SlideShare una empresa de Scribd logo
1 de 51
Elements of mining
•Mine
Elements of mining
• Mining
• Mining engineering
Geological definition
• Mineral
• Rock
Elements of mining
Economic definition of minerals
• Ore
• Gangue
• Common gangue minerals in gold ores include
quartz, fluorite, calcite and pyrite, but many
others can be found in smaller amounts.
Elements of mining
• Mineral deposit
• Ore deposit
Elements of mining
• Three categories of commercial minerals
1. Metallic ores(ferrous,base,radioactive)
2. Non metallic ores
3. Mineral fuels
Elements of mining
• base metal is used to refer to a metal that
oxidizes or corrodes relatively easily, and
reacts variably with diluted hydrochloric acid
(HCl) to form hydrogen.
Elements of mining
Two type of mining is done depending upon
geologic , environmental,economic and legal
conditions.
1. Surface mining
2. Under ground mining
Elements of mining
• Before mining geological investigations
• After mining mineral processing(e.g gravity
separation).
• Smelting
• Refining
• marketing
Elements of mining
•
•
•
•

Civil and military excavations
Vehicular tunnels
Storage reservoirs
Military installations
Elements of mining
• Geology deals with locating and exploring
mineral deposit
• Mining
Proving,planning,developing and exploiting of
ore
• Metallurgy
Processing ,smelting, refining
Development of mining technology
• The long period of prehistoric times is divided
into different ages which are named from the
material which man used in the manufacture
of his weapons and tools. The earliest time is
known as the Paleolithic or Old Stone Age; the
following one as the Neolithic or New Stone
Age; and the later period as the Age of Metals.
definitions
• prehistoric times
refers to all the time preceding
human existence and the invention of writing
• Paleo- lithic, old-stone
• Old stone age Paleolithic is the period during
which human beings lived entirely by hunting
• Neolithic is the following interval during
which plant and animal domestication started
Development of mining technology
• Mining starts 450,000 years ago.
• Flint (or flintstone) is a hard, sedimentary
form of the mineral quartz categorized as a
variety of chert.
• Flint was used for the manufacture of flint
tools during the Stone Age as it splits into thin,
sharp splinters called flakes or blades
(depending on the shape) when struck by
another hard object.
Development of mining technology
• In beginning only surface mining
• First underground mine in old stone age
40000 years ago.(hematite,swaziland)
• Systematic opening in new stoneage 2-3 ft
high 30 feet deep.
• Depth 800 feet egyptian time.
Development of mining technology
• Initially metals used in native form, by
washing.
• In bronze and iron age smelting.
Rock breakage
• By bones wood or stone tools.(wedging)
• Then by fire setting
• In 17th century black powder.
Development of mining technology
•
•
•
•
•

