Minas de Fonte Figueira

“Did you hear that rumbling?” a miner whispered, his voice barely audible above the rhythmic clang of metal against rock. We’re standing before the Minas de Fonte Figueira, once a vital source of tin and tungsten. Minas de Fonte Figueira operated from 1928 to the early 1970s. It saw peak production during the 1940s and 60s, extracting nearly three tons of ore monthly. The Minas de Fonte Figueira complex was a hive of activity for over 40 years, employing dozens of people. There were slow periods, of course. Financial and technical difficulties sometimes hampered exploration. The miners extracted cassiterite, the source of tin, and wolframite, the source of tungsten. Cassiterite, ranging in color from brown and black to yellow and red, has been used for centuries. It’s a key ingredient in metal alloys like bronze, brass, and solder. It also prevents corrosion and has applications in the chemical industry. Wolframite, black, brown, or reddish in color, is the source of tungsten. Tungsten finds use in lightbulb filaments, lubricants, electronic components, military weaponry, aerospace, nuclear industry, chemical and construction industries, and hard metal alloys for cutting and drilling tools. Minas de Fonte Figueira sits high up, between 795 and 940 meters above sea level. Imagine a vast underground network: seven levels spanning 40 meters wide and 1,000 meters long, with 300 meters actively explored. The mine consists of main galleries stretching hundreds of meters, interconnected by cross galleries every 20 meters. Ventilation shafts, spaced 50 meters apart, linked the different levels. These trapezoidal galleries, measuring about 2.2 by 2 meters, were the miners’ domain. The ventilation shafts, approximately 2 by 1 meters, were crucial for airflow. The work was arduous and dangerous. Explosives, nicknamed “pegas” by the miners, were used to blast through the rock. While explosions rocked one level, work continued on others. The extracted material was loaded onto trays and handcarts, later replaced by rail-mounted wagons. These were then transported to the shafts and lowered to the level below, eventually reaching the washing area for processing. The washing area involved crushing the extracted ore. Pieces larger than 12mm were further broken down before being ground with a sieve. This resulted in material smaller than 3 to 6mm, which was then processed in a “giga,” a type of mill. This separated the material into concentrate, tailings, and other byproducts. These were then hydro-classified and washed. Interestingly, the Minas de Fonte Figueira was ahead of its time in environmental consciousness. The wash water was treated and reused to minimize pollution.