FORM-2
THE PATENT ACT,1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
(As Amended)
COMPLETE SPECIFICATION (See section 10;rule 13)
"AN INNOVATIVE PROCESS FOR PRODUCING HIGH STRENGTH STABLE BLEACHING POWDER"
GEIST Research Private Limited, a corporation organized and existing under the laws of India, of L-9A, Phase-1, Verna Industrial Estate, Verna, Goa, India.
The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The present invention relates to a process of manufacturing of high strength stable Bleaching Powder from Calcium Hydroxide and chlorine as basic raw materials. The invention in particular relates to a process for the manufacturing of high strength stable Bleaching Powder having more than 35% available chlorine or at least 40% of available chlorine.
BACKGROUND OF THE INVENTION
Stable Bleaching Powder (SBP) has been conventionally manufactured by chlorination of calcium hydroxide. The conventional methods used for production of Stable Bleaching Powder, involves reacting lime or Calcium Hydroxide with chlorine. The limitation of the earlier processes is this method produces SBP having 32 to 35 percent of available chlorine. There is need, for a process for producing high strength SBP having more than 35% available chlorine or at least 40 % available chlorine and which is at the same time economically attractive as well as environmentally benign.
OBJECT OF THE INVENTION
An object of the present invention is therefore to provide a process for producing high strength Stable Bleaching Powder having more than 35% available chlorine or at least 40 % of available chlorine.
Yet another object of the present invention is to provide a process for manufacturing of high strength Stable Bleaching Powder which is economically attractive and environmentally benign.
Another object of the present invention is to provide a process for producing high strength Stable Bleaching Powder, which produces pure calcium chloride as a valuable side product.

Another object of the present invention is to provide a process for producing high strength Stable Bleaching Powder, from which it is easy to recover unreacted calcium hydroxide and reuse it as raw material.
SUMMARY OF THE PRESENT INVENTION
The present invention provides an innovative process to manufacture Stable Bleaching Powder having more than at least 35%, preferably more than 40% available chlorine from calcium hydroxide and chlorine as the basic raw materials.
In the present invention the calcium hydroxide is chlorinated and the product is purified further. Purification is attained by selective separation of calcium Chloride or Calcium Hydroxide or both from stable bleaching powder. In specific embodiments selective separation is based on difference in physical or chemical characteristics, of the constituents of a mixture containing calcium chloride, calcium hydroxide, and calcium hypochlorite.
BRIEF DESCRIPTION OF DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 illustrates a flow chart of an embodiment of the process of manufacturing of Stable Bleaching Powder having at least 40% available chlorine from calcium hydroxide and chlorine as basic raw materials.
The figure depicts a simplified structure only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The connections shown are logical connections; the actual physical connections may be different
DETAILED DESCRIPTION

Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. The terminology used in the detailed description of the particular exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.
The specification may refer to “an”, “one” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.
The present invention in particular relates to a novel process to manufacture calcium hypochlorite having more than 35% available chlorine or at least 40% available chlorine along with pure calcium chloride from calcium hydroxide and chlorine as basic raw materials. The process described herein in specific embodiment comprises the following steps, mainly: Chlorination of calcium hydroxide to obtain a composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride; and Separation of constituents based on difference in physical, chemical or magnetic characteristics from composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride. In specific embodiment separation of constituents from composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride involves the steps of: washing with calcium chloride selective solvent to obtain a slurry; filtering the slurry to obtain a filtrate and wet cake; and vacuum drying the wet cake. In a particular aspect of this embodiment, the filtrate obtained is evaporated to obtain Calcium Chloride.
The present invention relates to a process of manufacturing stable bleaching powder having more
than 35% available chlorine, comprising the steps of:-
a) Chlorination of calcium hydroxide to obtain a composite mixture of calcium hypochlorite,
calcium hydroxide and calcium chloride;

b) Washing the composite mixture obtained in step a) with calcium chloride selective solvent to obtain a slurry;
c) Filtering the slurry to obtain a filtrate and wet cake; and
d) Vacuum drying the wet cake obtained in step c) to obtain stable bleaching powder;
e) Optionally evaporating the filtrate obtained in step c) to obtain calcium chloride.
In specific embodiments of the invention the calcium chloride selective solvent is water.
In specific embodiments of the invention the ratio of calcium hypochlorite composite to water in step b) is maintained within the range of about 1:05 to 1:10, preferably at 1:1.
In specific embodiments of the invention the steps a) to d) are repeated till the strength of bleaching powder of more than 35% available chlorine is obtained, preferably more than 40% available chlorine is obtained.
In specific embodiments of the invention the step of chlorination comprises passing chlorine gas through a packed column filled with calcium hydroxide.
In specific embodiments Separation of constituents from composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride involves the steps of: washing with water maintaining the ratio of calcium hypochlorite composite to Water between the range of 1:0.5 to 1:10, in particular at about 1:1 to obtain a slurry; filtering the slurry to obtain a wet cake; and vacuum drying the wet cake. In a particular aspect of this embodiment, the filtrate obtained is evaporated to obtain Calcium Chloride.
An embodiment of the present invention has also been depicted using figure 1. The Chlorination of calcium hydroxide using chlorine is first carried out to obtain a composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride. The constituents are then separated. A slurry is first obtained by mixing composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride with a selective calcium chloride solvent. . The slurry is filtered, to obtain a wet cake and a filtrate. The wet cake can be vacuum dried to obtain bleaching powder which may again

