SOLID WASTE MANAGEMENT THROUGH
GEOPOLYMER TECHNOLOGY FOR THE
DEVELOPMENT OF VALUE ADDED PRODUCTS
Prof. (Dr.) N. R. Bose
Gandhi Institute of Engineering & Technology,
Gunupur, Rayagada, Orissa, India
INTRODUCTION
1. Name
2. Qualifications
3.
4.
5.
6.
7.
8.
:
:
DR. NRIPATI RANJAN BOSE
B. Sc. ; B. Tech. (Chemical) ; M.Tech. (Chemical) ; Ph.D.(Tech.) in
Polymer Science & Technology
Nationality
:
Indian
Past position
:
Principal Scientist at Central Glass & Ceramic Research Institute
under Council of Scientific & Industrial Research (C.S.I.R.), Govt. of India
Work Experience
: (a) 8 years in Plastics, Paints, Fibreglass Reinforced Plastics (FRP) and
Plywood Industries
(b) 24 years as Scientist for R & D work having following output :
* Publications in International Journals
:
25
* Patents : 1 International ; 5 Indian
* Presented Papers in International Conferences : 15
* Technical Know-How Transferred to Industries : 2
* -Guided Ph.D. students
: 2
Present Activities
: (a) Director of New Era Polyset Engineering Pvt. Ltd., Kolkata, India
(b) Consultant of Sols 4 All Consultants , Kolkata, India
(c) Expert for the project “Development of Bullet Resistant Armour
Panels “ at Central Glass & Ceramic Research Institute, Kolkata
under CSIR, Govt. of India
(d) Contract research, Product Development and Commercial Utilisation
Author of two Chapters
:
Books published by Woodhead Publications, U.K.
Membership with Professional Scientific bodies :
(a) Institute of Materials, U.K. , (b) Indian Concrete institute
(c) Indian Plastics institute , (d) Indian Science Congress Association
Serious Pollution Hazards
•Rapid urbanization
-----Building industries
-----Uses of Diesel & Petrol
-----Generation of Solid Waste
-----Increase of Population
•Industrialization
-----Increase of Cement Industries
-----Generation of Solid Waste such as :
* Fly Ash * GGBS * Rice Husk Ash * Red Mud * Food Waste
* Wood Dust * Hospital Waste * Radioactive Waste etc.
*
Present Scenario(1)
1. One ton cement production require 2 tons of shale and limestone ---releases 0.87 ton Co2, 3 Kg. NO and airborne particulate matter that is
harmful to the respiratory tract when inhaled.
2. Thermal Power Stations, and Steel Industries are using coal and creating
environmental pollution by their by-products (a) Fly Ash (FA), and (b)
Ground Granulated Blast Furnace Slag GGBS)
3. Aluminium Industries creating environmental pollution by their by-products
------Red Mud
4. Uranium Industries, Nuclear Power Plants & Atomic Reactors are generating
toxic radioactive waste
5. Chemical Industries are creating (a) liquid waste which are polluting river &
underground water, (b) Toxic gases from chimneys polluting air in the
environment
Present Scenario(2)
6. Food Industries are generating solid & liquid waste
7. Plywood Industries and saw mills are generating
wood dust --- creating air pollution
8. Ceramic processing industries are polluting air by
releasing carbon dioxide from chimneys
9. Bricks manufacturing industries are polluting air by
releasing carbon dioxide from chimneys
10. Surface coating industries are creating air pollution
by using solvent based paint and coating resins
Recent trends for controlling pollution
• Total Quality Management of production processes and to
ensure zero pollution hazard in the environment
• Development of green building materials
• Production of Geopolymer binder from solid waste
• Conversion of chimney gases into products or absorpsion of
chimney gasses in suitable chemical solution by scrubbers
• Production of fire resistant composite panels by using
Waste-Waste System
• Encapsulation of radioactive waste & other toxic materials in
Geopolymer binder and to produce composite panels
Major industrial wastes in India
• Fly ash
------------------------- 100 million tonnes
• Granulated blast furnace slag--- 12 million tonnes
• Rice husk ash --------Huge quantity
• Red mud ------------- 4 million tonnes
Composition of waste materials
• These waste materials contain SiO2 and Al2O3
along with Fe2O3, CaO, MgO, MnO, etc, and
have immense potential as man made raw
materials for the production of geopolymeric
cement and binder.
Geopolymerisation reaction
• Alumino-silicate fraction + alkaline media -----------------------Geopolymer binder, via dissolution ----------–
polycondensation ----------------------- structural
reorganisation mechanism-------------- develop
strength.
