FORM 2 THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10 and rule 13)
Title: An egg shell glass composition and method for preparation thereof. We, GUJARAT BOROSIL LIMITED
having office at Ankleshwar Rajpipla Road , Village - Govali, Taluka - Jhagadia, Dist
Bharuch- 393 001, Gujarat; and
Corporate Office at Crescenzo, 1101,11th Floor, G Block, Plot No. C 38/39, Bandra Kurla Complex, Bandra (E), Mumbai - 400 051, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.
TECHNICAL FIELD
The present invention discloses a composition and method for preparation of glass by use of egg shell in the composition. Use of egg shell in glass provides good melting for soda-lime-silica glass composition.
BACK GROUND OF THE INVENTION
Gujarat Borosil Limited (GBL), promoted by Borosil Glass Works is dedicated to serve in the field of renewable energy, for the purpose of encouraging green energy which causes to keep the environment green and clean and especially the air which gets polluted by the particles and other pollutants which remain and/or are emitted when nonrenewable energy is used and/or consumed. The production and/or use of nonrenewable energy when consumed and/or used for the purpose of heating and/or lighting causes harmful particles to be realized and emanated into the air which when inhaled give rise to in some cases skin allergies, cancer, lung diseases etc., besides causing global warming.
It is a known fact that everyday large quantity of egg shells are discarded and thrown to waste by egg processors and hatcheries. If these egg shells which are wasted everyday are utilized, then on one hand it would substitute the dependency on processed raw material which is used in glass which in turn would save the cost of mineral processing, while on the other hand this will help the society by preventing the air and environment from being polluted by the decay and contamination of the contents and residue remaining in the egg shells which

besides causing breeding ground for various bacteria and germs which are harmful to life also cause and create foul smell, hence will make clean environment.
OBJECTS OF THE PRESENT INVENTION
The important objective of the present initiative is that the use of egg shells will make the glass batch composition soft and can easily be crushed to convert into
flakes.
Egg shell waste form Hatcheries and Process is the potential pollutant of our environment. Therefore, other objective would be reusable this waste in Glass processing and support maintaining hygiene environment.
We observe, that the physical and chemical property of Soda Lime Silica Glass with usage of Egg Shell as resource of Lime n glass remains same.

DESCRIPTION
In view of above objectives the present act describes, a composition for making better quality glass comprising, an egg shell waste taking in a range of : 0.5to 15 % by weight of the composition, silica sand which contains Si02 above 95 % , AI203 < 1 % ,Fe203 < 0.5 % , Ti02 < 0.5 %; quartz powder contains Si02 above 99 % , AI203 > 0.1 %, Ti02 < 0.1 % , Fe203 < 0.05 %; dolomite contains Si02 >0.1 %, CaO< 40 %, MgO> 10 %,Fe203 < 0.1 % ; limestone contains CaO> 50 %, MgO CaO> 50 % , MgO < 5% ; Feldspar contains Si02 > 40 %, AI203 < 25 %, Na20 and K20 > 5 %;
Further embodiment of invention an Alumina hydrate contains water > 30 % rest is alumina; Sodium nitrate, contains above 30 % Na2O; sodium carbonate contains
> 50 % Na20; potassium carbonate contains < 75 % K2O; Cerium dioxide contains
> 95 % Ce02; zinc oxide contains > 95 % ZnO; Barium carbonate contains above 65 % BaO; synthetic carbon, contains above 85 % fixed carbon; blast furnace slag contains Si02 < 2 %, AI203< 0.5 %, CaO> 2%, MgO< 15 %, S03 > 2 %;sodium sulphate contains > 40 % Na20.Grain size of raw materials: silica sand or quartz < 710 micron, > 100 micron; dolomite <1.7 mm , > 0.1 mm; limestone > 0.1 mm, < 2 mm; feldspar < 50 mesh ASTM, alumina hydrate < 150 micron, sodium carbonate< 2 mm, > 150 micron; Potassium carbonate < 8 mesh BSS, > 100 mesh BSS; egg shell waste < 0.1 mm, > 150 micron; cerium dioxide < 250 micron; zinc oxide < 45 mesh ASTM; barium carbonate < 300 micron; blast furnace slag< 500 micron, > 150 micron.
A method for preparation of batch compositions were prepared in our in house R &D laboratory and weight of all materials were taken in high precision laboratory weighing scale. Laboratory furnace used: R&D electric melting furnace, rate of

increase in temperature:6°C to 10°C per minute maximum temperature :< 1460 C, Soaking time :< 4 hrs Crucible used: High quality refractory crucible, batch charging temperature:< 500°C molten glass taken out from the furnace with special arrangement under observation of highly skilled manpower. After taken out glass from melting furnace, glass sample is immediately transferred in to annealing furnace and allowed to cool at room temperature before conducting tests to check properties like chemical composition, density, chemical durability etc., when required glass sample is further processed on glass reducer, grinding and polishing machines.
A number of successful trials done with different ratio of egg shell in Batch composition with proper adjustment by maintaining glass composition and physical property. Some of the examples are given here next

