CHEM 31122
Material Chemistry, Earth Resources and
Introduction to Quality Management
Course content:
-Metals and Metallurgy
-Inorganic Material Chemistry
-Petroleum chemistry
-Quality management, intellectual
property and green chemistry
Minerals and Metallurgy
Minerals
Only a few minerals occur as pure elements in
the earth’s crust - Native Element Minerals
Native sulfur
Diamond
Native copper
Native gold
Native silver
Beryl
Quartz SiO2
Calcite CaCO3
Minerals
-are
naturally occurring, inorganic solids with
well-defined chemical compositions and crystal
structures
In order for something to be classified as a
mineral, it must meet the following criterion.
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 metals
are;
Oxide
Sulfide
Carbonate minerals
What is a Rock?
Rocks are naturally occurring solid aggregates
of different minerals
Ores
Metal distribution in the earth depends on
geologic processes that have taken place. Some
processes may form minerals with high metal
contents
An ore is a mineral or aggregate of minerals from
which a valuable constituent, especially a metal, can
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 in
international politics as nations compete for
access 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
nature in a free state as well as in ores.
Gold headband from
750–700 BC
Metallurgy
Metallurgy is the science and technology of
extracting metals from their natural sources and
preparing them for practical use.
General metallurgical operations
Mining
Concentration of ore
Conversion of ore into oxides
Conversion of ore into free metals
Purification of metal
Metallurgical processes
1. Pyrometallurgy
Extraction and purification of metals by
processes involving the application of
heat
Some of the techniques used in
pyrometallurgy are;
(i)
(ii)
(iii)
(iv)
Calcination
Roasting
Smelting
Refining
2. Hydrometallurgy
Metal is extracted from its ore by use of aqueous
reactions.
3. Electrometallurgy
Processes that are used to reduce metal ore
or refine metals, are based on electrolysis.
How to Identify Minerals:
Physical Properties
• Colour
• Streak
• Luster
• Hardness
• Cleavage
Fracture
Specific Gravity
Other Special Properties
Colour
Minerals tend to occur in a range of colours, and
color patterns help to identify them
The most common elements affecting colour are:
chromium, iron, manganese, titanium and copper.
Quartz comes in a wide range of colours. It is very
easily colored by even trace amounts of impurities.
colourless- clear
purple quartz - amethyst
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.
• 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
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 Scale
1.0
TALC
2.0 GYPSUM
2.5 FINGERNAIL
3.0 CALCITE
3.5 COPPER PENNY
4.0 FLUORITE
5.0 APATITE
5.5 STEEL KNIFE BLADE/GLASS PLATE
6.0 ORTHOCLASE FELDSPAR
7.0 QUARTZ
8.0
TOPAZ
9.0
CORUNDUM (RUBY)
10.0 DIAMOND
Fingernail Hardness (2.5) Scratches Gypsum (2)
Cleavage................
No cleavage
Specific Gravity……
Specific gravity is defined as the ratio of the
weight of a substance compared to that of an
equal volume of water
Gravity separation, which relies on the difference
in specific gravities of minerals, is one of the
oldest techniques for separating minerals.
Magnetic Property
-Magnetic properties are useful for
identifying a mineral.
-Several minerals react when placed
within a magnetic field.
Magnetism refers to the reaction of a mineral
in a magnetic field.
-Some minerals are strongly attracted to
the magnet, others are weakly attracted, and some
minerals are actually repelled.
Magnetic Property
-The way a substance behaves in a magnetic
field provides an important insight into the
arrangements of its electrons.
Most minerals can be classified
as;
(i)
Diamagnetic
(ii) Paramagnetic
(iii) Ferromagnetic
-
-This is a piece of
MAGNETITE with a
magnet adhering to it
Ferromagnetic material
An everyday example of
ferromagnetism is
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
iron meteorite
magnetite
calcite
-Material is fed in
through the top where a
revolving cylinder carries
it over a stationary
magnet.
Magnetic Separation
-The magnetic field
attracts and holds
magnetic material and
discharge the nonmagnetic material
-The magnetic fraction is
then released as it leaves
the magnetic field.
Non –magnetic particles
Nonmagnetic
fracti
magnetic
particles
Nonmagnetic
fracti
Other Properties
Characters Depending upon Senses
Feel
- What the mineral feels like.
Ex. Graphite - greasy
Mineral Identification Basics
• CHEMICAL PROPERTIES
REACTION TO HYDROCHLORIC ACID
Some minerals, notably the
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 (*)
Pyrometallurgy
The Pyrometallurgy of Iron
Most important sources of iron are hematite
Fe2O3 and magnetite Fe3O4.
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 contains
many undesired impurities
Hydrometallurgy
The Hydrometallurgy of Aluminum
Aluminum is the second most useful metal.
Bauxite is a mineral that contains Al as
Al2O3.xH2O.
Major impurities are silicates (SiO2) and iron
oxides (Fe2O3).
Electrometallurgy
Electrometallurgy is the process of obtaining
metals through electrolysis.
Two different starting materials:
molten salt or
aqueous solution
Electrometallurgy
Electrometallurgy of Sodium
Sodium is produced by electrolysis of molten NaCl
in a Downs cell.
Electrometallurgy
Electrometallurgy 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 Al
Electrometallurgy
Electrorefining of Copper
Because of its good conductivity, Cu is used to
make electrical wires.
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
Diamond
Graphite
Fullerenes
Nano tubes
Graphite
Applications
Pencils
Brake linings
Carbon brushes
Crucibles &
fire proof
products
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 and
chlorapatite
hydroxylapatite,
Ca5(PO4)3OH
fluorapatite
Ca5(PO4)3 F
chlorapatite
Ca5(PO4)3Cl
Apatite in Sri Lanka
-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.
-The reserve extents over 7 km2 and about 125 m
deep from the surface.
Heavy Mineral Sands
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,
Ilmenite
All with specific gravity
Rutile
more
Zircon
than 2.9
Monazite
Magnetite
Garnet
Cassiterite (oxide of tin)
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.
Ilmenite (FeTiO3) and rutile (TiO2) found in
enormous concentrations in the Pulmoddai beach
sand deposit.
This deposit
extends from
Nilaveli to
Kokilai
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
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
Dolomite
by-nc-nd: Il Topone / Emiliano 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.
by-nc:
nc: Dane Larsen
by-nc:
nc: Nofolete / Dane Larsen
by-nc-sa: spike55151
Hard
water
causes
“scaling”
.
by-nc-sa: Alan Penner
Hard water can
be improved by
“water
softening”
treatment.