The present invention relates to a process for making high moisture resistant radiation
shielding green hybrid polymer composite panels with high mechanical strength using
industrial waste particulates red mud with epoxy/polyester resin with and without glass
5 fabrics. Preparation process describe a method for manufacturing red mud based green
composites moisture resistant X-Ray radiation shielding hybrid composites panels using
compression moulding system with a pressure of 20-50 kg/ cm2 at varying temperature of
25 ac - 60 °C. Industrial waste particulates such as red mud reinforced in epoxy resin
based radiation shielding hybrid composite panels with density in range of 1.4 -2.2 glee,
10 moisture absorption in the range of 0.20- 0.30 % and half value layers (HVL) of about
0.36- 0.47 em and 0.48 -0.52 corresponds to X-ray radiation of energy 60 kVp and 100
kVp are prepared. The developed red mud based hybrid composite sheet shows tensile
strength and tensile modulus 12-120 MPa and 1.5 - 7.5 GPa respectively. The specific
applications of the radiation shielding red mud based hybrid composite panels are for
15 construction of radiation shielding partition doors, panels, false ceilings, and radiation
shielding roofing sheet.
BACKGROUD OF THE INVENTION
Unwanted exposures to high-energy electromagnetic radiations such as X-Ray or gamma
ray are hazardous to human health and life. Particularly, during last two decades the use
20 of X-ray radiation has gain extensive popularity covering all sectors of human life,
industry, security, aviation and medical care. Specially, in medical radiation applications,
X-ray are utilised for treating cancer patients, severe thyroid eye disease, abnormal
growth of mucousal tissue (pterygium) etc. During operation and handling of the X-ray,
tissues and organ near the affected region of treatment usually got exposed to the
25 penetrative X-rays leading to harmful side effects to both internal and superficial organs.
Thus, the safety of the personal and general public from the harmful effect of radiation
has been a great concern. Conventionally, X-ray procedures radiation safety has been
! achieved using L- bench and lead apron and adequate room shielding. Presently, lead
based apron is utilised as for radiation shielding during operation of X-Ray machine.
30 However, lead is extremely toxic and prolonged exposure to it can result in serious health
concerns. To construct the diagnostic and computed tomography (CT) scanner rooms,
• the ceramic tiles, concrete and bricks are utilised to provide adequate shielding against
X-ray photons. However, moisture resistant along with high mechanical strength
radiation shielding hybrid composite sheet without using lead or lead based compound
materials for application as radiation shielding doors, panels, false ceiling, partition
5 panels and roofing sheet using industrial waste particulate such as red mud are yet not
developed.
Earlier work m US7897949B2 claimed a radiation shielding multi-layer materials,
comprising at least two individual composite layers, where in each individual composite
layer comprises. a secondary radiation layer with a low Z radiation protection material
10 and a barrier layer with a high Z radiation protection material (tantalum and/or bismuth
and/or tungsten). In this work fibres/PVC are used as outer layer in each individual
components. Reference may be made to US Pat. No. US7041995B2, wherein a lead
substitute material for radiation protection purposes is reported. Composite structure of
lead substitute material such as 10-20% by weight of a matrix material, Sn, or Sn
15 compounds, Bi, or Bi compounds, nominal lead equivalent are used to prepare the
radiation shielding materials. Similarly various other radiation shielding materials on the
basis of the atomic numbers are invented. Reference may be made to the DE 199 55 192
A 1, where in a method for producing a radiation protection material from a powder of a
metal with a high atomic number and polymer as the matrix material are used. In other
20 work, highly elastic, lightweight, flexible and rubber-like radiation protection material,
with an atomic number greater than or equal to 50 and their oxides are mixed with
polymer to develop the radiation shielding materials. Lead free radiation protection
material comprising at least two layers with different shielding characteristics are
developed and their methods are claim in the US patent US 7,449,705 B2. In this work,
25 two layers are used made from tin, cerium and matrix material as first layer and
gadolinium, bismuth, tungsten and matrix as second layer. However, their processing
are complex and costly. The moisture resistant and mechanical properties of these
materials are not reported.
US Patent US8728349B2 disclose a method for lead-free X-ray shielding rubber
30 composite which contained polymerized rare earth organic complex metal tin and/or tin
compound bismuth element and/or inorganic compound and silane coupling agent and
• softener crosslinker. However, density, moisture/water absorption, mechanical strength
of developed materials was not given and their application . as radiation sheilding
building materials is limited. In present invention, industrial waste particulates such as
red mud is processed using simple p1ethods such as hot water soaking and their drying in
5 oven and compression moulding techniques is used to achieve the moisture resistant
radiation shielding hybrid composite reinforced with red mud in single operation mode
using compression moluding without using any lead element.
Reference may be made to US20 170257987 A 1, wherein a brine sludge, an industrial
waste generated in chloral alkali industry and sodium hexametaphosphate was utilised to
10 make the non - toxic radiation shielding materials where a heating of the brine sludge is
done in a furnace in the temperature range of 800 to 1300° C for a period of 1 to 2.
However, in this work, half value layer, density and mechanical strength for X-Ray
radiation shielding are not reported. However, in present invention, industrial waste
particulates such as red mud generated from aluminium industry is processed in oven in
15 temperature range of 60-80 °C and reinforced in the epoxy resin using compression
moulding method is used to achieve the .moisture resistant radiation shielding hybrid
composite panels with density in range of 1.68- 1.98 glee and half value layer in range of
0.34 -0.50 em.
