The document is a lab report submitted by Rida Aqsa to Sir Irfan at the University of Engineering and Technology Lahore. It describes 3 experiments conducted regarding particle technology: 1) measuring the angle of balls carried against the wall of a ball mill, 2) measuring the angle of repose for rice and wheat using a rotary cylinder, and 3) describing the operation of an ultrafine grinder which uses a vertical shaft and multi-chambered rotor units to grind materials at high speed. The ball mill and ultrafine grinder experiments aimed to optimize grinding efficiency while the angle of repose experiment analyzed how solids flow out of containers.

1. LAB REPORT OF
PARTICLE TECHNOLOGY
SUBMITTED TO: SIR IRFAN
SUBMITTED BY: RIDA AQSA
( 2O13-BET-CHEM-21)
UNIVERSTY OF ENGINEERING AND TECHNOLOGY LAHORE

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LAYOUT OF PARTICLE
TECHNOLOGY LAB
Experiment#1

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Ball Mill
Objective:
Calculate angle α (to which the balls are carried against the wall of the ball mill), between
perpendicular (top of the ball mill) and the point at which the outermost ball lose contact with the
wall of the mill
MaterialRequired:
 Ball mill
 Balls
 Vibratory shaker and a set of sieves
 Collecting tray
 Solid for a study
Theory:
Ball mill (also named grinding ball) is one of the most important grinding mills in the mining
industry which is used to break all kinds of minerals and other materials in the industries of ore
beneficiation, construction materials and chemical engineering. There are two grinding modes:
wet type and dry type. The discharging ways can be divided to grid type and over flow type. Ball
mills are in many shapes: short drum one, long drum one, pipe one and cone shaped one.

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Materials enter the first cabin of ball mills via the feeding device
across the hollow shaft uniformly. In the first cabin, there is a ladder scale board or a ripple scale
board with different steel balls which will be lifted to certain height in the effect of centrifugal
force produced by the rotating cylinder. Then the balls fall to impact and grind the materials.
After the rough grinding process, materials enter the second cabin through the single layer cabin
separating board. There is a scale board with steel balls in the second cabin which will grind
materials. The finished powder materials are discharged from the unloading plate, thus finishing
the grinding process.
Procedure:
 Measure the inside diameter of the ball mill.
 Measure the size of the ball with the help of venire calipers.
 Fill the ball mill to about half of its volume with balls of the same diameter.
 Feed t ball mill with 250 g mass of sugar of homogenous size (obtained by screening) and
note the particle diameter.
 Before turn on the mill, set speed regulators to maximum.
 Measure the speed of rotation of the ball mill in the revolutions per minutes.
 Analyze the product with the help of screen and note the particle diameter
 Calculate the angle α (to which the balls are carried against the wall of the ball mill)
between perpendicular (top of the ball mill) and the point at which the outermost balls
lose contact with the wall of the mill.
 Calculate the critical speed of the ball mill.
 Describe the speed of the revolution of the ball mill as the percentage of the critical
speed.

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Observationand calculation:
Mesh
No.
Differential Analysis
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟐
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟑 𝑫̅ 𝒑 𝒊
. 𝒙 𝒊
Cumulative
Analysis
Mass
retained
(g)
Opening
of sieve
(mm)
Average
particle
size
𝑫̅ 𝒑 𝒊
(mm)
Mass
fraction
(𝒙 𝒊)
8 160 2.38 - 0.64 - - - - 1
10 22 1.68 2.03 0.088 0.0433 0.0214 0.0105 0.1786 0.36
14 22 1.19 1.435 0.088 0.0613 0.0427 0.0298 0.1263 0.272
20 2 0.841 1.0155 0.008 0.0079 0.0078 0.0076 0.0081 0.184
25 8 0.707 0.774 0.032 0.0413 0.0534 0.0690 0.0248 0.176
Pan 36 - - 0.144 - - - - 0.144
Advantages:
1. high production capacity and crushing ratio;
2. low power consumption, uniform particle size;
3. simple structure, easy to operate;
4. low investment cost, big profit;
5. perfect services, both before-sales servies and after-sales services.
Ball mill is mainly made up of feeding part, discharging part, rotary part, rotating part (reduction
box, small rotating gear, motor, electronic control). Hollow shaft adopts steel casting, and inner
plate is replaceable. Rotary wheel adopts casted hobbling. Inside the barrel, it has wearable liner.
Ball mill works very stably, and can choose dry ball mill and wet ball mill.
Industrial Application:
An industrial ball mill has the ability to operate continuously. These ball mills are often
controlled by a machine that feeds materials through one end of the mill and out the other end.
Smaller mills can only operate with the help of a cylindrical container containing a tight cap.
These mills are part of a pulley system that uses belts and pulleys to operate smaller ballmills.

