HudBay Minerals Inc.

HudBay Minerals Inc.

March 11, 2005 09:29 ET

HudBay Minerals Inc. Announces 2004 Production Results and 2005 Ore Reserves for its Hudson Bay Mining and Smelting Co., Limited Subsidiary


NEWS RELEASE TRANSMITTED BY CCNMatthews

FOR: HUDBAY MINERALS INC.

TSX SYMBOL: HBM

MARCH 11, 2005 - 09:29 ET

HudBay Minerals Inc. Announces 2004 Production Results
and 2005 Ore Reserves for its Hudson Bay Mining and
Smelting Co., Limited Subsidiary

TORONTO, ONTARIO--(CCNMatthews - March 11, 2005) - HudBay Minerals Inc.
(TSX:HBM) (HudBay) is pleased to announce full year 2004 production
results for its wholly owned subsidiary, Hudson Bay Mining and Smelting
Co., Limited (HBMS), as well as ore reserves as at January 01, 2005.

HudBay completed the purchase of HBMS from Anglo American plc on
December 21, 2004. The tabulated production volumes are unaudited and
are subject to change once HudBay's audited 2004 financial results are
released at the end of March 2005. HudBay's audited results for 2004
will incorporate HBMS results for only the period following HudBay's
acquisition of HBMS.

HBMS is the principal operating subsidiary of HudBay and contributes all
of HudBay's production.

Key production statistics are provided for HBMS' mines and metallurgical
plants, including metal production attributable to HBMS' mines and to
concentrates purchased by HBMS.

Mine production volumes increased in 2004 as compared to 2003 at
improved ore grades, due in part to the new 777 mine reaching commercial
production on January 01, 2004. Production of metal attributable to HBMS
owned mines was also substantially increased.

Total copper and zinc metal production was slightly reduced in 2004
compared to 2003, reflecting the higher volumes of concentrate treated
from HBMS mines and to more planned maintenance days. Gold and silver
production was increased related to a higher precious metal content from
HBMS mined ores and to improved recovery technology in the Flin Flon
concentrator.

HudBay Minerals Inc. is an integrated mining and metal producing company
that operates mines and concentrators in northern Manitoba and
Saskatchewan and a metal processing complex in Flin Flon, Manitoba. The
company also operates a zinc oxide production facility in Brampton,
Ontario and the former producing mines of Balmat in New York State and
Gays River in Nova Scotia that are being evaluated for re-opening.



Hudson Bay Mining and Smelting Co., Limited

----------------------------------------
Mine Production
----------------------------------------
2003 2004

Q4 Full Year Q4 Full Year
----------------------------------------
Trout Lake Mine: tonnes 204,800 872,700 226,600 916,100
Zinc % 5.0 4.8 6.1 5.3
Copper % 1.2 1.2 1.4 1.5

Konuto Mine: tonnes 80,800 321,500 75,000 327,200
Zinc % 1.8 1.8 2.1 2.1
Copper % 3.8 3.7 3.9 4.1

777 Mine: tonnes 206,700 709,200 245,700 975,900
Zinc % 4.4 4.0 4.2 4.5
Copper % 2.9 2.8 2.5 2.9

Chisel North Mine: tonnes 73,800 303,200 83,200 327,900
Zinc % 12.4 11.3 8.9 10.0
Copper % 0.2 0.2 0.2 0.2
---------------------------------------------------------------------

Total Mines: tonnes 566,100 2,206,600 630,500 2,547,100
Zinc % 5.3 5.0 5.3 5.2
Copper % 2.1 1.9 2.0 2.2
---------------------------------------------------------------------


----------------------------------------
Metal Production
----------------------------------------
Zinc from:
HBMS Mines tonnes 22,700 93,100 28,300 108,400
Purchased
concentrate tonnes 6,100 24,800 0 1,800
-----------------------------------------
Total Zinc tonnes 28,800 117,900 28,300 110,200