Lead based and non lead materials such as Pb--rubber, Ph-PVC vinyl, Hx-lead, W-
20 rubber and Sn-Ba polymer were used to make radiation shielding garments to protect
medical patients and workers from exposure to direct and secondary radiation during
diagnostic imaging in hospitals, clinics and dental offices (see e.g. J. P. McCaffrey, et al,
Radiation attenuation by lead •and non-lead materials used in radiation shielding
garments. Med. Phys. 34, 2007530-537.) . However, such radiation shielding garments
25
30
are not effective.
A facile method for the fabrication 9f X-ray radiation shielding panels using red mud,
barium Sl;llphate, carbon powder in organa-shielding gel are reported (see; Sarika Verma
et al, . Development of advanced, X-ray radiation shielding panels by utilizing red mudbased
polymeric organa-shielding gel-type material, Waste and Biomass Valorization,
2017, 8, 2165-2175). In this work, high temperature ceramic processing at 1300 °C was
carried out to make the radiation shielding organo-gel-based material. However, this
.... ~•'-••- -••• --••••••. -------•-•---- --•-•- ••-•• ..
4
..
• work has vanous disadvantages such as high temperature annealing, usmg radiation
shielding organo-gel, cost and limitation of materials •dimensions. The developed
materials have limited application for construction of diagnostic and CT scanner rooms
to provide adequate shielding against X-ray photons. Further, this work has not reported
5 any studies regarding half value layer, density and mechanical strength which is crucial
to design the radiation shielding panels. However, in present invention, industrial waste
particulates such as red mud generated from aluminium industry is processed in oven in
temperature range of 60-80 °C and reinforced in the epoxy resin using compression
moulding method is used to achieve the moisture resistant radiation shielding hybrid
10 composite panels with density in range of 1.68- 1. 98 glee and half value layer in range of
0.34 -0.50 em.
Reference may be made to US patent 7524452B2, where in a low temperature process
for making radiopac materials utilizing industrial/agricultural waste as raw material is
claimed. Ceramic materials using industrial/agricultural waste materials, an alkali or
15 alkaline earth metal compound and phosphatic binde were utilised. However, in this
work ceramic are prepared at temperature in the range of 920 to 1300° C. Further the
fabrication of radiation shielding green hybrid composite panels using industrial waste
particulates such as red-mud in epoxy/poly~ster resin system .. is not yet reported tor
application of radiation shielding doors, panels, false ceiling and roofing sheet.
20 The drawbacks in earlier developed process for making X-ray radiation shielding
materials are as follows:
25
/
I. The processes for fabricating X-ray radiation shielding materials based on lead
.metal, lead based compound and their polymer composites have toxicity and poor
mechanical strength.
II. Lead based compound radiation shielding materials have high density and need
high temperature processing.
III. The process used more than two metal oxide materials and polymer and required
high temperature treatment of raw materials.
•
5
IV. The use of cement based concrete for radiation shielding application exhibits high
water absorption which results a gradual decreased in its mechanical strength with
the period of radiation exposure.
v. The processing of red mud, fly ash based concrete /cement for radiation shielding
applications required high temperature of about 800-1000 °C and usually shows
high water absorption.
VI. Red mud based concrete have limited application for radiation shielding
application and can be used as only tiles/bricks and not suitable as radiation
shielding doors, panels, partition panels and roofing sheet.
10 OBJECTIVE OF THE INVENTION
• The main object of the present invention is to provide a high moisture resistant radiation
shielding green polymer hybrid composite panels with high mechanical strength using
industrial waste particulates red mud with epoxy/polyester resin with and without glass
fabrics.
15 Another object of the present invention is to provide a process .for prepanng high
moisture resistant radiation shielding green hybrid polymer composite panel with high
mechanical strength using industrial waste particulates red mud with epoxy/polyester
resm.
Another object of the present invention is to provide a process for making effective
20 radiation shielding doors, panel, roofing sheet at low temperature which obviates the
drawbacks as detailed above.
Another object of the present invention is to utilize industrial waste particulate specially
red mud generated from aluminium production containing major elements namely iron,
silicon, aluminium, titanium and calcium and thus fabricate polymeric sheets which are
25 non toxic as they are lead free. Still another object of the present invention is to develop a
low temperature process for making large scale size of radiation shielding sheet utilizing
above mentioned raw materials.

• Still another object of the present invention is to develop moisture resistant radiation
shielding sheet up to dimension of 220 em x 120 em with varying thickness of 1.3 5 mm,
3 mm, 6 mm, 9 mm, 12 mm, and 19 mm, 25 mm, 30 mm and 50 mm.
Still another object of the present invention is to fabricate a low temperature process for
5 making glossy finish radiation shielding panels reinforced with epoxy/polyester resin
system.
Still another object of the present invention is to fabricate the radiation shielding hybrid
composite panels using nanoscale size of red mud process through high energy planetary
ball mill.
10 Still another object of the present invention is to fabricate a low temperature process for
making glossy finish radiation shielding hybrid composite panels reinforced with glass
fabric under compressive moulding process system.
Still another object of the present invention is to fabricate high performance radiation
shielding hybrid composite panels with variable mechanical strength and density.
