Flyash Synthesis

2. Introduction
 Zeolites are crystalline, microporous, hydrated
aluminosilicates of alkaline or alkaline earth metals.
The frameworks are composed of [SiO4]4 and [AlO4]5
tetrahedra, which corner-share to form different open
structures.

3.  The synthesis of zeolites in forms suitable for
industrial applications is of great importance. The first
synthesis of zeolite was attempted by St. Claire-Deville
in 1862. Barrer’s pioneering work in 1948
demonstrated that a wide range of zeolites could be
synthesized from aluminosilicate gels.
 At present, synthetic zeolites are used commercially
more often than natural zeolites due to the purity of
crystalline products and the uniformity of particle
sizes. However, the preparation of synthetic zeolites
from chemical sources of silica and alumina is
expensive. Such costs may be reduced by the use of
clay minerals, volcanic glasses (perlite and pumice),
rice husks, diatoms, fly ash or paper sludge ash as
starting materials.

4. Fly ash, also known as "pulverised fuel ash" in the
United Kingdom, is a coal combustion product that is
composed of the particulates (fine particles of burned
fuel) that are driven out of coal-fired boilers together
with the flue gases.

5. Raw Materials
Calcination
Ageing
Drying
Fusion
Water Bath
Drying
Grinding
Testing
General Flow Diagram

6. Calcination of Flyash
 Take known quantity of fine Flyash sample in an
fireclay crucible. Take the dry weight of the crucible
and add the Flyash in the crucible. Now place the
crucible in an muffle furnace at 850⁰C for 2 hours.
After 2 hours shut down the furnace & allow the
sample to cool down. After cooling, note down the
weight of the sample

7. Fusion of Flyash
 Then take 10 g of calcined sample in an
alumina crucible. Make an alkaline
solution of NaOH by taking 12g of
NaOH pellets & dissolving it in 8 ml
distilled water, stir the solution
properly until the pellets gets
dissolved completely. Now mix the
solution properly with the Flyash
solution with a stirrer & place the
crucible in the muffle furnace for 5
hours at 850⁰C. After 5h shut down the
furnace & allow the sample to cool
down. After cooling dry the sample
and grind it to the fine size.
 Result:- Pista green color obtained

8. Ageing
 Take 10g of dried, fused Flyash
in an clean container of
polypropylene so that there
should be no contamination.
Add distilled water of 1:4 ratio in
the sample and place a small
magnet inside the container and
close the container, place it on a
magnetic stirring machine for 24
hours. After 24 hours shut down
the machine. The sample settles

9. Preparation of EDTA
 Ethylenediaminetetraacetic acid (EDTA) is an
aminopolycarboxylic acid and a colorless, water-soluble
solid. Its conjugate base is ethylenediaminetetraacetate.
It is widely used to dissolve limescale. Its usefulness arises
because of its role as a hexadentate ("six-
toothed") ligand and chelating agent, i.e., its ability to
sequester metal ions such as Ca2+ and Fe3+. After being
bound by EDTA into a metal complex, metal ions remain in
solution but exhibit diminished reactivity. Take 4 gram of
EDTA powder in a clean test tube & add 10 ml distilled
water and mix them properly

10. Water Bath
 Take polypropylene tube & clean it thrice with
distilled water & once with acetone & one more
time with distilled water, then dry it & add known
quantity of prepared Flyash solution in the tube
along with EDTA solution. Close the tubes tightly
& mix the solution properly & place it in water
bath. Place the tubes tightly inside the water bath
& fill the water bath upto the mark with distilled
water & set the temperature to 85 ⁰C and close the
water bath. Keep it in water bath for 5 hours so
nucleation can take place. After 5 hours remove
the tubes from the water bath, the sample and
water will separate inside the tube. Then drain the
water from the tube and take the sample in a clean
container/beaker & wash it with distilled water
for 10 – 12 times & dry it in an hot air oven for 2-3
hours at 110 ⁰C for water to get evaporated. After
drying the color of the sample changes to white
color. Then grind the sample to fine particle size &
the pack it in an air tight container/packets.

11. Before Drying After Drying

12.  Flyash From Raichur Thermal Power
Station was taken as a starting material.
Known amount of flyash was taken in a
fireclay crucible and heated at 850℃ for
2hrs in a muffle furnace. This calcined
sample was fused with NaOH at 850℃ for
5hrs in a muffle furnace. The fused flyash
was than mixed with distilled water in a
polypropylene container and aged for
24hrs using a magnetic stirrer. EDTA
Solution was prepared separately in a
clean test tube by taking 4gms of EDTA
with 10ml of distilled water. The Aged
solution was mixed with the freshly
prepared EDTA Solution in a
polypropylene tube and this polypropylene
tube was kept in a water bath at 80℃ for
5hrs