Sodium Silicate is a colourless compound of oxides
of sodium and silica. It has a range of chemical formula
varying in sodium oxide (Na2O) and silicon
dioxide or silica (SiO2 ) contents or ratios.
It is soluble in water and it is prepared by reacting
silica sand and sodium carbonate at a high temperature
ranging from 1200 to 1400oC. Aqueous solution
of sodium silicate is called water glass.
Sodium silicates are produced in the form of a variety
of compounds ranging from Na2O.4SiO2 to
2Na2O.SiO2 by properly proportioning the
reactants. Sodium silicates varying in ratio from Na2O.1.6SiO2
to Na2O.4SiO2 are known as colloidal
silicates. These are sold as 20% to 50% aqueous solutions
called water glass.
Sodium metasilicate has the ratio of Na2O.SiO2
and is a definite crystalline compound, which
forms various hydrates. Substances having higher sodium
oxide content are sodium squisilicate 1.5Na2O. SiO2
and sodium orthosilicate 2Na2O. SiO2 .
The more alkaline silicates including sodium metasilicate
(Na2O.SiO2 ) are crystalline materials with
definite structures and characteristic properties. These
are used chiefly as cleaners and detergents. The more
siliceous sodium silicates are glasses, typical non-crystalline
solid solutions, which are important mostly for their
adhesive and binding properties.
Market Potential
Sodium Silicate is used in soaps detergents and in
the manufacture of silica gel. It is used as a cement,
binder, filler and adhesive. And also used as a wall
coating, in concrete, fire proofing material and as
a sealant. It is also used to preserve eggs and wood.
Sodium Silicate also finds use in textile and pharmaceutical
industries. Neutral sodium silicate in liquid form is
suitable for use in pharmaceutical and toilet preparations.
Sodium silicates of certain ratios are used for application
over concrete floors for hardening making dustless concrete
floors and protecting pervious building materials against
the effects of moisture. Sodium silicate is also used
in foundries and welding electrode industries. In ceramic
industries, sodium silicate is used as a deflocculant
in the preparation of casting slips for keeping solid
particles in suspension without settling. Sodium silicate
is used in refractories industries as an air-setting
bond for manufacturing refractory cements and mortars.
In vitreous enamel industries, it is used for cleaning
the metal, known as pickling, prior to enamelling.
Basis and Presumptions
Efficiency: Since manufacture
of Sodium silicate is a continuous process, it is envisaged
that the unit will run 3 shifts a day continuously for
25 days in a month or 300 days in a year. 75 percent
efficiency of machinery and manpower is considered.
Time Period: Full capacity
utilization is expected to be achieved within 12 months
of commencement of commercial production.
Labour Wages: Minimum applicable
wages is considered. Interest Rate: An interest rate
of 12% per annum on the total capital investment has
been considered. Margin Money: Promoter is expected
to bring in one-third of the total capital investment.
Pay Back Period: The project
will have a payback period of about 4 years. Land and
Construction Costs: Land cost is considered at Rs. 3000
per square metre, and Construction cost for office and
stores at Rs. 6000 per square metre, and work shed at
Rs. 4000 per square metre.
Implementation Schedule
Sl. No.
Activity
Period
(in months)
1.
Preparation of the project report,
selection of site, provisional registration from
DIC, availability of finance
3
2.
Construction of building, procurement
of machinery and equipment availability of electrical
power
4
3.
Erection and Commissioning, recruitment
of manpower, trial runs and commencement of commercial
production
2
Total implementation period
9
Technical Aspects
Process of Manufacture
Silica sand and Sodium carbonate are the two principal
raw materials used in the manufacture of sodium silicate.
The proportions of these two raw materials will vary
depending on the ratio of Na2O and SiO2
required in the final product. Processed quartz with
a particle size distribution of –20 and +80 BS
Sieve can also be used in place of natural silica sand.
Sodium carbonate, also called soda ash, is available
in two forms: dense and light. Only dense variety of
sodium carbonate is used for manufacture of sodium silicate.
The raw materials are charged from a charging end,
which is called a dog house, into a continuous glass-melting
furnace operated at 1200o C to 1400o C. The exact melting
temperature will depend on the batch constituents. There
will be weight loss of approximately 10% in the weight
of the charge to the weight of finished fused melt drawn
from the furnace due to loss of gases and volatilization
of alkali oxides.
The fused melt is drawn from the discharging end of
the furnace continuously or periodically as a thin stream.
This melt will be solidified by passage into a moving
chilled conveyor of steel moulds, in which the melt
cools to a semi-transparent solid.
If the hot melt is sprayed with a stream of cold water,
it is shattered into fragments. The fragments are either
charged into grinding and screening equipment to yield
solid sodium silicate (granular) or are passed into
a rotary dissolver. In the rotary dissolver, the solid
material is dissolved by superheated (80 psi) steam.
