Tin mining Dredging for ore off the islands shores has churned up sediment which has buried coral reefs where fish live and harmed the local fishing industry. This is despite a prohibition on mining in waters within four miles of Bangka’s shore. Tin mining Tin mining began early in the Bronze Age, as bronze is a copper-tin alloy. Tin is a relatively rare element in the Earth’s crust, with approximately 2 ppm (parts per million), compared to iron with 50,000 ppm. Tin extraction and use can be dated to the beginnings of the Bronze Age around 3000 BCE, when it was observed
2195 aluminium alloy 2195 aluminium alloy 2195 aluminium alloy is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It is one of the most complex grades in the 2000 series, with at least 91.9% aluminium by weight. Like most other aluminium-copper alloys, 2195 is a high-strength alloy, with bad workability, and poor corrosion resistance. Being highly alloyed, it tends to fall on the higher strength and lower corrosion resistance side. As a wrought alloy, it is not used in casting. It can be welded, and is fracture resistant at cryogenic temperatures. It is one of the Weldalite family of aluminum-lithium