Search results
Results from the WOW.Com Content Network
Tin is an essential metal in the creation of tin- bronzes, and its acquisition was an important part of ancient cultures from the Bronze Age onward. Its use began in the Middle East and the Balkans around 3000 BC. Tin is a relatively rare element in the Earth's crust, with about two parts per million (ppm), compared to iron with 50,000 ppm ...
Mining Concession C-18 Panasqueira. Minas da Panasqueira or Mina da Panasqueira (English: 'Panasqueira mine') is the generic name for a set of mining operations between Cabeço do Pião (Fundão municipality) and the village of Panasqueira (Covilhã municipality), which has operated in a technically integrated and continuous manner practically since the discovery of ore there.
Most of the wolframite mines in Europe, such as the Barruecopardo mine, are in northwestern Spain and northern Portugal. [ a ] The high demand for this scarce strategic mineral in war time had created a bubble in prices, with the otherwise desolate post- Civil War Spanish economy heftily profiting from it, as its income from tungsten exports ...
Early tin exploitation appears to have been centered on placer deposits of cassiterite. [3] Map of Europe based on Strabo's geography, showing the Cassiterides just off the northwest tip of Iberia where Herodotus believed tin originated in 450 BC. The first evidence of tin use for making bronze appears in the Near East and the Balkans around ...
In its raw form, tungsten is a hard steel-grey metal that is often brittle and hard to work. Purified, monocrystalline tungsten retains its hardness (which exceeds that of many steels), and becomes malleable enough that it can be worked easily. [18] It is worked by forging, drawing, or extruding but it is more commonly formed by sintering.
Wolframite is an iron, manganese, and tungstate mineral with a chemical formula of (Fe,Mn)WO4 that is the intermediate mineral between ferberite (Fe2+ rich) and hübnerite (Mn2+ rich). [4] Along with scheelite, the wolframite series are the most important tungsten ore minerals. Wolframite is found in quartz veins and pegmatites associated with ...
This list of mines in Portugal is subsidiary to the list of mines article and lists working, defunct and future mines in the country and is organised by the primary mineral output. For practical purposes stone, marble and other quarries may be included in this list.
Mining in Portugal is regulated by the Portuguese Ministry of Economy and the Geology and Energy Resources authority under the state-run research institute INETI. Mining activities have continued since the pre- Roman era, when most of the region was known as Lusitania. Gold was once mined. The country remains among the largest European ...