15 Still another object of the present invention is to fabricate a and low cost process for
making glossy finish radiation shielding hybrid composite panels reinforced with red
mud and epoxy resin.
SUMMARY OF THE INVENTION
Accordingly the present invention provides a lead free radiation shielding hybrid
20 composite panel/sheets comprising 30-50% of industrial waste red mud and 50-70% of
epoxy/polyester resin with or without glass fibre/fabric, wherein the radiation shielding
hybrid composite panel has density in the range of 1.4 -2.2 glee, water absorption in the
range of 0.20 -0.3 %, tensile strength and tensile modulus in the range of 12-120 MPa
and 1.5- 7.5 GPa respectively, half value layer of 0.36- 0.47 em and 0.48 -0.52 em for
25 X-ray beam energies of 60 and 100 kVp respectively.
The present invention also provides a process for making lead free radiation shielding
panel through compressive moulding technique comprising the steps of:
a) dry and wet processing of industrial waste red mud particulates followed
by hot air oven curing to obtain processed waste red mud particulates;
b) ball milling of the processed waste red mud particulates using high energy
planetary ball milling under 250 rpm for 8 hour;
5 c) homogeneous mixing of the milled• processed waste red mud particulates
with epoxy/polyester resin;
d) • casting under compress1on moulding of radiation shielding hybrid
composite panel;
e) • optionally calendaring of glass fibres and cunng of radiation shielding
10 hybrid composite panel at room temperature
f) demoulding of the obtained glossy finish red-mud reinforced radiation
shielding hybrid composite panel and
g) . natural and or hot air oven curing of composite sheet to obtain lead free
hybrid composite radiation shielding panel.
15 In an embodiment of• the present invention the industrial waste red mud particulates
comprises of 10-45% iron oxide, 5-20% alumina, 3 -10% silica, 1- 1.5 % magnesium
oxide, 0.5 %potassium oxide, 0.5-1 %calcium oxide and 0.2% lead oxide.
In an embodiment of the present invention the industrial waste red mud particulates are
processed using hot water, mechanical grinding and hot air oven curing at 60 - 120 °C
20 for 12 - 24 hours, and final size of processed waste red mud particulates are in the range
of 500 nm-175 J.lm, density in the range of 1.6 1.9 glee, porosity in the range of 30- 68%
and water holdi'ng capacity of 48%.
25
In another embodiment of the present invention the milled processed waste red mud
particulates are mixed with epoxy/polyester resin at a volume ranging from 30-50 % and
at a rate of 1000- 3000 rpm.
In another embodiment of the present invention the in step b, 2 - 5% of methyl ethyl
ketone peroxide (MEKP) and cobalt naphthenate are used as catalyst.
In another embodiment of the present invention, step d is performed by usmg
compression I'noulding at a temperature range of 25°C - 60°C and at a casting pressure in
the range of 20-50 kg/cm2 in single operation mode.
In another embodiment of the present invention, step e is performed by using calendaring
5 of glass fabric. layer as sandwich structure and under casting pressure in the range of 20-
50 kg/ cm2 in single operation mode.
In another embodiment of the present invention, step g is performed by hot air oven
curing at a temperature range of 60 -120°C for 12 - 24 hours .
. The present invention also provides a lead free radiation shielding panel prod1Jced by the
10 above said process, wherein the radiation shielding panel has density of 1.4 -2.2 glee,
water absorption in the range of 0.20 -0.30 %, tensile strength and tensile modulus in the
. '
range of 12-120 MPa and.1.5- 7.5 GPa and flexural strength and flexural modulus in
range of 24-I20 MPa and 2.5 - 9.5 GPa, respectively, half value layer of 0.36- 0.47 em . . .
and 0.48 -0.52 em for X-ray beam energies of 60 and I 00 kVp respectively.
15 BRIEF DESCRIPTION OF DRAWING
FIG. 1 is a X-Ray diffraction pattern of red mud samples used as raw materials for our
invented moisture resistant radiation shielding hybrid composite panels.
FIG. 2 is a Fourier-transform infrared spectroscopy (FTIR) spectrum recorded for
invented moisture resistant red mud reinforced in epoxy resin based radiation shielding
20. hybrid composite panels.
25
FIG. 3 is a experimental results for measuring half value layer under X-ray radiation of
energy 60 KVp for invented moisture resistant red mud based radiation shielding hybrid
composite panels
FIG. 4 is an experimental results for measuring half value layer under X-ray radiation of
energy I 00 KVp for invented moisture resistant red mud based radiation shielding hybrid
composite panels.
• FIG. 5 is an explanatory v1ew showing. the manufacturing process of the high
performance radiation shielding red mud reinforced hybrid composite shielding hybrid
composite panels in single operation mode.
DETAILED DESCRIPTION OF INVENTION
5 Universally, more than 20 billion tons of such waste particulates have been annually
produced and India alone produces about one billion tonnes of solid wastes during 2014-
2015. Accordingly, the present invention provides a process for making water resistant
high strength and efficient X-ray radiation shielding hybrid composite sheet/panel, which
comprises of industrial waste particulate namely, red mud (50 %) reinforced in the epoxy
10 resin, compression of this polymer composite in a mould ,at a pressure in the range of 20-
50 Kg/cm2 followed by demoulding at a temperature in the range of 50°-80 C and curing
at 70 -120 °C in an air oven for 2 hours to obtain water resistant and efficient green
hybrid radiation shielding panel/sheet.