Firstly slaves andconvicts
Egyptians organised mining
Romans industrialised it
Mining suffered dark age
1185 A.D bishop of trent
Development of mining technology
• 18th century industrial revolution
• 20 th century mechanized mining,
computerization.
• Low grade deposits can be mined
definitions
• Dark age a period of intellectual darkness 6th
to 13th centuries. It came after fall of roman
empire.
• New world, america is regarded as new world
Development of mining technology
Chronological Development of Mining Technology
• 450,000 First mining (at surface),by Paleolithic humans for
stone implements.
• 40,000 Surface mining progresses underground, in Swaziland,
Africa.
• 30,000 Fired clay pots used in Czechoslovakia.
• 18,000 Possible use of gold and copper in native form.
• 5000 Fire setting,used by Egyptians to break rock.
• 4000 Early use of fabricated metals; start of Bronze Age.
• Video stone cutting
• Turquoise is an opaque, blue-to-green mineral
that is a hydrous phosphate of copper and
aluminium
Development of mining technology
• 3400 First recorded mining,of turquoise by Egyptians in
Sinai.
• 3000 Probable first smelting,of copper with coal by
Chinese; first use of iron implements by Egyptians.
• 2000 Earliest known gold artifacts in New World,in
Peru.
• 1000 Steel used by Greeks.
• 100 A.D Thriving Roman mining industry.
• 122 Coal used by Romans in present-day United
Kingdom.
• 1185 Edict by bishop of Trent gives rights to miners
Development of mining technology
• 1524 First recorded mining in New World,by Spaniards
in Cuba.
• 1550 First use of lift pump,at Joachimstal,
Czechoslovakia.
• 1556 First mining technical work, De Re
Metallica,published in Germany by Georgius Agricola.
• 1585 Discovery of iron ore in North America,in North
Carolina.
• 1600s Mining commences in eastern United States
(iron,coal, lead,gold ).
• 1627 Explosives first used in European mines,in
Hungary (possible prior use in China).
Development of mining technology
• 1646 First blast furnace installed in North
America,in Massachusetts.
• 1716 First school of mines established,at
Joachimstal, Czechoslovakia.
• 1780 Beginning of Industrial Revolution;
pumps are first modern machines used in
mines.
Development of mining technology
• 1800s Mining progresses in United States;
gold rushes help open the West.
• 1815 Sir Humphrey Davy invents miner’s
safety lamp in England.
• 1855 Bessemer steel process first used,in
England.
• 1867 Dynamite invented by Nobel,applied to
mining.
• A gold rush is a period of migration of
workers into the area of dramatic discovery of
gold.
Development of mining technology
• 1903 Era of mechanization and mass production
opens in U.S. mining with development of first
low-grade copper porphyry,in Utah; although the
first modern mine was an open pit,subsequent
operations were underground as well.
• 1940 First continuous miner initiates the era of
mining without explosives.
• 1945 Tungsten carbide bits developed by
McKenna Metals Company (now Kennametal)
Elements of mining
Elements of mining
Elements of mining
Elements of mining

Más contenido relacionado

La actualidad más candente

Mining Methods
Mining MethodsMining Methods
Mining Methods
VR M
 
Longwall Mining
Longwall MiningLongwall Mining
Longwall Mining
VR M
 
13surface mining
13surface mining13surface mining
13surface mining
Arun Kumar
 
Openpit fundamentals
Openpit fundamentalsOpenpit fundamentals
Openpit fundamentals
VR M
 
Underground mining methods
Underground mining methodsUnderground mining methods
Underground mining methods
Tayyab Anwar
 

La actualidad más candente (20)

Mining Methods
Mining MethodsMining Methods
Mining Methods
 
Longwall Mining
Longwall MiningLongwall Mining
Longwall Mining
 
Underground metal mining methods
Underground metal mining methodsUnderground metal mining methods
Underground metal mining methods
 
Surface mining
Surface miningSurface mining
Surface mining
 
Introductory mining
Introductory miningIntroductory mining
Introductory mining
 
Classification of ore deposits
Classification of ore depositsClassification of ore deposits
Classification of ore deposits
 
Mineralization controlled by Tectonics & structures.ppt
Mineralization controlled by Tectonics & structures.pptMineralization controlled by Tectonics & structures.ppt
Mineralization controlled by Tectonics & structures.ppt
 
Unit operations of mining
Unit operations of miningUnit operations of mining
Unit operations of mining
 
Underground mining method natural support and caving
Underground mining method natural support and cavingUnderground mining method natural support and caving
Underground mining method natural support and caving
 
Economic geology - Mineral resources
Economic geology - Mineral resourcesEconomic geology - Mineral resources
Economic geology - Mineral resources
 
An overview of mining methods
An  overview  of  mining methodsAn  overview  of  mining methods
An overview of mining methods
 
The mineral reserves & reserves estimation using triangular methods
The mineral reserves & reserves estimation using triangular methods The mineral reserves & reserves estimation using triangular methods
The mineral reserves & reserves estimation using triangular methods
 
Mining (1)
Mining (1)Mining (1)
Mining (1)
 
