The Blackwater gold project is an open-pit gold project being developed in British Colombia, Canada, by New Gold.
Feasibility study of the project was completed in January 2014, while the Canadian Environmental Assessment Agency granted approval in April 2019.
Estimated to cost C$1.8bn ($1.3bn), the project is expected to produce 485,000 ounces (oz) of gold a year over its initial nine years of operation. It is forecasted to produce seven million ounces (Moz) of gold and 30Moz of silver, through its anticipated mine life of 17 years.
The project is estimated to create 1,500 construction and 495 operations jobs.
Blackwater gold project background
Exploration activities on the Blackwater gold project were started in 1973 by Granges, while Richfield Ventures acquired the project in 2009. New Gold acquired Richfield in June 2011 to gain the full ownership of the project.
Blackwater location, geology, and mineralization
Located approximately 446km from Vancouver, the Blackwater project is made up of 75 mining claims extending over 30,578ha.
The project is located on the Nechako plateau, a part of the Intermontane Belt super terrane situated between the Coast Belt and the Omineca Belt in British Colombia. The Intermontane Belt is made up of three accreted tectonostratigraphic terranes namely Stikine, Cache Creek, and Quesnel.
The project area comprises rocks of the Stikine terrane, which consists of an assemblage of magmatic arc and related sedimentary rocks belonging to the Jurassic to early Tertiary period.
Mineralization at Blackwater is contained in felsic to intermediate composition volcanic rocks, which underwent extensive silicification and hydrofracturing. The deposit hosts disseminated mineralization, which remains open at depth in the south-western portion and to the north and north-west regions.
The Blackwater project is estimated to contain proven and probable ore reserves of 344.4 million tons (Mt) of ore graded at 0.74 grams per ton (g/t) gold (Au), 5.5g/t silver (Ag), as of December 2018. It is estimated to contain 8.2Moz of Au and 60.8Moz of Ag.
Mining and ore processing
Conventional open-pit mining method, using truck and shovel, will be used to mine the Blackwater deposit. Open-pit mining will continue for the first 14 years, following which the ore stockpiles will be the main feed through the life of mine.
Ore will be processed using conventional whole ore leach technique. Run-of-mine ore will be forwarded to the primary crusher of the processing plant and the resultant product forwarded to the coarse ore stockpile (COS).
The ore will be reclaimed from the COS and delivered to the two semi-autogenous grinding (SAG) mills, along with an associated ball mill and a dedicated cyclone cluster.
Leaching process starts with the grinding of ore with the recycled cyanide solution, following which the product will be classified, thickened, and forwarded to the leach circuit. Lime will be added to the leached product to maintain the pH value.
The resultant slurry will be forwarded to the CIP tanks for gold and silver adsorption. The loaded carbon will undergo pressure elution, electro-winning, and smelting to produce gold doré.
The project can be reached from Highway 16 through the Kluskus-Ootsa forest service road. Power supply will be provided from the BC Hydro Glenannan Substation through a 139.5km-long, 230kV transmission line.
Fresh water is proposed to be supplied from the Tatelkuz Lake, while the reclaim water recovered from air compressors, column heat exchangers, the thickeners, and the TSF will be used for the processing plant operations.
Workers and management personnel will be accommodated at the existing 250-person exploration camp, which will be expanded to accommodate up to 880 members.
Amec prepared the preliminary economic assessment report for the project as well as prepared the feasibility study report of the project. Amec partnered with Allnorth Consultants (Allnorth), GeoSim Services, Norwest Corporation, and Knight Piésold for the feasibility study.