EXAMPLE NO. 1
Composition 1
Batch composition:
Silica sand: 50 to 70 %
Soda ash: 15 to 20 %
Dolomite: 10 to 40 %
Limestone: 5 to 15 %
Alumina hydrate: 1 to 5 %
Feldspar: 0 to 10 %
Sodium sulphate: 1 to 5 %
Charcoal: 0.1 to 1 %
Egg shell: 0.5 to 15 %

RESULTS OF TRIAL MELTING:
Glass analysis:
Si02: >69 - < 80 % AI203: >0.5 - < 5 % CaO: > 2 - < 15 % MgO: > 0.2 - < 10 % Na20; > 5 - < 20 % S03 : 0.05 to 0.3 %
Glass density: 2.49 (+0.02) gm / cm3
Chemical durability: < 9 ml of 0.02 N acid
EXAMPLE NO. 2
Quartz powder: 53 to 65 %
Soda ash: < 20 %
Dolomite: < 20 %
Limestone: < 15 %
Feldspar: <10%
Sodium sulphate: 0 to 5 %
Charcoal: 0 to 1 %
Sodium nitrate: 0 to 5 %
Egg shell: 0.5 to 15%

RESULT OF TRIAL MELTING :
Glass analysis:
Si02 : >67 - < 79 % AI203: > 0.5 - < 5 % CaO : < 15 %, MgO: < 10 % Na20: < 20 % S03: 0.1 to 0.4%
Glass density: 2.49( ± 0.02 ) gm / cm3
Chemical durability: <9 ml of 0.02 N acid

EXAMPLE NO.3
Silica sand: 55 to 67 %
Soda ash: 15 to 20 %
Dolomite: 5 to 30 %
Limestone: 5 to 10%
Alumina hydrate: l to 5%
Feldspar: 0 to 10%
Sodium sulphate : 1 to 5%
Charcoal: 0.1 to 1%
Potassium carbonate: 0.05 to5 %
Egg shell: 0.5 to 15 %

Glass analysis:
Si02: < 80 % AI203: > 0.5 - < 5 % CaO :< 12 % MgO :< 5 % Na20:<15 % K20 : <2% S03: 0.1 to 0.3%
Glass density: 2.49 (+ 0.02) gm / cm3
Chemical durability :< 8.5 ml of 0,02 N acid

EXAMPLE NO. 4
Quartz powder: 52 to 58 %
Soda ash: 15 to 20 %
Dolomite: 12 to 38 %
Limestone: 5 to 15 %
Alumina hydrate: 1 to 5 %
Feldspar: 0 to 10 %
Sodium sulphate: 1 to 5 %
Charcoal: 0.1 to 1%
Potassium nitrate: 0 to 5%
Cerium dioxide: 0.05 to 1
Egg shell : 0.5to 15 %

Glass analysis:
Si02: > 65 - < 78 %
AI203 :>0.5-<5%
CaO : 10 to 13 %
MgO: 1 to 5 %
Na20: < 15 %
K20: 0.2 to 2 %
Ce02: < 2 %
S03: 0.05 to 0.4 %
Glass density: 2.47 to 2.51 gm/cm3 Chemical durability :≤ 8.5 ml of 0.02 N acid

EXAMPLE NO.5
Silica sand: 53 to 63 %
Soda ash: 15 to 20 %
Dolomite: 5 to 30 %
Limestone: 5 to 10 %
Alumina hydrate: 1 to 5 %
Feldspar: 0 to 10 %
Sodium sulphate: 1 to 5 %
Charcoal: 0.1 to 1 %
Barium carbonate: 0.04 to 5%
Egg shell : 0.5 to 15 %

Glass analysis
Si02 : >64 - < 80 %
AI203 : > 0.5 - < 5 %
CaO : 10 to 13 %
MgO : 1 to 5 %
BaO : 0.5 to 2.5 %
Na20 : < 15 %
S03 : 0.1 to 0.42%
Glass density : 2.47 to 2.51 gm/cm3
Chemical durability :≤ 8.5 ml of 0.02 N acid

EXAMPLE NO.6
Silica sand: 51 to 60 %
Soda ash: 15 to 20 %
Dolomite: 5 to 30 %
Limestone: 5 to 10 %
Alumina hydrate: lto 5 %
Feldspar: 0 to 10 %
Sodium sulphate: 1 to 5%
Charcoal: 0.1 to 1 %
Blast furnace slag: 0.5 to 5 %
Egg shell: 0.5 to 15 %

Glass analysis :
Si02 : >62 - < 76 %
AI203 : > 0.5 - < 5 %
CaO : 10 to 13 %
MgO : 1 to 5 %
Na20 : < 15 %
K20 : < 0.3 %
S03 : < 0.3 %
Glass density : 2.47 to 2.51 gm / cm3
Chemical durability : < 8.5 ml of 0.02 N acid