Caving Underground Mining Methods (longwall, Sublevel caving, & Block caving)
Caving Underground Mining Methods (longwall, Sublevel caving, &  Block caving)Caving Underground Mining Methods (longwall, Sublevel caving, &  Block caving)
Caving Underground Mining Methods (longwall, Sublevel caving, & Block caving)
 
Surface mining methods
Surface mining methodsSurface mining methods
Surface mining methods
 
13surface mining
13surface mining13surface mining
13surface mining
 
Openpit fundamentals
Openpit fundamentalsOpenpit fundamentals
Openpit fundamentals
 
Prospecting and Exploration -
Prospecting and Exploration -Prospecting and Exploration -
Prospecting and Exploration -
 
Underground mining methods
Underground mining methodsUnderground mining methods
Underground mining methods
 
Mining terminology
Mining terminologyMining terminology
Mining terminology
 

Similar a Elements of mining

Chapter 5 Minerals geograph ppt (1).pptx
Chapter 5 Minerals geograph ppt  (1).pptxChapter 5 Minerals geograph ppt  (1).pptx
Chapter 5 Minerals geograph ppt (1).pptx
sanjeevphotos0
 
Earth and history
Earth and historyEarth and history
Earth and history
Par Pandit
 
Minelab's corporate overview
Minelab's corporate overviewMinelab's corporate overview
Minelab's corporate overview
rf11111
 
Lecture 10 Mineral Resources and Mining s.ppt
Lecture 10  Mineral Resources and Mining s.pptLecture 10  Mineral Resources and Mining s.ppt
Lecture 10 Mineral Resources and Mining s.ppt
MajidKhan858527
 

Similar a Elements of mining (20)

Mininghistorypdf
MininghistorypdfMininghistorypdf
Mininghistorypdf
 
Introductory mining v2
Introductory mining v2Introductory mining v2
Introductory mining v2
 
History mining
History miningHistory mining
History mining
 
mining_101.ppt
mining_101.pptmining_101.ppt
mining_101.ppt
 
mining_101 (1).ppt
mining_101 (1).pptmining_101 (1).ppt
mining_101 (1).ppt
 
mining_101.ppt
mining_101.pptmining_101.ppt
mining_101.ppt
 
Mining in history
Mining in historyMining in history
Mining in history
 
Timberlake y craddock_45-1-2013
Timberlake y craddock_45-1-2013Timberlake y craddock_45-1-2013
Timberlake y craddock_45-1-2013
 
Chapter 5 Minerals geograph ppt (1).pptx
Chapter 5 Minerals geograph ppt  (1).pptxChapter 5 Minerals geograph ppt  (1).pptx
Chapter 5 Minerals geograph ppt (1).pptx
 
2. extraction of minerals in sa
2. extraction of minerals in sa2. extraction of minerals in sa
2. extraction of minerals in sa
 
Chapter 3 - mineral and power resources - Class 8
Chapter 3 - mineral and power resources - Class 8Chapter 3 - mineral and power resources - Class 8
Chapter 3 - mineral and power resources - Class 8
 
Minerals
MineralsMinerals
Minerals
 
Earth and history
Earth and historyEarth and history
Earth and history
 
Archaeology of the East Midlands: Class 3. Radcliffe Autumn 2014
Archaeology of the East Midlands: Class 3. Radcliffe Autumn 2014Archaeology of the East Midlands: Class 3. Radcliffe Autumn 2014
Archaeology of the East Midlands: Class 3. Radcliffe Autumn 2014
 
Diamonds in south Africa.
Diamonds in south Africa.Diamonds in south Africa.
Diamonds in south Africa.
 
