ABOUT
US

MINES

OPERATIONS

The Mission Complex, an open-pit mine composed of the Mission, Eisenhower, Pima, Mineral Hill and
South San Xavier properties and the nearby North San Xavier mine. The current pit, 2.5 miles long by
1.5 mile wide and 1,200 feet deep, is situated on 20,000 acres.
Benches are 40 feet high.

HISTORY

1959

Pre-mine development

1961

Mill began operating at 15,000 tons per day.

1967

Two additional rod mills and one flotation
section added tobring capacity to 22,000
tons per day.

1976

Partnership formed with Anamax Mining
Company to mine the Eisenhower property
between Mission pit and South San Xavier Pit.

1979

Production commenced from Eisenhower.

1980

Flotation cells upgraded.

1985

Pima mine, contiguous to Mission, acquired.

1987

Refinements increased mill capacity to
28,000 tons per dayEisenhower acquired
by ASARCO from Anamax.

1989

Pima Mill acquired.

1991

Refurbishing and new construction
of (Pima Mill) Mission SouthMill.

1993

Expansion of Mission Mine completed
Flotation CellModification.

1995

Secondary crusher modifications and
DCS installed in MissionMill. Increases
capacity to 43,000 (Total 63,000 with
20,000 from South Mill).

1996

Underground mine expansion.

1997

Underground mine expansion;
Overland conveyor installed to
movenon-mineral rock.

1999

Mission Mill Secondary Crusher Upgraded.

2000

Mission Mill throughput reduced
to 41,000 tons per day.

2001

Mission Mill throughput reduced to
31,000 tons per day, SouthMill placed under
care and maintenance.

2002

Mission Mill throughput reduced to
24,000 tons per day.

2003

Mission Mill throughput reduced to
17,000 tons per day. Underground
mine closed.

2006

Restart of Molybdenum Circuit.

2009

Pumping system installed to utilize
CAP water.

2011

Reclamation of Tailings Dams 1-3 and
the Mission North Dump.

2011

Mine utilizes biosolids from Pima County
Green Valley Wastwater treatment plant.

2013

South Mill Expansion Completed.

OPERATIONS

The mine operates four open-pits (North Silver Bell, El Tiro, West Oxide and East Oxide). All copper in these pits will be extracted from the ore utilizing dump leaching.

The four open-pits and other plant facilities are situated on 19,000 acres. Mining affected areas of the facility: 3,900 acres.
Copper-bearing solutions from the dump leach and rubble areas are collected and pumped to the solvent extraction plant where the copper in solution is concentrated over 30 times before being pumped to the tank house. In the tank house, the copper is recovered from solution using the electrowinning process and plated on stainless steel starter sheets as high-purity cathodes.

Cathode copper produced in the solvent extraction / electrowinning (SX/EW) operation is sold to producers of copper rod, tubing and wire.

HISTORY

1850

Gold and silver exploration leads to
discovery of high-grade copper
mineralization suitable for direct shipment
to the east coast or England.

1880

Several prospects are developed as
commercial ventures and small smelters
are built.

1900

The consolidation of underground mines
begin.
A concentrator is built and concentrates are
shipped by railroad.

1910

Mining operations cease due to poor
economic conditions.

1915

ASARCO completes the purchase of
consolidated mining companies in the area.

1946

ASARCO geologists begin reevaluation of
the properties in the area.

1951

Stripping begins for open-pit mining of
El Tiro and Oxide pits.

1954

Milling operations begin for sulfide copper
and molybdenum.

1960

Dump leaching of copper oxides and
precipitation of copper begins at 10 tons
per day (TPD).

1965

An expansion of the precipitation plant
increases copper production to 15 TPD.

1967

Mill and secondary crusher expansion is
completed. Mill throughput is increased
to 10,500 TPD.

1978

A feasibility study is made to build a 15
TPD SX/EW facility that would replace the
precipitation plant.

1980

A study is made of a 20 TPD SX/EW
facility by adding on-stream leaching
of mill tailings and high grade in-pit
leaching.

1984

Evaluation of the North Silver Bell property
begins. Mine and mill operations suspended,
leach-precipitation operations continue.

1988

A drilling program started in North
Silver Bell to redefine the ore bod y.

1989

The BS&K property is purchased and a
30 TPD SX/EW facility is proposed.

1990

A rubble leaching evaluation is completed
and a 50 TPD SX/EW facility is approved
by the ASARCO Board of Directors.
Authorization to proceed is dependent
upon the receipt of applicable permits.

1992

The Bureau of Land Management land
trade is completed.

1994

Permits are approved and the
authorization to proceed with the SX/EW
project is granted.