EXAMPLE NO.7
Silica sand: 52 to 59 %
Soda ash: 15 to 20 %
Dolomite: 5 to 30 %
Limestone: 5 to 10%
Alumina hydrate: 1 to 5 %
Feldspar: 0 to 10%
Sodium sulphate: 1 to 5 %
Charcoal : 0.1 to 1 %
Zinc oxide : 0 to 5 %
Egg shell : 0.5 to 15 %

Glass analysis:
Si02 : >60 - < 80 %
AI203 : > 0.5 - < 5 %
CaO : 10 to 13 %
MgO : 1 to 5 %
ZnO : < 2 %
Na20 : < 15 %
K20: 0.1 to 0.5%
S03: 0.1 to 0.4%
Glass density : 2.47 to 2.51 gm / cm3
Chemical durability :< 8.5 ml of 0.02 N acid
In laboratory trial, highest possible quantity of egg shells added in batch and melted to achieve successful result.

Typical batch composition with egg shell for trial melting
Silica sand or quartz 900 to 1000 kg
Soda ash 200 to 300 kg
Dolomite 100 to 200 kg
Limestone 0 to 150 kg
Eggshell 20 to 200 kg
Feldspar / Al hydrate 25 to 100 kg
Sodium sulphate 5 to 75 kg
Carbon 0 to 5 kg

TRIAL MELTING RESULT:
Glass sample showed good glass melting
Glass melting with egg shell on production scale
Successful trials made in laboratory with use of egg shell in glass melting.
After making successful laboratory trial, GBL has bought egg shells from egg processing industries. Egg shell waste needs to clean as it is collected from waste dump, sometimes it is contaminated with road stones and other foreign materials. This has been experienced when first trial with egg shell was made on the production scale. GBL has been using egg shell in glass melting in tank furnace of 350 Tons holding capacity of molten glass. With 175 TPD pull of glass and 100 batch per day feeding in the furnace, quantity of egg shell waste can be started with ≤ 20 kg per batch and it can be reached up to ≥ 120 kg per batch performing good glass melting and production.

We Claim,
1. An egg shell glass composition for making better quality glass comprising, an egg shell waste taking in a range of 0.5to 15 % by weight, silica sand Si02 above 95 % , AI203 < 1 % ,Fe203 < 0.5 % , Ti02 < 0.5 %; quartz powder contains Si02 above 99 % , AI203 > 0.1 %, Ti02 < 0.1 % , Fe203 < 0.05 %; dolomite taken Si02 >0.1 %, CaO< 40 %, MgO> 10 %,Fe203 < 0.1 % ; limestone contains CaO> 50 %, MgO CaO> 50 % , MgO< 5% ; Feldspar contains Si02 > 40 %, AI203 < 25 %, Na20 and K20 > 5 %;
2. A composition as claimed in claim 1, wherein an Alumina hydrate contains water > 30 % rest is alumina; Sodium nitrate, contains above 30 % Na20; sodium carbonate contains > 50 % Na20; potassium carbonate contains < 75 % K20; Cerium dioxide contains > 95 % Ce02; zinc oxide contains > 95 % ZnO; Barium carbonate contains above 65 % BaO; synthetic carbon, contains above 85 % fixed carbon; blast furnace slag contains Si02 < 2 %, AI203< 0.5 %, CaO> 2%, MgO< 15 %, S03 > 2 %;sodium sulphate contains > 40 % Na20;
3. A composition as claimed in claim 1 and 2, wherein the Grain size of raw materials: silica sand or quartz < 710 micron, > 100 micron; dolomite <1.7 mm, > 0.1 mm; limestone > 0.1 mm, < 2 mm; feldspar < 50 mesh ASTM, alumina hydrate < 150 micron, sodium carbonate< 2 mm, > 150 micron; Potassium carbonate < 8 mesh BSS, > 100 mesh BSS; egg shell waste < 0.1 mm, > 150 micron; cerium dioxide < 250 micron; zinc oxide < 45 mesh ASTM; barium carbonate < 300 micron; blast furnace slag< 500 micron, > 150 micron

A composition as claimed in above claims wherein in the
Silica sand: 50 to 70 %
Soda ash: 15 to 20 %
Dolomite: 10 to 40 %
Limestone: 5 to 15 %
Alumina hydrate: 1 to 5 %
Feldspar: 0 to 10 %
Sodium sulphate: 1 to 5 %
Charcoal: 0.1 to 1%
Egg shell: O.5to 15 %
5. A method of preparation of egg shell composition , comprising the following steps for trials;
a. the desired weight of all materials were taken in high precision
laboratory weighing scale;
b. after weighting the composition taken into melting furnace, increase
the rate of temperature 6°C to 10°Cper minute maximum
temperature < 1460°C, Soaking time < 4 hrs;
c. a high quality refractory crucible, batch charging temperature <
500°C;
d. after melting the molten glass taken out from the furnace glass
sample is immediately transferred in to annealing furnace followed
by cooling at room temperature before conducting tests to check