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A ball mill is a grinding device that is used to turn material into fine powder. Ball mills are
cylindrical in shape, and are often the grinder of choice when it comes to mashing paints, ores,
ceramic materials, and certain hard chemicals. By rotating on a horizontal axis, a ball mill can
effectively convert a hard material into a loose powder.
In addition to the material that is meant to be ground, ball mills also contain a grinding material.
Ceramic balls, stainless steel balls, and flint pieces are often used as grinding materials. When
this matter grinds against another matter, the result is a crushed powder that can then be used for
other applications.

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Experiment#2
Pebble Mill
Angle of Repose:
1. To report the angle of repose of the given sample
Require Materials:
1. Rotary cylinder
2. Solid Objects to study
Theory:
The angle of repose or the critical angle of repose, of a granular material is the steepest angle of
descent or dip relative to the horizontal plane to which a material can be piled without slumping.
At this angle, the material on the slope face is on the verge of sliding. The angle of repose can
range from 0° to 90°. Smooth, rounded sand grains cannot be piled as steeply as can rough,
interlocking sands. If a small amount of water is able to bridge the gaps between particles,
electrostatic attraction of the water to mineral surfaces will increase soil strength.
When bulk granular materials are poured onto a horizontal surface, a
conical pile will form. The internal angle between the surface of the
pile and the horizontal surface is known as the angle of repose
and is related to the density, surface area and shapes of the
particles, and the coefficient of friction of the material.
However, a 2011 study shows that the angle of repose is
also gravity-dependent. Material with a low angle of
repose forms flatter piles than material with a high angle

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of repose.
The term has a related usage in mechanics, where it refers to the maximum angle at which an
object can rest on an inclined plane without sliding down. This angle is equal to the arctangent of
the coefficient of static friction μs between the surfaces.
Procedure:
 Take the sample of granules solid of a particle size around sugar grains or similar, and
with suitable humidity grade.
 Fill the rotary cylinder to half using pneumatic conveyer system (sucking up from a
hopper and separating the particle through a cycle)
 Turn the cylinder slowly, clockwise, until the very moment that particles start sliding.
 Take note of the angle described by the solid.
 Now rotate the cylinder anticlockwise and take note of the angle described by the solid.
 Calculate angle of repose as the mean between these two measures.
 Repeat the test several times for better thoroughness of the data.
Observationand Calculation:
ANGLE OF REPOSE OF RICE:
Clockwise Anticlockwise
30o
31o
Mean angle of repose = 30.5o
ANGLE OF REPOSE FORE WHEAT:
Clockwise Anticlockwise
38o
35o

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Mean angle of repose = 36.5o
Others:

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Experiment#3
Ultrafine Grinder
Ultrafine Grinder is an elegant vertical type of pulverizer that is globally appreciated for being
most innovative regarding excellent functionality. The modern machine is a unique assembly of
multi-chambered rotor units which have been strategically interpolated with circular disc. It is
mounted on a vertical shaft.
A standard base frame and drive are offered with the ultrafine grinder machine. It is made to
grind materials with not just desired perfection but also lightning fast speed.
As it doesn’t require any special feeding system like, screw conveyor or rotating valve, it’s very
user-friendly
.
There is High-pressure spring which can bear 1,500kg to 2,000 kg force tighten on the roller
grinder of the High-pressure Grinder Mill. Inside the mainframe, the roller subassembly is
suspended on the roller suspender through horizontal supporting axis, and the roller suspender
fixed up with the main shaft and shovel stand. Located outside of the roller bearing house, the
pressure springs make rollers push down the inside surface of ring through horizontal supporting
axis. Shovels installed on the shovel stand and rollers rotate together when the motor drives main
shaft through transmission device and the rollers roll appressed the inside surface of ring and
rotate at the same time. The separator impellers are driven by motor through transmission device
to rotate, more higher the speed of separator impellor, more fine the powders been separated.

