(FORM-2)
PATENT ACT 1970
(39 OF 1970)
COMPLETE SPECIFICATION
Title of the Invention : Process for preparation of alkali metal iodide.
Name of Applicant : Omkar Speciality Chemicals Ltd.
Address of Applicant : B-34, M.I.D.C., Badlapur (E),
Dist-Thane - 421503, Maharashtra, India.
Field of the invention : Process for preparation of alkali metal iodide more particularly to sodium iodide and potassium iodide.

Back Ground of Invention with regard to the drawback associated with the known art:-
Halogen salts have long been used for a myriad of useful purposes, such as analytical reagents, medicines, mordants, photography, single crystals for spectroscopy, feed additives and cloud nucleation. Many pure metals will react directly with halogens to form the corresponding halogen salts. However the cost involved in obtaining metals in their elemental form have made this process economically impractical. Thus, methods were sought which would permit reaction between metals in the form of metal salts and elemental halogens. As a consequence, their salts are more easily formed from the elemental state than is possible with iodine. Until recently many steps were required for the production of many iodide salts.
The commercial and economic importance of the iodides has long been recognized and large quantities of potassium iodide and sodium iodide are now commonly used in the manufacture of various foods, animal feeds, photographic materials, medicinal preparations, sanitizing compositions and other products. The methods by which the iodides have been produced commercially have been quite cumbersome and expensive. According to one of these method, iodine was dissolved in a solution of potassium hydroxide or potassium carbonate and the solution evaporated to dryness, the dry residue being mixed with powdered carbon, heating of the mixture takes place to effect reduction of the iodate and the resulting mass extracted with water and potassium iodide were recovered by crystallization. According to a second procedure, iodine and iron were reacted in presence of water to form ferrous iodide, followed by addition of iodine to form ferric iodide

which again reacted with potassium hydroxide to form ferric hydroxide in precipitated form and potassium iodide was formed.
Potassium iodide can be prepared by the reaction of a potassium base with hydroiodic acid is described in prior art. Many patents involving preparation of alkali metal iodide are disclosed in prior art. In prior art, method of preparing alkali metal iodide is disclosed in patent no.3402995 in which reaction between iodine and alkali metal hydroxide takes place to form desired alkali metal iodide. In patent no 2828184, preparation of alkali metal or alkali earth metal iodate and iodides is described. This process is for preparation of iodate and iodides in which reaction between elemental iodine and alkali metal or alkaline earth metal hydroxide takes place to form alkali metal iodate or iodide.
A method for co production of aromatic carboxylate and alkyl iodide is described in prior art. In this process, carbonylation of aromatic iodides takes place in presence of alkanol and nickel or ruthenium or palladium or rhodium catalyst, ether is disclosed in patent no Us 4,827,018, Us 4,847,406, Us 4,912,250; Us 4,866,200, Us 4,780,563, Us 4,778,917, Us 4,778,918.A process for the co production of (1) an alkyl iodide and (2) an alpha -iodocarboxylic acid, a mono-alpha-iodo-carboxylic anhydride or a mixture thereof is disclosed in US 5144067 in which reaction between an iodine compound and a carboxylic anhydride with a peroxide takes place. A process for preparation of alkali metal iodide salt solution and method for producing the same is disclosed in patent no Us 2010/0021369 which provides a liquid for combustion by removing a compound from a liquid containing the compound and iodine.
A method for production of potassium iodide is disclosed in patent no.HU48547 in which potassium iodide is formed by reaction between

