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 Tlamamatlaco, built in 1941 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, crosscuts and galleries, 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 of ore 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 Tlamamatlaco 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 layers 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. The geological makeup of this particular porphyry copper deposit is typical for formations of this type. The rocks are the intrusive products of past volcanic activity from the relatively recent geological past, during the formation of the Xallipan Mixtepemec when Mount Yaotachcauh was an active volcano. The ring-shaped ore body is surrounding on both sides by internal and external formations of volcanic breccia with little to no content of industrial mineral ores.

Operations

The mine is under the direct control of the Acoquiza Calpolli Coalition, an industrial combine comprised of the Acoquiza miners calpolli, the smelter and metalworkers calpolli, and a small local calpolli of rail operators who oversee the mountain railway connecting the mountainside mine to the outside world. The Coalition is governed by the Acoquiza council, which is subdivided into the Big Circle which is open to all adult members of the community and the Little Circle which is made up of specially elected representatives, usually the deputies of a foreman in one of the calpolli. The Little Circle is responsible for electing a Warden, who serves as the chief law enforcement officer for Tlamamatlaco and the Acoquiza mine. All disputes within and between the calpolli over lodging, working conditions and compensation are handled by the Acoquiza council. Historically, the miners calpolli have pushed for greater proportional compensation for the mine workers compared to the smelters and especially the rail workers due to the especially dangerous work conditions down in the tunnels. This has spurred the creation of informal political factions within the Acoquiza Calpolli Coalition, representing surface workers and subsurface workers respectively in their competing interests. The Warden and Little Circle of the council are primarily concerned with preventing factionalism between these two interest groups from escalating to the point of disrupting the operation of the Acoquiza mine in good order.

Tlamamatlaco

The town of Tlamamatlaco

The town of Tlamamatlaco, literally the "Place of Staircases", was built through funding released by the Xallipan government for the development of the mine which included both the construction of a proper rail connection up the mountainside as well as the foundation of Tlamamatlaco as a workers village to house what was expected to be hundreds of new workers that would move to the site. This was necessary due to the remote location of the mine which made it impractical for the workers to commute from any of the existing nearby communities. The earliest housing, completed in 1941, consisted of two buildings divided into small dorm-style accommodations for the population of male workers. Many of the workers were migrants who had traveled without their families to work at the mine. The lack of family housing was a pressing issue within a few years of the mine's redevelopment, as many of the workers began to campaign for their families to be relocated to the mountainside. New apartments with accommodations for whole families would be built in 1945, which would set off a cascade of additional projects to turn the small workers village into a fully functional community with all the necessary amenities to support the growing number of workers and their families. A combination Nemachtilcalli-Nemachtiloyan school building was built in 1947 alongside the city's central hospital which was specially equipped to handle potential casualities from accidents in the mine as well as treat the long term health effects which the miners would inevitably experience. Two public parks and a playground for the town's newfound population of children would be built in 1949.

The central staircase

The city was named after its main peculiarity, its central staircase and peripheral staircase network extending from the Acoquiza-Tlamamatlaco railway station serving the mine's freight needs as well as the passenger needs of the town. Tlamamatlaco operates an entirely pedestrian system of streets and staircases for the movement of its citizens. Wheeled vehicles and streets to accommodate them were rejected because of the very steep slope upon which the town was built, as well as the harsh winter conditions would would make transportation by car or truck impractical at best and dangerous at worst. Because the planners did not anticipate that the town would grow beyond 30,000 citizens, there was never a need to expand the town's transit network to anything beyond the pedestrian accommodations which had been made.

The town is under significant threat from avalanches triggered by earthquakes and explosions in the mine. A system of catchment basins and slides has been built to help mitigate the danger posed by avalanches after a disastrous avalanche in 1956 killed 20 residents of the town including 4 children. This has only served to somewhat reduce the severity of any avalanche towards the town, and active monitoring of the slopes and at times, pre-emptive triggering of an avalanche using explosives is called for in order to prevent any reoccurrence of the 1956 disaster.