London Metal Exchange (LME) is the largest non-ferrous metal exchange in the world. The price and inventory of LME have an important influence on the global production and sales of non-ferrous metals. /kloc-In the middle of 0/9th century, Britain was the largest producer of tin and copper in the world.
With the passage of time, the industrial demand is increasing, and Britain urgently needs to import a large number of industrial raw materials from foreign mines. Since the beginning of this century, the London Metal Exchange has publicly released its trading price, which has been widely used as the benchmark price of world metal trade. 70% of the global copper production is traded according to the official quotation published by the London Metal Exchange.
Nickel (niè), English name Nickel, is a transition metal element, with element symbol Ni, located in the eighth group of the fourth cycle, with atomic number 28. Nickel is a silvery white metal with good mechanical strength and ductility. Insoluble in water, very corrosive to acid and alkali, but soluble in dilute nitric acid and aqua regia. High temperature resistance, melting point1455 c, boiling point 2730°C, density 8.902g/cm_. Can be used to make money and so on. Plating on other metals can prevent rust.
Nickel plays an important role in the development of human material civilization. Because the melting points of nickel and iron are close, nickel was mistaken for good iron by the ancients. In ancient times, China, Egypt and Babylonia all used meteorites with high nickel content to make artifacts, and because nickel did not rust, it was also regarded as silver by Peruvian aborigines.
As early as 235 BC, China began to use nickel minerals to make coins, and white copper, that is, copper-nickel alloy, was invented and used by the ancients in China in 200 BC. In 175 1 year, Alex Frederic Kronst of Stockholm studied a new metal called nickel. He thought it contained copper, but he extracted a new metal, which was announced in 1754 and named nickel.
In the process of extraction, the alloy of cobalt, arsenic and copper appears as trace pollutants, which is mistaken for trace pollutants by many chemists. It was not until 1775 that Tobenberg made pure nickel and proved that it was an element. 1952 reported that there was nickel in animals, and later it was suggested that nickel was an essential trace element for mammals. 1975, the nutrition and metabolism of nickel were studied.