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Operation:
1. It is most convenient to drive the grinder with a motor.
2. When driven by internal combustion engine or any other power mechanism, the
following two precaution must be kept in mind.
a. The rotational speed required by the grinder must be guaranteed, therefore, if necessary,
the pulley of the driving mechanism can be replaced, or, a medium driving apparatus can
be adopted.
b. To Guarantee a smooth and steady operations, it is advisable to fix the base of the grinder
to a cement platform or other solid supports.
3. To guarantee safety, reliable protection apparatus should be adopted; the material to be
crushed should be selected carefully and no tiny metal pieces and other foreign materials
should be allowed; Constant inspection on the grinder, especially on the fastness of the
gears, should be made and the grinder should not be operated if any trouble have not been
done away with. During the course of operations. No repair is allowed; once any trouble
ore abnormal noise is found , operation should be stopped, can be inspection and repair
be carried out.
4. Operation of Hopper:
When fodder, such as soyabean cake and dried sweet potato slices are crushed, and the
hopper should be adjusted. To help the filling and crushing, soyabean cake should be
firstly broken into pieces of 20-40mm. According to the specification, when crushing
fresh sweet-potato or fresh fruit, they must be sliced beforehand and mixed with enough
water.
5. Replacement of Screens:

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The sieve size of various screens is different and they can be replaced according to the
thickness of the product required.
When replacing screens are placed in machine, the inner joint should be in the same
direction with the revolution of rotator.
6. Exit (outlet)
When processing various grains, the exit should be covered with a cloth sack., of which
both ends are open. During the course of the operation, one end of the sack should be
fastened onto the exit so that the processed material will be able to pass through to get
into the flour bag. It is not necessary to hold the operation to alter grains. The grains can
be altered while the machine is in operation.
In crushing fodder, cloth sacks are not necessary; instead, pits or other means are
available.
Observationand calculation:
Mesh
No.
Differential Analysis
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟐
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟑 𝑫̅ 𝒑 𝒊
. 𝒙 𝒊
Cumulative
Analysis
Mass
retained
(g)
Opening
of sieve
(mm)
Average
particle
size
𝑫̅ 𝒑 𝒊
(mm)
Mass
fraction
(𝒙 𝒊)
7 80 1 - 0.40 - - - - 1
6 68 0.5 0.750 0.34 0.4533 0.6044 0.8059 0.2550 0.60
5 12 0.355 0.428 0.06 0.1404 0.3283 0.7680 0.0257 0.26
4 14 0.212 0.284 0.07 0.2469 0.8709 3.0721 0.0198 0.20
3 9 0.15 0.181 0.03 0.1657 0.9157 5.0592 0.0054 0.13
2 6 0.106 0.128 0.03 0.2344 1.8311 14.3051 0.0038 0.10
1 4 0.0603 0.083 0.02 0.2405 2.8927 34.7891 0.0017 0.07
Pan 10 - - 0.05 - - - - 0.03
Advantages:
 Higher yields of particles in your target range, less recycling
 More uniform particle size, shape and distribution
 Fine to coarse particles from soft to hard materials
 Higher production rates
 Lower operating cost
 Small footprint
 Easy to clean

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Uses:
The machine is mainly used in processing powder of mineral materials of metallurgy, building
materials, chemical industry, mining, etc. It can grind non-flammable and non-explosive
materials with moisture less than 6% such as Feldspar, calcite, talc, barite, fluorite, rare earth,
marble, ceramics, bauxite, manganese ore, iron ore, copper ore, phosphate rock, iron oxide red,
slag, slag, activated carbon, dolomite, granite, iron oxide yellow, bean cake, chemical fertilizer,
compound fertilizer, fly ash, bituminous coal, coke, lignite, Ling U.S. sand, gold, red mud, clay,
Kaolin, coke, coal gangue, porcelain clay, kyanite, fluorspar, bentonite, muddy green rock, leaf
wax rock, shale, purple rock, Diego rock, basalt, gypsum, graphite, insulation material, etc.