ferrous iodide and potassium carbonate. Another one KI production process is disclosed in prior art in patent no. RU2210532 in which chemical interaction of iodine with potassium hydroperoxide takes place to form potassium iodide. Method of production of sodium iodide is disclosed in prior art having patent no. JP2004315470.The use of each of these procedures is complicated and involves process steps which are commercially expensive.
All the processes mentioned in prior art are multistep processes.Therefore there is need for such a process which is cost effective, simple and commercially beneficial. The present embodiment relates to a process for preparation of alkali metal iodides more particularly to sodium iodide and potassium iodide. The process disclosed herein for preparation of sodium iodide and potassium iodide is a three step reaction in which ammonium compounds and iodine are reacted with each other in presence of catalyst like hydrogen peroxide or hydrazine hydrate to form ammonium iodide. In second step, ammonium iodide is further reacted with alkali hydroxide or carbonate or bicarbonate. In third step, evaporation of the obtained solution takes place to form corresponding alkali metal iodide.
Advantages of the preferred Embodiment:-
1) These Products are simple, cost effective, easy to use, safe and eco-friendly,
2) These Products are having strong industrial applicability and are having good yield.
3) No side reactions.
4) All the processes produce less effluent.
5) Products obtained with good yield.

Object of the Invention:-
The main object of invention is that to overcome all the associated drawbacks and to prepare a process for preparation of alkali metal iodides more particularly to sodium or potassium iodide.
The object of the present invention is to provide a process for preparation of alkali metal iodides which is simple, cost effective and having strong industrial applicability with no side reactions.
Another object of the present embodiment is to provide a process for preparation of alkali metal iodide which is safe, eco-friendly along with less effluent production.
Statement of the Invention:-
This novel process disclosed herein is invented by scientist team of "Omkar specilaity chemicals ltd" and is a process for preparation of alkali metal iodides more particularly to sodium iodide and potassium iodide. The process disclosed herein is simple and cost effective with good yield, easy to use, safe and eco-friendly. The disclosed processes herein are having strong industrial applicability and are having good yield with no side reactions. The disclosed processes produce less effluent.

Summary of Invention:-
The novel processes for production of alkali metal iodide are disclosed herein are three step processes for preparation of sodium iodide and potassium iodide respectively. In preparation of alkali metal iodide, ammonium compounds and iodine are reacted with each other in presence of catalyst like hydrogen peroxide or hydrazine hydrate to form ammonium iodide. In second step alkali metal iodide is prepared by reaction of alkaline hydroxide or carbonate or bicarbonate with ammonium iodide to form alkali metal iodide In third step, evaporation of the obtained solution takes place to form crystals of corresponding alkali metal iodide.
Detailed Description of the Invention:-
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or matter.
The present disclosed invention is a three step process for preparation of alkali metal iodide more particularly to sodium iodide and potassium iodide respectively.

a) Process for preparation of sodium iodide:-
In first step of reaction, Ammonium compounds like ammonium hydroxide, ammonium carbonate and ammonium bicarbonate and iodine are reacted with each other in presence of catalyst like hydrogen peroxide or hydrazine hydrate to form ammonium iodide.

The second step used in this invention is reaction between alkaline hydroxide/ carbonate/ bicarbonate like a Sodium hydroxide / carbonate/ bicarbonate to form sodium iodide.

Third step include evaporation of the obtained solution to form crystals of
sodium iodide.
The following example illustrates the present invention:
Example 1:
106 ml water was charged m a 1 lit 4 neck round bottom ilask along with stirrer, condenser & thermo sensor fitted on water bath. 64 gm of ammonium bicarbonate was charged, stirred well and checked for clear solution. A solution of 13.5 ml hydrazine hydrate and 13.5 ml water were prepared and 100 gm iodine and hydrazine hydrate solution were added simultaneously & a low temperature was maintained at 50-60°C.This addition of hydrazine