The present invention provides a simple process of making X-ray radiation shielding
15 hybrid composite sheet utilizes solid waste raw materials such as red mud which are
produced in the process of alumina production from bauxite powder. In the present
invention, the process of making X-ray radiation shielding hybrid composite sheet does
not contained conventionally used toxic lead metal or its compounds. The process of the
present invention, does not involved high temperature annealing or soaking process of
20 raw materials and final product as radiation shielding panels.
25
30
The process of making X-ray radiation shielding hybrid composite sheet utilizes solid
industrial waste material such as red mud that cause environmental and health problem
can be utilize to make highly value added; sheet for application as radiation shielding
panels, partition panels, roofing sheet. In yet another embodiment of the present
invention, the process of making X-ray radiation shielding hybrid composite panel/sheet
does not involve more than two raw materials i.e. red mud and epoxy resin are only used
to fabricate the radiation shielding sheet. Nanoscale size of red mud was used to fabricate
the radiation shielding materials.
In the process of the present invention red mud and epoxy resin/polyester and glass
fibres are used to fabricate the radiation shielding sheet. _In yet another embodiment of

the present invention, the process of making X-ray radiation shielding hybrid composite
sheet a simple and one step calendaring process of glass baric under low temperature
range with polymer matrix of epoxy and resin.
Table l.Physical characteristics of industrial waste red mud particulate
-
S.No Physical Properties Values
1. Particle size (J..lm) 0.5- 170
2. Bulk density (glee) 1.25 - 1.8
3. Specific gravity 2.2- 3.4
4. Porosity(%) 45-68
5. pH 4- 12.5
6. Water holding capacity (%) < 45
7. Electrical conductivity
450- 800
(J..lmohs/HP)
Table 2. Chemical characteristics of industrial waste red mud particulates
S.No Elements Composition
(%)
1. Si02 02-12
2. Fe20 3 10-45
3. Al20 3 5-20
4. CaO 3-10
5. MgO < 01
6. K20 < 0.5
7. ZnO < 0.5
8. CuO < 0.3
9 . Loss on Ignition 10
Physical and chemical characteristics of industrial waste particulate red mud is as shown
in Table 1 and Table 2. Composition and crystal structure of red mud powder was
confirmed by the X-Ray Diffraction method and XRD spectrum is shown in Figure 1. It
• was confirmed that red mud waste powder has four major phase of gibbsite: Al(OH)3,
hematite: Fe203, sodalite: N&tAbSi]012Cl, Quartz: Si02, Rutile: Ti02, and geothite:
FeO(OH). The diffraction peaks of red mud powder waste sample are well-matched to
the corresponding JCPDS card. XRD spectrum (Fig. 1) also confirmed that gibbsite and
5 hematite concentration in sample was high compared to other mineral phase.
The Fourier-transform infrared spectroscopy (FTIR) spectrum was measured from the
red mud reinforced epoxy hybrid composite sheet to determine the functional groups
(Fig. 2). The broad band at 3500 cm-1 is assigned to 0-H stretching of hydroxyl groups.
The single peak at 2900 cm-1 is assigned to C-H stretching of CH2 and CH aromatic and
10 aliphatic. This may be due to epoxy resin. The peak at 1603 cm-1 may be taken as the
stretching C=C of aromatic rings and peak appeared at 15 09 em -I is assigned as
stretching of C-C of aromatic. The sharp peak corresponds to 1036 cm-1 is due to the
stretching C-0-C of ether. The peaks at 965 and 826 cm-1 shows the stretching vibration
of C-0 of oxirane group and stretching vibration of C-0-C of oxirane group,
15 respectively.
The peak appeared at 818 cm-1 can be assigned as stretching vibration of Fe3
+ OH
indicating iron rich samples. The band between 1010-850 em -I occur due to the presence
of metallic oxide. The bands around 1180-1090 em -I appeared due to the Si--0
asymmetrical stretching vibration indicating presence of quartz (Si02). The peak at 540
20 cm-1 emerging in FT-IR spectrum shows the presence of Fe- 0 vibrations, confirming the
hematite phase in the hybrid composite sheet. A peak observed at 1000 cm-1 is due to
stretching of Al-OH indicating the presence of gibbsite Al(OH3) phase.
The complete description of all the process steps using industrial solid waste in the
present invention of a process of making moisture resistant radiation shielding hybrid
25 material involves use of red mud containing 10-45% iron oxide, 5-20% alumina, 3 -10%
silica, 1- 1.5 %magnesium oxide, 0.5 %potassium oxide, 0.5-1 % calcium oxide, 0.2 %
lead oxide. Raw materials red mud are mechanically grinded and then dried using hot
water ( ~ 60 °C) for 12 hours. The dried and processes red mud was homogeneously
mixed with the epoxy polymer at 1000-3000 rpm for 1 hour. The homogenous mixture of
30 then casted under compression moulding at temperature of 30-60 °C and at varying
casting pressure of 20-50 kg/ cm2 in single operation mode, followed hot air oven curing

• at 60 - 120 °C temperature for 12 - 24 hours to fabricate glossy finish moisture resistant
X-ray radiation shielding hybrid composite sheet.