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Experiment#4
Double roll crusher
Objective:
To report different types of diameters for the product obtained from Double roll Crusher, such as
Bond’s diameter, weight mean diameter, mean volume diameter, surface mean diameter, and
mean length diameter.
Require Material:
1. Scale
2. Tray
3. Vibrating sieve
4. Set of sieves with different mesh no.
5. Material to study

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Theory:
Double Roll Crushers provide a 4:1 reduction ratio and are typically used as secondary or tertiary
crushers for materials such as ROM coal with refuse, limestone, gypsum, trona, shale, bauxite,
oil shale, clean coal, coke, salt, quicklime, burnt lime, glass, kaolin, brick, shale, and wet, sticky
feeds. They can also be used following other McLanahan equipment, such as Feeder-Breakers,
Rotary Breakers, primary DDC-Sizers, or Single Roll Crushers, when further reduction of
primary crushed material is required.
In a Double Roll Crusher, the impact forces needed to crush material are created through the
rotating energy of the opposing rolls. Since each machine is custom engineered, roll elements
and tooth patterns are selected depending on each unique application to produce a cubical
product with minimal fines.
Designed for safety and many years of operation, effective tramp protection against non-
crushable materials is provided by an automatic spring-and-toggle system. This allows a
movable roll to open, pass the material and return to its original setting for continued operation.
Hydraulic product size adjustment allows producers to adjust for changes in product size
requirements or to compensate for roll wear.
Double-Roll-Crushers are used for the crushing or medium-hard rock as well as for sticky and
soft materials, i.e. lignite and mineral coal, clay, marl, limestone and similar raw materials as
well as for overburden and ores.

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Procedure:
 Prepare 5 kg of feed (red bricks) of the size that can pass through
 From one end of the crusher. Start introducing the feed pieces one by one and start the
stop watch simultaneously, in order to measure the total time (T) required for the
crushing.
 When crushing is completer stop the stop watch and turn off the crusher. Note down the
total time required for crushing.
 Analyze the material by sieving and weigh out the mass retained on each sieve.
Observationand calculation:
Mesh
No.
Differential Analysis
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟐
𝒙 𝒊
𝑫̅ 𝒑 𝒊
𝟑 𝑫̅ 𝒑 𝒊
. 𝒙 𝒊
Mass
retained
(g)
Opening
of sieve
(mm)
Average
particle
size
𝑫̅ 𝒑 𝒊
(mm)
Mass
fraction
(𝒙 𝒊)
4 198 4.76 - 0.2475 - - -
8 280 2.38 3.57 0.3500 0.098 0.0275 0.007692 1.2495
10 72 1.68 2.03 0.0900 0.0443 0.0218 0.01076 0.1827
14 60 1.19 1.435 0.0750 0.05226 0.0364 0.0254 0.107625
20 10 0.841 1.015 0.0125 0.01231 0.01212 0.01195 0.012688
25 26 0.707 0.774 0.0325 0.0419 0.0543 0.070091 0.025155
Pan 154 - - 0.1925 - - - -
Advantages & Disadvantages of Double Roll Crusher:
(Application)
In the chemical plant, crushing grinding machine widely used in crushing and grinding raw
materials and used to grind income products. Due to many of the crushing machine type and
models, so they are in the repair process in common limited to broken parts and protection of

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components (repair process. In all of this kind of machine, these parts All is abradability gallery
wipe and impact conditions of work.
Double roll crusher:
1.The two roll surface are smooth; 2. Two roll surface are band saw; 3.A roller surface is
smooth, and on A roller Surface foot with door of the branch.
 For two roll surface are smooth double roll crusher, and the material is mainly by
extrusion effect. The second is grinding effect and crushing. Is mainly used in crushing
clay, coal , clinker and limestone, etc in fine broken.
 The two roll surface are belt saw double roll crusher, and the material is mainly by
splitting broken and tear effect and crushing.
 On to a roll surface smooth and another roll surface with convex branch of the double
stick crusher, material squash, bending and grinding effect and crushing. They are mainly
used to Crushing clay and coal.
Double roll crusher is the main advantages:
simple structure, easy maintenance, low manufacturing cost. The main drawback is: the machine
unit mass production capacity Low, covers an area of big, the roll surface grinding damage
uneven, need often repair
In order to improve the roll crusher of crushing ratio, can use two crushing roller, put a pair of
crushing roller device in the top of the other pair. So the above a pair of broken Broken roll used
as a crusher, and below a pair is used as a secondary crusher.

