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INTORDUCTION TO ANCIENT

METALLURGY

ANCIENT METALS METAL SYMBOL MPOC BPOC DENSITY GOLD Au 1060 2970 19.3 SILVER Ag 961 2210 10.5 COPPER Cu 1083 2695 8.92 LEAD Pb 327 1725 11.3 ZINC Zn 420 906 7.14 TIN Sn 232 2270 7.28 IRON Fe 1536 3000 7.86

STUDY OF ANCIENT METALLURGY

•  Formation of minerals •  Exploitation of minerals in antiquity •  Development of metallurgy •  Metal trade •  Impact of metal and metal trade on social,

economic and military history

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ORE SOURCE MINING ORES AND

STONES ORE

DRESSING

GONGUE

ORE

SMELTING

SLAG INGOT REFINING AND

CASTING THE CASTING

HOT AND COLD WORKING

FINISHED OBJECT

STAGES FROM ORE TO FINISHED METAL OBJECT Significant properties of metallurgy to ancient metal smiths

•  Color: (determined value) •  Luster: (determined value) •  Acoustics: (copper gongs, bells) •  Casting ability: (mass production) •  Hardness: (tool and weapons) •  Strength and malleability: (tools and weapons) •  Welding and soldering: (flexibility in construction) •  Recycling: (remelting)

STAGES IN THE DEVELOPMENT OF METALLURGY

Date BC •  First use of native copper 9500 •  First evidence for the extraction of metal (Pb) 6000 •  Lead glazing 5000 •  First copper object made by casting 5000 •  First alloys (Cu-As) 4500 •  First bronze (Cu-Sn alloy) 3200 •  First iron implements (meteoric) 2500 •  First evidence for iron smelting 1700 •  Full use of steel (carburizing & quenching) 800

ANATOLIA

CHINA

INDIA PALESTINE IBERIA

AEGEAN TROY

CENTRAL EUROPE

BRITISH ISLES

TRANS-

CAUCASIA

IRAN

MESOPO- TAMIA

SKANDI- NAVIA

DIFFUSION OF COPPER METALLURGY IN THE OLD WORLD

EGYPT

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DISTRIBUTION OF SOME METALS IN EARTH’S CRUST* 

Cu Ag Au Pb Sn

Surface Rocks 25 0.15 0.01 15 3.6

Continents 82 0.2 0.03 12 2.0

Basement rocks 120 0.3 0.04 6.0 0.9

In ppm

FORMATION OF SECONDARY ORES

DEVELOPMENT OF MINING •  Neolithic Age (>3500 BC): Quarries, open workings,

sloping shafts, gradual galleries •  Early Bronze Age (3200-2000 BC): Stripping of out-

crops, shafts with staircases •  Middle and Late Bronze Age (2000-1200 BC):

Timbering of shafts, drainage, wider galleries. •  Iron Age (1st millennium BC): Drainage exits, large

quarries, transportation, ventilation

FIRE SETTING

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ORE DRESSING

Ore dressing is the treatment of ores and mineral products by mechanical, physical or chemical means to separate the valuable minerals from the worthless constituents to increase its concentration

METAL CYCLE

Ore

Metal Metal Artifacts

Production

Smelting Corrosion

SMELTING REQUIREMENTS

•  A furnace that can reach high enough temperatures where metals will melt.

•  Supply of heat at a sufficient rate to maintain temperatures and conduct the smelting and slag forming reactions.

•  Generate a reducing gas that can decompose the metal oxides disseminated in the ore

COMBUSTION OF CARBON

2C + O2 2CO CO2 C + O2 _______________________ C + CO2 2CO

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REDUCTION OF METAL OXIDES�BY CARBON MONOXIDE

1.  Reduction of metal ore with CO MO + CO M + CO2

2.  Conversion of CO2 back to CO C + CO2 2CO

ANCIENT SHAFT FURNACE

USE OF BLOW PIPES IN ANCIENT SMELTING FURNACES

Human lungs can produce intermitent flow of 40l/min and

10-20 l/min on continuous basis.

This can heat a small area over 1000 oC.

TYPES OF BELLOW

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OPERATION OF POT BELLOW IONIC COMPOUNDS vs METALS 

GRAIN STRUCTURE IN METALS

Grain

Grain Boundary

Vacancy

EFFECTS OF TEMPERATURE

ON GRAIN STRUCTGUE

AND MECHANICL PROPERTIES OF METALS

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ALLOYS

Alloys are metallic substances that contain at least two elements. The base element in an alloy is a metal. The minor component of an alloy distribute in the base metal in two ways: a)  They may occupy the spaces between the base metal

b) They may substitute for base metal atoms.