Copper from:
HBMS Mines tonnes 10,900 42,100 12,600 43,700
Purchased
concentrates tonnes 12,600 41,300 9,400 33,200
-----------------------------------------
Total Copper tonnes 23,500 83,400 22,000 76,900

Gold from:
HBMS Mines 000 ozs 16 57 26 78
Purchased
concentrates 000 ozs 2 4 0 1
-----------------------------------------
Total Gold 000 ozs 18 61 26 79

Silver from:
HBMS Mines 000 ozs 168 630 240 696
Purchased
concentrates 000 ozs 151 460 136 418
-----------------------------------------
Total Silver 000 ozs 320 1,091 376 1,115

Zinc Oxide: (1) tonnes 7,900 36,700 10,100 38,700
---------------------------------------------------------------------

(1) Zochem division zinc oxide is produced primarily from HBMS zinc.


HBMS Ore Reserves as at January 01, 2005

The mineral resources have been prepared under the guidance of a
Professional Geoscientist, Kim Lau BSc. P.Geo., who is employed by HBMS
as a Senior Mineral Resource Analyst and who is designated as a
Qualified Person under National Instrument 43-101 with the ability and
authority to verify the authenticity and validity of the data. The
January 01, 2005 ore reserves have been prepared under the guidance of a
Professional Mining Engineer, Gary Allen MSc. P.Eng., who is employed by
HBMS as Manager of Mines Technical Services and who is designated as a
Qualified Person under National Instrument 43-101 with the ability and
authority to verify the authenticity and validity of the data.

The mineral resource is determined in a 12 step process, which includes
determination of the integrity and validation of the data including
confirmation of specific gravity, assay results and methods of data
recording. Additionally the understanding of the geological model,
selection of data and the application of statistics including
probability plots and restrictive kriging to establish continuity and
model validation. The resultant mineral resource in the measured and
indicated category are converted to proven and probable ore reserves by
the application of mining dilution and recovery, as well as the
determination of economic viability using historical operating costs.
Other factors such as depletion from production are applied as
appropriate.

The ore reserves are contained within operating mines in Saskatchewan
and Manitoba, which have been in operation for several years in
compliance with operational and environmental regulations. A material
change impacting the viability of the ore reserves is not anticipated.



---------------------------------------------------------------------
---------------------------------------------------------------------
Estimate of HBMS Ore Reserves (as at January 01, 2005)
---------------------------------------------------------------------
Tonnes Au (g/t) Ag (g/t) Cu (%) Zn (%)
---------------------------------------------------------------------

Trout Lake
Proven 1,584,000 1.2 14.0 1.3 4.6
Probable 1,727,000 1.2 15.1 1.8 4.0

777
Proven 2,963,000 2.4 30.7 2.2 4.5
Probable 13,633,000 2.1 27.6 2.4 4.7

Konuto Lake
Proven 184,000 2.3 7.2 4.0 0.9
Probable 34,000 1.9 5.3 4.8 0.9

Chisel North
Proven 628,000 0.2 21.0 0.1 9.5
Probable 846,000 0.5 18.9 0.3 8.1

Total Proven 5,360,000 1.8 23.8 1.8 5.0
Total Probable 16,240,000 1.9 25.8 2.3 4.8
Total Reserve 21,600,000 1.9 25.3 2.2 4.8
---------------------------------------------------------------------
---------------------------------------------------------------------


According to the technical report dated November 05, 2004 and filed on
SEDAR on November 11, 2004, HBMS' total reserves (proven and probable)
were estimated, as at January 01, 2004, to be 24,371,400 tonnes at 1.8
Au (g/t), 23.7 Ag (g/t), 2.2 Cu (%) and 4.8 Zn (%).

-30-

Contact Information

  • FOR FURTHER INFORMATION PLEASE CONTACT:
    HudBay Minerals Inc.
    Tom Goodman
    Vice-President, Human Resources and Technical Services
    (204) 687-2380
    tom.goodman@hbms.ca