Civil and Minerals unit, still based in San Francisco, and
this continued until the commodities market recovered
from the lows of that cycle. In the 1990s M&M completed
a number of signature copper concentrators including
Asarco Ray and the Kennecott Copperton Concentrator
amongst others. In recent times Quebrada Blanca II, Las
Bambas, Antapaccay and OGP1 projects were completed.
CONCENTRATOR TRACK RECORD
Copper was the product of the first mining project that
Bechtel undertook, at the Morenci Mining facility for
Phelps Dodge in the early 1940s. Bechtel’s past copper min-
ing and processing successes include Palabora in Southern
Africa Antamina, Los Pelambres, Collahuasi, Candelaria,
and Escondida Concentrators in Latin America Kennecott
and Ray Concentrator in North America and Olympic
Dam, Freeport, Ok Tedi, and Cadia Hills in the Asia-
Pacific Region.
Bechtel has built a significant portion of copper con-
centrators and is one of the leading designer and installer of
autogenous and semi-autogenous grinding mills.
The following Table 1, Table 2 and Table 3 provides a
list of the key copper projects completed and the timeline
together with the execution approach.
As expected and due to declining ore grades the con-
centrator project sizes have increased over time. Many of
Bechtel’s projects are based on studies conducted in the
early stages of project development. Bechtel has also con-
duct modernization and de-bottlenecking studies of exist-
ing facilities. Feasibility studies typically progress from
conceptual and pre-feasibility through detailed feasibility
studies used for financial analysis. In many of the develop-
ment projects the optimization and trade-off studies have
been an essential part of the studies and these studies can
continue through basic and detail engineering as opportu-
nities are recognized to improve the economics and tech-
nology of a project.
Table 2 and Table 3 indicates the SAG and Ball Mills
sizes hat Bechtel has been designed and constructed.
Note: Svedala is now Metso-Outotec and Fuller is FLSmidth
The following are some examples of some of the proj-
ects listed.