The fabricated radiation shielding hybrid composite sheet are tested for their X-ray
attenuation characteristics using high energy electromagnetic X-ray beam radiation of
5 energy of 60 kV with 1 mm Cu-filter and 100 kV with 1 mm Cu-filter. Different
thickness ( 1, 2, 3 and 5 mm) of fabricated red mud reinforced composite sheet are
utilised to precisely measure the half value layer corresponds to various X-Ray beam.
The half value layer (HVL) of red mud based hybrid composite corresponds to the X-ray
beam of energy 60 kV with 1 mm Cu-filter sheet is found to be in range of 0.34 -0.35 em.
10 The half value layer (HVL) of red mud based hybrid composite sheet corresponds to the
X-ray beam of energy 100 kV with 1 mm Cu-filter is found to be• 0.48 - 0.50 em. The
obtained graphs for the estimation of half value layer for red mud reinforced hybrid
composite sheet corresponds to each 60 and 100 kV energies are given in Figure 3 and
4. X-ray radiation shielding properties of waste stones powder (calcite rich samples)
15 based epoxy composite sheet which was fabricated under similar condition is also tested.
Radiation shielding composite sheet with epoxy/polyester polymer and calendaring with
glass fabric under compressive moulding process was developed in single step. It is
clearly evident that no X-Ray shielding/attenuation property is detected for stones waste
based hybrid composite samples. Radiation shielding red mud and epoxy based hybrid
20 composite sheet showed the moisture absorption and density of about 0.20-0.30 % and
1.4- 2.2 glee, respectively. The resultant tensile and tensile modulus of radiation
shielding composite sheet was in range of 12-120 MPa and 1.5 - 7.5 GPa respectively
under epoxy and polyester resin. The fabricated red mud reinforced radiation shielding
hybrid composite shows flexural strength of24-120 MPa and 2.5-9.5 GPa, respectively.
25 The important features of the invention lies in the fact that
I. The process of present invention obviates the need of high temperature
sintering/annealing of raw materials.
II. The process of present invention obviates the use of toxic lead and its compound,
costly rare earth materials as raw materials
III. The process of present invention utilizes waste materials such as red mud which
inherently contains the various important radiation shielding element such as
iron, aluminium, silicon, and titanium.
IV. The conventional radiation shielding materials such as glasses that fabricated
using barium sulphate have very low poor strength, whereas in the present
process of invention the use of red mud waste particulates and epoxy resin as
hybrid composite sheet shows high mechanical strength.
V. The radiation shielding radiation sheet panels made in the present invention
process shows very small moisture resistant.
10 The process of present invention making large scale radiation shielding hybrid
composite is very simple in nature and therefore can be utilised for application as XRay
radiation shielding panels doors, partition, roofing sheet and radiation shielding
false ceiling. The following example is given by way of illustration and therefore
should not be construed to limiting the scope of the present invention.
15 The term "Density" herein refers to the mass density of a substance and is defined as
mass per unit volume. The symbol most often used for density is p (the lower case Greek
letter rho), although the Latin letter D can also be used. The technique used in the present
invention for the measurement of density of the materials is ASTM 792-08.
The term "Tensile strength" herein refers to refers to maximum convention (Tensile)
20 stress that can be sustained by the materials. before failure and is calculated based on the
load applied corresponding to its area. The te.c hnique used in the present invention for the
measurement of Tensile strength of the materials is according to ASTM D 638-10 using ,
UTM, LRX Plus, Lloyd, UK. Young modulus and strain were calculated from the stressstrain
data.
25 The term "Tensile Modulus" herein refers amount of stress applied to a material and
dividing it by the strain the material undergoes. The technique used in the present
invention for the measurement of Tensile Modulus of the materials is measured during
material tensile testing using plot that has stress on the vertical axis and strain on the
horizontal axis.
The term "half value layer " herein refers to or half-value thickness, is the thickness of
the material at which the intensity of radiation entering it is reduced by one half. The
technique used in the present invention for the measurement of half value layer of the
materials is standard test method for determining the attenuation properties in a X-Ray
5 beam of materials used to protect against radiation generated during the use of X-Ray
equipment.
The term "Water holding capacity" herein refers to the total amount of water materials
can hold at field capacity The technique used in the present invention for the
measurement of Water holding capacity of the materials is measured in saturated soil
10 paste international pipette technique as well as Keen Box Method.
EXAMPLE 1 : Red mud based radiation shielding panels/sheet in epoxy/polyester
resin
RAW MATERIALS: Industrial waste particulates red mud was used as reinforced
15 materials. Polymer used to make glos~y finish sheet was commercial grade
epoxy/polyester resin. Aliphatic polyamine (Lapox K-6) was used as hardener and curing
agent in case of epoxy resin and methyl ethyl ketone peroxide (MEKP) and cobalt
naphthenate were used as catalyst in case of polyester resin. Industrial waste particulates
used in these glossy finish green hybrid composites have particle size in range of 5- 175
20 J.lm, density of 1.25 -1.8 glee, pH in range of 4 -12.5, porosity of 45-68 % and water
holding capacity in range of 48 %.