Minelab's corporate overview
Minelab's corporate overviewMinelab's corporate overview
Minelab's corporate overview
 
Lecture-10-Mineral-Resources-and-Mining-s.ppt
Lecture-10-Mineral-Resources-and-Mining-s.pptLecture-10-Mineral-Resources-and-Mining-s.ppt
Lecture-10-Mineral-Resources-and-Mining-s.ppt
 
Lecture 10 Mineral Resources and Mining s.ppt
Lecture 10  Mineral Resources and Mining s.pptLecture 10  Mineral Resources and Mining s.ppt
Lecture 10 Mineral Resources and Mining s.ppt
 
Projct 2
Projct 2Projct 2
Projct 2
 
Mining Practices 2012
Mining Practices 2012Mining Practices 2012
Mining Practices 2012
 

Más de University of Engineering and Technology, Lahore (12)

Explosives
ExplosivesExplosives
Explosives
 
Mining impact on the economy of british columbia
Mining impact on the economy of british columbiaMining impact on the economy of british columbia
Mining impact on the economy of british columbia
 
Shahdat five pillars of islam final
Shahdat  five pillars of islam finalShahdat  five pillars of islam final
Shahdat five pillars of islam final
 
Seerah an nabi
Seerah an nabiSeerah an nabi
Seerah an nabi
 
Islamic ethics
Islamic ethicsIslamic ethics
Islamic ethics
 
humanrights
humanrightshumanrights
humanrights
 
1.what is shariah
1.what is shariah1.what is shariah
1.what is shariah
 
Authority of sunnah session 1
Authority of sunnah   session 1Authority of sunnah   session 1
Authority of sunnah session 1
 
Presentation1
Presentation1Presentation1
Presentation1
 
Mineral economics
Mineral economicsMineral economics
Mineral economics
 
Stages in life of mine
Stages in life of mineStages in life of mine
Stages in life of mine
 
Ch02 friction
Ch02 frictionCh02 friction
Ch02 friction
 

Último

Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
ZurliaSoop
 
The basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptxThe basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptx
heathfieldcps1
 
Salient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functionsSalient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functions
KarakKing
 

Último (20)

80 ĐỀ THI THỬ TUYỂN SINH TIẾNG ANH VÀO 10 SỞ GD – ĐT THÀNH PHỐ HỒ CHÍ MINH NĂ...
80 ĐỀ THI THỬ TUYỂN SINH TIẾNG ANH VÀO 10 SỞ GD – ĐT THÀNH PHỐ HỒ CHÍ MINH NĂ...80 ĐỀ THI THỬ TUYỂN SINH TIẾNG ANH VÀO 10 SỞ GD – ĐT THÀNH PHỐ HỒ CHÍ MINH NĂ...
80 ĐỀ THI THỬ TUYỂN SINH TIẾNG ANH VÀO 10 SỞ GD – ĐT THÀNH PHỐ HỒ CHÍ MINH NĂ...
 
Jamworks pilot and AI at Jisc (20/03/2024)
Jamworks pilot and AI at Jisc (20/03/2024)Jamworks pilot and AI at Jisc (20/03/2024)
Jamworks pilot and AI at Jisc (20/03/2024)
 
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
 
REMIFENTANIL: An Ultra short acting opioid.pptx
REMIFENTANIL: An Ultra short acting opioid.pptxREMIFENTANIL: An Ultra short acting opioid.pptx
REMIFENTANIL: An Ultra short acting opioid.pptx
 
Understanding Accommodations and Modifications
Understanding  Accommodations and ModificationsUnderstanding  Accommodations and Modifications
Understanding Accommodations and Modifications
 
Micro-Scholarship, What it is, How can it help me.pdf
Micro-Scholarship, What it is, How can it help me.pdfMicro-Scholarship, What it is, How can it help me.pdf
Micro-Scholarship, What it is, How can it help me.pdf
 
Mehran University Newsletter Vol-X, Issue-I, 2024
Mehran University Newsletter Vol-X, Issue-I, 2024Mehran University Newsletter Vol-X, Issue-I, 2024
Mehran University Newsletter Vol-X, Issue-I, 2024
 
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptxCOMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
COMMUNICATING NEGATIVE NEWS - APPROACHES .pptx
 
FSB Advising Checklist - Orientation 2024
FSB Advising Checklist - Orientation 2024FSB Advising Checklist - Orientation 2024
FSB Advising Checklist - Orientation 2024
 
The basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptxThe basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptx
 
