Sample Preparation Equipment

Most metallic samples are not obtained in their desired state for analysis. These
samples have been contaminated with dirt and other substances from the
environment.They also come in different sizes and shapes therefore certain equipment
is needed to prepare these samples for analysis.

1. Cutting Equipment
● Contact Cutting Machine
Circular Saw cut off machine
Cutting machine with a rotating circular sharp toothed blade
❖ Abrasive cut off machine: Blade is made from abrasive materials
such as aluminum oxide and used for general purpose cutting of
various materials due to it’s thick blade size
❖ Precision cut off machine: Blade is also from abrasive materials but
has a thinner size for precise and controlled cutting of smaller
material samples.
❖ Diamond saw cut off machine: Blade has diamond teeths for
precisely cutting hard variety of materials
❖ Metallographic cut off machine: Blade has diamond embedded all
around for both even wear leading to long life span and precise
cutting of smaller metallic materials
❖ Cold Saw machine: Its circular blade has teeths specifically
designed to withstand heat generated during cutting.

Rectangular saw cut off machine

Cutting machines with a continuous band of toothed rectangular blade
❖ Band Saw Cut Off Machine:Uses a continuous band with teeth to
cut through materials. The material is fed into the saw and guided
along the path of the moving blade, which continuously cuts
through the material in a straight or curved line.

Other machines
❖ Guillotine shear: Used in cutting metal sheets. It operates as a
scissors but has only one movable blade
❖ Hydraulic Press: Uses hydraulic force to cut material

● Non - Contact Cutting Machine

 Media based cut off machine
These machines use certain substances under certain conditions to
perform the cutting operation.
❖ Abrasive Water Jet Cut - Off Machine: Uses high pressure water mix
with some abrasive material to cut through hard materials.
❖ Water Jet Cut - Off Machine: Uses high pressure pure water to cut
through soft materials
❖ Oxy-fuel Cut-Off Machine: Uses combustion of oxygen and fuel gas
(eg. acetylene) to create high temperature flame for cutting
❖ Plasma Cut-Off Machine: Plasma arc is used in cutting the material
(electrical conductive materials). Plasma arc is obtained by passing
electric current through a gas.

Electromagnetic based cut off Machine

❖ Laser cut off Machine: It uses lasers to cut materials with high
precision and accuracy.
❖ Wire EDM(Electrical Discharge Machining):: It uses electric spark
from a thin wire in cutting the material. The workpiece is connected
to the positive terminal (made the anode) since oxidation occurs on
the anode it corrodes faster leading to effective cutting.

● CNC Machines
These refer to the machines listed above that have been equipped with Computer
Numerical Control (CNC) technology. This technology employs computerized
controls to automate and precisely control the operation of the machine.

2) Crushing Equipment
● Compression Crushers
These crushers use pressure to reduce lumpy particles to fragments by
squeezing with an applied force.
❖ Jaw Crushers : It has a fixed jaw set at an acute angle to a movable
jaw which has been pivoted such that it swings relative to the fixed
jaw during the crushing process.They are normally used in the
primary crushing stage.Below are the various types of jaw crushers.
Dodge Crusher: It is pivoted at the discharge end rendering it less
throughput (less efficient for industrial scale) that is small materials
get crushed in a long time frame.
 Blake Crusher: It is pivoted at the top rendering it an increased
throughput(efficient for industrial scale).Double toggle and single
toggle are classified under Blake crusher.
a. Single toggle has its movable jaw driven by a pitman giving it a
linear motion with a single toggle plate on both sides of the jaw on
each whilst
b.Double toggle has its movable jaw driven by a more robust
eccentric shaft giving it a rocky motion with double toggle plate on
both sides of the jaw. It has a higher crushing force due to this
robust eccentric shaft.
Universal Crusher: It is pivoted at the center making it capable of
handling a wide range of materials

❖ Gyratory Crusher: It has a crushing head connected to a shaft which

moves in a circular manner without touching the shells of the
crusher. This crusher has a high capacity( efficient for industrial
scale) due to its full cycle crushing.It is mostly used at the primary
crushing stage.It various types includes
Standard Gyratory crusher: It is just like the general gyratory crusher.
Short Head Gyratory crusher: It has a compact design with a short
head for crushing fine particles. Used for small scale or laboratory
works.
Superior Gyratory crusher: It has advanced features such as the use
of hydraulics for adjustment, a larger feed opening with an
increased eccentricity and diameter of mantle leading to increased
crushing speed and througput.
Spiderless Gyratory crusher: The spider in the traditional crusher
holds the shaft in support along its axis and is also used in making
adjustments but it is too complex to repair and maintain. Spiderless
Gyratory employs bearings to hold the upper part of the shaft and
eccentric assembly to hold the bottom part. It also uses hydraulics
to make the vertical adjustments.