25
PROCESS: Detailed laboratory experimental programme was conducted where in red
mud industrial waste particulates were processed and 50-60% of red mud were used and
they were homogeneously mixed with the epoxy/polyester resin based binder system
using mechanical stirrer at room temperature Aliphatic polyamine (Lapox K-6) of 8-10
% was used as hardener and curing agent in case of epoxy resin and in case of polyester
resin methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate were used as catalyst
(2 - 5%). A compression moulding machine was used to fabricate the glossy finish red
mud reinforced polymer composite sheet. Casting and fabrication of the composite sheet
30 was done at varying temperature of 25 - 60 °C and at varying casting pressure from 20-
50 kg/ cm2 in single operation mode. The fabricated radiation shielding glossy finish red
mud sheets were cured in an oven at 60-120 °C for 12 - 24 hours. Up- scaling of radiation
shielding sheets/panels was also done and glossy finish red mud waste particulates based
composites up to the dimension of 220 em x 120 em with varying thickness of 1.35 mm,
5 3 mm, 6 mm,9 mm, 12 mm, and 19 mm) were fabricated.
Properties: The following are the some of the measured properties of above described
example for moisture resistant radiation shielding hybrid composite panels/sheet based
on red mud waste particulates with epoxy/polyester polymer system
Density: I .4- 2.0 glee
10 Tensile Strength: 12- 45 MPa
Tensile Modulus: 1.5-3.5 GPa
Flexural Strength: 24- 60 MPa
Flexural Modulus: 2.5 - 6.5 GPa
Water Absorption: 0.25- 0.30%
15 Half Value layer (X-Ray Photon -60kVp): 0.39-0.42 em
20
25
Half Value layer (X-Ray Photon- I OOkVp): 0.48-0.50 em
Example 2 : R~d mud based radiation shielding panels/sheet reinforced with glass
fabric in epoxy/polyester resin
RAW MATERIALS: Industrial waste particulates red mud was used as reinforced
materials. Polymer used to make glossy finish sheet was commercial grade epoxy and
polyester resin. Aliphatic polyamine (Lapox K-6) was used as hardener and curing agent
in case of epoxy resin and methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate
were used as catalyst for polyester resin and
Industrial waste particulates used in these glossy finish green hybrid composites have
particle size in range of 5- 175 ~m, density of 1.25 -1.8 glee, pH in range of 4 -12.5,
16
• porosity of 45-68 % and water holding capacity in range of 48-68 %. Glass Fibres/fabric
was used as reinforced materials. Commercial grade bi-directional glass fabric of density
'
2.56 glee, elongation 4.5 %, Young's modulus of 73 GPa, and tensile strength of 2000
MPa was used.
5 PROCESS Detailed laboratory experimental programme was conducted where in red
mud industrial waste particulates were processed and 40-60% of red mud were used.
Then they were hoinogeneously mixed with the epoxy resin/polyester resin based binder
system using mechanical stirrer at room temperature. Aliphatic polyamine (Lapox K-6)
of 8-1 0 % was used as hardener and curing agent in case of epoxy resin and in case of
10 polyester resin methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate were used
as catalyst (2- 5%). A compression moulding machine was used to fabricate the glossy
finish red mud reinforced polymer composite sheet. Casting and fabrication of the
composite sheet was done at varying temperature of 25 - 60 oc and at varying casting
pressure from 20-50 kg/ cm2 in single operation mode. Calendaring of glass fabric/textile
15 sheet was done over red mud composite sheet. (2-1 0 %). The fabricated radiation
shielding glossy finish red mud sheets reinforced with glass fabric sheet were cured in an
oven at 60-120 °C for 12 - 24 hours. Up- scaling of radiation shielding sheets was also
done glossy finish red mud particulates with epoxy/resin system up to the dimension of
220 em x 120 em with varying thickness of 1.35 mm, 3 mm, 6 mm,9 mm,12 mm, and 19
20 mm) were fabricated
25
Properties: The following are the some of the measured properties of above described
example for moisture resistant radiation shielding 'hybrid composite panels based on red
•
mud particulates and epoxy/polyester polymer system
Density: 1.6-2.2 glee
Tensile Strength: 20- 85 MPa
Tensile Modulus: 2.5 - 6.5 GPa
Flexural Strength: 30-95 MPa
Flexural Modulus: 3.5-8.5 GPa
• Water Absorption: 0.25 - 0.30%
HalfValue layer (X-Ray Photon -60kVp): 0.37-0.42cm
Half Value layer (X-Ray Photon- lOOkVp): 0.47-0.49 em
•,
5 Example 3 : Nanoscale Red mud based radiation shielding panels/sheet in
epoxy/polyester resin
RAW MATERIALS: Industrial waste particulates red mud was used as reinforced
materials. Polymer used to make glossy finish sheet was commercial grade
epoxy/polyester resin. Aliphatic polyamine (Lapox K-6) was used as hardener and
10 curing agent in case of epoxy resin and methyl ethyl ketone peroxide (MEKP) and cobalt
naphthenate were used as catalyst in case of polyester resin. Industrial waste particulates
used in these glossy finish green hybrid composites have particle size in range of 500
nm- 50 J.lm, density of 1.25 -1.8 g/cc, pH in range of 4 -12.5, porosity of 45-68 % and
water holding capacity in range of 48-50 %.
