Presentation Transcript
Slide 1:DIAMOND MINING BY,
E.L.ANTONEY JACOB)
ANNA UNIVERSITY.
Slide 2:CONTENTS INTRODUCTION
IMPORTANT DIAMOND PRODUCING COUNTRIES AND COMPANIES IN THE WORLD.
TYPES OF DIAMOND.
TYPES OF DIAMOND MINING
MINERAL PROCESSING OF DIAMOND
DIAMOND MINING IN INDIA
TYPES OF DIAMOND MINING
CONCLUSION
Slide 3:INTRODUCTION Diamond is a transparent gem made of carbon
The Diamond came from the Greek word adamas which means unconquerable
Diamond forms in the kimberlite pipes
The formation of diamonds began very early in the earth's history
The centre of the planet to become subjected to incredible extremes of temperatures and pressure.
It was these conditions that caused deposits of carbon to begin to crystallise deep in the earth.
Slide 4:As the earth's surface cooled, volcanic activity forced streams of magna (liquid rock) to the surface, carrying with it the diamond crystals.
Later, the diamond-bearing rock hardened, encasing the diamonds in vertical volcanic "pipes".
Subsequent erosion of the topsoils over millions of years washed some of the diamonds into streams and rivers, and sometimes as far away as the sea.
The diamond is thousands of times harder than corundum, the next hardest substance from which rubies and sapphires are formed.
Slide 5:PROPERTIES Chemistry – C
Class – Native Mineral
Sub class – Non Metallic
Group – carbon
IMPORTANT DIAMOND PRODUCING COUNTRIES :IMPORTANT DIAMOND PRODUCING COUNTRIES AFRICA
Angola, Botswana, South africa
AUSTRALIA
NORTH AMERICA
Canada, USA.
ASIA
Russia, India.
TYPES OF DIAMOND :TYPES OF DIAMOND PINK DIAMOND
WHITE DIAMOND
WHITE WITH SECONDARY PINK COLOUR
CHAMPAGNE DIAMOND
YELLOW DIAMOND
PINK DIAMOND
BLUE DIAMOND
GREEN DIAMOND.
PINK DIAMOND :PINK DIAMOND The pink diamond is the world's most rare and valuable diamond.
The Argyle mine is the world's foremost source of unrivalled intense pink diamonds, producing 95% of the world's supply.
WHITE DIAMOND :WHITE DIAMOND White diamonds are produced by mines all over the world in a wide variety of shapes and sizes.
The white diamonds recovered from the Argyle mine are particularly brilliant and of high quality.
WHITE DIAMOND WITH SECONDARY PINK COLOUR. :WHITE DIAMOND WITH SECONDARY PINK COLOUR. white diamond will display slight to bold flashes of pink when viewed from the top.
CHAMPAGNE DIAMONDS :CHAMPAGNE DIAMONDS Champagne diamonds are naturally coloured diamonds that are produced in a wide range of colours from light straw to rich cognac
YELLOW DIAMOND :YELLOW DIAMOND Fancy yellow diamonds come in a broad range of shades ranging from light yellow colour.
A limited quantity of fancy yellow diamonds is recovered from the Argyle mine.
GREEN DIAMOND :GREEN DIAMOND A limited quantity of fancy green diamonds is recovered from the Argyle mine.
The penetration of colour is not deep.
BLUE DIAMOND :BLUE DIAMOND Fancy blue diamonds are available in a wide range of shades, from the blue of the sky to a more "steely" colour than sapphire.
less number of this diamond is mined in argyle mines.
ARGYLE DIAMOND MINING :ARGYLE DIAMOND MINING Key Data
Producer -- Diamonds
Location -- Kimberley, northeast Western Australia
Ownership -- Rio Tinto (100%)
Geology type -- Precambrian diamond-bearing lamproite pipe with associated placer deposits
Mineral type -- Native diamonds
Reserve base -- 83Mt at 2.7ct/t hard-rock, plus 28Mt at 0.2ct/t alluvial (2005)
Argyle diamond mine. :Argyle diamond mine.
SOUTH AFRICAN DIAMOND MINING :SOUTH AFRICAN DIAMOND MINING DIAMOND IS MINED IN 3 PROVINCES IN SOUTH AFRICA.