Alternatively, the fused melt is directly passed into
water, in which it is dissolved with steam. The resulting
solution is clarified by settling in a tank and is adjusted
to the desired specific gravity. Specific gravity of
sodium silicates range from 22 to 69 Be with 40 Be being
the most common.
Dry, powdered sodium silicates may be produced by taking
liquors of proper specific gravity and forcing them
through a very fine opening into a solidification chamber.
The chamber is swept by a rapid current of cold air,
which carries off the moisture. The desired sodium silicate
is obtained by varying the ratio of the raw materials
charged as well as the working up of proper solution.
Quality Control and Standards
a) Indian Standard Specifications The Bureau of Indian
Standards has published the following Indian Standard
Specifications for Sodium silicate based on its use
in various industries:
i. IS 381:1995: Sodium silicate (Second Revision).
ii. IS 6773:1978: Sodium silicate for use in foundries
(First Revision) Re-affirmed 1991.
iii. IS 9601:1980: Sodium silicate for cosmetic industries
(Amendment No. 1) Re-affirmed 1991.
iv. IS 14212:1995: Methods of test for sodium silicate
and potassium silicates.
b) Grades and Types of Sodium Silicate
According to IS 381, both the solid and liquid form
of sodium silicate are of two grades: (a) Neutral, and
(b) Alkaline.
Sodium Silicate
Further, the above standard also categorizes the liquid
form of sodium silicates into the following types: Liquid,
neutral sodium silicates are of two types:
i. Type 1: For use in pharmaceutical and toilet preparations.
ii. Type 2: For use as an adhesive and other purposes.
Liquid, alkaline sodium silicates are of three types:
Type 1, Type 2, and Type 3: For use in soap, detergent,
textile, welding electrode and cement industries.
Quality Requirements
The quality requirements according to the IS 381 are
as follows:
Neutral sodium silicate shall be clear, free from dirt
and other visible impurities. Liquid sodium silicate
shall be thick, viscous, translucent mass of water white
or slightly grey colour. Solid sodium silicate shall
be in the form of glassy lumps of pale grey or green
colour. The particle size shall be as mutually agreed
to between the purchaser and the supplier to meet the
special requirements. Other quality requirements for
sodium silicate viz., matter insoluble in water, relative
density, total soluble silicates, ratio of total alkalinity
to total soluble silica, loss in mass on ignition, viscosity
and limits for iron, chloride and sulphate contents
are given in the IS 381.
Packing
The materials shall be packed in airtight mild steel
(MS) drums of capacity as mutually agreed to between
the purchaser and the supplier.
Marking
Each package shall be legibly and indelibly marked
with name and grade of the material, source of manufacture,
gross and net mass, year of manufacture and lot number.
Production Capacity (per annum)
Quantity
:
4000 tonnes
Value
:
Rs. 4,19,60,000
Motive Power
:
60 HP.
Pollution Control
Both raw materials, silica sand and sodium carbonate
are purchased in the ready to use powder form. Only
mixing of these materials in appropriate proportions
is done in the batch house in the plant. Hence, dust
collectors and exhaust systems are recommended in the
batch house. In the melting operation, chimney of sufficient
height, say 60 to 75 feet, is recommended to exit the
gases of combustion, carbon dioxide from the soda ash
and also volatilization of alkali oxides.
Energy Conservation
Modern glass tank furnace is recommended using furnace
oil, LDO or gas firing systems. Combustion systems,
for example, burners, blowers, preheating of fuel will
depend on the fuel selected. Care should be taken in
selecting the type and design of the furnace, refractories
to be used for construction of the furnace, proper thermal
insulation of the furnace walls and crown. All these
factors have a bearing on the thermal efficiency of
the furnace and energy conservation achieved in the
melting operation. Melting operation constitutes a significant
cost factor in production of sodium silicate.
Financial Aspects
A. Fixed Capital
(i) Land and Building
Particulars
Sq. Meters
Rate (Rs.)
Value (Rs.)
Land
4000
3000
1200000
Built Area
Office and Stores
100
6000
600000
Working Shed
400
4000
1600000
Raw Material Storage
400
4000
1600000
Finished goods Storage
500
4000
2000000
Total
7000000
(ii) Machinery and Equipments
Description
Imp/ Ind.
Qty. (Nos.)
Rate (Rs.)
Value (Rs.)
Production Unit
Glass Tank Furnace, drawing capacity: 5 tonnes
per day, melting area: 6 square metres
Ind.
1
2000000
20,00,000
Chimney of 60 to 75 feet height
Ind.
1
300000
3,00,000
Combustion equipment for furnace oil firing, including
burners, blowers, oil pipelines, preheating systems,
etc.
Ind.