15 PROCESS: Detailed laboratory experimental programme was conducted where in red
'
mud industrial waste particulates were processed and 40-60% of red mud were used. Red
mud inorganic particulates are ball milled with high energy planetary ball milling
machine under 250 rpm for 8 hour. Then they were homogeneously mixed with the
epoxy resin/polyester resin based binder system using mechanical stirrer at room
20 temperature. Aliphatic polyamine (La pox K -6) of 8-l 0 % was used as hardener and
curing agent in case of epoxy resin and in case of polyester resin methyl ethyl ketone
peroxide (MEKP) and cobalt naphthenate were used as catalyst (2- 5%). A compression
moulding machine was used to fabricate the glossy finish red mud reinforced polymer
25
composite sheet. Casting an? fabrication of the composite sheet was done at varying
temperature of 25 - 60 oc and at varying tasting pressure from 20-50 kg/ cm2 in single
operation mode. The fabricated radiation• shielding glossy finish red mud sheets were
cured in an oven at 60-120 °C for 12 - 24 hours. Up- scaling of radiation shielding sheets
was also done and glossy finish red mud particulates with epoxy/resin system up to the
dimension of 220 em x 120 em with varying thickness of 1.35 mm, 3 mm, 6 mm,9
mm, 12 mm, and 1 9 mm) were fabricated
Properties: The following are the some of the measured prope11ies of above described
example for moisture resistant radiation shielding hybrid composite panels based on red
5 mud particulates and epoxy/polyester polymer system
Density 1.6- 2.1 glee
Tensile Strength 22- 50 MPa
Tensile Modulus : 2.0- 4.5 GPa
Flexural Strength: 30 -- 65 MPa
10 Flexural Modulus: 3.0-6.5 GPa
Water Absorption: 0.20- 0.30%
Half Value layer (X-Ray Photon -60kVp): 0.39-0.47 em
Half Value layer (X-Ray Photon- I OOkVp): 0.48-0.52 em
15 Example 4 : Nanoscale Red mud based radiation shielding panels/sheets reinforced
with glass fabric in epoxy/polyester resin
20
RAW MATERIALS: Industrial waste particulates red mud was used as reinforced
materials. Polymer used to make glossy finish sheet was commercial grade epoxy and
polyester resin. Aliphatic polyamine (Lapox K-6) was used as hardener and curing agent
in case of epoxy resin and methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate
were used as catalyst in case of polyester resin. Industrial waste particulates used in these
glossy finish green hybrid composites have particle size in range of 500 nm - 5 ~m,
density of 1.25 -1.8 glee, pH in range of 4 -12.5, porosity of 45-68 % and water holding
capacity in range of 48-68 %. Glass Fibres/fabric was used as reinforced materials.
25 Commercial grade bi-directional glass fabric of density 2.56 glee, elongation 4.5 %,
Young's modulus of73 GPa, and tensile strength (of2000 MPa was used.
• PROCESS Detailed laboratory experimental programme was conducted where in red
mud industrial waste particulates were processed and 40-60% of red mud were used.
Then they were homogeneously mixed with the epoxy resin/polyester resin based binder
system using mechanical stirrer at room temperature. Aliphatic polyamine (Lapox K~6)
5 of 8-1 0 % was used as hardener and curing agent in case of epoxy resin and in case of
polyester resin methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate were used
as catalyst (2 - 5%). Red mud inorganic particulates are ball milled with high energy
planetary ball milling machine under 250 rpm for 8 hour. Glass fabric of 2-10 % was
used as reinforced materials in radiation shielding materials. A compression moulding
10 machine was used to fabricate the glossy finish red mud reinforced polymer composite
sheet. Casting and fabrication of the composite sheet was done at varying temperature of
25 - 60 oc and at varying casting pressure from 20-50 kg/ cm2 in single operation mode.
Calendaring of glass fabric/textile sheet was done over red mud composite sheet. (2-1 0
%) The fabricated radiation shielding glossy finish red mud sheets reinforced with glass
15 fabric sheet were cured in an oven at 60-120 'oc for 12 - 24 hours. Up- scaling of
radiation shielding hybrid composite sheets was also done and glossy finish red mud
particulates with epoxy/resin system up to the dimension of 220 em x 120 em with
varying thickness
Properties: The following are the some of the measured properties of above described
20 example for moisture resistant radiation shielding hybrid composite panels/sheets based
on red mud and epoxy/polyester polymer system
Density: 1.6- 2.4 glee
Tensile Strength: 25 - 120 MPa
Tensile Modulus: 3.0- 7.5 GPa
25 Flexural Strength: 35- 120 MPa
Flexural Modulus: 4.5- 9.5 GPa
Water Absorption: 0.25 - 0.30%
Half Value layer (X-Ray Photon -60kVp): 0.36-0.43 em

• HalfValue layer (X-Ray Photon- IOOkVp): 0.47-0.51 em
The red mud based hybrid composites materials for radiation shielding panels and doors
are not yet developed globa]ly. In the present invention, the mixing processing of red
mud, mixing with polymer in optimized rpm condition such as 1000-3000 rpm is
5 essential to make the rheological/viscosity properties of composites for preparation of
radiation composite sheet with claimed physical property.! Further casting temperature
and pressure values as disclosed in the present invention is important as it is not possible
to fabricate the glossy finish polymer composite with red mud in epoxy and polyester
resin without applying given temperature and pressure range and without processing of
10 red mud powder. Moreover, high energy planetary ball milling process is also required to
get specific property of the final product. The invention further provides a process to
make the radiation shielding panels through calendaring of layered glass fabric between
radiation shielding hybrid composite sheet.
