d.a.v public senior secondary school, rajpura

TOPIC:- METALLURGY

SUBMITTED TO:-Mrs. NIDHI BANSAL

SUBMITTED BY:- JATIN

CHOUDHARY

CLASS:- XTH A, ROLL NO:- 19

CONTENTMETALLURGYTYPES OF METALLUGYFERROUS METALLURGYMETEORIC IRONNATIVE IRON Iron smelting and the Iron AgeNON-FEROUS METALLURGYRecycling and pollution control

metallurgy Metallurgy is a domain of materials science and engineering that

studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. Metallurgy is also the  technology of metals: the way in which science is applied to the production of metals, and the engineering of metal components for use in products for consumers and manufacturers. The production of metals involves the processing of ores to extract the metal they contain, and the mixture of metals, sometimes with other elements, to produce alloys. Metallurgy is distinguished from the craft of metalworking, although metalworking relies on metallurgy, as medicine relies on medical science, for technical advancement. Metallurgy is subdivided into ferrous metallurgy (sometimes also known as black metallurgy) and non-ferrous metallurgy or colored metallurgy. Ferrous metallurgy involves processes and alloys based on iron while non-ferrous metallurgy involves processes and alloys based on other metals. The production of ferrous metals accounts for 95 percent of world metal production.

PROCEESS

Types of metallurgy

Ferrous Metallurgy

Meteoric iron

Native iron

Non-Ferrous Metallurgy

Recycling and pollution control

Ferrous metallurgy Ferrous metallurgy involves processes and alloys based on iron. It began

far back in-prehistory. The earliest surviving iron artifacts, from the 4th millennium BC in Egypt, were made from meteoritic iron-nickel. By the end of the 2nd millennium BC iron was being produced from iron ores from South of the Saharan Africa to China. The use of wrought iron was known in the 1st millennium BC. During the medieval period, means were found in Europe of producing wrought iron from cast iron (in this context known as pig iron) using finery. For all these processes, charcoal was required as fuel.

Steel (with a carbon content between pig iron and wrought iron) was first produced in antiquity as a South Indian alloy, its Wootz process of production exported before the fourth century BC to ancient China, Africa, the Middle East and Europe. Archaeological evidence of cast iron appears in 5th century BC China. New methods of producing it by carburizing bars of iron in the cementation process were devised in the 17th century. In the Industrial Revolution, new methods of producing bar iron without charcoal were devised and these were later applied to produce steel. In the late 1850s, Henry Bessemer invented a new steelmaking process, involving blowing air through molten pig iron, to produce mild steel. This and other 19th century and later processes have led to wrought iron no longer being produced.

Meteoric iron

Iron meteorites consist overwhelmingly of nickel-

iron alloys. The metal taken from these meteorites

is known as meteoric iron and was one of the

earliest sources of usable iron available to humans.

Iron was extracted from iron-nickel meteorites,

which comprise about 6% of all meteorites that fall

on the earth. That source can often be identified

with certainty because of the unique crystalline

 features of that material, which are preserved

when the metal is worked cold or at low

temperature. Those artifacts include, for example,

a bead from the 5th millennium BC found in Iran

 and spear tips and ornaments from Ancient Egypt

 and  Sumer around 4000 BC. Meteoric iron

 has been identified also in a Chinese axe head fro

m the middle of  the 2nd millennium BC.

These early uses appear to have been largely ceremonial or

ornamental. Meteoritic iron is very rare, and the metal was

probably very expensive, perhaps more expensive than gold. The

early Hittites are known to have bartered iron (meteoritic or

smelted) for silver, at a rate of 40 times the iron's weight, with 

Assyria.

Meteoric iron was also fashioned into tools in the Arctic,

beginning around the year 1000, when the Thule people of 

Greenland began making harpoons, knives, ulos and other edged

tools from pieces of the Cape York meteorite. Typically pea-size

bits of metal were cold-hammered into disks that were fitted

into a bone handle. These artifacts were also used as trade

goods with other Arctic peoples: tools made from the Cape York

meteorite have been found in archaeological sites more than

1,000 miles (1,600 km) away. When the American polar explorer 

Robert Peary shipped the largest piece of the meteorite to the 

American Museum of Natural History in New York City in 1897, it

still weighed over 33 tons. Another example of a late use of

meteoritic iron is an adze from around 1000 AD found in Sweden.

