The Camino Rojo gold-silver project is located near the town of San Tiburcio within the southern portion of the Concepci?n del Oro district in the northeastern part of Zacatecas State, Mexico.
The Mesa Central region near San Tiburcio has experienced many periods of exploration and mining since the Spaniards. Recent exploration activity led to the discovery, exploration and development of the Pe?asquito gold-silver-lead-zinc mine owned by Goldcorp.
Camino Rojo was discovered in 2007 by two Canplats geologists. Goldcorp acquired Canplats Resources in early 2010.
The project will be developed using conventional truck and shovel open pit mining technology involving contractor mining.
The pit was estimated to contain containing 74.9 Mt of mineralized material grading 0.71 g/t gold and 14.2 g/t silver at a stripping ratio of 0.70 tonnes of waste per tonne of material processed.
Gold and silver would be recovered from the oxide and transition material by employing heap leaching technology at a treatment rate of 20,000 tpd.
The precious metal recovery circuit is designed to process approximately 123,000 ounces of gold and 755,500 ounces of silver annually over a mine life estimated at 11 years.
Situated 50 km southeast of Goldcorp?s Penasquito mine the Camino Rojo would become a low cost satellite operation that will augment Penasquito?s production.
The Camino Rojo property is situated approximately 206 kilometers northeast of the state capital city of Zacatecas near the town of San Tiburcio within the southern portion of the Concepcion del Oro, Mexico. The town of San Tiburcio is situated at 1,890 m altitude and has about 500 inhabitants.
Mexico is a federation comprising thirty-one states and a Federal District, the capital city. Zacatecas is a state located in northern Mexico ? Nahatl, a group of indigenous people named the region Zacatlan and its inhabitants Zacatecas. Spanish conquistadores discovered the first rich mines in 1546 and founded the city of Zacatecas. Historic silver production estimates exceed 750 million ounces for the Zacatecas district.
The colonial centre of the city was declared a UNESCO World Heritage site and is a major touristic attraction. The region's main economic activities are mining, agriculture and tourism.
The Camino Rojo deposit was discovered in 2007 by two Canplats geologists that were driving a gravel road near San Tiburcio when they saw gossanous red gravel along the shoulder of the road. They returned to San Tiburcio and inquired where the source was for the local road building material. When told, they found a quarried ?borrow? pit approximately 500 m off the road that had exposed highly fractured and hematitized limy siltstone-sandstone bedrock, now called the ?Represa? zone.
There are numerous gravel roads within the Camino Rojo property linking the surrounding countryside with the two highways, Highways 54 and 62, which transect the property.
The elevations within the property range from approximately 1,850 to 2,460 m a.s.l. and relief is low.
The climate is typical of the high altitude Mesa Central, dry and semi-arid. Annual precipitation for the area is approximately 700 mm, mostly during the rainy season in June and July. Temperatures commonly range from +30 deg to 20deg C in the summer and 15 deg to 0 deg C in the winter.
The vegetation is dominantly scrub bushes with cacti, maguey, sage and coarse grasses with rare yucca. The natural grasses are used to locally graze domestic livestock. Wild fauna is not abundant but several varieties of birds, rabbits, coyote, lizards, snakes and deer reportedly inhabit the area
The Camino Rojo property is situated in the southern half of the Concepci?n del Oro district at the possible junction of the regional northwesterly striking Caopas horst with the projected extension of the north-south trending San Carlos graben. It is in an area with very poor bedrock exposure, which may account for its mineralization not being recognized until recently.
The gold-silver-lead-zinc mineralization within the Represa zone on the Camino Rojo property appears to be intrusive-related, similar in metallogenesis to the Penasquito deposit and others in the Concepcion del Oro district. Intrusive-related gold (+ silver, lead, zinc) mineralization, as fracture filling veins and veinlets with accompanying propylitic to phyllic alteration of the host rocks, commonly occurs peripheral to subvolcanic plutons in the transitional setting between subvolcanic porphyry and epithermal systems.
Gold- and silver-bearing oxide and sulphide mineralization at the Represa zone is dominantly controlled by steeply dipping shears and fractures cutting the calcareous metasedimentary country rocks.
Mineral resources were estimated at 74.9 Mt grading 0.71 g/t gold, 14.2 g/t silver, 0.256% lead and 0.373% zinc.
Mining & Operations
The Camino Rojo project will be developed using conventional truck and shovel open pit mining technology involving contractor mining. It has been anticipated that the primary production equipment in the contractor?s mining fleet will consist of 14.3 cubic metre hydraulic excavators operating in backhoe configuration paired with 91 tonne capacity haul trucks.
Stripping ratio was estimated at 0.70 tonnes of waste per tonne of material processed.
Ore will be drilled and blasted on 5 m high benches, while waste will be drilled and blasted on 10m high benches. Blasting will be performed using bulk ANFO (ammonium nitrate fuel oil) at powder factors in the range of 0.20 to 0.40 kg/t.
The open pit will operate 24 hours per day; 365 days per year with a five day allowance for bad weather and major holidays.
The waste storage area will be located east and adjacent to the open pit. A separate area will be devoted to topsoil storage near the waste storage area, with this material used during surface reclamation activities. Lower grade stockpile(s) will be located in the vicinity of the primary crusher.
Mineralized material for the Camino Rojo project has been classified into Oxide, Transition and Sulphide zones.
The conceptual processing route chosen to recover gold and silver from oxide and transition material involves heap leaching at a treatment rate of 20,000tpd.
The process comprises of a crushing plant supplying feed material to the heap leach processing circuit. Processing considers a primary gyratory crusher will reduce the run-of-mine (ROM) feed size to a P80 of 120mm. Primary crushed material will be stockpiled on a coarse ore stockpile and reclaimed by apron feeders. Secondary and tertiary crushing will reduce the size of material to a nominal minus 100% passing 19mm (?"). Fine crushed material will be screened and fed to a fine ore bin. Material will discharge the fine ore bin through dump gates onto a conveyor where lime is added before feeding into the truck loadout bin. Material will discharge from the truck loadout bin into 91t haul trucks and transported to the heap leach pad where it will be stacked.
The heap leach pad consists of a prepared sub-base surface and a double liner system (geomembrane and clay/geosynthetic clay liner (GCL)). A crushed ore drainage layer with perforated pipe forms the drainage system on top of the liner to enhance drainage and recovery of pregnant leach solution.
The leach pad is loaded by haul trucks which end dump to form 11 metre thick lifts. Barren process solution is applied over a 45 day primary leach cycle. During steady state operation with the 45 day primary leach cycle, a total of approximately 900,000 tonnes is under primary leach (single lift basis). Secondary leaching, tertiary leaching, etc., occurs in the lower lifts as the leach pad is loaded in multiple lifts. Buried drip emitters are used to minimize evaporation losses and reduce surface ponding
Gold and silver will be leached using sodium cyanide solution. The gold and silver will then be recovered from pregnant leach solution in a Merrill Crowe plant. Zinc precipitate will be mixed with fluxes and smelted to produce silver-gold dor?, the final product from the processing facility.
The precious metal recovery circuit is designed to process approximately 123,000 ounces of gold and 755,500 ounces of silver annually.