FIELD OF INVENTION
[001] The present disclosure broadly relates to the field of industrial production of
salt, and in particular discloses a process for obtaining free-flowing salt.
BACKGROUND OF INVENTION
[002] Salt is majorly of two types, rock salt and common salt. The sources for rock salt are very less in India, few of the mining for rock salt includes Jaipur (Rajasthan) and Mandi (Himachal Pradesh). Major source for common salt is sea water accounting for almost 82% of total common salt produced in India. Common salt, when pure, is in form of a white mineral halite and is considered as an essential commodity for human consumption. Conventionally, sea water is subjected to solar evaporation to obtain common salt. Another method to obtain common salt that requires elaborate set up is vacuum evaporation. Common salt so obtained is fortified with iodine which is an essential element required for human metabolism. [003] Thus, the iodised salt is a daily commodity used for general human consumption, therefore, the production and exportation is continuously monitored for streamlining of the process in salt industry. India is the third largest producer of salt in the world next to China and United States of America. [004] Solar evaporation comprises steps for trapping sea water in shallow confinements which are then allowed to be evaporated by sun. Further, concentrated brine is used to precipitate salt and the precipitated salt is gathered by mechanical harvesters. Vacuum evaporation is mostly used when high-quality salt is desired and leads to formation of fine crystals of salt. It includes steam heat exchangers for evaporation and brine is further used for precipitating salt. This process is expensive as compared to the solar drying process. Both the processes face issues with regards to quantities of impurity and quality of salt thus obtained. The mentioned features cannot be uniform for both the methods. Therefore, given the importance of common salt in day-to-day life, new and beneficial processes for producing salt having desirable quality need to be developed and researched upon.

[005] US20100143220A1 discloses a process for improving solar drying process for producing salt to bring about improvements in purity and salt whiteness. The disclosure is focused upon removing of impurities from brine used in the process. [006] WO2014167185A1 discloses a co-crystallized low-sodium salt product for food and commercial use.
SUMMARY OF THE INVENTION
[007] In an aspect of the present disclosure, there is provided a process of preparing free-flowing salt, the process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns.
[008] In an aspect of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns. [009] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0010] The following drawings form a part of the present specification and are
included to further illustrate aspects of the present disclosure. The disclosure may be
better understood by reference to the drawings in combination with the detailed
description of the specific embodiments presented herein.
[0011] Figure 1 depicts a graph illustrating overall comparison of angle of repose
among different salt samples, in accordance with an embodiment of the present
disclosure.
[0012] Figure 2 depicts a graph illustrating overall comparison of moisture content
among different salt samples, in accordance with an embodiment of the present
disclosure.
[0013] Figure 3 depicts a graph illustrating overall comparison of iodine content
among different salt samples, in accordance with an embodiment of the present
disclosure.
[0014] Figure 4 depicts a graph illustrating overall comparison of turbidity among
different salt samples, in accordance with an embodiment of the present disclosure.
[0015] Figure 5 depicts a graph illustrating overall comparison of water insoluble
matter among different salt samples, in accordance with an embodiment of the present
disclosure.
[0016] Figure 6 depicts a graph illustrating variation in magnesium content in
Sample-2, in accordance with an embodiment of the present disclosure.
[0017] Figure 7 depicts a graph illustrating variation in calcium content in Sample-
2, in accordance with an embodiment of the present disclosure.
[0018] Figure 8 depicts crystal shape of Sample-1, in accordance with an
embodiment of the present disclosure.
[0019] Figure 9 depicts crystal shape of Sample-2, in accordance with an
embodiment of the present disclosure.
[0020] Figure 10 depicts crystal shape of Sample-3, in accordance with an
embodiment of the present disclosure.
[0021] Figure 11 depicts crystal shape of Sample-4, in accordance with an
embodiment of the present disclosure.