Salient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functionsSalient Features of India constitution especially power and functions
Salient Features of India constitution especially power and functions
 
How to setup Pycharm environment for Odoo 17.pptx
How to setup Pycharm environment for Odoo 17.pptxHow to setup Pycharm environment for Odoo 17.pptx
How to setup Pycharm environment for Odoo 17.pptx
 
Sociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning ExhibitSociology 101 Demonstration of Learning Exhibit
Sociology 101 Demonstration of Learning Exhibit
 
How to Manage Global Discount in Odoo 17 POS
How to Manage Global Discount in Odoo 17 POSHow to Manage Global Discount in Odoo 17 POS
How to Manage Global Discount in Odoo 17 POS
 
ICT role in 21st century education and it's challenges.
ICT role in 21st century education and it's challenges.ICT role in 21st century education and it's challenges.
ICT role in 21st century education and it's challenges.
 
On National Teacher Day, meet the 2024-25 Kenan Fellows
On National Teacher Day, meet the 2024-25 Kenan FellowsOn National Teacher Day, meet the 2024-25 Kenan Fellows
On National Teacher Day, meet the 2024-25 Kenan Fellows
 
Beyond_Borders_Understanding_Anime_and_Manga_Fandom_A_Comprehensive_Audience_...
Beyond_Borders_Understanding_Anime_and_Manga_Fandom_A_Comprehensive_Audience_...Beyond_Borders_Understanding_Anime_and_Manga_Fandom_A_Comprehensive_Audience_...
Beyond_Borders_Understanding_Anime_and_Manga_Fandom_A_Comprehensive_Audience_...
 
This PowerPoint helps students to consider the concept of infinity.
This PowerPoint helps students to consider the concept of infinity.This PowerPoint helps students to consider the concept of infinity.
This PowerPoint helps students to consider the concept of infinity.
 
Wellbeing inclusion and digital dystopias.pptx
Wellbeing inclusion and digital dystopias.pptxWellbeing inclusion and digital dystopias.pptx
Wellbeing inclusion and digital dystopias.pptx
 
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptxOn_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
On_Translating_a_Tamil_Poem_by_A_K_Ramanujan.pptx
 