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Experiment#5
Jaw Crusher
Objective:
To report the results of the screen analysis, for the product obtained by the jaw crushers, in the form of
cumulative and fractional distributions
Required materials:
1. Scale
2. Tray
3. Vibrating sieves
4. Set of sieves with different mesh no.
5. Material
Theory:
Jaw Crushers are used for the rapid, powerful crushing and pre-crushing of medium hard,
hard, brittle and tough materials. The variety of materials offered, their efficiency and safety
make them ideal for sample preparation in laboratories and industrial plants.
Jaw crushers are often used as primary crushers and are perhaps the most popular crusher
worldwide. These compressive crushers are suitable for most any type of material.

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In this type of crusher, reduction takes place between a stationary jaw plate and a moving jaw
plate. The moving jaw plate is mounted on the pitman, which is given a reciprocating motion.
Crushing takes place when the pitman moves toward the stationary jaw, compressing the
material.
Two main types of jaw crushers :
1.single toggle
2. toggle.
McLanahan produces single toggle jaw crushers, which feature a pitman mounted on an
eccentric shaft at the top. At the bottom of the assembly, the pitman is held in position by a
toggle plate. The combination of eccentric motion at the top and rocking motion at the bottom
provides a positive downward thrust throughout the crushing chamber.
Single toggle jaw crushers have better feed acceptance capability than the corresponding double
toggle crushers. Jaw crushers are reliable, robust machines, offering a 6:1 reduction ratio in most
applications, and will accommodate hard, abrasive materials.

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Other types
Procedure:
 Prepare 5 kg of feed (red bricks) of the size that can pass through a 3 in hole and retain on
a 2 in hole.
 Note down the time (t1) required for 2 revolutions (n1) of the energy meter disc under un-
loaded conditions. Also note down the energy meter factor (N).
 Note down the initial meter reading (R1) and turn on the crusher. Start introducing the
feed pieces one by one and start stop watch simultaneously in order to measure to total
time (T) required for the crushing
 When crushing is completed, stop the stopwatch and turn off the crusher. Note down the
total time required for crushing and the final material reading (Rs)
 Again turn on the crushers and note down the time required for two revolutions under
unloaded conditions. Take the average value of the two t1s.
 Analyze the material by sieving (preferably using 2, 4, 10, 20, 30, 40, 50, 70, and 100 US
ASTM mesh sieves) and weigh out the mass retained on each sieve and in the pan.

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Industrial Application:

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Experiment # 6
1.Apparent density
Apparent Density of the Solid Particles:
1. Calculate the apparent density of the given material.
2. Calculate the material density of the given material.
3. Calculate the crushing rate of the give sample of particulate solids
Required Materials:
1. Polypropylene 1000 ml graduated test tube.
2. Vibrating sieves
3. Solid Object to study
Theory:
Apparent Density:
The weight per unit volume of a material, including voids that exist in the tested material. Also
called Bulk Density. Provides a measure of the "fluffiness" of a material in its supplied form.
Bulk Factor:
The ratio of the density of a material after molding to the density of the raw material. Provides a
measure of the volume change that can be expected during processing.

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Material density: more often referred to simply as density, is
a quantitative expression of the amount of mass contained
per unit volume . The standard unit is the kilogram per meter
cubed (kg/m 3 or kg · m -3 ).
Density is sometimes expressed in grams per centimeter
cubed (g/cm 3 or gm · cm-3). Pure liquid water at a
temperature of 4 degrees Celsius has a density of 1 g/cm 3 ,
which is the equivalent of 1 kg per 1000 cm 3 , or 1 kilogram
per liter . To convert from kg/m 3 to g/cm 3 , multiply by
0.001. Conversely, to convert from g/cm 3 to kg/m 3 ,
multiply by 1000.
Occasionally, density is expressed in unusual units such as
pounds per cubic foot, pounds per cubic inch, or metric tons
per cubic meter. Expressions such as this can be confusing
unless reduced to standard form for comparison. Sometimes
density is expressed in relative terms as the specific gravity (sp gr), which is the ratio of the
density of a given substance to the density of pure liquid water at 4 degrees Celsius.
Method Use Test
A For fine granules and powders
that can be poured through a
small funnel.
Test is performed by pouring the material through a
funnel into a cylinder of known volume. The
apparent density is calculated by dividing the
weight of the material in the cylinder by the volume
of the cylinder.
B For coarse, granular materials
that either can't be poured or
that pour with difficulty
through the funnel from
Method A.
Test is performed by pouring the material through a
funnel into a cylinder of known volume. The
apparent density is calculated by dividing the
weight of the material in the cylinder by the volume
of the cylinder.
C For coarse flakes, chips, cut
fibers or strands that can't be
tested with Methods A or B.
Test is performed by pouring the material into a
graduated cylinder and allowing a 2300g plunger to
pack the material for one minute. The apparent
density is taken as the mass of the material divided
by the settled volume.