1 set
700000
7,00,000
Oil storage tank, Capacity: 10 kilolitres and
pumps and piping
Ind.
1
300000
3,00,000
Dissolving tanks and agitators
Ind.
2 sets
400000
8,00,000
Bore well with pump set
Ind.
1
400000
4,00,000
Portable combustion analyzer
Imp
1
800000
8,00,000
Mild steel barrels of 200 lit capacity
Ind
1000
1000
10,00,000
Cost of laboratory instruments
Pollution Control Devices
Ind.
1
7,00,000
Cost of erection, installation and electrification,
at 10% of the above
Ind.
1
7,00,000
Cost of office equipment, furniture,
Ind.
1
3,00,000
Total
83,00,000
(iii) Pre-Operative Expenses
(Rs.)
Project report cost, non-refundable deposits,
etc
5,00,000
Total Fixed Capital
1,58,00,000
B. Working Capital (Per Month)
(i) Personnel (per month)
Designation
No.
Salary (Rs.)
Total (Rs.)
Administration and Supervisory personnel
Manager
1
15,000
15,000
Supervisors
2
10,000
20,000
Salesman
1
10,000
10,000
Accountant
1
10,000
10,000
Clerk
1
6,000
6,000
Watchman
4
3,500
14,000
Technical-Skilled and Semi or Unskilled
Personnel
Skilled workers
6
5,000
30,000
Un-skilled workers
15
3,000
45,000
Perquisites: @ 22% of the above
30,000
Total
1,80,000
(ii) Raw Materials (per month)
Particulars
Imp/ Ind.
Qty.
Unit
Rate (Rs.)
Value (Rs.)
Soda ash
Ind.
70
Tonnes
13000
9,10,000
Silica sand
Ind.
123
Tonnes
4000
4,92,000
Chemicals
Ind.
LS
Total
14,48,000
(iii) Utilities (per month)
Particulars
Qty.
Unit
Rate (Rs.)
Value (Rs.)
Furnace oil
45
Kiloliters
18000
8,10,000
Electrical power
12500
kWh
4
50,000
Water
4000
Kilolitres
2
8,000
Total
8,68,000
(iv) Other Contingent Expenses (per
month)
Particulars
Value (Rs.)
Postage and stationery
5000
Telephone
10000
Consumable stores
25000
Repairs and maintenance
11500
Transport charges
20000
Advertisement and publicity
25000
Insurance
10000
Taxes
5000
Sales expenses
11500
Miscellaneous expenses
10000
Total
133000
(v) Total Recurring Expenditure (per month)
26,29,000
(vi) Total Working Capital (on 3 months basis)
78,87,000
C. Total Capital Investment
2,36,87,000
Machinery Utilization
Machinery utilization of 75 percent has been considered
in the project.
Financial Analysis
(1) Cost of Production (per year)
Description
Value (Rs.)
Total recurring cost
3,15,48,000
Depreciation on building @ 5%
1,16,000
Depreciation on Machinery and Equipment
@ 10%
5,70,000
Depreciation on Furnace @ 20%
4,00,000
Interest on capital investment @ 12%
28,42,000
Depreciation on office equipments
and furniture @ 20%
60,000
Total
3,55,36,000
(2) Sales Turnover (per year)
Item
Qty.
Unit
Rate (Rs.)
Value (Rs.)
Sodium silicate liquid
4000
Tonnes
10490
4,19,60,000
(3) Net Profit Before Tax
Rs. 4,19,60,000-
3,55,36,000
= Rs. 64,24,000
(4) Net Profit Ratio
=
Net Profit per year x 100
---------------------------
Sales Turnover per year
=
64,24,000
---------------x100
4,19,94,000
=
15.3%
(5) Rate of Return
=
Net Profit per year
-----------------------x 100
Total Capital Investment
=
69,94,000
---------------x100
2,36,87,000
=
27.1%
(6) Break-even Point
Fixed Cost (per year)
Description
Value (Rs.)
Total depreciation
11,46,000
Interest on total capital investment
28,42,000
Insurance
1,20,000
40% of Salaries and wages
8,64,000
40% other contingent expenses
638,000
Total
56,10,000
B.E.P.
=
Fixed Cost ×100
---------------------
Fixed Cost + Not Profit
=
56,10,000
-------------x100
56,10,000 + 64,24,000
=
56,10,000
-------------x100
1,20,34,000
=
46.6%
Addresses of Machinery and Equipment
Suppliers
1. M/s. Glass Plant Construction Cor.
13, Km Stone,
Chandigarh-Ambala Road,
Bishanpura,
P.O. Dhankoli, Via Mubarakpur,
District. Patiala, (Punjab)
2. M/s. United Works Pvt. Limited
7-8, Mahalakhmi Bridge,
Mumbai-400 011
