Metals are divided into two categories: ferrous metals and non-ferrous metals. Ferrous metals include iron, chromium, and manganese; non-ferrous metals refer to all metals other than iron, chromium, and manganese, roughly according to their density, price, reserves and distribution in the earth’s crust, and the time they are discovered and used by people The non-ferrous metals can be divided into the following five categories.
(1) Light non-ferrous metals: refers to non-ferrous metals with a density less than 4.5. Including aluminum, magnesium, potassium, sodium, calcium, strontium, and barium.
(2) Heavy non-ferrous metals: refers to non-ferrous metals with a density greater than 4.5. Including copper, lead, zinc, nickel, cobalt, tin, antimony, mercury, cadmium, bismuth, etc.
(3) Precious metals: refers to non-ferrous metals that are less in the earth’s crust, are difficult to mine and extract, are stable to oxygen and other reagents, and are more expensive than ordinary metals. Including gold, silver, platinum, palladium, osmium, iridium, ruthenium, and rhodium.
(4) Semi-metal: generally refers to the five elements of silicon, selenium, tellurium, arsenic and boron. Its physical and chemical properties are between metals and non-metals. For example, arsenic is a non-metal, but it can transfer heat and conduct electricity.
(5) Rare metals: Rare metals do not mean that they are scarce, but that they are not widely distributed in the earth’s crust, are difficult to mine and smelt, and are late in industrial application, so they are called rare metals. Including lithium, beryllium, rubidium, cesium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, rhenium, gallium, indium, germanium, thallium, etc.
Ferrous metals and non-ferrous metals together constitute a modern material system, which is an indispensable basic material and important strategic material for the national economy and people’s daily life, as well as the development of national defense industry and science and technology. The modernization of agriculture, industry, national defense, and science and technology cannot do without ferrous metals and non-ferrous metals. For example, aircraft, missiles, rockets, satellites, nuclear submarines and other cutting-edge weapons, as well as atomic energy, television, communications, radar, electronic computers and other cutting-edge technology required components or parts are mostly made of light metals and rare metals in non-ferrous metals; in addition, Without nickel, cobalt, tungsten, molybdenum, vanadium, niobium and other non-ferrous metals, there would be no production of alloy steel. The consumption of non-ferrous metals in certain applications (such as the power industry, etc.) is also considerable. Now many countries in the world, especially industrialized countries, are racing to develop non-ferrous metal industries and increase their strategic reserves of non-ferrous metals.
China is rich in non-ferrous metal resources, with a relatively complete variety. The reserves of metals such as tungsten and rare earths rank first in the world, and the reserves of metals such as lead, nickel, mercury, aluminum and niobium are also quite abundant. Among mineral resources, non-ferrous metals are a major advantage of China. China’s non-ferrous metal industry has developed rapidly, and has formed a production system with relatively complete varieties and relatively complete processes, from commonly used non-ferrous metals to rare metals. The mining, beneficiation, smelting, and processing of various non-ferrous metals in China are of considerable scale, providing important material guarantees for the rapid development of the national economy.