金属铝简介（Introduction to metal aluminum）.doc

金属铝简介（Introduction to metal aluminum） Reading 337 comments 0: medium and small What can we think of when we hear the term aluminum? You may immediately think of aluminum products: aluminum POTS, aluminum basins, and so on. But have we ever wondered how aluminum was discovered? How is it produced? Where can I find the bauxite? What other USES does aluminum have? Does it hurt our body? Today we all share this knowledge. 1. Basic knowledge of aluminum -- light metals (density less than 4g/cm3) Element symbol: Al element Chinese name: aluminum Density: 2.702 melting point: 660.37 boiling point: 2467 Sound propagation rate in aluminum: 5000 (m/S) color: silver white Aluminum is very high in the earths crust, and above 7%, second only to oxygen and silicon, to third place. Aluminum, the worlds second largest metal, is second only to steel in volume and volume. In 1956, world aluminum production began to surpass copper and became the first non-ferrous metal. 2. The source of aluminum Aluminum is in the form of a combination of two or more elements, such as feldspar, mica, gaeling, bauxite, alum and so on. Aluminum is very reactive in its chemical nature, so it is rare to find aluminum in the state of the element in nature. There are more than 250 kinds of aluminum containing minerals, mainly bauxite, kaolin and alum. The most common is aluminum silicate and their weathering products ─ ─ clay (mainly containing aluminum and its chemical composition). Bauxite is a kind of ore which is mainly composed of alumina hydrate. Their physical properties and chemical properties vary greatly, so the mineral form of bauxite is divided into: 1. 3 water aluminum stone type 2, 1 water soft aluminum stone type 3, 1 water hard aluminum stone type 4, mixed type 3. Characteristics of aluminum Aluminium is light metals, nature is very lively, low melting point, so in the dry air immediately formation on the surface of aluminum thickness about 50 nanometers (billionths of a metre) or a nano den