❖ Cone Crusher: It is just like the gyratory crusher but it has a shorter
spindle which is supported below.It is mostly used in the secondary
stage of crushing.The various types of the cone crusher are
 Standard cone crusher: This cone crusher has liners of different
height on the immovable conical surface. This enables it to accept
coarser feed size
Short head cone crusher: It has a smaller crushing chamber, limiting
it to laboratory scale.It does not have stepped liners to help in
accommodating coarser feed size.It has a steeper head angle for
preventing choking of fine particles
Gyradisc crusher: It is a specialized type of cone crusher used in the
secondary or tertiary stages of crushing, where smaller particles
are required to be further broken down to fines.Apart from the use
of hydraulics for its adjustments, it has high capacity for operation
at low cost since the crushing head rotates full cycle providing a
narrow size distribution.

❖ Roll crushers: It involves the use of horizontally placed cylinder(s) in

a revolving motion to break down coarser samples into fragments.It
crushes rocks by nipping it between the approaching revolving
cylinder face.Smooth faces produces fine particles while
corrugated faces produces coarser particles. Types of roll crushers.
Single roll crusher: It involves only one horizontally placed cylinder
revolving against a plate on which the crushing is done.
Double roll crusher: It involves two horizontally placed cylinders held
in positions for adjustments by hydraulic systems.The space
between the revolving cylinders tells the average product size.One
type of this crusher is

● Impact Crushers
This crushing involves collision by high speed forces.
❖ Hammer mills: This crusher contains swinging hammers which
break feed particles by hard striking or collision of particles against
surrounding wall plates.These can be used in primary
crushing.They produce fine particles though due to the longer stay
of particles in the chamber.
❖ Vertical Shaft Impact Machine has a vertical shaft that sets the
material in motion against a high-speed rotor, resulting in the
crushing of the particles.
 ❖ Horizontal Shaft Impact Machine has a horizontal shaft that utilizes
blow bars to create impacts on the material. THis impact sets the
particle on high velocities leading to its breakdown.

3)Grinding Equipment
These are equipment used in reducing particles to finer size for further processes.
● Ball Mill: These are cylindrical devices used in grinding materials like ores and
ceramic raw materials. They rotate around a horizontal axis and are partially filled
with the material to be ground and grinding media, such as steel balls or ceramic
balls.Types of ball mill
Semi-Autogenous Mill: The grinding is done by a combination of the particles
themselves and the grinding media
Autogenous Mill: The mill utilize grinding media generated within the mill from
suitably sized pieces of the ore itself

● Rod Mill: They are similar to ball mills but they use long rods as a grinding
media.Types of rod mill are based on the discharge position of the mill.
Overflow Rod Mills: In overflow rod mills, the material is discharged through the
overflow discharge opening at the end of the mill.
Grate Discharge Rod Mills: In grate discharge rod mills, the material is
discharged through the grate openings at the end of the mill.
Peripheral Discharge Rod Mills:The material is discharged through peripheral
discharge ports located in the trunnion liners.
Central Discharge Rod Mills: The material is discharged at the center of the mill
shell.

4)Mounting Press Equipment

Mounting press equipment is used in metallurgy labs to securely embed metallographic
specimens in a mounting material,
● Hot Mounting Press:It is used to securely attach metal samples to a hard
material called resin. The press uses heat and pressure to make the resin
harden, creating a strong attachment for further examination
● Cold Mounting Press:It is used for mounting metallographic specimens in
cold-curing resins. Unlike hot mounting, cold mounting does not require heating
and curing under high temperatures.
5)PARTICLE SIZE ANALYSIS

● Laser Diffraction Particle Size Analyzer: Laser diffraction analyzers are widely
used for particle size analysis in metallurgy. They utilize laser light scattering to
measure the particle size distribution of a sample. This distribution is presented
on a histogram chart.

● Sedimentation Particle Size Analyzer: Sedimentation analyzers are used to

measure particle size by observing the settling behavior of particles in a fluid
medium. This follows the principle behind Dense Medium Separation.