[0022] Figure 12 depicts crystal shape of newly developed salt, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Those skilled in the art will be aware that the present disclosure is subject to
variations and modifications other than those specifically described. It is to be
understood that the present disclosure includes all such variations and modifications.
The disclosure also includes all such steps, features, compositions, and compounds
referred to or indicated in this specification, individually or collectively, and any and
all combinations of any or more of such steps or features.
Definitions
[0024] For convenience, before further description of the present disclosure, certain
terms employed in the specification, and examples are delineated here. These
definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the meanings
recognized and known to those of skill in the art, however, for convenience and
completeness, particular terms and their meanings are set forth below.
[0025] The articles "a", "an" and "the" are used to refer to one or to more than one
(i.e., to at least one) of the grammatical object of the article.
[0026] The terms "comprise" and "comprising" are used in the inclusive, open sense,
meaning that additional elements may be included. It is not intended to be construed
as "consists of only".
[0027] Throughout this specification, unless the context requires otherwise the word
"comprise", and variations such as "comprises" and "comprising", will be
understood to imply the inclusion of a stated element or step or group of element or
steps but not the exclusion of any other element or step or group of element or steps.
[0028] The term "including" is used to mean "including but not limited to".
"Including" and "including but not limited to" are used interchangeably.
[0029] For the purposes of the present document, "regular solar salt refining
process" refers to the process which is currently followed for producing solar dried
salt. "Solar dried salt" refers to the salt obtained by using regular solar salt refining

process. "Newly developed salt" refers to the salt obtained by the process of the present disclosure. "Vacuum dried salt" refers to the salt obtained by vacuum drying process known in the art. "Raw solar salt" refers to the impurified form of salt which is obtained by solar evaporation of sea water. In regular solar salt refining process, the raw solar salt is further processed to obtain a solar dried salt which is purified and refined. "Automatic feeding mechanism" refers to the mechanism well known in the art that are used for segregation and packaging systems ensures that the final salt product gets directly poured and packaged in individual packaging units. "Add¬on-salt agent" refers to any agent that is usually added to salt for modifying its characteristics, it can be any agents well known in the art like anticaking agent, habit-modifiers, anti-solvents, and the like.
[0030] Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
[0031] The manufacturing of raw solar salt involves natural sun drying of sea water where the concentration of brine is measured in degree Baume (Be). According to this process, sea water evaporates up to the saturation point in open basins. Crystallization occurs in dedicated open basins as well, where the saturated brine is finally poured. Once the salt crust is formed, the exceeding water is eliminated before harvest.
[0032] Vacuum salt is fine cubic-crystal salt formed by the artificial evaporation of chemically treated brine. One of the shortcomings associated with salt obtained by solar evaporation method is that it needs to ad-mixed with various non-salt water insoluble substances to ensure better free-flowing ability.
[0033] Further, solar salt is produced using sea brine. Calcium sulfate (CaS04), magnesium sulfate (MgS04) and magnesium chloride (MgCh) are identified as the main impurities of crude salt. With the excessive hydro-attraction capacity, dried free flowing salt absorbs water because of these compounds. Ca, Mg and SO4

impurities in solar salt can be reduced by mechanical washing. The drawbacks of the method are that though the Ca content of salt is reduced, the MgSCM content cannot be reduced. Moreover, it involves compositional changes which are many times difficult from a logistics and economic point of view (Mukhopadhyay, et al. Process for the preparation of solar salt having high purity and whiteness U S Patent 8282690).
[0034] Though vacuum drying process ensures better free-flowing ability, it is a much expensive process as compared to solar drying process. In view of this, a core part of research is concentrated to overcome the problems associated with refinement of salt obtained by solar evaporation. There exists a need to minimize impurities in the final salt product obtained by solar evaporation. The present disclosure provides an improved process for producing high-quality salt having desirable characteristics of purity, free-flowing ability, and lesser turbidity because of insoluble solids. [0035] The present disclosure discloses a high-purity, free-flowing solar salt without add-on-salt agent so as to maintain a minimum level of insoluble matter, turbidity and black particles. The present disclosure discloses a process wherein the dried salt from the fluidised bed dryer was passed through gyro sieves having sieve size of 850 micron and 300 micron. The product retained between these specific sizes was transferred to hopper through conveyor. Further potassium iodate in a required amount was added before passing the product to silos. Finally, product was passed to filling machine through screw conveyer. Addition of silica as add-on-salt agent was avoided in the process of present disclosure. The process of the present disclosure is a modification of regular solar drying process to obtain a high-quality free-flowing salt.
[0036] The process of the present disclosure provides salt with high purity having composition characterized by crystal size ranging between 300-850 micron with proportion of less than 0.1 % Mg (magnesium) and less than 0.1% Ca (calcium) wherein the composition is essentially devoid of add-on-salt agent which in turn minimizes the turbidity of salt solution. The salt is demonstrated to have superior flow property when compared to vacuum evaporated salt.

