Metallurgical terms of gold processing refer to a series of processing technologies and processes adopted to further improve the value of gold as a precious metal and expand its application as a special industrial material.
1. Gold is the basic form of chemical element gold (Au), which is a soft, golden yellow and corrosion-resistant precious metal. Gold is a rarer, more precious and more valuable metal. Generally speaking, the gold in the world is in ounces. In ancient China, "beam" was a very important metal. It is not only a special currency for reserve and investment, but also an important material for jewelry industry, electronics industry, modern communication, aerospace and other departments.
2. The chemical symbol of gold is Au, and the financial English code is XAU or gold. The name Au comes from the story of Aurora, the goddess of dawn in Roman mythology, which means bright dawn. As of 202112, the gold price is $0/760 per ounce.
It can produce a thin gold foil that can be easily rolled up. An ounce of gold can be hammered into a quarter of a million feet thick, covering an area of 65,438+000 square feet. The ancients hammered it into thin slices and made it into decorations for temples and palaces. All these can explain the flexibility and ductility of gold.
4. The color of gold is golden yellow, which is metallized and difficult to decompose. The density is 19.3g/cm3 and the melting point is1064.4℃; It has good ductility, can be pressed into thin foil, and has extremely high heat transfer and conductivity. The resistance of pure gold is 2.4P, and it has good chemical resistance, so it is the best electroplating material.
5. As a precious metal, gold has good physical properties. "Real gold is not afraid of fire" means that gold has high chemical stability and is not easy to react with other substances, so there is no need to worry about oxidation and discoloration. Even in the molten state, it will not be oxidized and discolored, and it will still be golden yellow after cooling. High density and heavy feel. It has good toughness and ductility and good electrical conductivity. Pure gold is bright yellow, but its color changes greatly when mixed with other metals such as dark red gold-copper alloy, light yellow or grayish white silver-containing alloy. Gold is easily ground into powder, which is why gold is dispersed in nature. Pure gold jewelry is also easy to wear and lose weight.
6. In Mendeleev's periodic table, the atomic number of gold is 79, that is to say, the nucleus of gold contains 79 positively charged protons. At the same time, gold has good chemical stability because of its semi-regularity. In the metal market, gold and ruthenium, rhodium, palladium, osmium, iridium, platinum and other metals are collectively called precious metals.
Although gold is a very soft metal, it is not as good as lead and tin. Nail prints can be painted on pure gold. This softness makes gold easy to process. But this is not ideal for accessories manufacturers, because it is easy to scratch the accessories, make them lose luster, and even affect the appearance. Therefore, when making jewelry, gold, copper and silver are generally added to improve the hardness of jewelry.
Gold is easy to forge and has strong plasticity. It can be ground into transparent green gold foil with a thickness of 0.00 1 mm, and 0.5g gold can be drawn into gold wire with a length of 160m.