15 The main advantages of the present invention arc:
20
25
I. The process of present invention utilizes industrial wastes specially red mud
generated in aluminium production and epoxy polymer as binder and obviates the
need of use of toxic lead materials and rare earth compounds.
II. The process of present invention significantly utilizes waste materials containing
the various important elements such as silicon, aluminum, titanium and specially
iron which are necessary for designing radiation shielding materials.
III. The conventional radiation shielding glass panels based on barium .have low
mechanical strength such as tensile. strength, whereas in the present invented
radiation shielding panels have very high tensile and flexural strength which are
capable of withstanding relatively high pressure and load/impact.
IV . The process of present invention does not involved high temperature annealing to
make efficient radiation shielding panels and metal oxides presented in the waste
materials in the novel process act as active component for obtaining the desired
..... o radiation shielding properties.
V. The process of present invention is carried out at a low temperature in the range
of only 60 - 80°C at casting pressure of 20-50 kg/ cm2 in case of compressive
moulding preparation technique.
VI.
VII.
The process of present invention is carried out at a low temperature range along
with calendaring of glass fabric as reinforce materials as sandwich structures.
The process of present invention helps in converting waste materials into value
added product as moisture red mud highly strength radiation shielding panels
VIII. Radiation shielding panels that can be fabricated in a single operation

We claim:

I. A lead free glossy finish radiation shielding hybrid composite panel/sheet
comprising 30-50 % of industrial waste red mud and 50-70% of epoxy/polyester
resin with or without glass fibre/fabric, wherein the radiation shic;:lding panel has
5 · density in the range of 1.4 -2.2 glee, water absorption in the range of 0.20 -0.3 %,
tensile strength and tensile modulus in the range of 12-120 MPa and 1.5 -- 7.5
GPa respectively, half value layer of 0.36- 0.47 em and 0.48 -0.52 em for X-ray
beam energies of 60 and 100 kVp respectively.
2. A process for making lead free radiation shielding hybrid composite panel/sheet
10 through compressive moulding technique comprising the steps of: ·
a) dry and wet processing of industrial waste red mud particulates followed by
hot air oven curing to obtain processed waste red mud particulates;
b) ball milling of the processed waste red mud particulates using high energy
planetary ball milling under 250 rpm for 8 hour;
15 c) homogeneous mixing of the ball milled processed red mud waste particulates
with epoxy/polyester resin;
d) casting under compression moulding of radiation shielding hybrid composite
panel/sheet;
e) optionally calendaring of glass fibres and curing of radiation shielding hybrid
1.1') 20 composite panel/sheet at room temperature
E....
0
LL. f) demoulding of the obtained glossy finish red-mud particulates waste based -en
(0
0 r-- radiation shielding hybrid composite panel/sheet and

0 g) natural and or hot air oven curing of composite sheet to obtain lead free
N

radiation shielding hybrid composite panel/sheet.

3. The process as claimed in claim 2, wherein the industrial waste red mud
particulates comprises of 10-45% iron oxide, 5-20% alumina, 3 -10% silica, 1-
1.5 % magnesium oxide, 0.5 % potassium oxide, 0.5-1 % calcium oxide and 0.2
% lead oxide.
5 4. The process as claimed in claim 2, wherein industrial waste red mud particulates
are processed using hot water, mechanical grinding and hot air oven curing at 60
- 120 °C for 12 - 24 hours, and final size of processed waste red mud particulates
are in the range of 500 nm-175 J.lm, density in the range of 1.6 1.9 glee, porosity
in the range of 30 - 68 % and water holding capacity of 48%.
10 5. The process as claimed in claim 2, wherein ball milled and/or processed waste red
mud particulates are mixed with epoxy/polyester resin at a volume ranging from
30-50% and at a rate of 1000- 3000 rpm.
6. The process as claimed in claim 2, wherein in step b, 2 - 5% of methyl ethyl
ketone peroxide (MEKP) and cobalt naphthenate are used as catalyst in case of
15 polyester resin and 8-10 % aliphatic polyamine (Lapox K-6) was used as hardener
and curing agent in case of epoxy resin.
7. The process as claimed in claim 2, wherein step d is performed by usmg
compression moulding at a temperature range of 25°C - 60°C and at a casting
pressure in the range of 20-50 kg/cm2 in single operation mode.
20 8. The process as claimed in claim 2, wherein step e is performed by usmg
calendaring of glass fabric layer as sandwich structure and under casting pressure
in the range of 20-50 kg/ cm2 in single operation mode.
9. The process as claimed in claim 2, wherein step g is performed by hot air oven
curing at a temperature range of 60 -120°C for 12 - 24 hours. 10. A lead free glossy finish radiation shielding hybrid composite panel/sheet
produced by the process as claimed in claim 2-10, wherein the radiation shielding
hybrid composite panel/sheet has density of 1.4 -2.2 glee, water absorption in the
range of0.20 -0.30%, tensile strength and tensile modulus in the range of 12-120
MPa and 1.5 - 7.5 GPa and flexural strength and flexural modulus in range of
24-120 MPa and 2.5 - 9.5 GPa, respectively, half value layer of 0.36- 0.47 em
and 0.48 -0.52 em for X-ray beam energies of 60 and 100 kVp respectively.