[0037] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.
[0038] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally-equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein. [0039] In an embodiment of the present disclosure, there is provided a process of preparing free-flowing salt, the process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns. [0040] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the process further comprises subjecting the free-flowing salt to automatic feeding mechanism.
[0041] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the at least one solution is brine.
[0042] In an embodiment of the present disclosure, there is provided a process as described herein, wherein processing the slurry comprises processes selected from a group consisting of wet milling process, separation, washing, concentration, centrifugation, and combinations thereof.
[0043] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the gyro-sieves have a mesh size in a range of 300 microns -850 microns.

[0044] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt has an angle of repose in a range of 30 degree - 45 degree.
[0045] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt has particles in an irregular morphology.
[0046] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt has moisture content in a range of 0.9- 1.2 % after storing for 15 - 20 weeks at a temperature of 37 °C and 85 % relative humidity.
[0047] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt comprises calcium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt. [0048] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt comprises calcium having a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt. [0049] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt comprises magnesium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt. [0050] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the free-flowing salt comprises magnesium having a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt. [0051] In an embodiment of the present disclosure, there is provided a process as described herein, wherein the process results in the reduction of water-insoluble impurities in the percentage range of 78 - 82 % with respect to a regular solar salt. In another embodiment of the present disclosure, the reduction of water-insoluble impurities is in the percentage range of 79 - 81 % with respect to a regular solar salt. [0052] In an embodiment of the present disclosure, there is provided a process of preparing free-flowing salt, the process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5

%; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt comprises calcium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt, and magnesium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt, and the process results in the reduction of water-insoluble impurities in the percentage range of 78 - 82 % with respect to a regular solar salt.
[0053] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns. [0054] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the process further comprises subjecting the free-flowing salt to automatic feeding mechanism.
[0055] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5

%; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the at least one solution is brine.
[0056] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein processing the slurry comprises processes selected from a group consisting of wet milling process, separation, washing, concentration, centrifugation, and combinations thereof.
[0057] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the gyro-sieves have a mesh size in a range of 300 microns -850 microns. [0058] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the

dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt has an angle of repose in a range of 30 degree - 45 degree. [0059] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt has particles in an irregular morphology. [0060] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt has moisture content in a range of 0.9- 1.2 % after storing for 15-20 weeks at a temperature of 37 °C and 85 % relative humidity. [0061] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt comprises calcium having a weight percentage in a range of

0.01- 0.15 % with respect to the free-flowing salt. In another embodiment of the present disclosure, calcium has a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt.
[0062] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the free-flowing salt comprises magnesium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt. In another embodiment of the present disclosure, magnesium has a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt.
[0063] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process, said process comprising: (a) obtaining raw solar salt; (b) contacting the raw solar salt with at least one solution to obtain a slurry; (c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %; (d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture; (e) drying the iodised mixture to obtain dried product; and (f) sieving the dried product through gyro sieves to obtain free-flowing salt, wherein the free-flowing salt has a particle size in a range of 300 microns - 850 microns, and wherein the process results in the reduction of water insoluble impurities in the free-flowing salt in a percentage range of 78 - 82 % with respect to a regular solar salt. [0064] In an embodiment of the present disclosure, there is provided a free-flowing salt obtained by a process as described herein, wherein the salt is useful as edible salt, or non-edible salt.
[0065] Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, other implementations are possible.

EXAMPLES
[0066] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply.
[0067] The present disclosure is focused to address the challenges as described in the background section, so as to obtain high quality free flow salt. The basic requirements, role and impact of the components associated with salt production along with the parameters of the process to obtain desirable granular size of salt particles was tested. Further to understand the seasonal variation of components which are associated with salt in terms of quantity, 12-month samples have been screened at different granular size, and derived at a range of particle size and process control to improve the flow ability to achieve salt quality better than vacuum evaporated salt.
Materials and Methods
Comparison studies of commercially procured salts with free-flowing salt of present
disclosure
[0068] The raw salt samples harvested at Gandhidham, Gujarat from January to
June 2016 have been subjected to analyze calcium and magnesium content by
complexometric titration as per IS 7224: 2006.
[0069] Commercial salt sample (Sample-2) manufactured from January to
December 2016 have been collected from Terapanth Foods Limited, Gandhidham,
Gujarat. Samples have been sieved through 850, 600, 420, 300, 212 and 150 microns,