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Procedure:
 Weight the given sample of dry solid
 Pour the sample into the test tube and determine the volume that it takes up without
compacting.
 Calculate the apparent density of the sample particles with data.
 Put the graduated tube in the sieve and fit it with a lid to immobilize it.
 Subject it to a vibrations cycle for some minutes until the taken volume does not decrease
anymore.
 Once the solid has been compacted, note down the value of the volume taken by the solid
and calculate the material density.
 Calculate crushing ratio of the particles dividing the apparent density by the material
density.
Results:
Apparent density = 1.61 g/ml
Bulk density = 1.785
2.Deposit Unloading

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Objective:
1. Calculate the unloading masic flow
2. Compare the experimental masic flow with those predicted by the Johanson and Beverloo
equations.
Required Material:
1. Hoppers
2. Scale
3. Tray
4. Chronometer
5. Solid to study
Theory:
1. Depositions that happen because of a chemical reaction:
o Chemical Vapor Deposition (CVD)
o Electrodeposition
o Epitaxy
o Thermal oxidation
These processes exploit the creation of solid materials directly from chemical reactions in
gas and/or liquid compositions or with the substrate material. The solid material is usually
not the only product formed by the reaction. Byproducts can include gases, liquids and
even other solids.
2. Depositions that happen because of a physical reaction:
o Physical Vapor Deposition (PVD)
o Casting
Common for all these processes are that the material deposited is physically moved on to
the substrate. In other words, there is no chemical reaction which forms the material on the
substrate. This is not completely correct for casting processes, though it is more
convenient to think of them that way.
Deposition is a thermodynamic process, a phase transition in which gas transforms into solid.
The reverse of deposition is sublimation. One example of deposition is the process by which,
in sub-freezing air, water vapor changes directly to ice without first becoming a liquid.

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Procedure:
1. Select one of the four available hoppers, each with a different hole size.
2. Weight the sample whose unloading characteristics are to studied with the help of scale
and a tray.
3. Measure the apparent density of the particles
4. Calculate the diameter of the particles
5. Fill up hopper with a dry solid, approximately 2/3 of its total capacity.
6. Open the discharge valve below the hopper and it starts being unloaded on the tray.
7. Note the unloading time with a chronometer.
8. With the mass and unloading time, calculate the unloading masic flow m.
9. Calculate the masic flow using Jhonson and Baverloo equations.
10. Compare the results of the result of these equations with that obtained practically.

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3.Angle of Repose
Objective:
To report the angle of repose of the given sample
Require Materials:
1. Rotary cylinder
2. Solid Objects to study
Theory
The angle of repose or the critical angle of repose, of a granular material is the steepest angle of
descent or dip relative to the horizontal plane to which a material can be piled without slumping.
At this angle, the material on the slope face is on the verge of sliding. The angle of repose can
range from 0° to 90°. Smooth, rounded sand grains cannot be piled as steeply as can rough,
interlocking sands. If a small amount of water is able to bridge the gaps between particles,
electrostatic attraction of the water to mineral surfaces will increase soil strength.
When bulk granular materials are poured onto a horizontal surface, a conical pile will form. The
internal angle between the surface of the pile and the horizontal surface is known as the angle of
repose and is related to the density, surface area and shapes of the particles, and the coefficient of
friction of the material. However, a 2011 study shows that the angle of repose is also gravity-
dependent. Material with a low angle of repose forms flatter piles than material with a high angle
of repose.
The term has a related usage in mechanics, where it refers to the maximum angle at which an
object can rest on an inclined plane without sliding down. This angle is equal to the arctangent of
the coefficient of static friction μs between the surfaces.
Procedure:
 Take the sample of granules solid of a particle size around sugar grains or similar, and
with suitable humidity grade.
 Fill the rotary cylinder to half using pneumatic conveyer system (sucking up from a
hopper and separating the particle through a cycle)
 Turn the cylinder slowly, clockwise, until the very moment that particles start sliding.
 Take note of the angle described by the solid.
 Now rotate the cylinder anticlockwise and take note of the angle described by the solid.