● Sieve Shaker: Sieve shakers are commonly used for coarse particle size
analysis. They consist of a stack of sieves with varying mesh sizes, and the
sample is mechanically shaken to separate particles according to their size. This
technique is useful for analyzing larger particles and can be combined with sieve
analysis methods.
● Mastersizer Equipment: This equipment uses techniques like laser diffraction or
sedimentation to determine the size of particles in a given material.

6)Polishing Equipment
These are machines used to polish and smoothen surfaces of materials by removing
imperfections from the surface of the material for scientific analysis.
examples of polishing machines commonly used in metallurgy and assay labs include:

● Rotary Polisher: These polishers use wheels or discs as the means of

polishing. They provide rotational motion to the polishing wheel, ensuring even
and consistent polishing.

● Vibratory Polisher: This machine has smaller even shape materials (made up
of steel or ceramics or plastic) which are set to vibrating motion together with the
material to be polished to facilitate the polishing process. Polish liquid is added to
the media to help reduce friction and also remove debris from surface of metals
● Planar Grinder/Polisher: Planar polishers are mostly used for the preparation of
large, flat metal samples.This contain a polishing head which moves linearly to
facilitate the polishing process.
 ● Electrolytic Polisher: Electrolytic polishing machines use an electrolytic
process to remove surface roughness and improve the quality of the metal
surfaces.The sample is immersed in the electrolyte and current is applied across
it to selectively dissolve surface imperfections.

7)Etching Equipment
These are equipment which are generally used to expose the microstructure of metals
or alloys. They employ the use of certain chemicals known as etchants which remove
some thin layers from the surface of the sample in order to reveal the microstructure
under a microscope.

● Electrochemical etching equipment: The sample is connected to the cathode

which in turn is connected to the negative terminal of the voltage supply.The
anode is connected to the electrolyte and current is allowed to flow which causes
an electrochemical reaction at the metal with the electrolyte, releasing some
layers from the surface.
● Hot etching equipment: The etchant is reacted directly with the sample for the
etching process. The etching solution is heated using specialized heating plates
or temperature-controlled bathsHot etching involves heating the etching solution
to accelerate the etching process.

● Ultrasonic etching equipment: This equipment has a tank or bath in which

suitable etchant and the sample material are present together with ultrasonic
transducers embedded in the walls or immersed in the solution. These
transducers produce high frequency sounds leading to vibratory motion in the
tank therefore creating low and high pressure zones.This creates and collapses
microscopic bubbles. This action causes some agitation force on the surface of
the sample aiding in the etching process.

● Laser etching equipment: Laser beams are use to selectively remove material
from metal surfaces. The laser acts as the etching solution in this case. This
system works with high precision and accuracy.
Microscopy and Imaging Equipment: These tools are used for examining
the microstructure of metals.

1)Optical Microscopy: Optical microscopy involves examining metal specimens under

a microscope to study their microstructure, grain size, and other features.

2) Scanning Electron Microscopy (SEM): SEM uses a focused beam of electrons to

obtain high-resolution images and surface morphology details of metal samples. It also
allows for microanalysis using EDS/EDX for elemental mapping and analysis.

3) Transmission Electron Microscopy(TEM): TEM provides high-resolution imaging

and analysis of metal samples, allowing for the examination of microstructures,
dislocations, and crystal defects at the atomic scale.

4) Image Analysis System: Image analysis systems employ optical microscopy and
image processing techniques to measure particle size and shape. By capturing images
of particles and analyzing them using specialized software, it is possible to obtain
detailed information about the size and morphology of individual particles or aggregates.

Spectroscopy tools and equipment is used to analyze chemical

compositions of the sample given in metallurgical engineering laboratory

1) Spectrophotometer: A spectrophotometer is used to measure either the absorption

or transmission of light by a sample, enabling the quantitative analysis of various
elements or compounds.

2) Atomic Absorption Spectrophotometer (AAS):This machine operates by first

changing the sample to a gaseous ion or atoms state using nebuliser and the hot flame.
Specific light with known elements is sent into the chamber to be absorbed by similar
elements present.This absorption renders these ions excitation and when they
de-excite, they give out photons which are used to quantify the element present from
the intensities.

3) Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES):

ICP-OES is similar to a spectrophotometer in that it measures the emission of light by
ions or atoms excited in an inductively coupled plasma. The intensity of the emitted light
will help me, providing elemental analysis for a wide range of elements.
4) Inductively Coupled Plasma Mass Spectrometry (ICP-MS): ICP-MS is similar to
ICP- OES in terms of combination with plasma ionization.The ions are then sent to
electric field were mass spectrometry is use to take the mass to charge ratio.
Sophisticated apps do the reading of concentrations against the mass to charge ratio on
a graph.