retention on each sieves have been subjected to analyze calcium & magnesium
content by complexometric titration as per IS 7224 : 2006.
[0070] Sample-2 and Sample-1 manufactured on same month were purchased from
market (Bangalore) for shelf life study.
[0071] Accelerated study has been carried out at 37°C and 85% RH along with
Sample-1 and Sample-2 by storing samples in stability chamber (Rinac India Ltd
Walk in stability chamber). Samples have been drawn every fortnight and monitored
the depletion of flow ability & Iodine content and increment of moisture. The study
was carried out for 16 weeks. Flow ability has been measured by passing salt through
2.18mm sieve over G4 crucible to form a heap which is interrelated with free-flowing
ability(In-house method). Moisture and Iodine content (on dry basis) have been
estimated as per IS 7224: 2006.
[0072] Number of black particles present in developed salt have been counted along
with Sample-2 and competitor sample (Sample-1 salt), by spreading the salt on
acrylic tray of 20 x 20 cm (In-house method). Total chloride has been estimated to
understand the increment of NaCl content in developed salt compared to control and
competitor salt samples.
[0073] Sample-1, Sample-2, Sample-3, Sample-4, and Sample-5 have been
purchased from market (Bangalore). Turbidity of 10% aqueous solution have been
compared among all branded salt by using Turbidity meter (TN-100 Eutech
Instruments Made in Singapore). Water insolubility has been estimated as per IS
7224: 2006.
[0074] Sample-1 is a vacuum dried salt, whereas Samples 2, 3, 4, and 5 are solar
dried salt. Newly developed salt or free-flowing salt refers to the salt product
obtained by the process of the present disclosure.
Example 1
Process for production of salt as disclosed in the present disclosure
[0075] The process as disclosed in the present disclosure is as follows. The raw
solar salt is obtained by natural sun drying of sea water. According to this process,
sea water evaporates up to the saturation point in open basins. Crystallization occurs

in dedicated open basins as well, where the saturated brine is finally poured. Once the salt crust is formed, the obtained salt is considered as raw solar salt. As per the process of the present disclosure, the raw solar salt was treated with brine to obtain a slurry. The slurry so obtained was treated with multiple steps of milling, washing, concentrating, and centrifugation to obtain a mixture having moisture level in the range of 3 - 5%. Centrifugation was done at 2000 to 3000 rpm, preferably 2200 to 2500 rpm. The mixture was contacted with potassium iodate to obtain an iodised mixture. The iodised mixture was subjected to drying in a fluidised bed dryer, to obtain a dried product. The dried product was passed through gyro sieves having sieve size of 850 microns and 300 microns. The product retained between these specific sizes was transferred to hopper through conveyor. Finally, the product was passed to filling machine through belt conveyer, to obtain free-flowing salt. An important point to note in this process is that addition of anticaking agent, habit-modifiers, anti-solvents, and the like was avoided. The free-flowing salt obtained by the process of the present disclosure can be used for edible or non-edible purposes. [0076] A detailed process for production of free-flowing salt using the automatic feeding mechanism is described in Table 1 below:

[0077] The free-flowing salt obtained by the process of present disclosure was compared with the commercially available samples in an acceleration study as per the conditions as described in the following paragraph.
[0078] The free-flowing salt (newly developed salt) was stored in humidity chamber at 37°C and 85% RH (Relative Humidity) along with solar dried salt (control) and vacuum dried salt (Sample-1). Samples were pulled once in fortnight and estimated moisture, Angle of Repose (AOR) and iodine content. AOR depicts the free-flowing ability of the salt samples, lesser AOR indicates better free-flowing ability of the respective sample. Table 2 depicts the observations. Pull-1 refers to taking out sample after 15 days of storage, Pull-2 refers to taking out of sample after 30 days of storage, and so on.
[0079] Free-flowing ability was measured by passing salt through 2.18mm sieve over G4 crucible to form a heap which is interrelated with free-flowing ability. Referring to Table 2, upon analyzing AOR, it can be inferred that newly developed salt of the present disclosure is 95% and 80% more free flow than regular solar as

