Gibraltar mine is the 2nd largest unfastened cavity Cu mine in Canada, which is located near Williams Lake in British Columbia. The Gibraltar sedimentation is a copper-molybdenum porphyritic rock. The chief primary mineral is sulphide mineral Pyrite and Chalcopyrite. As the militias proclamation at December 31, 2008, Gibraltar mine got a mine life to at least 2035. After finishing the Phase I & A ; II undertakings, the Gibraltar mine achieves the capacity of 55,000 metric tons per twenty-four hours. There are two sorts of mineralization ores, which are sulfide ore and oxide ore. The former 1 could be done by the regular mineral processing method, and the latter one should be done by the method called SX/EW ( solvent extraction electro-winning ) . Gibraltar mine besides updated their excavation and processing equipments for the development. Additional, Gibraltar mine has done a great occupation on the environment and sustainability issues.
The Gibraltar copper-molybdenum mine is located about 65 km Northwest of Williams Lake in south-central British Columbia with a well-developed substructure. The mine is accessible by a combination of main roads ( 97 ) and paved roads, and it is close to a rail web that provides service for cargo of Cu dressed ores through the Pacific Ocean port of North Vancouver ( Taseko, 2009 ) .
Figure 1: Gibraltar – Regional Location
( Beginning: Taseko, 2009 )
The Gibraltar mine is the 2nd largest unfastened cavity Cu mine in Canada ( Gibraltar, 2009 ) . The mine is a 46,000 metric tons per twenty-four hours operation with a life of mine mean one-year production of 100 million lbs of Cu and 1.1 million lbs of Mo. The mine is undergoing an enlargement and modernisation undertaking that will increase one-year Cu production capacity to 115 million lbs by 2011 ( Taseko, 2009 ) .
Figure 2: The Satellite View of the Gibraltar Mine
( Beginning: Google Earth, 2009 )
The development of the mine is as follow ( MREP, 2009 ) ,
1910 The Gibraltar ore sedimentation was foremost discovered
1971 Originally built by Placer Development
1972 Began operation, 24 hours/day, 7 yearss a hebdomad
1998 Shutdown by Boliden due to the low Cu monetary values after 26 old ages operation
1999 Acquired by Taseko Mines Limited ( 100 % ) , put on standby
2003 Copper monetary values begin to increase, explorative boring plan began
2004 Reopened, and the SX-EW works was being restarted
2006 An extended boring plan discovered extra 30 % of militias
2008 Gibraltar proven and likely militias are increased by 28 % to 472 million metric tons, or 2.7 billion lbs of recoverable Cu widening mine life to 2035 ( Gibraltar, 2009 )
2009 Prosperity Environmental Assessment study is submitted to both Provincial and Federal authoritiess
Figure 3: Gibraltar – Minesite layout
( Beginning: InfoMine, 2009 )
The Gibraltar sedimentation is a copper-molybdenum porphyritic rock. The chief primary mineral is sulphide mineral Pyrite and Chalcopyrite. The ore occurs in seven detached zones, all within a 204 million twelvemonth old flinty stone. The mineralized zones are Gibraltar East, Pollyanna, Gibraltar West, Gibraltar West Extension, Gibraltar North, Connector and Granite Lake ( MREP, 2009 ) .
“ The cavities occur within the Granite Mountain batholite in a wide zone of shearing and change. The Sawmill zone lies about 6 kilometres to the South, along the southern border of the batholite, within a complex contact zone between the batholite and Cache Creek Group stones ” ( InfoMine, 2009 ) .
The mine site covers about 109 square kilometres and consists chiefly of 251 mineral claims and 30 excavation rentals ( InfoMine, 2009 ) . When the mine restarted in 2004, militias were merely 149 million metric tons, or about 12 old ages of mine life. The mission for the Gibraltar mine direction squad is to increase militias and widen the mine life. Over the past four old ages, over $ 20 million has been spent on three major drill plans, each plan ensuing in a important addition to turn out and likely militias. The most recent drill plan, in the spring and summer of 2008, resulted in a 28 % addition to turn out and likely militias, as announced in December 2008. Under present militias, the mine is expected to stay in current operation state of affairs until at least 2035. Here is the proclamation at December 31, 2008.
