Acoquiza mine

View of the Acoquiza mine and smelting plant

The Acoquiza mine is a copper mine located on Mount Yaotachcauh in western Xallipan, Zacapican. It is the largest mine in Xallipan and one of the largest in Zacapican, employing some 7,000 miners and supporting a community of roughly 23,000 people in the nearby town of Netemachico, built in 1940 to house the workers and their families. Unlike other porphyry coppers which are typically mined with an open pit, Acoquiza is an entirely underground mine consisting of a network of some 3,300 kilometers of tunnels and underground drifts, the deepest of which is 550 meters below the surface which is itself at 2,800 meters above sea level. An expansion project has been underway at the time since 2016, aiming to deepen the mine to 700 meters below the adit level, or some 2100 meters above sea level.

Acoquiza produces a staggering 120,000 metric tons per day on average. This ore is processed in the on-site smelting plant into copper metal. In the year of 2022, some 450,000 tons of copper metal was smelted at Acoquiza and exported off the mountain by rail to Cuauhuatzal some 100 kilometers to the south where it is transferred to the standard gauge network for transport to the factories and ports of the Zacaco Republic. The Acoquiza mine is the largest mine in Zacapican in terms of the extent of its underground system of tunnels and shafts, and it is also one of the most productive copper mines in the world in terms of the weight of ore it extracts from Mount Yaotachcauh every year.

History

The origins of the Acoquiza mine are tied to the Xallan Gold Rush of 1921-1929, which had been triggered due to the chance discovery of gold nuggets in the Yoliliz River in 1920. That gold would later be attributed to the small amounts of gold which can occur in porphyry deposits such as the one under Mount Yaotachcauh. The mine itself was one of the first places to be prospected for gold as a result of the gold rush in late 1920. By 1921, a small mining operation had been established in the high valley on the slopes of Yaotachcauh, although the remoteness and lack of infrastructure of the locale prevented it from growing very large in these early years. As with other mining settlements of the gold rush, Acoquiza mainly discovered copper rich ores which when sold only barely enabled the mine to stay operational. Many of the original settlers would soon leave behind the inhospitable life of the high mountain slopes, settling in the milder Tzopilopan area instead. The major developments regarding the Acoquiza mine would only come after the Xolotecate era had ended. The mining community there would benefit from greater investment in the mining industry all across the Xallipan Republic which followed the 1939 completion of the Moyocoya Dam and the subsequent urban boom of the Tzopilopan valley. The main rail links to the mountainside would be built in 1941, the same year that the calpolli town of Netemachico was established to house the hundreds of new workers streaming into the area. As Zacapican industrialized, the copper which mines like Acoquiza were producing began to increase in value as factory towns like Tzopilopan began to prosper on the production of copper conductors, wires and other industrial components. This would drive the constant expansion of the mine and its accompanying residential town through the 20th century into the modern day.

Geology

Acoquiza sits above a major porphyry copper deposit within the extinct Mount Yaotachcauh volcano. Within its main ayers of copper sulfide minerals such as chalcocite and covelline near the surface overlying the primary mineralization zone containing bornite, chalcopyrite as well as iron pyrite formations surrounding the Yaotachcauh pipe. The ore body forms a ring 1400 meters across near the surface which narrows to 700 meters across at a depth of 300-400 meters below adit level.