HOW CAN THE ATOMS OF TWO DIFFERENT METALS CAN MIX?

Solid solution

Solid mixture

ALLOY vs PURE METAL HARDNESS OF Cu- As ALLOYS

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EARLIEST METAL OBJECTS

Location Object Date (BC) Technique Aşıklı Cu beads 9000 Cold work Zawi Chemi Cu beads 8500 Cold work Cayonu Cu pins 7000 Cold work Çatal Höyük Cu,Pb beads 6000 Annealing

Cu slag Smelting Yarım Tepe I Pb bracelet 5700 Smelting Can Hasan Cu Mace 6000 Cold work Mersin Cu pin, axe 5000 Casting

COPPER BELT OF NEAREAST

SITES OF EARLY NATIVE METALS

1:Can Hasan, 2:Asikli hoyuk, 3: Catal Hoyuk, 4. Hacilar, 5: Yumuk tepe, 6: Nevali Cori, 7: Cayonu, 8: Ramad,

AŞIKLI HÖYÜK METAL BEADS

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CAN HASAN MACE HEAD COPPER SOURCES OF TURKEY

SOME COPPER ORES

Azurite Chalcopyrite Chalcosite

Malachite Cuprite Tenantite

COPPER INGOTS

Uluburun Shipwreck (1350 BC) Rows of ox hide ingots. Bun ingot

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CHALCOLITHIC CULTURES

 This is the period that yielded the earliest copper smelting evidence in Anatolia. The period is divided into three roughly corresponding to cultural interactions with Mesopotamia:

•  Early Chalcolithic (6th millennium BC) is also known as the Halaf Period.

•  Middle Chalcolithic (5th millennium BC) is also known as the Obeid Period.

•  Late Chalcolithic (4th millennium BC) is also known as the Uruk Period.

EARLY MESOPOTAMIAN SITES

URUK TRADE NETWORK HACINEBI TEPE

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URUK EVIDENCE IN HACINEBİ

An Uruk house Tokens in stamped container

Beveled Rim Bowls (BRB) Wall cones (Uruk decoration)

METAL FINDS AT HACINEBİ

ARRIVAL OF CAUCASIAN CULTURES INTO EAST ANATOLIA

Evidence for the Caucasian cultures was recognized by the appearance of red burnished Karaz pottery.

MAJOR ELEMENTS ADDED TO COPPER FOR ALLOYING

•  Cu-As Earliest copper alloy, accidental •  Cu-Sn Bronze, began to appear ~3000 BC •  Cu-Zn Brass, also known as orichalcum •  Cu-Sb Rare, mostly found in the Caucasus •  Cu-Pb Found mostly in cast copper objects (Highly used by the Romans)

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Cu-As ALLOYS First Cu-As alloys appeared in the Near East in the latter part of 4th Millennium BC. Since Arsenic was not known in metallic form, it was believed that these alloys were accidentally produced from smelting arsenic containing copper ores such as: Energite (3CuSAs2S5) Tennantite (Cu3SAsS3) Arsenopyrite (FeAsS) with chalcopyrite (CuFeS2) Sometimes arsenic minerals orpiment (As2S3) or realgar (AsS) were added to copper ore during smelting.

NAHAL MISHMAR

APPEARENCE OF Cu-As ALLOYS ARSLANTEPE

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LOCATION OF İKİZTEPE İKİZTEPE METALS

0

1

2

3

4

5

% A

s

LC EB I EB II EB III MB I

ARSENIC CONCENTRATION OF İKİZTEPE METALS ACCORDING TO PERIODS

DISTRIBUTION OR ARSENIC CONCENTRATION IN İKİZTEPE

OBJECTS

0

10

20

30

40

50

60

70

80

Nu

mb

er

of

Sa

mp

les

< 1.0 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 >10

As %

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ARSENIC SOURCES FOR İKİZTEPE METALURGISTS

WHY Cu-As ALLOYS WERE ABANDONED

•  Roasting of sulfide ores with arsenic caused arsenic to be lost as a sublimate

•  Due to the volatility of arsenic, its composition in copper could not be easily controlled.

•  The availability of recognizable arsenic rich ores were limited

•  Toxic effect of arsenic was detrimental to the health of the smith.

HOW Cu-Sn ALLOY WAS RECOGNIZED? 

•  Since stannite (Cu2SFeS.SnS2) resembles arsenical copper ores, it could have been accidentally smelted and Cu-Sn bronze could be obtained.