Fundamentals of Geopolymer
• Geopolymer is essentially a mineral chemical
compound or mixture of compounds
consisting of repeating units, for example
silico-oxide (-Si-O-Si-O-), silico-aluminate (-SiO-Al-O-), ferro-silico-aluminate (-Fe-O-Si-O-AlO-) or alumino-phosphate (-Al-O-P-O-)--------------------------------created through a process of
geopolymerization
Applications of Geopolymer
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Geopolymers are new materials for :
Fire- and heat-resistant coatings
Adhesives & medicinal applications
High-temperature ceramics
New binders for fire-resistant fiber
composites
Toxic and radioactive waste encapsulation
New cements for concrete.
Methods of making geopolymers(1)
•
A novel three-dimensional mineral polymers named as geopolymers are
designated in IUPAC International Symposium on Macromolecules, Stockholm in
1976, Topic III; and PACTEC IV, 1979, Society of Plastic Engineers, USA, preprint
page 151. These mineral polymers are called polysialates, and have this empirical
formula :
Mn[(-Si-O2)z -Al-O2-]n, wH2O
• Wherein z is 1,2 or 3; M is a monovalent cation such as potassium or sodium, and
n is the degree of polycondensation. When z is 2, the polysialate has the formula :
•
Mn(-Si-O-Al-O- Si-O -)n,,wH2O
•
O O
O
• and is called poly(sialate-siloxo) or PSS for short. These new polymers are of the
PSS type where M is sodium or a mixture of sodium and potassium. In the latter
case, the polymer is called (sodium, potassium) poly(sialate-siloxo) or (Na, K) PSS. The chemical formula of (Na, K) - PSS may be written as :
•
•
(Na, K)n (-Si-O-Al-O- Si-O -)n,,wH2O
•
O O O
Method of making geopolymers(2)
• The method of making (Na, K) - PSS comprises preparing a
sodium silico-aluminate / potassium silico-aluminate and
water mixture where the composition of the reactant
mixture, in terms of oxide-mole ratios, falls within the ranges
shown in Table 1 below.
• Table1. Oxide-Mole-Ratios of the Reactant Mixture
•
_____________________________________
•
(Na2O, K2O) / SiO2
0.20 to 0.28
•
SiO2 / Al 2O3
3.50 to 4.50
•
H2O / (Na2O, K2O)
15.00 to 17.50
•
(Na2O, K2O) / Al 2O3
0.80 to 1.20
•
______________________________________
Geopolymer binder from Fly Ash
• ____________________________________________________________
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Amount of component
(grams) Wt %
•
____________________________________________________________
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50 % Sodium Hydroxide Solution
741
14.82
•
37.60 % Sodium Silicate Solution
702
14.03
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Class F Fly Ash
3557
71.15
•
Additional water
Nil
Nil
•
___________________________________________________________
Preparation of specimens & test results
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Two samples of Fly Ash based GP binder mixture of are casted in a mould and heat cured
at 90 oC for 18 hours, and then removed to ambient conditions. After two days, the
specimens are prepared in accordance with ASTM C-192 and ASTM C-617 for measurement
of compressive strength. The specimens are then tested for compressive strength according
to ASTM C-39.
________________________________________________________
Preparation of specimens & test results
________________________________________________________
Example No. Curing
Curing
Compressive
Temp. (oC) Time (hrs.)
Strength (MPa)
________________________________________________________
1
90
18
86.80
2
90
18
77.00
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There is an enormous scope for the development of various value added products by
reinforcing fibres and fillers in Fly Ash based geopolymer binder mixture. Notable value
added products such as bricks, pavement tiles, fire resistant panels etc. can be
manufactured
GGBS based Geopolymers
• Conventional iron manufactures leaves slag as a crystalline
stone that is dispersed as waste or used as road-railway-track
base material in replacement of crushed basalt or granite
• Such crystalline structure does not provide geopolymeric
reactivity. Only those slags that are glassy and have been
prevented from crystallization can be used as geopolymer
precursor
• The blast furnace slag is a molten material that is formed
from the smelting of the siliceous gangue found in iron core,
the residue of coke combustion, the limestone and other
added ingredients. Its temperature is in the range between
1400o and 1600oC and is close to that of the molten iron.
Contd.