hydrate requires 45 to 60 min. Then water bath was replaced by oil bath. After completion of addition, the temperature was raised slowly to 90-95°C and iodate test was taken. If test result does not compliances, few drops of hydrazine hydrate were added and temp was maintained for 15 min. If iodate test compliances, caustic soda solution was added .At the time of addition of caustic soda solution, liberation of ammonia gas by adjusting PH of the reaction mixture to 9.0-9.2 using caustic solution at temp. 100-105 °C upto complete liberation of ammonia. Activated carbon was added and stirred for 30 min at steady PH in between 9.0-9.2.The reaction mixture was cooled to 80°C and filtered through hyflow gives 20-40 ml water wash. The mixture was concentrated till thick slurry form and the reaction mass was cooled to 50-60 C and filtered through buckner funnel. Filtrate was collected and PH was adjusted to 9.0-9.2 using caustic soda solution and activated carbon was added and stirred for 15 min and filtered through hyflow gives 10-20 ml water wash and concentrated to get second crop.lsl& 2nd crop were dried at 110-115°C,
Yield: 115 gm, Purity: min 99.0 %,
If purity shows less than 99.0 % then minimum quantity of water used for washing the product followed by drying.
Example 2:
Substantially the procedure of example 1 was repeated using 37.8 gm of hydrogen peroxide. The resulting sodium iodide was produced in amounts same to that of example 1.

Example 3:
300 ml of liquor ammonia was charged in a 1 lit 4 neck RB flask with stirrer, condenser & thermo sensor fitted on water bath. A solution of 16 ml hydrazine hydrate and 13.5 ml water were prepared and 100 gm of iodine and hydrazine hydrate solution were added simultaneously by maintaining a temp at 50-60°C.This addition of hydrazine hydrate and iodine required 45 to 60 min. Then water bath was replaced by oil bath. After completion of addition, the temperature was raised slowly to 90-95 C and Iodate test was taken. If test does not compliances, few drops of hydrazine hydrate was added and temp was maintained for 15 min. If iodate test compliances, caustic soda solution was added. At the time of addition of caustic soda solution, liberation of ammonia gas takes place by adjusting PH of the reaction mixture to 9.0-9.2 using caustic solution at temp 100-105 °C. If the solution was not colorless, few drops of 20 % hydrazine hydrate solution were added at a steady PH 9.0-9.2. Activated carbon was added & stirred for 30 min followed by cooling upto 80°C and filtered through hyflow gives 20 ml water wash. The solution was concentrated upto the formation of thick . slurry and the reaction mass was cooled to 50-60 C followed by filtration through Buckner funnel. The filtrate was collected and PH was adjusted to 9.0-9.2 using caustic soda solution and activated carbon was added by stirring for 15 min. The solution was filtered through hyflow gives 10 ml water wash and concentrated to get second crop. lst& 2nd crop were dried at 110-115°C.
Yield: 115 gm, Purity: min 99.0 %,
If purity shows less than 99.0 % then the product was washed with minimum quantity of water and dried.

Example 4:
Substantially the procedure of example 3 was repeated using 37.8 gm hydrogen peroxide. The resulting sodium iodide was produced in amounts same to that of example 3.
5) Iodate test:-
5 ml sample + pinch of citric acid + 2-4 drops of starch solution and keep for 10-15 min. colorless to pale yellow colour passes test and yellow to red fails test. b) Process for preparation of potassium iodide:-
This is a three step process for preparation of alkali metal iodides particularly potassium iodide. In first step of reaction, Ammonium compounds like ammonium hydroxide, ammonium carbonate and ammonium bicarbonate and iodine are reacted with each other in presence of catalyst like hydrogen peroxide or hydrazine hydrate to form ammonium iodide.

The second step used in this invention. is reaction between alkaline hydroxide/ carbonate/ bicarbonate like a Potassium hydroxide/ carbonate/ bicarbonate to form potassium iodide.

In third step, evaporation of the obtained solution takes place to form
crystals of potassium iodide.
The following example illustrates the present invention.

