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
Melchior (alloy) Melchior (alloy) In metallurgy, melchior is an alloy of copper, mainly with nickel (5–30%). Its name originates from , which in turn is distorted , honoring the French inventors of the alloy, Maillot and Chorier. The term melchior sometimes refers not only to the copper-nickel alloys, but also ternary alloys of copper with nickel and zinc ("nickel silver") and even a silvered brass. Melchior is easily deformable by application of pressure, both in the hot and cold state. After annealing, it has a tensile strength of about 40 kg/mm. The most valuable property of melchior is its high resistance to