• The slag becomes suitable for geopolymeric reaction when
quenched from the melt. It is called granulated slag or ground
granulated blast furnace slag (GGBS)
• The glassy material is obtained either poured into pits filled
with water or by high-pressure water jets at the blast furnace,
when it flows out of the spout
• A modern system of granulation, the pelletizer, has been
developed in Canada (Margesson ) and in England during the
year 1971. From a geopolymeric chemistry point of view,
gehlenite [Ca-poly(alumino-sialate) based blast furnace slag
is the reactive molecule with effective potential as
geopolymeric precursor
Composition
of gehlenite based
GGBS
• The average composition of gehlenite based blast furnace slag
with the main oxides of different countries is given in the following
Table
• ____________________________________________________________
• Slag origin
SiO2 %
Al 2O3 %
CaO %
MgO %
• ____________________________________________________________
• Australia
35.00
11.50
41.50
6-12
• USA
32.83
11.59
41.43
8.03
• Germany
33.27
10.90
44.77
5.27
• Czeh. Rep.
36.18
9.61
35.39
14.49
• Canada
35.30
9.90
34.70
14.60
• France
35.00
12.20
43.20
8.10
• ____________________________________________________________
Mole ratios of oxides
For making GGBS based geopolymer composite
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For making GGBS based geopolymer composite, the following oxide mole ratios are
optimized at the laboratory of Prof. Joseph Davidovits at Saint Quentin, France. The mole
ratios of oxides are given in the following Table
Mole ratios of oxides
_____________________________________________
Oxides
Mole-ratio
_____________________________________________
M2O / SiO2
:
0.21 to 0.36
SiO2 / Al 2O3 :
3.00 to 4.12
H2O / M2O
:
12 to 20
M2O / Al 2O3 :
0.60 to 1.36
______________________________________________
where M2O represents either Na2O, or K2O, or the mixture of Na2O and K2O. To 100g
of the oxide mixture given in the above Table about 15g to 26g of a finely ground blast
furnace slag is used. High early compressive strength of more than 250 MPa is obtained by
using this mineral polymer composition with filler and /or fibres.
Rice husk ash based geopolymers
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Rice milling generates a by-product known as husk. This surrounds the paddy
grain. During the milling about 78 % of weight is received as rice and bran. The
remaining 22 % is the husk
The latter is used as fuel in the rice mills to generate steam. The husk contains
about 75 % organic volatile matter and 25 % of the weight is converted into ash
during the firing process, known as rice husk ash
Rice husk ash in turn contains around 85 % - 90 % amorphous silica SiO2. For
every 1000 kg. of paddy milled, about 220 Kg. (22 %) husk is produced, and when
the husk is burnt in the boilers, about 55 Kg. (25 %) of rice husk ash is generated
The most profitable use of silica fume and rice husk ash is in the cement and
concrete industries
Geopolymer binder is made by mixing rice husk ash and silica fumes with NaOH
or KOH solution. For the development of geopolymer concrete Al(OH)3 powder
is used up to 10 % as activator and 1 % Boric acid as stabilizer at 115o C
The compressive strength of rice husk ash mortar is 20.0 MPa
High compressive strength value added products can also be developed by
incorporating fibres in this geopolymer cement binder.
Geopolymer Technology Developed By
Prof. Davidovids, Founder of Geopolymer
Institute, Saint Quentin, France
(Paper presented in July, 2013)
Essential Phases For Composite
*Fibres
*Matrix
*Fillers
*Additives (Fire resistant, Impact
resistant, Wear resistant etc.)
New Avenues For The
Development of High Value
Composite Materials
Fibre Reinforced Geopolymer Cement Based Composite Materials
1. Fire Resistant Structural Panels
2. Insulated Foamed Roof Panels
3. Chemical Resistant Panels
4. Door Panels
5. Bricks
6. Tiles
Importance of Geopolymer
PART-1
Geopolymer has great potential to reduce the
environmental pollution in two ways :
1 Fulfillment of the demand of portland cement by using
Geopolymer cement without going for new cement industries
2. Fruitful utilisation of waste materials such as FA and GGBS
for the production of good quality Geopolymer cement by
chemical transformation of Al and Si
Importance of Geopolymer
PART-2
Properties of GPCC mixes :
1.Compressive strength in 24 hours : 25-35 MPa
2.Compressive strength in 28 days : 60-70 MPa
3.Modulus of Elasticity : Marginally lower than
cement concrete
4.High stiffness
5.Acid, Alkali, Heat and Fire Resistant
6.Bond Strength with Steel is higher than cement concrete
( IS : 456-2000 )
7.Durability as per ASTM 1202 C : Better protection of steel
as compared to cement concrete
Importance of Geopolymer
PART-3
Geopolymer Cement
Concrete (GPCC)
materials are inorganic polymer composites
using Geopolymer Cement prepared by alkali
activation of industrial aluminosilicate waste
materials such as FA & GGBS
Proposed Design of Fire Resistant
Composite Panels
1.
