1. Introduction to Metallurgy METL 1301
A History of Metals
Lecture1
Introduction to Metallurgy METL 1301

2. Metallurgy
The art and science of extracting metals from their ores and modifying those metals for use.
Metallurgy usually refers to commercial rather than laboratory methods.

3. Element
Each of more than 100 substances that cannot be chemically broken down into simpler substances.
The atoms of each element is distinguished by its atomic number.
The atomic number of an atoms is determined by the number of protons in its nucleus.

4. Atom
The basic unit of a chemical element.

5. Iron Atom

6. Periodic Table

7. Ore
A naturally occurring solid material from which a metal or valuable mineral may be mined and treated for extraction of any of its components, metallic or otherwise for profit.

8. Gold Ore

9. How gold can be produced
Supplementary

10. Copper extraction-demonstration
Supplementary

11. Mineral
A naturally occurring inorganic substance, usually a solid material of crystalline structure, representable by a chemical formula.
Minerals usually have a consistent and distinctive set of physical properties (color, hardness, crystalline structure).

12. Organic Compounds
Compounds of natural matter with a carbon base, related to, or derived from living things.
Note or pertains to a class of chemical compounds that formerly comprised only those existing in or derived from plants or animals, but now includes all other compounds of carbon.
Compounds of carbon (organic compounds) form the physical basis of all living organisms.

13. Organic Compounds
Some textbooks define an organic compound as one that contains one or more C-H bonds.
Other textbooks include C-C bonds in the definition.
Still others state that if a molecule contains carbon, it is organic.

14. Inorganic compounds
Inorganic compounds are traditionally viewed as being synthesized by the agency of geological systems.
In contrast to inorganic compounds, organic compounds are found in biological systems.

15. Inorganic compounds
The distinction between inorganic and organic compounds is not always clear.
Organic chemists traditionally refer to any molecule containing carbon as an organic compound.
By default inorganic chemistry deals with molecules lacking carbon.

16. Metallurgy
Metallurgy is concerned with the chemical, physical, and atomic properties and structures of metals.
Metallurgy is inclusive of the principles by which metals are combined to form alloys.

17. Alloy
An alloy is a substance that has metallic properties and is composed of two or more chemical elements of which at least one is an elemental metal.

18. Ancient Metals Most metals occur naturally as minerals or compounds.
One of the primary task of the metallurgist is to extract the metal from the compound.

19. Native Metals
The few metals found in an un-reacted state are termed native metals.
Ores which were over 99.9% pure were found in many parts of the world.
The six native metals used by ancient man were: Gold, Silver, Copper, Tin, Lead, and Iron.

20. Early Man’s use of Native Metals
Gold and silver was too soft to be useful for much except decoration.
Man discovered that copper could be hardened by hammering or forging and made useful as tools, but of little value as weapons. (hence the copper Age was born)

21. Early Man’s use of Native Metals
Lead was soft, easily worked and and could be made into vessels, and later in history was made into pipes such as was used in the Roman Empire.

22. Hammering or Forging Is frequently termed cold working.
The process of shaping copper at elevated temperatures (~300oC [~572oF]) did not significantly increase the strength of the copper.

23. Heat Treatment
Metal fabricated at elevated temperatures have different properties than metal fabricated at low temperatures.
The difference in the behavior of a metal processed at elevated temperatures and that of a metal processed at near ambient temperature remains an important factor in the shaping of metals and alloys today.

24. Cold Work
The Introduction of permanent strain by an external force in a metal below its recrystallization temperature.

25. Strain
An indication of how much a material has been stretched (or compressed) when compared to its original length.
The most common measure of strain in metals is called engineering strain, which is calculated as the change in length divided by the original length.

26. Recrystallization
Recrystallization can be defined as the process in which destroyed grains of a crystal structure are replaced by the new strain free grains.

27. Recrystallization Temperature
The minimum temperature at which complete recrystallization occurs in an annealed cold-worked metal within a specified time.

28. Anneal
Heat and allow to cool slowly, in order to remove internal stresses and toughen.

29. Early Metallurgy
By 3000 B.C. ancient metallurgist had learned to intentionally mix ores of copper and tin to produce bronze which is very similar in composition to some modern alloys.
The alloys which were made from intentionally mixed ores marked the real onset of the Bronze Age.