available in the market and vacuum salt respectively (Figure 1). Thus, the newly developed salt of the present disclosure has desired qualities as compared to the well-established solar and vacuum dried salt samples.
[0080] Referring to Table 2 and Figure 2, it can be inferred that moisture content of Sample-2 has increased 3.28 times more after storing for 16 weeks at 37°C and 85% RH, whereas in case of Sample-1 and newly developed salt, moisture content has increased 3 and 5.2 times respectively. It can be appreciated that in spite of increased moisture content in newly developed salt, the free-flowing ability of the newly developed salt is higher than the commercial solar-dried and vacuum-dried salt samples.
[0081] Referring to Table 2, and Figure 3, it can be inferred that depletion of iodine content in Sample-1 is 10.63% higher as compared to newly developed salt & 21.88 % higher as compared to Sample-2 during storage.
Example 3
Comparison of total sodium content and black particle content in the salt
samples
[0082] The newly developed salt samples (free-flowing salt) produced by the
process of the present disclosure was compared with commercial samples; Sample-
1 (vacuum dried salt), and Sample-2 (solar dried salt). Table 3 depicts the result
obtained.
m 11 o
[0083] Referring to Table 3, it can be observed that sodium chloride is present in higher percentage purity in newly developed salt as compared to vacuum and regular

solar salts which can be attributed to lower magnesium & calcium content and absence of any added silica. Generally, the size of black particles are less than 300 microns hence it can be inferred that newly developed salt contains less number of black particles which is equivalent to vacuum salt.
Example 4
Comparison of turbidity and water insoluble matter in the salt samples [0084] The turbidity of 10% aqueous solution of newly developed salt has been compared with solar branded salts (Sample-2, 3, 4, and 5) and vacuum evaporated salt (Sample-1). 10 % solution of sodium chloride was considered as a control. Figure 4 depicts the comparative study on turbidity of solar and vacuum evaporated salt as with the newly developed salt obtained by the process as disclosed in the present disclosure.
[0085] Referring to Figure 4, the study depicts that turbidity of newly developed salt is nearly 80% lesser compared to all commercially available solar salts (Samples 2, 3, 4, and 5) wherein turbidity of newly developed salt is marginally higher than Sample-1 (vacuum dried salt). The turbidity of newly developed salt can be further reduced by performing modifications in the refining process, but it should be noted that the present level of turbidity (desirable as compared to regular solar dried salt samples) was achieved in far lesser cost as compared to the vacuum dried process. [0086] Water insoluble content was also measured for same set of salt samples as described for turbidity measurements. Figure 5 depicts the comparative study on water insoluble matter of solar and vacuum dried salt with newly developed salt. Referring to Figure 5, water insoluble content in newly developed salt is comparable to vacuum dried salt (Sample-1). The study also depicts that reduction of water insoluble matter in newly developed salt is in a range of 78-82% as compared to all branded solar salt samples (Samples 2, 3, 4, and 5).
Example 5
Rationale for the process of producing salt as per the present disclosure

[0087] The present example highlights the rationale behind the process of the present disclosure. Since the process of the present disclosure involves the use of raw solar salt, it was imperative to study the quality of raw salt for its various properties to establish the process of the present disclosure.
[0088] Properties of salt in terms of calcium and magnesium content tends to differ at various time points throughout the year. Therefore, in order to depict the rationale behind the process of the present disclosure, calcium and magnesium content in raw salt in different months of a year were determined to assess variation in calcium and magnesium levels.
[0089] Calcium and magnesium present in salt are primarily in chloride, sulphate & carbonate form and all these compounds are soluble in water other than sulphates and carbonates of calcium. The raw salt samples harvested from January to June was examined for calcium and magnesium content. Table 4 depicts the calcium and magnesium content present in raw salt used for the process of present disclosure.
[0090] Referring to Table 4, it can be observed that calcium content of raw salt varies from 0.16% to 0.21% whereas the magnesium content varies from 0.31% to 0.49%.
[0091] To understand the reduction and distribution of calcium & magnesium with respect to particle size after refining process, commercial sample (Sample-2) manufactured from January to December were procured and sieved through 850, 600, 420, 300, 212 and 150 microns. Sample retained on each sieve were subjected to magnesium and calcium content analysis.

