South Railroad oxide gold project, owned by Gold Standard Ventures, is an open-pit gold mine located in Nevada, US.
Pre-feasibility study of the South Railroad project was completed in October 2019, which estimated a capital cost of £157m ($194m) for development. Construction is expected to be started in 2021, with commercial production scheduled for 2022.
The South Railroad project is expected to produce 116,000 ounces (oz) of gold and 205,000oz of silver a year, through its mine life of approximately eight years.
South Railroad oxide gold project location, geology, and mineralisation
The South Railroad oxide gold project is a part of the Railroad Pinion property, which also includes the North Railroad gold project. The Railroad Pinion property is situated in the Bullion mining district in Carlin trend in Nevada.
The site is located 442km to the west of Salt Lake City and 467km to the east of Reno and can be reached through the U.S. Interstate 80. Located between 13km and 29km south of I-80, it is accessible by a series of paved and gravel roads from Elko, Nevada.
The property has Carlin-type gold mineralisation in its deposit areas. The mineralisation predominantly is in the form of finely disseminated, submicroscopic gold in stratiform bodies in Mississippian, Devonian, and Pennsylvanian-Permian rocks.
South Railroad oxide gold project reserves
The proven and probable reserves of the South Railroad project are 47.3Mt, graded at 0.82g/t of gold, while contained gold is estimated to be 1.25 million ounces (Moz).
Mining and ore processing
Conventional open-pit mining method using truck and shovel operations will be used at the South Railroad oxide gold project.
Run-of-mine (ROM) ore from the deposit will be sent to the heap leach facility through trucks. The heap leach facility will comprise a three-stage crushing circuit, agglomeration and leaching facilities, and a dedicated leach pad. High-pressure grinding roll (HPGR) will be used as part of tertiary crushing.
Oxide and transition materials will be leached in a heap leach pad using dilute cyanide solution and the resultant pregnant leach solution (PLS) will be processed in an ADR (adsorption, desorption, and recovery) plant.
Gold and silver will be adsorbed onto activated carbon at the ADR plant, followed by stripping using a desorption process. The recovered product will be then conveyed to electro-winning circuit to produce a precipitate sludge.
The precipitate sludge will be further processed in a retort oven for drying and mercury recovery. The resultant product will be refined in a melting furnace to produce gold and silver doré bars.
The project site can be accessed from Highway-278 through a dirty road followed by an existing 10-mile access road. The site entrance will be located around 20 miles to the south of Carlin.
Power supply for the site will be provided by Wells Rural Electric Company (WREC) in Carlin, Nevada, via its existing supply line along Highway 278.
The site has buildings such as administration, security, ADR plant, and truck shops.
M3 Engineering and Technology (M3) led a group of consultants for preparing the PFS technical report for the South Railroad project.
The consultants group included MDA, Stantec Consulting Services, Kappes, Cassiday & Associates, GL Simmons, The Mines Group, EM Strategies, Golder Associates, Barr Engineering, and NV Energy.