SMM Network News:
The Caylloma mine is located in the Caylloma region of southern Peru, about 225km from Arejipa (Arequipa).
Holding company: Caylloma is 100 per cent owned by Fortuna Silver Mines (formerly known as Fortuna Ventures).
The earliest mining activities recorded in the Caylloma area can be traced back to the mining activities of Spanish miners in 1620. British miners had activities in the late 19th and early 20th centuries. Many companies have been involved in the mining of the Caylloma area, but the detailed records are limited.
Caylloma was acquired in 1981 by Compania Minera Arcata (CMA), a wholly owned subsidiary of Hochschild Mining. Fortuna acquired the mine from CMA in 2005.
Minerals are located in the historic mining area of Caylloma, in the northwest of the Caylloma volcanic mortar complex and in the southwest of the Chonta volcanic mortar complex. The main rock in Caylloma area is volcanic rock, which belongs to Tacaza formation. Mineralization is a low to moderately sulphide superthermal vein system.
The mine includes mining concessions, surface rights, licensed flotation plants, connections to the national grid, camp facility licences for 890 workers and the maintenance of infrastructure required for mining operations.
Products: silver / gold / lead / zinc.
Geology / mineralization
The main feature of Caylloma is a series of fault vein structures, from northeast to southwest.
There are two different types of mineralization-silver-dominated veins and polymetallic veins dominated by silver, lead, zinc, copper and gold.
A shallow oxide deposit has been identified, containing secondary minerals such as silica mica, pyrolusite, goethite, hematite, chalcopyrite, indigo copper ore and Jiguan stone. The oxidation zone is very thin and there is no evidence of secondary silver enrichment.
Hydrothermal alteration of quartz-feldspar quartz-Illite and Qingpan lithofacies has been found by Caylloma. Quartz alteration is limited to the edge of the vein, and the thickness of the alteration area is usually proportional to the thickness of the vein. The width ranges from a few centimeters to a few meters. Quartz replaces the volcanic matrix in the rock, while quartz and feldspar are small veinlets. Pyrite is distributed in iron and manganese minerals in wall veins and wall rocks. Illite is the product of matrix alteration of plagioclase and volcanic rocks. Quartz ice feldspar does not exist in the upper part of the vein system. The alteration assemblage in the upper region is composed of the narrow edges of quartz Illite near the vein. Quartz Illite is quartz ice feldspar in the depth. The change of Qingpan is widespread in the whole region, which may be regional and may have nothing to do with mineralization events. The change of Qingpan is a fine aggregate of chlorite, epidote, calcite and pyrite.
Reserves: the confirmed and approximate reserves as at 30 June 2014 are estimated at 3.03 million tons with grades of 189g / t silver and 1.15g / t gold.
Resources: identified and controlled resources as at 30 June 2014 are estimated at 1.7 million tons with a grade of 76 g / t silver, 0.31g / t gold, 0.95 per cent lead and 1.88 per cent zinc. It is inferred that the amount of resources is 4.36 million tons, silver content is 133g / ton, gold content is 0.59g / ton, lead is 1.98%, zinc is 3.17%.
Mining method: upward filling mining.
Major infrastructure and equipment:
Caylloma has a well-established infrastructure to maintain operations. The infrastructure includes roads, 1300 tons / day tailings treatment facilities, mine waste treatment facilities, ore yards, camp facilities, concentrate transport of 30 tons of trucks, power generation and communication systems.
Caylloma's team successfully transferred mining to the high-grade polymetallic Animas vein. Zinc and lead production have increased by 42 per cent and 51 per cent, respectively, compared with 2014, and mining has focused on regional planning for higher operating margins.