[0092] Table 5 depicts magnesium content of samples at refining step in various particle sizes.
[0093] As depicted in Table 5 and Figure 6, the magnesium content is low in higher particle size whereas it is very high in particles which are passing through 150 microns. Magnesium content of particles passing through 850 microns and retaining on 300 microns is 0.08% on average whereas magnesium content of those particles passing through 212 microns is 0.14%. Those particles obtained after passing through 150 microns contains 0.25% on average. As per the present disclosure, since, the newly developed salt also has particles ranging between 850 and 300 microns, it
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can be inferred that the average magnesium content of newly developed salt should be around 0.08% which is 51% less as compared to particles passing through 300 microns (0.163%).
[0094] Table 6 depicts the calcium content of salt sample in various particle granular sizes.
[0095] As depicted in Table 6 and Figure 7, it can be observed that particles between 850 and 300 microns contains average of 0.08% calcium which is 56.9% less compared to particles passing through 300 microns. Particles passing through 150|l contains more amount of calcium which ranges from 0.19 to 0.37%. Thus, it

can be inferred that the newly developed salt of the present disclosure should also have lower calcium content as the particle size ranges between 850 and 300 microns. [0096] Therefore, analyzing the calcium and magnesium content in various particle sizes, it can be inferred that salt particles between 850 and 300 microns contain the lowest levels of calcium and magnesium, thus, it can be inferred as the preferred range of particle size for desirable quality of salt. Particle size distribution pattern among salt samples
[0097] The Sample-2 (solar dried salt) was sieved through 850 and 300 microns mesh. Iodine content in following particles: (i) retained on 300 microns; (ii) passing through 850 microns; and (iii) passing through 300 microns mesh, was estimated. [0098] Table 7 below depicts the distribution pattern of particle size of the commercially available vacuum dried and solar dried salts. Table 7:
[0099] It can be observed from Table 7 that amount of salt particles having size between 150 and 300 microns in all commercially procured salts are more than 20% with respect to the total salt content. This indicates a possibility that the salt sample between 150 and 300 microns may contain more amount of hygroscopic compound which also have a similar granular size, thereby, affecting the free-flowing ability of

the salt. The stickiness increases because of the smaller particle size which has tendency to attract water molecules and thereby decreasing the surface area ultimately affecting the free-flowing ability.
Testing of parameters: calcium, magnesium, moisture contents and angle of repose [00100] The commercially procured samples were subjected to calcium and magnesium levels, apart from measuring moisture content and angle of repose. [00101] Table 8 depicts moisture content of particle size 850-300 microns and retention at 300 microns. Table 8:
[00102] Table 9 below depicts calcium content of particle size 850-300 microns and retention at 300 microns.
[00103] Table 10 depicts magnesium content of particle size 850-300 microns and retention at 300 microns.

[00104] Table 11 depicts angle of repose of particle size 850-300 microns and retention at 300 microns.
[00105] As can be observed from Table 8, particles passing through 300 microns contains 128.2 % more moisture compared to particles between 300 to 850 microns in Sample-2.
[00106] Similarly, calcium and magnesium content have been estimated in both the samples (retention and passing through 300 microns), interestingly calcium content is increased by 139% (Table 9) and magnesium content is increased by 57% in Sample-2 (Table 10) which is a refined solar evaporated salt. Analytical data interprets that in Sample-2 particles retention on 300 microns are nearly 40% more free flow in comparison with particles passing through 300 microns (Table 11). [00107] Further to understand particle size distribution pattern of solar and vacuum evaporated salt between 850 to 300 microns, commercially procured salts were

sieved through 850, 600, 420 and 300 microns sieves. The results obtained are tabulated in Table 12.
[00108] It can be observed from Table 12 that 87.09 % of vacuum evaporated salt (Sample-1) contains particles between 300 to 600 microns whereas in solar salt (Sample-2) it ranges from 66.34 to 73.71%.
[00109] Table 13 depicts the iodine content (mg/kg) of particles of varying sizes 850-300 micron and retention at 300 microns.
i i i i
[00110] As is depicted in Table 13, it can be observed that iodine content of particles passing through 300 microns is more as compared to particles retaining on 300 microns.
[00111] With the observations of the present example, the process of the present disclosure was worked upon to provide a solution to the shortcomings of the properties of solar dried salt and vacuum dried salt that are commercially available. The process of the present disclosure discloses a process to produce free-flowing salt which has high free-flowing ability in spite of lacking any anti-caking agent. [00112] Overall, it can be summarized that quality of salt is very much dependent on the process used for producing the salt. Magnesium which is present naturally in salt