Impregnation of Ceramic Blanket with Geopolymer
Cement Slurry Blended with Water Settable Polyester
Resin + Redox Catalyst + SBR Latex + Fillers + Water
as required : Formed into Prepreg Layers
2. Assembly of Multiple Prepreg Layers as per desired
thickness in between two Aluminium Metal Sheets
3, Pressing in Cold Hydraulic Press
The above design is based on ESTERCRETE
USES :
* Blast Resistant Structural Panels for Defense Sector
* Bridge Decks & Industrial Flooring
Compressive Strength : More than Ordinary Concrete
Proposed Design of Insulated
Foamed Roof Panels
1. Geopolymer Cement Slurry + Water Settable Phenolic Resole Resin
+ SBR Latex + PTSA Catalyst + Sand + Stone aggregates + Superplasticizer + Polypropylene Fibre + Water as required
2. Polyurethane Foam System (Part A & Part B)
3. Silicone Rubber Mould
4. Anti Sticking Silicone Spray
5. Compacting Box System to Hold Silicone Rubber Mould
Production Process :
After Mixing Part A & Part B of item No. 2 then add Item No. 1 -------------After mixing -------------pour into the closed Mould properly coated with
anti sticking Silicone Spray
Proposed Design of Chemical
Resistant Floor
1. Water Settable Isophthalic Polyester Resin
2. Geopolymer Slurry
3. Redox Catalyst System
4. SBR Latex
5. Sand
6. Stone (6-8 mm) Aggregates
7. Polypropylene Fibre
8. Water as required
Application : After Mixing item Nos. 1-8 in a Gear Mixer
it is to be pumped through Hose Pipe inside the Framed
workplace. Curing for 12 hours will develop high
compressive strength.
Proposed Design For Doors and
Windows
1. Fibre Reinforced Plastics (FRP) Casings as per size of the doors
and windows
2. Geopolymer Slurry + PU Foam System + Water Settable
Polyester Resin + Redox Catalyst + SBR Latex + Polypropylene
Fibre + Superplasticizer + Water as required
Production :
1. Mixing all ingredients of item No. 2 and then injection into
individual FRP casings
2. Curing time : 12 hours
PROPER SOLUTION
1. Production of Geopolymer for gainful
utilisation of FA and GGBS and to save
the environment by reducing stockpiles
2. Use of Geopolymer cement as a right
substitute of Portland Cement for the
production of value added composite
products
Possibilities for New Research
Projects
1. Nano fibre development from Geopolymer Gel
by using Electrospinning Equipment
2. Anti Rust and High Heat Resistant Inorganic
Waterbase Geopolymer-Zinc Rich Coating for
Cathodic Protection of Steel
3. Development of Advanced Nano Ceramic
Composites Based on Geopolymer Gel
Conclusion
• Geopolymer concrete shows significant potential to be a
material for the future because it is not only environmentally
friendly but also possesses excellent mechanical properties
• Recommendations on use of geopolymer concrete
technology in practical applications such as precast concrete
products and waste encapsulation need to be developed
* Geopolymeric binder can be utilized for fire resistant panels
and coatings on different substrates, advanced nano-ceramic
composites, development of foam concrete, encapsulation of
radioactive waste, low cost bricks etc.
Conclusion
Because of lower internal energy (almost 20% to 30 % less) and
lower CO2 emission contents of ingredients of geopolymer
based composites compared to those of conventional Portland
cement concretes, the new composites can be considered to be
more eco-friendly and hence their utility in practical
applications needs to be developed and encouraged.
Geopolymer based cement is having high early strength and
high setting characteristics. These characteristics of geopolymer
cement based products are ideal for patching or resurfacing of
highways and airport runways.
Conclusion
* It is possible to utilize various solid waste materials
( FA, GGBS, RHA and Red Mud ) through Geopolymer
Chemistry for the development of binder and cement
* It is poosible to formulate mixing compound with
semi solid waste materials , geopolymer binder and
water soluble polymer for the development of high
value products
Future course of action
*
To involve
myself
in collaborative or sponsored Research Project
• To work jointly with suitable organization for the development of new
products by utilizing any kind of waste materials
• To
save the environment through techno-commercial waste management
• To substitute prefabricated
based concrete
cement based
concrete with geopolymer
* To develop blast resistant composite panels for defence sectors
--------------- Thank you all ---------------