5) Optical Emission Spectroscopy (OES): OES is used to determine the elemental

composition of metal samples by measuring the light emitted when atoms in the sample
are excited by an energy source.

6) Carbon/Sulfur Analyzer: Carbon/Sulfur analyzers determine the carbon and sulfur

content in the sample by combustion in pure oxygen to form oxides of carbon and sulfur.
Carrier gses are used to collect these gasses and detectors are used to quantify their
amount present.eg. Non- Dispersive infrared sensors.

Mechanical testing equipment is used to assess the mechanical properties

and behavior of metals and alloys. Here are some common examples of
mechanical testing equipment in metallurgy labs:

1. Tensile Testing Machine: Tensile testing machines are used to check for the tensile
strength, yield strength, elongation,elastic limit and other mechanical properties of
metals by plotting a graph of strain against stress until it fractures from the axial
stretching experiment.

2. Hardness Tester: It measures the hardness of the sample, that is its resistance to
scratching.

3. Impact Testing Machine: Impact testing machines measure the impact resistance
and toughness of metals by striking a notched or unnotched sample with a weighted
pendulum or hammer. These machines provide information about a material's ability to
absorb energy and resist brittle fracture.

4. Fatigue Testing Machine: Fatigue testing machines subject metal samples to cyclic
loading to assess their fatigue strength and endurance limit. It helps us to know the
durability and the fatigue life of the sample

5. Creep Testing Machine: Creep testing machines apply sustained loads at elevated
temperatures to evaluate a metal's resistance to creep, which is the slow,
time-dependent deformation under constant stress. These tests provide information
about a material's ability to withstand prolonged exposure to elevated temperatures.

Thermal Analysis Equipments includes tools to study the thermal behavior

of the sample

1. Differential Scanning Calorimeter (DSC): This device comprises two pans, one
with the sample closed very tight and the other with nothing (reference pan). Both are
heated with their temperature difference closely monitored. This device is used to
measure the heat flow into or out of the pan with the sample to reach the temperature of
the reference pan. It can provide information about phase transformations and other
chemical transformations.

2. Thermogravimetric Analyzer (TGA): TGA is used to measure the weight changes

of a sample as a function of temperature. It can be used to determine the composition,
thermal decomposition, oxidation, and other thermal behavior of metals.

3. Dilatometer: Dilatometer measures the dimensional change of a sample as a

function of temperature. It helps in determining the coefficient of thermal expansion,
phase transformations, and other thermal properties of metals.

4. Thermal Mechanical Analyzer (TMA): TMA measures the dimensional change of a

sample under both mechanical and thermal stimuli. It can provide information about the
coefficient of thermal expansion, glass transition temperatures, and mechanical
behavior of metals.

5.Cupellation Furnace: They are designed for the cupellation process in assaying.
While the metal sample is being heated in the furnace at high temperatures,
atmospheric oxygen or well controlled flow of oxygen is allowed to react with the sample
(oxidation) which in turn removes certain impurities present.

Chemical Analysis tools and instruments are used to perform accurate and precise
measurements. Here are some common chemical analysis tools used in metallurgical
engineering laboratory
1) Titrations: Titrations are analytical techniques in which a solution of known
concentration is added to a sample to determine the concentration of a specific analyte,
● Burette:It is a long, graduated tube with a stopcock at the bottom. It is used to
accurately measure and dispense a precise volume of a titrant solution during the
titration process.

● Pipette: They are used to transfer precise volumes of liquids.

● Titration Flask: It is a glass container with a narrow neck. It is used to hold the
analyte solution during the titration process.

● Burette Stand:It is a support system used to hold the burette securely in an

upright position.

2) Gravimetry: Gravimetric analysis involves determining the quantity of an analyte

based on the measurement of weight changes, precipitation, or volatilization.
● Desiccator:It is a sealed container used to store samples in a dry environment. It
contains a desiccant such as silica gel or calcium chloride, which absorbs
moisture to prevent sample contamination during weighing.

● Crucible: It is a small, heat-resistant container typically made of porcelain, glass,

or metal. It is used to hold the sample during the gravimetric analysis process.

● Muffle Furnace: A muffle furnace is a high-temperature heating device used for

drying or calcination of samples in gravimetric analysis.