1995

All construction contracts are awarded.

1996

Silver Bell Mining, L.L.C. partnership is
formed – 75% Asarco and 25% Mitsui.
Mining operations begin in North S ilver
Bell in April. Construction of the new
facilities begins in May.

1997

Dump leach and copper precipitation
operations are shutdown in April.
Construction of new facilities is
completed and cathode production
begins in July.

1998

The cathode production rate is increased
to 55 TPD.

2003

SX/EW plant improves efficiency and
production increases to 65 TPD.

2007

No. 2 dump project approved and
production forecast is increased to
67 TPD.

2014

AR Silver Bell purchases the 25% s take
in Silver Bell LLC from Mitsui & C o., Ltd.

OPERATIONS

The Ray Operations consists of an open pit mine with a concentrator and a solvent extraction-electrowinning operation, and associated maintenance, warehouse and administrative facilities. Cathode copper produced in the SX-EW operation is shipped to outside customers and to the Amarillo Copper Refinery.

Ray is located in Pinal County, just 18 miles to the west of the Hayden Operations. The Hayden Operations and General Administrative Offices are located 70 miles northeast of Tucson and 64 miles southeast of Phoenix (Pinal and Gila Counties).

A local railroad, Copper Basin Railway, transports ore to the Ray concentrator to the smelter, and sulfuric acid to the leaching facilities.

HISTORY

1880

Mineral Creek Mining C ompany.

1883

Ray Copper Company.

1898

Globe Mines Exploration Co., Ltd.

1899

Ray Copper Mines, Ltd.

1906

Gila & Ray Copper Companies.

1910

Ray Consolidated Copper Company.

1911

Underground Mine.

1927

Nevada Consolidated Copper Company.

1933

Kennecott Copper Corporation, Ray Mines
Division.

1948

Stripping Began.

1952

Open-Pit Mine Began.

1955

Underground Mine Ceased.

1986

Ray Unit purchased from Kennecott.

1989

Hayden Concentrator modernization.

1991

Ray Complex formed.

1992

Ray Concentrator commissioned;
expansion of Ray mine completed.

1996

Hayden Concentrator modernization.

1998

Ferric cure leaching commenced.

1999

Ray secondary crusher commissioned,
Tankhouse renovation completed.

2000

Ray and Hayden Operations formed.

OPERATIONS

The Amarillo facility produces 5/16” copper rod.  The Rod line maximum capacity is 264,000 short tons per year.  Molten copper is molded into a bar at a rate less than ½ a mile per hour and exits the mill close to 72 miles per hour.  The bar is rolled through 16 stands and is reduced from a 2.5” x 5” rectangle bar to a 5/16” rod (1/200th of its original size).  Coils weigh 7,500 pounds and contain 5 miles or 26,400 feet of rod.  Copper rod is used for magnet wire, automotive wire, telecom wire, and building wire.

The Amarillo Copper Refinery is located nine miles northeast of Amarillo, Texas on State Highway 136.  The plant sits on 3,054 acres of which the operating facility occupies approximately 250 acres.  The surrounding ASARCO owned land is leased for farming and grazing.

Amarillo Copper Refinery is ISO 9001:2015 certified.

HISTORY

1922

Zinc plant construction began.

1924

Smelter was operational.

1974

Copper refinery constructed at a cost of
$210 million.

1975

First shipment of copper was made.
Zinc smelter closed.

1979

Patented Reatrol process (Reagent Control)
increased production efficiency, enabling plant
to eventually exceed design capacity.

1993

Electrolyte purification facility installed,
improving the quality of refined copper
production.

1994

Plant receives ISO-9002 certification for
copper cathode

1995

Plant receives ISO-9002 certification for
copper rod and cake; Stormwater recycling
and installation of Rod Zero stand.

1996

Plant receives ISO-9002 certification for
precious metals parting, Se/Te, nickel
sulfate and anode casting

1997

Rod mill upgrade

1998

Plant receives ISO-9002 certification for
anode/blister sampling, precious metals
sampling and anode mold making.

2000

Increased Rod and Cake Facilities capacities.

2001

Electrolyte purification upgrade.

2003

Plant receives ISO 9000:2000 certification
for copper cathode, rod, cake, precious
metals parting, Se/Te, nickel sulfate and
anode casting.

2006

Enviroalloy™ production and Rod shaft
Furnace shell replacement.

2012

Precious Metal, Se/Te Production
Suspended.
Injection Well No. 2 Upgrade.

2015

Automated Starter-sheet stripping circuit
installed.

2019

The Amarillo facility started focusing in
producing 5/16” copper rod.