Metals and their alloys are widely used in our daily lives. It is used to make machines, railways, motor vehicles, bridges, buildings, agricultural equipment, airplanes, ships, etc. Therefore, the economic development of a country requires the production of different amounts of metals. Few metals like gold, silver, mercury etc. are found free in nature. Most of the other metals are found in the Earth's crust in composite form, i.e., as compounds of various anions such as oxides, sulfides, hydrides, with this in mind, the recovery of metals from their ores is very much studied. Important. In this lesson, you will learn about some of the processes of extraction of metals from their ores, which are called metallic processes. Metals occur in nature in free form and in composite form.
Metals and Non metals:
Metals with low reactivity show little attachment to air, moisture, carbon dioxide or other non-metals present in nature. Such metals can remain in the basic or original (free) state in nature. Such metals are called "noble metals" because they exhibit minimal chemical reactions. For example gold, silver, mercury and platinum occur in the free state. Most metals, on the other hand, are active and combine with non-metals such as air, moisture, carbon dioxide, and oxygen, sulfur, halogens, etc. to form their compounds, such as oxides, sulfides, carbonates, hydrides, and silicates. That is, they occur in nature in the joint position. A naturally occurring material in which a metal or compound is formed is called a mineral. A mineral from which metals can be extracted economically is called ore. Ore is a mineral in which metals are present in appreciable quantities and from which metals can be economically corrected. The main active substances present in nature, especially in the atmosphere are oxygen and carbon dioxide. Large amounts of sulfur and silicon are found in the Earth's crust.
Sea-water contains large amounts of
chloride ions (derived from dissolved sodium chloride). Most fine metals are
highly electroprosthetic and therefore exist as ions. It is for this reason
that most of the important ores of these metals occur as (i) oxide (ii)
sulfides (iii) carbonates (iv) hyalides and (v) silicates. Some sulfide ore
undergoes oxidation to form sulfide. This explains the phenomenon of sulfate
ore. Exposure to rocky materials is always found in nature. These rocky or
earthy impurities that come with ore are known as gangue or matrix. India has a
large collection of minerals of some important metals like Iron, Manganese,
Aluminum, Magnesium, Chromium, Thorium, Uranium, Titanium and Lithium.
Mineral Sours :
They account for about a quarter of the world's known mineral resources. Genetic fuels (such as coal, petroleum and natural gas) account for more than 0%, while metallic minerals account for only 10% of the total mineral production in a year. In this section, we will list some common metals like Fe, Q, Egg, Zen, T, Al Sn, Pb and Na and some important minerals from their locations in India.
Aluminum is the most abundant metallic
element in the Earth's crust, occurring in a variety of aluminosilicates such
as clay, mica, and feldspar. The only ore of aluminum from which it is
profitable to make metal is bauxite. The bauxite is first liberated from silica
and iron (III) oxide impurities by sodium hydroxide (iron (III) oxide is
dissolved)) and then a little aluminum hydroxide (silica remains dissolved) by
solution. The cryolite, (Na +) 3 is dissolved in 1F6 3–, and is electrolyzed at
about 900C, using many graphite blocks as anodes and a
graphite bath as the cathode. The aluminum is discharged at the cathode and
collects at the bottom of the molten electrolyte as a liquid, from where it can
be closed and allowed to solidify. Oxygen develops at the anodes, which burn
slowly as carbon dioxide. Extraction of aluminum is only economical where cheap
electricity from water power is available. Low voltage is used to dissolve the
molten cryolite which acts as a solvent; Very high current density is used. One
theory assumes that aluminum oxide dissolves in al. The extraction of iron is
carried out in a blast furnace which can vary in size and can have a height of
25 to 60 m and a diameter of 10 m.
Aluminium :
It is made of steel, the interior is lined with firebricks. The true proportions of iron ore, limestone and coke are given at the top of the furnace by adjustment on the cone and per. Preheated air at a temperature of about 600 ° C is injected into the furnace through a number of pipes called tuares; Towers are fed from a ‘buzzing’ pipe surrounding the blast furnace. The blast furnace is provided with two tap holes that are connected to the clay; The molten iron is tapped from the lower one and the molten slag from the other. The production of iron is a continuous process and depending on its size, the blast furnace can produce 1000 to 1800 tons of iron every twenty hours. The radiation and reducing agent required for the smell of iron is obtained by the combustion of coke, the ascending temperature constantly increases as it passes through the ascending combustion gases. The reduction of iron oxide is completed by coke at a temperature of 1200 ° C and in the field of cementite, Fe 3C and graphite and enters the iron.
Other reactions also occur at high temperatures, for example silica is reduced to silicon and enters the iron as ferrosilicon. The molten metal either flows into the sand mold, when it is known as pig-iron, or is usually delivered in liquid form directly to the steel-producing plant. Slag is tapped as a liquid from the furnace and can be used in concrete or blown into ‘ool ni’ material and used for insulation. The hot gases emitted from the top of the furnace contain large amounts of carbon monoxide and are burned in a cooper stove to heat the air for an explosion.
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