•  Insoluble cassiterite during natural oxidation and enrichment of primary ores will remain in the iron hat (gossan). If cassiterite containing gossan is used as flux in copper smelting, tin could be incorporated into copper.

HARDNESS OF BRONZE

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PREPARATION OF Cu-Sn ALLOYS 

1.  Metallic copper and tin can be melted together at desired proportions.

2.  Copper and tin ore cassiterite may be smelted together.

3.  Cementation method can be used in which cassiterite is added to the surface of molten copper under charcoal in a furnace where the tin is reduced directly into the melt: SnO2 + C Sn + CO2

EARLIEST BRONZES

OCCURANCE OF BRONZE BEFORE 22OO BC,

OCCURANCE OF BRONZE AFTER 2200 BC

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BRONZES OF ANATOLIA

•  Figurines of Tell Atchana in the Amuq plain dated to around 3000 BC

•  Bronzes of Troy II, dated to 2800 BC •  Bronzes of Alacahoyuk and Horoztepe dated to

the 2nd half of 3rd millennium BC •  Bronze objects from the royal tombs at Ur Mesopotamia 2600-2400 BC

MAP OF SOUTH CENTRAL ANATOLIA

AMUQ FIGURINES ALACAHÖYÜK EBA OBJECTS

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ALACAHÖYÜK EBA METALS

11

12

14

0

0

2

4

6

8

10

12

14

Nu

mb

er

of

Sa

mp

les

Cu As>1.0 Sn>2.0 As & Sn

Alacahöyük EBA Metals

Esin 1967

TROY

TREAURES FROM UR

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KESTEL MINE ENTRANCE TO KESTEL

UNDERGROUND WORKINGS

ORE DRESSING AT KESTEL ENTRANCE TO KESTEL MINE

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KESTEL TIN MINE (2800-2200 BC) FIRE SETTING PACKETS AT KESTEL

C‐14 DATE FOR KESTEL CHARCOAL  KESTEL MINE PLAN

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GÖLTEPE WORKSHOP

GRINDING TOOLS AT�GÖLTEPE

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GÖLTEPE STORAGE VESSELS TIN METALLURGY AT GÖLTEPE

•  Hematite ores that contain 600-700 ppm cassiterite were not utilized.

•  The hematite ores found at Göltepe contained 5 times more cassiterite than Kestel ores.

•  Powdered hematite ores contained 13 times more cassiterite

•  A method must have been developed to recognize the tin content in hematite ores.

VANING KESTEL CASSITERITE VANNED (CONCENTRATED) KESTEL CASSITERITE

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ASSAYING CASSITERITE

GÖLTEPE SMELTING EXPERIMENT

TIN PRILL FROM SEMLTING EXPERIMENT

METAL FORMING �METHODS

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METAL WORKING

•  Mechanical: To bring the metal into desired shape, generally by hammering

•  Chemical: To change the surface appearance or to join pieces as in soldering.

•  Embossing: To increase the surface by hammering the metal into thin sheet and covering the modeled object made of clay or carved wood.

SHAPING OF METAL

•  Copper and its alloys can be shaped by repeated hammering and annealing. It can be hammered both hot or cold.

•  Iron and its alloys can be forged only when hot. Cooling rate is very critical for the strength of the alloy.

MECHANICAL SHAPING OF SHEET COPPER

SHAPING BY HAMMERING

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SHAPING SILVER PREPARATION OF COPPER BEFORE CASTING

•  Blister copper is remelted in a crucible to keep surface area minimum and avoid contact with air.

•  Residual inclusions float to the surface and are removed off as a dross.

•  The molten metal is polled by unseasoned wood to reduce copper oxide that may have formed during melting back to metal

EGYPTIAN CASTING OF TEMPLE DOORS

Temple door

Cu Ingot Sn Ingots

OPEN MOLDS FROM TARSUS

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OBJECTS THAT CAN BE MADE BY OPEN MOLD CASTING

CASTING AN AXE WITH A SHAFT HOLE

CASTING SHAFT HOLE AXE

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HOLLOW CASTING BY PIECE MOLDS

PIECE �MOLD�

CASTING

CHINEESE BRONZES

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LOST WAX CASTING LOST WAX CASTING

GRANULATION BRAZING

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METAL EMBOSSING MERCURY GUILDING •  Mix Gold or silver with mercury to form an amalgam

•  Apply the amalgam on the surface of copper object

•  Heat the object to evaporate the mercury

•  Thin layer of gold or silver coat will remain on copper object.