Native iron

Native iron in the metallic state occurs

rarely as small inclusions in certain basalt

rocks. Besides meteoritic iron, Thule people

of Greenland have used native iron from the 

Disko region

Iron smelting and the Iron Age

Iron smelting the extraction of usable metal from oxidized iron ores is more difficult than tin and copper smelting. While these metals and their alloys can be cold-worked or melted in relatively simple furnaces (such as the kilns used for pottery) and cast into molds, smelted iron requires hot-working and can be melted only in specially designed furnaces. Thus it is not surprising that humans only mastered the technology of smelted iron after several millennia of bronze metallurgy.

The place and time for the discovery of iron smelting is not known, partly because of the difficulty of  distinguishing metal extracted from nickel-containing ores from hot-worked meteoritic iron. The archaeological evidence seems to point to the Middle East area, during the Bronze Age in the 3rd millennium BC. However iron artifacts remained a rarity until the 12th

century BC.

The Iron Age is conventionally defined by the widespread use of steel weapons and tools, alongside or replacing bronze ones. That transition happened at different times in different places, as the technology spread through the Old World. Mesopotamia was fully into the Iron Age by 900 BC. Although Egypt produced iron artifacts, bronze remained dominant there until the conquest by Assyria in 663 BC. The Iron Age started in Central Europe around 500 BC, and in India and China sometime between 1200 and 500 BC.[8] Around 500 BC, Nubian became a major manufacturer and exporter of iron. This was after the Nubians were expelled from Egypt by the Assyrians, who used iron weapons.

ANCIENT IRON SMELTING AND IRON AGE MODREN IRON SMELTING AND

IRON AGE

Non-Ferrous metallurgy

Non-ferrous extractive metallurgy is one of the two branches of 

extractive metallurgy which pertains to the

processes of reducing valuable, non iron metals from ores or raw 

material. Metals like zinc, copper, lead, aluminium as well as rare and 

noble metals are particular interest in this field, while the more

common metal, iron, is

considered a major impurity. Like ferrous extraction, non ferrous extra

ction primarily focuses on the economic optimization

 of extraction processes in separating qualitatively and quantitatively 

marketable metals from its impurities  (gangue).

Any extraction process will include a sequence of steps or 

unit processes for separating highly pure metals from undesirables in

an economically efficient system. Unit processes are usually broken

down into three categories: Pyrometallurgy, Hydrometallurgy, and 

Electrometallurgy.

In Pyrometallurgy,

The metal ore is first oxidized through roasting or smelting.

The target metal is further refined at high temperatures

and reduced to its pure form. In hydrometallurgy, the object

metal is first dissociated from other materials using a 

chemical reaction, which is then extracted in pure form

using electrolysis or precipitation. Finally, electrometallurgy

generally involves electrolytic or electro thermal processing

. The metal ore is either distilled in a electrolyte or acid

 solution, then magnetically deposited onto a cathode plate

(electro winning); or smelted then melted using an electric

arc or plasma arc furnace (electrothermic

reactor). Extractive metallurgy of ferrous and non-ferrous

metals can involve Pyrometallurgy, but chemical processes

like hydrometallurgy and electrometallurgy are far more

common in method of non-ferrous extraction.

Another major difference in non-ferrous extraction is the

greater emphasis on minimizing metal losses in slag. This is

widely due to the exceptional scarcity and economic value

of certain non-ferrous metals which are, inevitably,

discarded during the extraction process to some extent.

Thus, material resource scarcity and shortages are of great

concern to the non-ferrous industry. Recent developments

in non-ferrous extractive metallurgy now emphasize the 

reprocessing and recycling of rare and non-ferrous metals

from secondary raw materials (scrap) found in landfills.

Recycling and pollution control

Due to its extensive use, non-ferrous scrap metal is usually recycled. The secondary materials in scrap are vital to the metallurgy industry, as the production of new metals often needs them. Some recycling facilities resmelt and recast non-ferrous materials; the dross is collected and stored onsite while the metal fumes are filtered and collected. Non-ferrous scrap metals are sourced from industrial scrap materials, particle emissions and obsolete technology (for example, copper cables) scrap.

T H A N X

F O R W AT C H I N G