be subjected to steps of chlorination and separation. The filtrate obtained is subjected to solvent recovery, to separate dry Calcium Chloride, and selective calcium chloride solvent.
In another aspect of the invention, the strength of bleaching powder may further be increased by: adding water, maintaining the ration of stable bleaching powder to water as 1:1; filtering the slurry & drying the wet cake to obtain stable bleaching powder
EXAMPLE 1.
The example discloses a novel process of producing of high strength stable bleaching powder essentially having at least about 40% available chlorine. Steps in the proposed innovative process producing of high strength stable bleaching powder are as follows.
Step (1): 392 g of calcium hydroxide was reacted with chlorine by passing chlorine gas through a
packed column filled with calcium hydroxide.
Step (2): After the chlorination step the composite mixture was given washing with water
maintaining the ratio of SBP TO Water as 1:1.
Step (3): The slurry then filtered and wet cake obtained was processed for vacuum drying
Step (4): The dried composite mixture then chlorinated
Step (5): After chlorination the composite mixture dried, after drying it gives 219 g of high strength
stable bleaching powder having 44% available chlorine.
Step (6): The filtrate obtained in in step (3) is evaporated to obtain Calcium Chloride.
EXAMPLE 2.
The example discloses a novel process of producing of high strength stable bleaching powder essentially having at least about 65% available chlorine.
Step (1): 400 g of calcium hydroxide was reacted with chlorine by passing chlorine gas through a
packed column filled with calcium hydroxide.
Step (2): After the chlorination step the composite mixture was given washing with water
maintaining the ratio of SBP TO Water as 1:1.
Step (3): The slurry then filtered and wet cake obtained was processed for vacuum drying

Step (4): The dried composite mixture then chlorinated further, which again dried to gives high
strength stable bleaching powder essentially having about 40% available chlorine.
Step (5): The product is added in water, maintaining the ration of stable bleaching powder to water
as 1:1 & slurry obtained is filtered to get wet cake of Calcium Hydroxide.
Step (6): The filtrate is evaporated to obtain slurry. The slurry is filtered & wet cake is dried to
obtain stable bleaching powder with 65% available chlorine.
Step (7): The filtrate obtained in Step (3) is evaporated to obtain Calcium Chloride.
The side product of the innovative process are Calcium Hydroxide and Calcium Chloride, out of which calcium hydroxide can again be reused as basic raw material for producing Stable bleaching powder.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

We claim:
1. A process of manufacturing stable bleaching powder having more than 35% available
chlorine, comprising the steps of:-
a) Chlorination of calcium hydroxide to obtain a composite mixture of calcium
hypochlorite, calcium hydroxide and calcium chloride;
b) Washing the composite mixture obtained in step a) with calcium chloride selective solvent to obtain a slurry;
c) Filtering the slurry to obtain a filtrate and wet cake; and
d) Vacuum drying the wet cake obtained in step c) to obtain stable bleaching powder;
e) Optionally evaporating the filtrate obtained in step c) to obtain calcium chloride.

2. The process as claimed in claim 1, wherein the calcium chloride selective solvent is water.
3. The process as claimed in claim 1, wherein the ratio of calcium hypochlorite composite to water in step b) is maintained within the range of about 1:05 to 1:10 , preferably at 1:1.
4. The process as claimed in claim 1, wherein the steps a) to d) are repeated till the strength of bleaching powder of more than 35% available chlorine is obtained, preferably more than 40% available chlorine is obtained.
5. The process as claimed in claim 1, wherein the step of chlorination comprises passing chlorine gas through a packed column filled with calcium hydroxide.

A process of manufacturing stable bleaching powder having more than 35% available chlorine, comprising the steps of Chlorination of calcium hydroxide to obtain a composite mixture of calcium hypochlorite, calcium hydroxide and calcium chloride; Washing the composite mixture obtained in step a) with calcium chloride selective solvent to obtain a slurry; Filtering the slurry to obtain a filtrate and wet cake; and Vacuum drying the wet cake obtained in step c) to obtain stable bleaching powder; Optionally evaporating the filtrate obtained in step c) to obtain calcium chloride.