Example 1:-
106 ml of water was charged in a 1 lit 4 neck RB flask with stirrer, condenser & thcrmo sensor fitted on water bath.64 gm of ammonium bicarbonate was charged and stirring was- done and clear solution was checked. 16 ml of hydrazine hydrate and 16 ml water was prepared in a beaker followed by addition of l00gm iodine and hydrazine hydrate solution simultaneously & a slow temperature was maintained at 50-60°C.This addition required 45 to 60 min. Water bath was replaced by oil bath. After completion of addition, the temperature was raised slowly to 90-95 C and lodate test was taken. If test does not compliances, few drops of hydrazine hydrate were added and temp was maintained for 15 min .If iodate test compliances, caustic potash solution was added. At the time of addition of caustic potash, liberation of ammonia gas takes place by adjusting PH 10.0-10.2 using caustic potash solution at temp.100-105 °C.A steady PH was maintained at 10.0-10.2 and activated carbon was added & stirred for 30 min. The mixture was cooled to 80°C followed by filtration through hyflow gives 20-40 ml water wash. The solution was concentrated upto thick slurry form, the reaction mass was cooled to 50-60 C and filtered through buckner funnel. The filtrate was collected and PH was adjusted to 9.0-9.2 using caustic potash solution. Activated carbon was added and the solution was stirred for 15 min. followed by filtration through hyflow gives 30-20 ml water wash and concentrated to get second erop.lst& 2nd crop were dried at 110-115°C.
Yield: 123 gm, Purity: min 99.0 %.
If purity shows less than 99.0 % then the product was washed with minimum quantity of water and dried.

Iodate test: 5 ml sample + 2-4 drops 2 N HCI (If colour changes are from colourless to pale yellow colour passes test and yellow to red fails test.)
Example 2:
Substantially the procedure of example 1 was repeated using 37.8 gm hydrogen peroxide. The resulting potassium iodide was produced in amounts same to that of example 1. '
Example 3:
300 ml of liquor ammonia was charged in a 1 lit 4 neck RB flask with stirrer, condenser & thermo sensor fitted on water bath. A solution of 16 ml hydrazine hydrate and 13.5 ml water were prepared and 100 gm of iodine. Hydrazine hydrate solution was added simultaneously & temperature was maintained at 50-60°C.This addition required 45 to 60 min. Water bath was replaced by oil bath. After completion of addition, the temperature was raised slowly to 90-95°C and Iodate test was taken. If test does not compliances, few drops of hydrazine hydrate were added and temp was maintained for 15 min. If iodate test compliances, caustic potash solution was added. At the time of addition of caustic potash solution, liberation of ammonia gas takes place by adjusting P of the reaction mixture to 9.0-9.2 using caustic potash solution at temp.100-105 (C. If the solution was not colorless, few drops of 20 % hydrazine hydrate solution were added at a steady PH 9.0-9.2 and activated carbon was added & stirred for 30 min and cooled to 80°C and filtered through hyflow gives 20 ml water wash. The solution was concentrated till thick slurry form and the reaction mass was cooled to 50-60 C and filtered through buckner funnel. Filtrate was collected

and PH was adjusted to 9.0-9.2 using caustic potash solution. Activated
carbon was added and stirred for 15 min followed by filtration through
hyflow gives 10 ml water wash and concentrated to get second crop.lst& 2nd
crop were dried at 110-115°C.
Yield: 123 gm, Purity: min 99.0 %.
If purity shows less than 99.0 % then the product was washed with minimum
quantity of water and dried.
Example 4:
Substantially the procedure of example 3- was repeated using 37.8 gm hydrogen peroxide. The resulting potassium iodide was produced in amounts same to that of example 3.
The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention; which is defined by the scope of the following claims.

Claims
I/we claim,
1. A process for preparation of alkali metal iodide comprising of
dissolving iodine and ammonium salts in presence of catalyst like
hydrogen peroxide or hydrazine hydrate;
reacting ammonium iodide with alkali salts like alkali hydroxide or
carbonate or bicarbonate;
evaporating the solution to form sodium or potassium iodide.
2. A process for preparation of alkali metal iodide as claimed in claim 1 where the said alkali metal iodide is either sodium iodide or potassium iodide.
3. A process for preparation of alkali metal iodide as claimed in claim 1 where the
said alkali salts such as hydroxide or carbonate or bicarbonate is anyone selected from a group consisting of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate.
4. A process for preparation of alkali metal iodide as claimed in claim 1
where the said ammonium salt is anyone selected from a group
consisting of ammonium hydroxide, ammonium carbonate or
ammonium bicarbonate.