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 Calculate angle of repose as the mean between these two measures.
 Repeat the test
Observationand Calulations:
Application:
It is commonly used by mountaineers as a factor in analyzing avalanche danger in mountainous
areas. This angle of repose is also crucial in correctly calculating stability in vessels.

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Experiment # 7
Solid handling unit:-
1.Cyclone and Pneumatic conveying
Objective:
1. Calculate the solid mass flow by an aerocylone.
Required material:
1. Pneumatic transport system
2. Cyclone
3. Hopper
4. Solids for study
5. Chronometer

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Theory:
Precious Pneumatic Conveying Systems are designed to convey dry powder or grains from one
place to another, which may a combination of horizontal as well as vertical conveying, even
through some intricate path. While conveying material it may be lifted from one or more than
one place and similarly may be dropped at one or at many places.
Basically the system works with the help of one or more suction fans to generate negative
pressure, which picks up the material and material moves with the air. Usually air and material
are separate in the cyclone separator where the material comes down in the cyclone and air
comes out from the top of cyclone, which is being delivered to a filter bag house. In some cases
air mixed with material may directly be taken in the filter bags avoiding the cyclone.
To design the conveying systemfollowing information must be forwarded to us:
1. Physical Properties of the material like density, abrasiveness, particle size distribution,
temperature, moisture content etc.
2. Any other special characteristics of the material like explosive, hygroscopic, heat
sensitive, corrosive, affinity/reaction with Mild Steel.
2. Rate of conveying that is quantity to be conveyed in one hour.
4. Distance, Height, bends etc. with full layout of the suggested path of the conveying.
5. Any specific material of construction if require.

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Procedure:
 Weigh some amount of solid, such as salt or fine sand.
 Place the solid in hopper with the discharge valve closed.
 Turn on air compressor and regulate the air inlet with the flow meter valve and note this
valve.
 Place the suction pipe in the hopper precisely and the solids start conveying from the
hopper to the cyclone.
 At the same time start the chronometer and place the particle discharge pipe of the
cyclone to another hopper with discharge valve closed.
 When the conveying of solids is finished, stop the chronometer.
 Calculate the solid masic flow.
Observationand Calculation:
Mesh no.
Mass passing before
erocyclone (g)
Mass after passing
erocyclone (g)
Efficiency %
7 38 35 92
6 50 48 96
5 50 49 98
4 50 46 92
Application:
Industrial cyclones are used in pollution control applications most commonly as a first stage,
lower cost method for removing larger particulate matter (PM) from effluent gas streams.
They can also be constructed to withstand harsh operating conditions.

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2.Agitator:
Industrial agitators are machines used in industries that process products in the chemical, food,
pharmaceutical and cosmetic industries, in a view of :
 mixing liquids together
 promote the reactions of chemical substances
 keeping homogeneous liquid bulk during storage
 increase heat transfer (heating or cooling)
The agitation is achieved by generating movement of the liquid phase, thanks to the impeller.
This is due, on mechanical agitators, to the rotation of an impeller. The bulk can be composed of
different substances and the aim of the operation is to blend it or to improve the efficiency of a
reaction by a better contact between reactive product. Or the bulk is already blended and the aim
of agitation is to increase a heat transfer or to maintain particles in suspension to avoid any
deposit.
The agitation of liquid is made by one or several agitation impellers. Depending on its shape, the
impeller can generate:
 the moving of the liquid which is characterized by its velocity and
direction.
 Turbulence which is an erratic variation in space and time of local
fluid velocity.
 Shearing given by a velocity gradient between two filets of fluids.

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Application:

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3.Ball mill
Objective:
Calculate angle α (to which the balls are carried against the wall of the ball mill), between
perpendicular (top of the ball mill) and the point at which the outermost ball lose contact with the
wall of the mill
MaterialRequired:
 Ball mill
 Balls
 Vibratory shaker and a set of sieves
 Collecting tray
 Solid for a study
Theory:
Ball mill (also named grinding ball) is one of the most important grinding mills in the mining
industry which is used to break all kinds of minerals and other materials in the industries of ore
beneficiation, construction materials and chemical engineering. There are two grinding modes:
wet type and dry type. The discharging ways can be divided to grid type and over flow type. Ball
mills are in many shapes: short drum one, long drum one, pipe one and cone shaped one.
Materials enter the first cabin of ball mills via the feeding device across the hollow shaft
uniformly. In the first cabin, there is a ladder scale board or a ripple scale board with different
steel balls which will be lifted to certain height in the effect of centrifugal force produced by the
rotating cylinder. Then the balls fall to impact and grind the materials. After the rough grinding
process, materials enter the second cabin through the single layer cabin separating board. There

