CHEM 31122

-Metals and Metallurgy

-Inorganic Material Chemistry

Material Chemistry, Earth Resources and Introduction to Quality Management

Course content:

-Inorganic Material Chemistry

-Petroleum chemistry

-Quality management, intellectual property and green chemistry

Minerals and Metallurgy Minerals and Metallurgy

MineralsOnly a few minerals occur as pure elements in the earth’s crust - Native Element Minerals

Native sulfur Diamond Native silver

Native copper Native gold

Beryl

Quartz SiO2

Calcite CaCO3

-are naturally occurring, inorganic solids with well-defined chemical compositions and crystal structures

Minerals

In order for something to be classified as a mineral, it must meet the following criterion.Minerals are:Minerals are:

(i) Naturally occurring, (ii) Inorganic, (iii) Have known chemical compositions (iv) Have definite physical properties(v) Are solid

Minerals are identified by common names

Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2

Commercially, the most important sources of metalsare;

OxideSulfideCarbonate minerals

What is a Rock?

Rocks are naturally occurring solid aggregates of different minerals

An ore is a mineral or aggregate of minerals from which a valuable constituent, especially a metal, can be profitably mined or extracted

OresMetal distribution in the earth depends on geologic processes that have taken place. Some processes may form minerals with high metal contents

be profitably mined or extracted

The value of an ore depends on,-how much metal is in the ore-how costly is it to remove the metal from the ore

-depends on the demand of the metal

The occurrence and distribution of concentrated deposits of metals often play a role ininternational politics as nations compete foraccess to these materials

Many processes are used to obtain pure metal from ore.

Some need to go through only a few steps, while other ores must go through many steps.

Copper and gold were probably the first metals man learned to use. They occur in metals man learned to use. They occur in nature in a free state as well as in ores.

Gold headband from750–700 BC

Metallurgy is the science and technology ofextracting metals from their natural sources and preparing them for practical use.

Metallurgy

General metallurgical operations

MiningMining

Concentration of ore

Conversion of ore into free metals

Purification of metal

Conversion of ore into oxides

Metallurgical processes

1. Pyrometallurgy

Extraction and purification of metals byprocesses involving the application of heat

Some of the techniques used in pyrometallurgy are;

(i) Calcination(ii) Roasting(iii) Smelting(iv) Refining

2. Hydrometallurgy

Metal is extracted from its ore by use of aqueous reactions.

3. Electrometallurgy3. Electrometallurgy

Processes that are used to reduce metal ore or refine metals, are based on electrolysis.

How to Identify Minerals: Physical Properties

• Colour

• Streak

• LusterLuster

• Hardness

• Cleavage

Fracture

Specific Gravity

Other Special Properties

Colour

The most common elements affecting colour are: chromium, iron, manganese, titanium and copper.

Minerals tend to occur in a range of colours, and color patterns help to identify them

chromium, iron, manganese, titanium and copper.

colourless- clear

purple quartz - amethyst

Quartz comes in a wide range of colours. It is very easily colored by even trace amounts of impurities.

yellow - citrine

brown - smoky quartz

pink - rose quartz. black - morion

Streak

• When minerals are scratched, the powder that is made by the scratch is called the streak.

• Sometimes the color of the streak can be used to identify the mineral.

• Eg. Haemetite a black mineral has a red streak. No other black mineral has a red streak.

-Minerals can be termed:

• Luster

- describes the appearance of a mineral when light is reflected from its surface

-Minerals can be termed:

glassy, opaque, transparent, shiny, pearly, silky or most commonly: metallic and non-metallic.

Hardness

Refers to "scratchability" or resistance to being scratched. Harder minerals will scratch softer minerals.

Geologists rank minerals according to hardness Geologists rank minerals according to hardness using the Moh's scale

He selected ten minerals and arranged them in order so that any one mineral could be used to scratch only minerals which are less.

Moh's Hardness Scale1.0 TALC2.0 GYPSUM2.5 FINGERNAIL3.0 CALCITE3.5 COPPER PENNY4.0 FLUORITE4.0 FLUORITE5.0 APATITE5.5 STEEL KNIFE BLADE/GLASS PLATE6.0 ORTHOCLASE FELDSPAR7.0 QUARTZ8.0 TOPAZ9.0 CORUNDUM (RUBY) 10.0 DIAMOND

Fingernail Hardness (2.5) Scratches Gypsum (2)

Cleavage................

No cleavage

Specific gravity is defined as the ratio of the weight of a substance compared to that of an equal volume of water

Specific Gravity……

Gravity separation, which relies on the difference in specific gravities of minerals, is one of the in specific gravities of minerals, is one of the oldest techniques for separating minerals.

Magnetic Property

-Magnetic properties are useful foridentifying a mineral.

-Several minerals react when placedwithin a magnetic field.

-Some minerals are strongly attracted to the magnet, others are weakly attracted, and some minerals are actually repelled.

Magnetism refers to the reaction of a mineral in a magnetic field.

-The way a substance behaves in a magnetic field provides an important insight into the arrangements of its electrons.

Magnetic Property

-Most minerals can be classifiedas;

-This is a piece of MAGNETITE with amagnet adhering to it

as; (i) Diamagnetic(ii) Paramagnetic(iii) Ferromagnetic

An everyday example of ferromagnetism is a refrigerator magnet used to hold

Ferromagnetic material

a refrigerator magnet used to hold notes on a refrigerator door

Magnetism in Minerals

1. Diamagnetic - not attracted to a magnet (e.g., calcite, quartz, feldspar)

2. Paramagnetic - weakly attracted (e.g., Hematite, ilmenite); not permanent

3. Ferromagnetic - very strong attraction (metal iron); also permanent

calcitemagnetite

iron meteorite

-Material is fed in through the top where a revolving cylinder carries it over a stationary magnet.