Table 1: Calpe Militias and Resources at December 31, 2008
Class ( at 0.20 % Cu Cut-off )
( M Tonnes )
Recoverable Metallic element
Contained Metallic element
Cu ( % )
Mo ( % )
Cu ( B pound )
Cu ( B pound )
Proven & A ; Probable Militias
Measured & A ; Indicated Resources
( Beginning: Gibraltar, 2009 )
Taseko Mines Limited Owns the 100 % of the Gibraltar mine ‘s involvement. The production of the Gibraltar mine is showed as below:
Table 2: Summary of the Operating Statisticss
Entire metric tons mined ( 1000000s )
Metric tons of ore milled ( 1000000s )
Copper class ( % )
Molybdenum class ( % )
Copper recovery ( % )
Molybdenum recovery ( % )
Copper production ( 1000000s lb )
Molybdenum production ( 1000s lb )
Copper production costs, cyberspace of by merchandise credits, per pound of Cu
US $ 0.94
US $ 1.87
US $ 1.03
Off belongings costs for conveyance, intervention ( smelting & A ; refinement ) & A ; gross revenues per pound of Cu
US $ 0.29
US $ 0.43
US $ 0.35
Entire hard currency costs of production per pound of Cu
US $ 1.23
US $ 2.30
US $ 1.38
Notes to postpone:
1 Q2 2009 relates to the 6 months stoping June 30, 2009
2 Fiscal 2008 relates to the 15 months stoping December 31, 2008. ( Beginning: Taseko, 2009 )
From the above tabular array, we can happen that the depriving ration of the Gibraltar mine is at a significantly reduced compared with the anterior old ages. Harmonizing the Taseko mines Second Quarter Results, the Gibraltar mine “ operated for the first six months of 2009 under a program initiated in November 2008, based on 45,000 metric tons per twenty-four hours factory ” ( Taseko, 2009 ) .
“ This new operational program along with worsening input costs, and the realisation of the Phase I enlargement, resulted in well reduced costs compared to prior old ages. The mine is presently reexamining a return to lodge mean strip ratio based on recent strength in Cu and molybdenum demand and corresponding additions in metal monetary values ” ( Taseko, 2009 ) .
As known, the market of metals suffered a historical hardest clip during 2008 and 2009, due to the planetary fiscal crisis. However, the entire hard currency cost of production per pound of Cu of Gibraltar mine declined aggressively to US $ 1.23 in 2009. Therefore, even though the monetary value of Cu has declined, Gibraltar ‘s net income border has still improved.
Mining at Gibraltar is carried out utilizing conventional unfastened cavity methods in the Pollyanna on the east side of the belongings, which is 1.8 kilometer long by 0.7 kilometers at its widest point. Drilling is done by a fleet of 3 rotary blast hole drills, which drill 32 centimeter diameter holes and 15 m deep. Blasting is done two to three times a hebdomad and creates 13.7 m high benches in the cavity wall ( MREP, 2009 ) .
“ Blasted ore is loaded by one of three P & A ; H shovels into one of 11 draw trucks that hold between 205 and 240 metric tons each. They haul the ore about 2.4 kilometers to a gyratory crusher located above the cavity near the factory edifice. The draw trucks transport most waste stone to dumps along the north wall of the Pollyanna cavity where they are bit by bit make fulling in the cavity. Some waste stone that contains oxidized Cu mineral ore is hauled out of the cavity to a reserve for polishing procedure ” ( MREP, 2009 ) . Harmonizing to the Annual General Meeting Presentation, the building for the Phase I enlargement and modernisation was completed in January 2008, accomplishing 46,000 metric tons per twenty-four hours steady province. And Phase II enlargement undertaking was completed in March 2009, to increase the capacity to 55,000 metric tons per twenty-four hours ( Gibraltar, 2009 ) .
Gibraltar mine acquired new excavation equipment in topographic point to manage higher factory rates, as below.
Figure 4: New Mining truck – 240 ton TEREX MT 4400AC
( Beginning: TEREX, 2009 )
Figure 5: New Mining Shovel – P & A ; H 4100C Electric MS
( Beginning: Zlotnikov, 2009 ; P & A ; H Mining Equipment, 2009 )
Figure 6: Mill Flowsheet of Gibraltar Mine
( Beginning: Gibraltar, 2008 )
Comminution is a procedure, which breaks the stone from big balls into smaller pieces and so to finer atoms. There are crushers used for interrupting the big stones and bomber to finer atoms.
In Gibraltar mine, the new provender & A ; crunching circuit described as, ROM goes in to a gyratory crusher ( 54×74 ) followed by four parallel secondary crushers ( 13×84 ) in closed circuit. Then, the crushed ores are conveyed into the 34 pess SAG factory through a 45A° conveyor at a rate of 49,000 metric tons per twenty-four hours. The ore was distributed to 6 ball factory circuits, which pulverize the ore to sand. Then, the stuff discharged from Millss is separated by hydro-cyclones ( The flood & lt ; 0.5mm, underflow & gt ; 0.5mm ) . In add-on, there are 2 re-grinding factory, which are used to cut down the rougher floatation merchandises from under 0.5 millimeter to under 0.1 millimeter ( Chen, 2008 ) .