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is a scale board with steel balls in the second cabin which will grind materials. The finished
powder materials are discharged from the unloading plate, thus finishing the grinding process.
Procedure:
 Measure the inside diameter of the ball mill.
 Measure the size of the ball with the help of venire calipers.
 Fill the ball mill to about half of its volume with balls of the same diameter.
 Feed t ball mill with 250 g mass of sugar of homogenous size (obtained by screening) and
note the particle diameter.
 Before turn on the mill, set speed regulators to maximum.
 Measure the speed of rotation of the ball mill in the revolutions per minutes.
 Analyze the product with the help of screen and note the particle diameter
 Calculate the angle α (to which the balls are carried against the wall of the ball mill)
between perpendicular (top of the ball mill) and the point at which the outermost balls
lose contact with the wall of the mill.
 Calculate the critical speed of the ball mill.
 Describe the speed of the revolution of the ball mill as the percentage of the critical
speed.
Industrial Application:
A ball mill is a grinding device that is used to turn material into fine powder. Ball mills are
cylindrical in shape, and are often the grinder of choice when it comes to mashing paints, ores,
ceramic materials, and certain hard chemicals. By rotating on a horizontal axis, a ball mill can
effectively convert a hard material into a loose powder.
In addition to the material that is meant to be ground, ball mills also contain a grinding material.
Ceramic balls, stainless steel balls, and flint pieces are often used as grinding materials. When
this matter grinds against another matter, the result is a crushed powder that can then be used for
other applications.

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Experiment # 8
Blake jaw Crusher:
Objective:
To report the results of the screen analysis, for the product obtained by the Blake jaw crushers, in
the form of cumulative and fractional distributions
Required materials:
1. Scale
2. Tray
3. Vibrating sieves
4. Set of sieves with different mesh no.
5. Material
Theory:
The Blake crusher was patented by Eli Whitney Blake in 1858. The Blake type jaw crusher has a
fixed feed area and a variable discharge area. Blake crushers are of two types- single toggle and
double toggle jaw crushers.
In the single toggle jaw crushers, the swing jaw is suspended on the eccentric shaft which leads
to a much more compact design than that of the double toggle jaw crusher. The swing jaw,
suspended on the eccentric, undergoes two types of motion- swing motion towards the fixed jaw
due to the action of toggle plate and vertical movement due the rotation of the eccentric. These
both motions, when combined, lead to an elliptical jaw motion. This motion is useful as it assists
in pushing the particles through the crushing chamber. This phenomena leads to higher capacity
of the single toggle jaw crushers but it also results in higher wear of the crushing jaws. This type
of jaw crushers are preferred for the crushing of softer particles.
In the double toggle jaw crushers, the oscillating motion of the swing jaw is caused by the
vertical motion of the pitman. The pitman moves up and down. The swing jaw closes, i.e., it
moves towards the fixed jaw when the pitman moves upward and opens during the downward
motion of the pitman. This type is commonly used in mines due to its ability to crush tough and
abrasive materials.
Procedure:
 Prepare 5 kg of feed (red bricks) of the size that can pass through a 3 in hole and retain on
a 2 in hole.
 Note down the time (t1) required for 2 revolutions (n1) of the energy meter disc under un-
loaded conditions. Also note down the energy meter factor (N).

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 Note down the initial meter reading (R1) and turn on the crusher. Start introducing the
feed pieces one by one and start stop watch simultaneously in order to measure to total
time (T) required for the crushing
 When crushing is completed, stop the stopwatch and turn off the crusher. Note down the
total time required for crushing and the final material reading (Rs)
 Again turn on the crushers and note down the time required for two revolutions under
unloaded conditions. Take the average value of the two t1s.
 Analyze the material by sieving (preferably using 2, 4, 10, 20, 30, 40, 50, 70, and 100 US
ASTM mesh sieves) and weigh out the mass retained on each sieve and in the pan.