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Potassium Chlorate
Introduction
Potassium chlorate, an important salt
of potassium widely used for manufacture of safety matchesIt
is also used in pyrotechniques, pharmaceutical industries
and for other minor uses.
The major consumption of potassium chlorate is in the manufacture
of safety matches. The potassium chlorate content in match
head composition varies from 50-55%. Generally, 6-8 kg. of
potassium chlorate is used per 100 gross of match containing
144 boxes each. In pyrotechnics potassium chlorates may be
mixed with certain organic compounds such as lactose to give
a relative cool flame so that certain dyes may be incorporated
in the mixture to give coloured flames. Potassium chlorate
is also used in the explosive percussion caps, in pharmaceutical
industry and dyes as oxidising agent.
Process
The manufacture of Potassium chlorate is carried out by electrolysis
of aqueous acidic solution of potassium chloride. The electrolyte
contains potassium chloride and potassium dichromate. Potassium
dichromate is used for the cathodic reduction process of chlorate
formation by an electrochemical reaction from hypochlorite.
In general in well designed system, electrolysis of chloride
is carried out by electrochemical oxidation of chloride to
hypochlorite ions at the anode. Further conversion of hypochlorite
to chlorate takes places as a chemical reaction. To achieve
high current efficiencies electrolysis is carried out in specially
designed electrolytic cells with integral reactors. Electrolysis
shall be carried out with controlled pH at a temperature of
70-75 degree C. Electrolyte shall be continuously fed in parallel
to all cells and from the cells, over flow shall be received
in RCC tile/lined tanks from where the solution is cooled
to 55-50 degree C in HDPE cooling tower by air. From the cooling
tower basin the electrolyte flow through a series of crystallising
pans which are RCC tile lined where the salt separates out
and accumulates. From time to time the salt is collected manually
by unskilled labour centrifuged and washed. The recovered
salt from centrifuge shall be of required purity which shall
be dried, pulverised and bagged. Mechanisation for conveying,
choice of centrifuge and handling operation can be designed
to minimise labour and supervisory requirement.
Properties and Specifications
Potassium chlorate, having a molecular
weight of 122.56, is a colourless solid and soluble in water.
Its solubility ranges from 3.3 gm at 0oC, 57 gms at 1000C
in 100 gms of water. Specific gravity of KClO3 is 2.32 and
melting point 3680 C. The product confirms to IS : 1987.
The Bureau of Indian Standard has specified
general properties of potassium chlorate (grade II ) suitable
for match industry as given below :
| Potassium chlorate weight
% min |
99.25 |
| Moisture weight % |
0.05 |
| Insoluble matter weight
% max. |
0.05 |
| Chloride (as Cl) weight
% max. |
0.10 |
| Perchlorate (as KClO4)
% max. |
0.15 |
| pH Value |
5.8 |
Advantages
- Low capital investment
- High employment potential
- Maximum use of local raw materials
and manpower resources
- Adaptable levels of sophistication
Plant Parameters
| Capacity, TPA |
1000 |
| Number of shifts |
3 |
| Working days / Yr. |
300 |
| Land Reqd., m2 |
12000 |
| Covered Area, m2 |
1200 |
Manpower
| Managerial |
1 |
| Skilled Worker |
5 |
| Unskilled Worker |
45 |
Raw Material (Tonne per Tonne of Product)
| Potassium chloride, T |
0.7 |
| Hydrochloric acid, Lit. |
20 |
| Potassium dichromate, T |
0.001 |
| Ethyl acetate |
0.01 |
| Activated carbon |
0.01 |
Utilities (Per day)
| DC Power, KwH |
5000 |
| Process water, Kl |
5.0 |
Plant & Machinery
| Electrolytic Cells |
Rectifier |
| Brine Head Tank |
Seal tank |
| Centrifugal Pumps |
HCl Tank |
| Crystallising Pans |
Centrifuge |
| Contact Hot Air Dryer |
Sump Tank |
| Centrifugal Pump |
Cell Insulator |
| Pulveriser |
Pipe Valves |
For further information please
contact :
National Research Development Corporation
( A Government of India Enterprise )
20-22, Zamroodhpur Community Center
Kailash Colony Extension
New Delhi 110 048. India
Tel: 91-11-26419904, 26417821, 26480767, 26432627
Fax: 011-26231877, 26460506, 26478010
Website: www.nrdcindia.com
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