Built in 1972, Gibraltar was originally designed to process 36,000 tons of ore per day, producing approximately 60 million pounds of copper annually. Soon after the re-start in 2004, Taseko realized the potential of this large resource and embarked on a program to increase the copper reserves and expand the mining and processing capacity.

In 2007, the first modernization phase commenced. The initial phase included the construction of a 34 foot semi-autogenous grinding (SAG) mill, conversion of rod mills to ball mills and the complete replacement of the flotation recovery system with 160m3 float cells, along with the addition of new mining equipment. Once completed in 2008, these modifications and new equipment increased the processing rate of the concentrator to 46,000 tons per day. This capital investment totaled $76 million.

Phase II modifications were designed to allow the new SAG mill to process up to its designed capacity of 55,000 tons per day by increasing capacity in other circuits of the concentrator.

In 2009, the Company initiated this phase of the modernization project which included an inpit crusher and conveyor system, increasing regrind and cleaner flotation capacity, the installation of a two-stage tailings pumping system plus a new coarse ore stockpile and SAG direct feed system. The mining fleet was further upgraded with the addition of a Bucyrus 495HR 60 yard shovel and four new 320 ton haul trucks This phase was completed in mid-2011 for a total cost of $224 million.

Gibraltar Development Plan 3 (GDP3) was originally planned to commence in 2009, but with the crash of the world financial markets and devalued copper price in late 2008, the Company placed the plans on hold.

In the spring of 2011, construction commenced for Gibraltar Development Plan 3 (GDP3). GDP3 included the construction of a standalone 30,000 ton per day concentrator, built adjacent to the existing 55,000 ton per day facility. The new design capacity of Gibraltar was designed to be 85,000 tons per day. An integral part of the project was a new molybdenum recovery facility. In addition to the new concentrator, the mining fleet will be upgraded with a new mining shovel, production drill and ten haul trucks

Capital costs for GDP3 were $235 million for the concentrator and molybdenum plant and approximately $90 million for mining equipment. GDP3 was completed on time and on budget in Q4 2012 and commissioning began in December 2012. In early 2013, first concentrate from GDP3 was produced and Gibraltar's processing capacity increased to 85,000 tons per day.

Gibraltar is an industry leader in health & safety, environmental and Indigenous relations and has achieved the following award recognitions:

• John Ash Safety Award for 2014, 2015, 2016, 2017, 2018, and 2020; awarded from the BC Ministry of Energy, Mines and Low Carbon Innovation to the BC mining operation with over 1 million hours worked and the lowest injury frequency rate
• Jake McDonald Annual Award for Metal Mine Reclamation for 2020 from the British Columbia Technical & Research Committee on Reclamation; the award recognized Gibraltar’s outstanding achievement in mine reclamation and indigenous collaboration
• MABC and the Province of BC Mining & Sustainability Award for 2012

Gibraltar is low carbon operation.

In 2020, Skarn Associates conduced an independent analysis and verified Gibraltar’s carbon intensity.

Benefiting from hydro power, Gibraltar is a low carbon intensity operation. As reported and qualified by Skarn Associates, Gibraltar ranks in the lowest quartile compared to other copper miners throughout the world with Scope 1 GHG emissions of 1.66 t CO2e/t Cu eq. per pound of copper produced and Scope 2 GHG emissions of 0.09 t CO2e/t Cu eq. per pound of copper produced.

Scope 1: direct greenhouse gas emissions
Scope 2: indirect greenhouse gas emissions associated with the purchase of electricity, steam, heat, or cooling