1.GAUTENG PROVINCE
2.LIMPOPO PROVINCE
3.KIMBERLEY.
4.LESTHOTHO.
The company that started mining there is DE BEER’S COMPANY.
KIMBERELEY :KIMBERELEY
GAUTENG AND LIMPOPO PROVINCE :GAUTENG AND LIMPOPO PROVINCE
LESTHOTHO :LESTHOTHO
MAJOR DIAMOND MINING IN INDIA :MAJOR DIAMOND MINING IN INDIA PANNA MINES
GUNTUR
CUDDAPAH
KARNOOL etc. INTERIORS OF PANNA MINES
DIAMOND PROJECTS IN INDIA :DIAMOND PROJECTS IN INDIA DHARWAR PROJECT
BUNDELKAND PROJECT
BHANDARA PROJECT.
DIAMOND MINING LOCATIONS IN INDIA :DIAMOND MINING LOCATIONS IN INDIA
TYPES OF DIAMOND MINING :TYPES OF DIAMOND MINING ALLUVIAL MINING
PIPE MINING
PIPE MINING :PIPE MINING Pipe mining refers to the extraction of diamonds from volcanic pipes.
Typically, a very large area has to be covered. An average of 250 tonnes of ore must be mined in order to produce a one-carat gem quality polished diamond.
In most countries, a diamond pipe mine is composed of kimberlite, or blue ground.
After the diamond-bearing rock is brought to the surface, it is then transported to a screening plant where the diamonds are separated from the hostrock.
ALLUVIAL MINING :ALLUVIAL MINING This process involves the extraction of diamonds from riverbeds or ocean beaches.
Millions of years ago, at the time the diamond pipes were formed, some diamonds were weathered out of the pipes and carried great distances along rivers and even into oceans.
A wall is built in beach to hold back the surf.
Up to 25 metres of sand is bulldozed aside to reach the diamond-bearing level.
Once reached, the diamond-bearing earth is removed and transported to screening plants
ALLUVIAL MINING :ALLUVIAL MINING
Screening Process :Screening Process Once a mining operation yields ore, the diamonds must
be sorted from the other materials.
This process relies primarily on diamond's high density.
An old but effective method is to use a washing pan, which forces heavy minerals like diamond to the bottom and waste to the top.
Cones and cyclones use swirling heavy fluids mixed with
crushed ore to achieve density separations.
With this process 99% of the waste in the ore removed.
Screening plant :Screening plant
Slide 31:Further separations may use either a grease table or an x-ray separator.
Final separation and sorting is done by eye.
Crushed ore is mixed with a muddy water suspension, called puddle, and all is stirred by angled rotating blades in the circular washing pan.
Heavier minerals settle to the bottom and are pushed toward an exit point, while lighter waste rises to the top and overflows as a separate stream of material.
Slide 32:The surface of diamond is highly unusual in that it resists being wetted by water but sticks readily to grease.
Here, wet gravel washes across 3 inclined surfaces covered with beeswax and paraffin.
Diamonds stick to the grease while wetted waste minerals flow past.
The operator routinely scrapes the material that adheres to the table into a grease pot, using a trowel.
The grease in the pot is melted and the diamonds are removed in a strainer .
More automated systems use a rotating grease belt and craper.
Slide 34:Cones (left) and cyclones (right) use heavymedia separation.
Diamond-bearing concentrate is mixed with a fluid near the density of diamond.
Separation occurs in cones and cyclones by swirling the mixture at low and high velocities respectively.
In the cone, rotational mixing permits lighter minerals to float to the top and run out as overflow, while diamonds and dense minerals sink to the bottom and are sucked out by a compressed air siphon.
Slide 35:In the cyclone, fast rotation of the suspension drives heavy minerals to the conical wall, where they sink to the bottom and are extracted
The float waste minerals are sucked from the center
of the vortex.
Cyclones are about 99.999% efficient at concentrating diamonds and similarly denseMinerals from the original ore.
PROCESS DONE AFTER SEPARATING DIAMOND :PROCESS DONE AFTER SEPARATING DIAMOND CUTTING
POLISHING
VALUING
CLARITY GRADINGS
CARAT ANALYSIS.
Slide 37:THANK YOU