-The magnetic field attracts and holds magnetic material and

Magnetic Separation

attracts and holds magnetic material and discharge the non-magnetic material

-The magnetic fraction is then released as it leaves the magnetic field.

Non-

magnetic

fracti

Non –magnetic particles magnetic

particlesNon-

magnetic

fracti

Other Properties

Feel- What the mineral feels like.Ex. Graphite - greasy

Characters Depending upon Senses

Mineral Identification Basics

• CHEMICAL PROPERTIES

REACTION TO HYDROCHLORIC ACID

Some minerals, notably the carbonates, react to cold carbonates, react to cold dilute HCl. In this illustration a piece of CALCITE is shown to react (fizz) after HCl is applied. (*)

Calcite Reacts to HCl (*)

PyrometallurgyPyrometallurgy

The Pyrometallurgy of Iron

Most important sources of iron are hematite Fe2O3 and magnetite Fe3O4.

Reduction occurs in a blast furnace.Reduction occurs in a blast furnace.

The ore, limestone and coke are added to the top of the blast furnace.

Formation of Steel

-Most of the iron is used to manufacture steel

-Steel is an alloy of iron

-Iron from a blast furnace typically containsmany undesired impuritiesmany undesired impurities

HydrometallurgyHydrometallurgy

The Hydrometallurgy of Aluminum

Aluminum is the second most useful metal.

Bauxite is a mineral that contains Al as Al O .xH O.Bauxite is a mineral that contains Al as Al2O3.xH2O.

Major impurities are silicates (SiO2) and iron oxides (Fe2O3).

ElectrometallurgyElectrometallurgy

Electrometallurgy is the process of obtaining metals through electrolysis.

Two different starting materials: molten salt or molten salt or aqueous solution

ElectrometallurgyElectrometallurgy

Electrometallurgy of Sodium

Sodium is produced by electrolysis of molten NaCl in a Downs cell.

ElectrometallurgyElectrometallurgyElectrometallurgy of Aluminum

-Al2O3 melts at 2000°C and it is impractical to perform electrolysis on the molten salt.

-Electrolysis cell is used to produce aluminum (Hall-Heroult process).

Electrometallurgy of AlElectrometallurgy of Al

ElectrometallurgyElectrometallurgy

Electrorefining of Copper

Because of its good conductivity, Cu is used to make electrical wires.

Impurities reduce conductivity, therefore pure Impurities reduce conductivity, therefore pure copper is required in the electronics industry.

-Metals (impurities) are collected in the sludge at the bottom of the cell.

HW problem

-Ni is one of the chief impurities in the crude Cu that is subjected to electrorefining. What happens to this Ni in the course of electrolytic process?

Economic Geology of Sri Lanka

Geological Survey and Mines Bureau (GSMB) in Sri Lanka is one of the responsible authorities for economic minerals in Sri Lanka.

Graphite

Bogala Graphite mine

The Allotropes of Carbon

DiamondDiamond

Graphite

Nano tubesFullerenes

Graphite

Applications

Pencils

Crucibles & fire proofproducts

Brake linings

Carbon brushes

Batteries

Applications

Batteries

Apatite

Apatites have the general formula,Ca10(PO4)6X2 or Ca5(PO4)3X

X = OH, F, Cl

Apatite

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite,

fluorapatite andchlorapatite

hydroxylapatite, fluorapatite chlorapatitehydroxylapatite, fluorapatite chlorapatite

Ca5(PO4)3 F Ca5(PO4)3ClCa5(PO4)3OH

-One of our best economic mineral reserves is the apatite rock phosphate at Eppawala.

-It is situated around 20 km south of the ancient city of Anuradhapura and 150 km north east of Colombo.

Apatite in Sri Lanka

of Colombo.

-The reserve extents over 7 km2 and about 125 m deep from the surface.

Heavy mineral sands are formed most usually in beach environments by concentration due to the specific gravity of the mineral grains. –Beach sand deposits

-Most common minerals in mineral sand are,

Heavy Mineral Sands

-Most common minerals in mineral sand are,IlmeniteRutile ZirconMonaziteMagnetiteGarnetCassiterite (oxide of tin)

All with specific gravitymorethan 2.9

Pulmoddai beach sand deposit is the most important mineral sand reserve in Sri Lanka to date.

It contains minerals which consist of one of the most expensive and important metals in the world that is titanium.that is titanium.

Ilmenite (FeTiO3) and rutile (TiO2) found in enormous concentrations in the Pulmoddai beach sand deposit.

This deposit extends fromNilaveli to Kokilailagoon mouth. lagoon mouth.

Ilmenite (FeTiO3) and rutile (TiO2)

Titanium Dioxide

• Titanium Dioxide is the most important white pigment currently produced commercially.

• The pigment is used in a wide • The pigment is used in a wide range of applications including inks, textiles, paper, paints, food, and pharmaceuticals.

Rutile Anatase Brookite

crystal structures of the three polymorphs of titanium dioxide, TiO2

2. Chloride process

Uses of TiO2/ white pigments

Production of Ti

Dolomiteby-nc-nd: Il T

opone / E

milia

no B.

The Dolomites are a mountain range in Italy that is made of dolomite rock.

Deodat de Dolomieu

Dolomite is composed of Calcium, Magnesium, and Carbonate [CaMg (CO3)2] and is classed as a carbonate.

Hard water causes “scaling”.

nc: Nofolete / Dane Larsen

nc: Dane Larsen

by-nc-sa: spike55151

by-nc-sa: A

lan Penner

Hard water can be improved by “water softening” treatment.

by-nc: Nofolete / Dane Larsen

by-nc: Dane Larsen