is hygroscopic in nature. The studies carried out in the present disclosure states that particle size of refined salt lesser than 300 microns contains high amount of magnesium. The process of the present disclosure ensures that particles will have larger surface area so that moisture absorbed over a period of time will not impact the free-flowing ability. Also, the newly developed salt produced by the process of the present disclosure contains 51% and 56.9% less magnesium and calcium respectively. Silica which is generally added as add-on-salt agent in solar dried salt is avoided in the process of the present disclosure. Water insoluble content of newly designed salt is comparable to Sample-1 which is a commercially available vacuum dried salt. The reduction of calcium, magnesium and added silica leads to enhancement of total chloride (as NaCl) of new developed salt. Number of black particles is also minimal as compared to solar dried salt (Sample-2). Accelerated study manifests that the flow ability of newly developed salt is much better than both vacuum dried salt (Sample-1) and solar dried salt (Sample-2). [00113] Crystal shapes of the salt samples that have been used in the present disclosure have been depicted in Figure 8 (Sample-1), Figure 9 (Sample-2), Figure 10 (Sample-3), and Figure 11 (Sample4). It can be observed that the crystal shapes of Sample-1 which is a vacuum dried salt is more regular as compared to those of other salts which are regular solar dried salts. The newly developed salt as per the present disclosure also has irregular crystal shapes as depicted in Figure 12.
Advantages of the present disclosure
[00114] The present disclosure discloses a process for producing high-quality salt which has the characteristics of free-flowing ability, low water insoluble matter, low calcium and magnesium content and lack of any anti-caking agent like silica. The process provides a significant advantage in terms of achieving a salt quality that is significantly better than regular solar dried salt and vacuum dried salt in many aspects. In terms of economic significance, the process of the present disclosure for providing high-quality salt is very economical and cost-effective as compared to vacuum drying process. Therefore, the process of the present disclosure produces a high-quality salt having superior free-flowing ability as compared to regular solar

dried salt and vacuum dried salt while proving to be economical in terms of cost as compared to the vacuum dried salt.

I/We Claim:
1. A process of preparing free-flowing salt, the process comprising:
(a) obtaining raw solar salt;
(b) contacting the raw solar salt with at least one solution to obtain a slurry;
(c) processing the slurry to obtain a mixture with a moisture level in the range of 3 - 5 %;
(d) contacting the mixture with a potassium iodate solution to obtain an iodised mixture;
(e) drying the iodised mixture to obtain dried product; and
(f) sieving the dried product through gyro sieves to obtain free-flowing salt,
wherein the free-flowing salt has a particle size in a range of 300 microns -
850 microns.
2. The process as claimed in claim 1, further comprises subjecting the free-flowing salt to automatic feeding mechanism.
3. The process as claimed in claim 1, wherein the at least one solution is brine.
4. The process as claimed in claim 1, wherein processing the slurry comprises processes selected from a group consisting of wet milling process, separation, washing, concentration, centrifugation, and combinations thereof.
5. The process as claimed in claim 1, wherein the gyro-sieves have a mesh size in a range of 300 microns -850 microns.
6. The process as claimed in claim 1, wherein the free-flowing salt has an angle of repose in a range of 30 degree - 45 degree.
7. The process as claimed in claim 1, wherein the free-flowing salt has particles in an irregular morphology.
8. The process as claimed in claim 1, wherein the free-flowing salt has moisture content in a range of 0.9- 1.2 % after storing for 15 - 20 weeks at a temperature of 37 °C and 85 % relative humidity.
9. The process as claimed in claim 1, wherein the free-flowing salt comprises calcium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt.

10. The process as claimed in claim 9, wherein the free-flowing salt comprises calcium having a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt.
11. The process as claimed in claim 1, wherein the free-flowing salt comprises magnesium having a weight percentage in a range of 0.01- 0.15 % with respect to the free-flowing salt.
12. The process as claimed in claim 11, wherein the free-flowing salt comprises magnesium having a weight percentage in a range of 0.01- 0.10 % with respect to the free-flowing salt.
13. The process as claimed as claimed in claim 1, results in the reduction of water insoluble impurities in the percentage range of 78 - 82 % with respect to a regular solar salt.
14. A free-flowing salt obtained by the process as claimed in claim 1.
15. The free-flowing salt as claimed in any one of the claims 9 or 10, wherein the salt is useful as edible salt, or non-edible salt.