30. Early Metallurgy
Mankind now had a metallic alloy which could be cast (i.e., poured as a liquid) or forged (hammered) to shape.
Bronze alloys was significantly stronger than relatively pure copper and was useful both as tools and weapons.

31. Ancient Metallurgy
Ancient metallurgist must be given credit for the following metallurgical facts:
Metal (in this case copper) could be strengthen by hammering.
Metals could be extracted from ores.

32. Early Copper Extraction
Between 3000 and 4000 B.C. it was discovered that copper could be obtained by heating covellite, malachite, and other bright blue stones or minerals.
The bright blue stones or minerals were primarily copper sulfide ores.
The metallic component of copper sulfide minerals is copper, Sulfur is one of the nonmetallic components

33. Covellite

34. Malachite

35. Copper Containing Ores
As the supply of native deposits depleted, early metallurgist were forced to turn to the extraction of metals from ore deposits to obtain the supply of copper.
Typical copper ores used for extraction were sulfides, meaning that the copper had reacted with sulfur to form various compounds.

36. Copper Containing Ores
A typical copper-containing sulfide mineral is Bornite which contains copper(Cu), Iron(Fe), and sulfur(S) in the ratio of five copper atoms to one iron atom to four sulfur atoms designated as Cu5FeS4.

37. Bornite

38. The Discovery of Bronze
Bronze, which was developed by alloying copper with tin, had useful strengths, and could be cast to shape.
The discovery of bronze significantly altered the development of civilization.

39. Bronze
A copper-rich, copper-tin alloy with or without small proportions of other elements such as zinc and phosphorus.

40. Bronze

41. The Bronze Age The metallurgical facts that:
Copper could be extracted from copper sulfide ores.
That the mixture of two metals were frequently stronger than either metal taken individually, probably being discovered around the same time.
Lead to the beginning of the Bronze Age

42. The Bronze Age
That period of ancient human culture characterized by the use of bronze that began between 3000 and 4000 b.c

43. The Bronze Age
The Bronze Age was the second part of a three-age system (Stone Age, Bronze Age, and the Iron Age)
The Bronze Age was that period during which a particular cultures most advanced metalworking was in the use of bronze.

44. Availability of Raw Materials
Before metallurgy could emerge as an art or science, ancient metallurgist had to become aware that the supply of raw materials could not be limited to native metals.

45. What Is a Metal?
A basic definition centers around the type of bonding existing between the atoms of the elements.
And the characteristics of certain of the electrons associated with the atoms.
In a more practical way, metals can be described by their particular package of properties.

46. What Is a Metal?
The distinction between a metal and a nonmetal is not always clear.
A metal is defined as an opaque, lustrous elemental chemical substance that is a good conductor of heat and electricity, and when polished, a good reflector of light. (according to the official ASM International’s definition)

47. What Is a Metal?
Metals are crystalline when in the solid state and solid at ambient temperatures (with the notable exception of Mercury).
Metals are good conductors of heat and electricity, and are opaque to light.
The force required to cause this deformation and the force required to finally break or fracture the metal are comparatively high.

48. What Is a Metal?
Metals usually have a comparatively high density, and many metals exhibit ductility.
Ductility means that the shape of metals can be changed permanently by an applied force without breaking.

49. Common Metallic Crystal Structures

50. Extractive Metallurgy
Metals are extracted from crude ore in two phases, mineral processing, (also known as ore dressing) and process metallurgy.
In mineral processing, the ore is broken down to isolate the desired metallic elements from the crude ore.
In process metallurgy, the resulting minerals are reduced to metal, alloyed, and made available for use.

51. Iron Ore

52. Branches of Extractive Metallurgy
Mineral Processing is the process of separating valuable minerals from their ore.
Pyrometallurgy is the extraction of metal from ores by chemical reaction at high temperatures in fuel-fired furnaces.
There is much overlap in this industry. Mineral Processing tends to be more the physical method of extraction. Most aluminum is extracted from its ore by electrometallurgy

53. Branches of Extractive Metallurgy
Hydrometallurgy is the leaching or removal of metal from an ore body by passing a strong acidic or alkaline solution over the ore.
Electrometallurgy involves the extraction of metals from their ore by the application of large amounts of electrical energy.

54. Smelting
Thermal processing wherein chemical reactions take place to produce metal from a beneficiated ore.