What is nonferrous metals? What are the characteristics
Among the 107 known elements, there are different classification methods for the metals in each country. Some are divided into iron metal (ferrous Meta-ls) and non-ferrous metal (non-ferrous Metals) Two categories: iron and Ferroalloy, Nonferrous metals ferrous metal refers to ferrous and ferrous metals outside the iron. Some are divided into ferrous metals and non-ferrous metals two categories. Nonferrous metals refer to all metals, such as iron, chromium and manganese, Nonferrous metals three kinds of metals. In 1958, China included iron, chromium and manganese in ferrous metals, and 64 kinds of metals other than iron, chromium and manganese were added to non-ferrous metals. These 64 kinds of non-ferrous metals include: aluminum, magnesium, potassium, sodium, calcium, strontium, barium, copper, lead, zinc, tin, cobalt, nickel, antimony, mercury, cadmium, bismuth, gold, silver, platinum, ruthenium, rhodium, Palladium, osmium, iridium, beryllium, lithium, rubidium, cesium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, gallium, indium, thallium, Germanium, rhenium, lanthanum, cerium, Praseodymium, ND , Samarium, Europium, gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Scandium, yttrium, silicon, boron, selenium, tellurium, arsenic, thorium.
Historically, the materials used for production tools have been continuously improved and are closely related to the development of human society. Therefore, historians have used the material of utensils to mark the historical period, such as the Stone Age, the bronze, Nonferrous metals the iron and so on. By the end of 17th century by the human clear understanding and application of non-ferrous metals total 8 kinds. The Chinese nation has made significant contributions to the discovery and production of non-ferrous metals (see metallurgical history). Nonferrous metals After entering the 18th century, the rapid development of science and technology has promoted the discovery of many new non-ferrous metal elements. The above 64 kinds of nonferrous metals have been discovered in 18th century, in addition to 8 kinds of applications which were recognized before 17th century. 19th century discovered 39 kinds, enters 20th century, also discovers 4 kinds.
Energy, information technology and materials are called the three pillars of contemporary civilization. Nonferrous Metals and their alloys are important components of modern materials, which are closely related to energy and information technology. According to 1981 World statistics, copper, aluminum, lead, zinc, nickel, tin, gold, Nonferrous metals silver 8 kinds of non-ferrous metals production is only steel production (700 million tons) 5.4%, but its output value to reach more than 50% of steel output value. Nonferrous Metals and ferrous metals complement each other, together constitute a modern metal system. Nonferrous metals are the basic materials and important strategic material for national economy, People's daily life and defense industry, scientific and technological development. Nonferrous metals The modernization of agriculture, industrial modernization, national defense and the modernization of science and technology are inseparable from non-ferrous metals. such as aircraft, missiles, rockets, satellites, nuclear submarines and other sophisticated weapons and atomic energy, most of the components or components required for cutting-edge technologies such as television, communications, radar, and electronic computers are made of light metals and metal in non-ferrous metals, Nonferrous metals and there is no such non-ferrous metals as nickel, cobalt, tungsten, molybdenum, vanadium, niobium, etc. The use of non-ferrous metals in certain uses, such as the power industry, is considerable. Now many countries in the world, especially the industrialized countries, compete to develop nonferrous metals industry and increase the strategic reserve of nonferrous metals. Nonferrous metals industry includes geological prospecting, mining, beneficiation, smelting and processing departments. In order to get 1 tons of non-ferrous metals, the ore is generally low in nonferrous metals, which are often mined into tons of minerals. So mine is the important foundation of developing nonferrous metal industry. In nonferrous metal ores, there are many kinds of metals symbiosis, so it is necessary to reasonably extract and recycle useful components and make comprehensive use of natural resources rationally. Many chemical products, such as rare metals, precious metals and sulfuric acid, are recovered in the process of handling non-ferrous ores or intermediate products as well as slag and soot. Non-ferrous Metal production process usually produces a large number of waste gas, waste water and waste residue, which contains a variety of useful components, sometimes containing toxic substances, some non-ferrous metals are also toxic. Therefore, in the process of producing non-ferrous metals, we must pay attention to comprehensive utilization and environmental protection. In addition, Nonferrous metals compared with the production of steel, generally speaking, non-ferrous metal production needs more energy. According to statistics, such as from the production of iron per ton of steel consumption of 100, magnesium is 1127, aluminum is 767, nickel is 455, copper is 352, zinc is 206. Therefore, in the non-ferrous metal industry, the problem of reducing energy consumption is very prominent.
In the process of mining, beneficiation, smelting, processing and recycling of nonferrous metals, there are many kinds of extraction methods to be selected. As far as smelting process is concerned, Nonferrous metals it is usually divided into fire metallurgy, hydrometallurgical metallurgy and electric metallurgy. Fire metallurgy generally has the ability to deal with fine ore, can use the sulfur in sulfide ore combustion heat, can economically recover precious metals, rare metals and other advantages, but often difficult to achieve good environmental protection. Hydrometallurgy is often used to deal with polymetallic ores, low-grade ores and refractory ores, while electric metallurgy is suitable for the production of more active metals such as aluminum, magnesium and sodium. Nonferrous metals These methods are intended to be used or used in combination with the selected mineral composition. In order to strengthen the smelting process of nonferrous metals, the development of a series of new technologies, new methods and equipment, such as high-pressure leaching, fluidized roasting, organic solvent extraction, ion exchange, metal heat reduction, regional melting, vacuum metallurgy, Jet metallurgy, plasma metallurgy, chlorinated metallurgy and continuous casting, such as static pressure processing, diffusion welding, Superplastic molding, etc., greatly enriched the theory and technology of metallurgy, and continuously promoted the development of non-ferrous metal production.
Non-ferrous metals are mostly used after processing, so how to reasonably and effectively produce good performance, inexpensive non-ferrous materials to achieve the greatest social and economic benefits, is a very important issue. Along with the progress of science and technology and the development of national economy, Nonferrous metals the new requirements for the quantity, variety, quality and cost of nonferrous materials are constantly put forward, which not only require better performance of structural materials and functional materials, but also chemical composition, physical properties, microstructure, Crystal State, processing state, surface and dimensional accuracy as well as product reliability, stability and other requirements are increasingly high. In general, Nonferrous metals the production of non-ferrous materials is becoming large-scale, continuous, automation, standardization of the direction of development, which requires high-precision, high reliability of technology, equipment, control technology and finished product testing technology. Some new materials, such as semiconductor materials, composites, superconducting materials, new technologies such as powder metallurgy, surface treatment, etc. have been formed or are being developed into a technology field.