The froth floatation is really a physical procedure that uses wetting agents and wetting reagents to increase the hydrophobicity of the minerals. The sulfide minerals, such as copper pyrites and peacock ore, are water-resistant ( hydrophobic ) . Therefore, foams are added to the slurry to do aggregator ( bubbles ) stronger adequate to keep the affiliated minerals to the surface ( EduMine, 2009 ) .
From the Millss the slurry is piped into floatation cells, which float a assorted Cu and moly dressed ore, which is piped to a Mo floatation circuit where the moly and Cu dressed ores are separated. These dressed ores pass through a thickening before being dried. In the Copper-Moly Separation Circuit, NaHS is added in this circuit as a Cu sedative in order to forestall the Cu from drifting. Meanwhile, the moly can still drift ( Chen, 2008 ) .
Figure 7: Original and Modernized Flotation Circuit
( Beginning: Gibraltar, 2009 )
In the early phase, Gibraltar besides operated a SX/EW ( solvent extraction electro-winning ) works on site to retrieve cathode Cu from Cu oxide minerals, viz. azurite, malachite, chalcocite and cuprite. The procedure involved fade outing these minerals in sulfuric acid with the aid of of course happening bacteriums in out-of-door hemorrhoids of waste stone, followed by electroplating the dissolved Cu metal from the acid in the enclosed refinery edifice. Gibraltar ‘s SX/EW works produced around 38,430 metric tons of cathode Cu from 1986 to 1999. The installation was reopened in 2007 and is one time once more bring forthing Cu cathode at a rate of 1.1 million kgs per twelvemonth ( MREP, 2009 ) .
The chiefly intent of the SX/EW works is to pull out Cu from the pregnant leach solutions ( PLS ) collected from the site ‘s leach mopess and heap leach tablet. “ The procedure takes PLS and extracts the Cu in three extraction mixer-settlers. The Cu is extracted through a liquid ion-exchange reagent carried in kerosine. ” The Cu is selectively transferred to the organic stage, due to the chemical reaction. The laden organic stage is separated and flows to a strip mixer-settler where the Cu is transferred from the organic to the electrolyte. “ The electrolyte is filtered and heated before being passed through the electro-winning cells where the Cu is plated out on chromium steel steel cathodes. Sporadically, the cathodes are removed from the cells, washed and the Cu sheets automatically harvested. The attendant high quality cathode Cu is bundled and sold ” ( InfoMine, 2009 ) .
ENVIRONMENT AND SUSTAINABILITY
Gibraltar Mine besides locates in the bosom of BC ‘s Cariboo Chilcotin tableland, which is a high interior part of assorted cone-bearing woods and grasslands. “ It is home to many different types of wild animate beings, cervid, moose, reindeer, black bears, wolves, every bit good as farm animal. ” The intent of Gibraltar ‘s renewal program is to return the site to the wild animate beings. In 1999, an environmental appraisal complete when Taskeo bought the mine concluded the cost to be $ 32.7 million for both renewal and H2O direction. Final inside informations have non been mapped out, but so far grass and legume vegetive screens have been established on disturbed land to instantly command air current eroding and supply eatage ( MREP, 2009 ) .
Meanwhile, Gibraltar formed a successful partnership with the Cariboo Regional District ( CRD ) , which designed, built ( 2003 ) and now maintains a landfill on one of the mine ‘s waste stone shit. The landfill accepts 13,000 metric tons of family waste from CRD communities each twelvemonth ( MREP, 2009 ) . The public gave a agree ballot to the landfill site plan, because they believed that set uping such a installation at a mine site would be environmentally, socially and economically sustainable, and could be developed as a public private partnership ( InfoMine, 2009 ) .
“ Under the understanding, Gibraltar would stay responsible for the waste stone and drainage below the landfill and the Cariboo Regional District would be responsible for the air infinite above the waste stone ” ( InfoMine, 2009 ) .
The benefits of set uping the landfill at the Gibraltar mine ‘s waste stone shit are legion: ( InfoMine, 2009 )
Located on industrial land, with no demand to construct roads and upset new land, environmental impact and extra cost of building were eliminated.
Large on-site mine equipment could construct the landfill at half the cost.
The landfill would congratulate mine renewal.
The mine ‘s extended surface and groundwater monitoring system would besides function the landfill.
Put a short decision, non like Fisher!