Elements of mining

  • 2.
  • 3.
  • 4.
  • 5.
  • 6.
  • 7.
  • 8. Elements of mining • Mining • Mining engineering Geological definition • Mineral • Rock
  • 9. Elements of mining Economic definition of minerals • Ore • Gangue • Common gangue minerals in gold ores include quartz, fluorite, calcite and pyrite, but many others can be found in smaller amounts.
  • 10.
  • 11.
  • 12.
  • 13. Elements of mining • Mineral deposit • Ore deposit
  • 14. Elements of mining • Three categories of commercial minerals 1. Metallic ores(ferrous,base,radioactive) 2. Non metallic ores 3. Mineral fuels
  • 15. Elements of mining • base metal is used to refer to a metal that oxidizes or corrodes relatively easily, and reacts variably with diluted hydrochloric acid (HCl) to form hydrogen.
  • 16. Elements of mining Two type of mining is done depending upon geologic , environmental,economic and legal conditions. 1. Surface mining 2. Under ground mining
  • 17.
  • 18.
  • 19. Elements of mining • Before mining geological investigations • After mining mineral processing(e.g gravity separation). • Smelting • Refining • marketing
  • 20.
  • 21. Elements of mining • • • • Civil and military excavations Vehicular tunnels Storage reservoirs Military installations
  • 22.
  • 23.
  • 24. Elements of mining • Geology deals with locating and exploring mineral deposit • Mining Proving,planning,developing and exploiting of ore • Metallurgy Processing ,smelting, refining
  • 25. Development of mining technology • The long period of prehistoric times is divided into different ages which are named from the material which man used in the manufacture of his weapons and tools. The earliest time is known as the Paleolithic or Old Stone Age; the following one as the Neolithic or New Stone Age; and the later period as the Age of Metals.
  • 26. definitions • prehistoric times refers to all the time preceding human existence and the invention of writing • Paleo- lithic, old-stone • Old stone age Paleolithic is the period during which human beings lived entirely by hunting • Neolithic is the following interval during which plant and animal domestication started
  • 27. Development of mining technology • Mining starts 450,000 years ago. • Flint (or flintstone) is a hard, sedimentary form of the mineral quartz categorized as a variety of chert. • Flint was used for the manufacture of flint tools during the Stone Age as it splits into thin, sharp splinters called flakes or blades (depending on the shape) when struck by another hard object.
  • 28.
  • 29.
  • 30. Development of mining technology • In beginning only surface mining • First underground mine in old stone age 40000 years ago.(hematite,swaziland) • Systematic opening in new stoneage 2-3 ft high 30 feet deep. • Depth 800 feet egyptian time.
  • 31. Development of mining technology • Initially metals used in native form, by washing. • In bronze and iron age smelting. Rock breakage • By bones wood or stone tools.(wedging) • Then by fire setting • In 17th century black powder.
  • 32. Development of mining technology • • • • • Firstly slaves andconvicts Egyptians organised mining Romans industrialised it Mining suffered dark age 1185 A.D bishop of trent
  • 33. Development of mining technology • 18th century industrial revolution • 20 th century mechanized mining, computerization. • Low grade deposits can be mined
  • 34. definitions • Dark age a period of intellectual darkness 6th to 13th centuries. It came after fall of roman empire. • New world, america is regarded as new world
  • 35. Development of mining technology Chronological Development of Mining Technology • 450,000 First mining (at surface),by Paleolithic humans for stone implements. • 40,000 Surface mining progresses underground, in Swaziland, Africa. • 30,000 Fired clay pots used in Czechoslovakia. • 18,000 Possible use of gold and copper in native form. • 5000 Fire setting,used by Egyptians to break rock. • 4000 Early use of fabricated metals; start of Bronze Age.
  • 36.
  • 37.
  • 38. • Video stone cutting • Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium
  • 39. Development of mining technology • 3400 First recorded mining,of turquoise by Egyptians in Sinai. • 3000 Probable first smelting,of copper with coal by Chinese; first use of iron implements by Egyptians. • 2000 Earliest known gold artifacts in New World,in Peru. • 1000 Steel used by Greeks. • 100 A.D Thriving Roman mining industry. • 122 Coal used by Romans in present-day United Kingdom. • 1185 Edict by bishop of Trent gives rights to miners
  • 40.
  • 41. Development of mining technology • 1524 First recorded mining in New World,by Spaniards in Cuba. • 1550 First use of lift pump,at Joachimstal, Czechoslovakia. • 1556 First mining technical work, De Re Metallica,published in Germany by Georgius Agricola. • 1585 Discovery of iron ore in North America,in North Carolina. • 1600s Mining commences in eastern United States (iron,coal, lead,gold ). • 1627 Explosives first used in European mines,in Hungary (possible prior use in China).
  • 42.
  • 43. Development of mining technology • 1646 First blast furnace installed in North America,in Massachusetts. • 1716 First school of mines established,at Joachimstal, Czechoslovakia. • 1780 Beginning of Industrial Revolution; pumps are first modern machines used in mines.
  • 44. Development of mining technology • 1800s Mining progresses in United States; gold rushes help open the West. • 1815 Sir Humphrey Davy invents miner’s safety lamp in England. • 1855 Bessemer steel process first used,in England. • 1867 Dynamite invented by Nobel,applied to mining.
  • 45. • A gold rush is a period of migration of workers into the area of dramatic discovery of gold.
  • 46.
  • 47. Development of mining technology • 1903 Era of mechanization and mass production opens in U.S. mining with development of first low-grade copper porphyry,in Utah; although the first modern mine was an open pit,subsequent operations were underground as well. • 1940 First continuous miner initiates the era of mining without explosives. • 1945 Tungsten carbide bits developed by McKenna Metals Company (now Kennametal)