Claims:We claim,

1. A novel process of pulverisation of iron electro deposit by an impact pulveriser involves the following steps -
i. Feeding of iron electro-deposit raw material into the crushing chamber of the impact pulveriser.
ii. Adjusting settings/parameters of all components of the impact pulveriser as per the quantity of needle and flaky shape particle requirement.
iii. Pulverising the raw material for a period of 8 hours under said settings/parameters.
iv. Separation of large particles from fine particles through the classification systems of the impact pulverisation.
v. Further separation of large particles by sieving.
vi. Collection of final product from the pulveriser – flake shaped and/or needle shaped particles of iron powder.

2. The novel process of pulverisation claimed in claim 1, wherein the pulverisation process results in the formation of an iron powder consisting of uniquely shaped particles – needle shaped and/or flake shaped.

3. The novel process of pulverisation claimed in claim 1, wherein the following parameters are maintained for the formation of a mixture of needle shaped and flake shaped particles (said mixture containing a higher percentage of needle shaped particles as compared to flake shaped) -
i. Whizzer and beater distance of 100 mm.
ii. Speed of crushing motor maintained at 1800 rpm.
iii. Speed of suction blower maintained at 2500 rpm.

4. The parameters claimed in claim 3, wherein 8 hours of crushing under these parameters produces 110-140 kg of 10 µm particles (also known as CM10 grade powder) and 800-900 kg of particles greater than 45 µm (also known as -325# particles).

5. The novel process of pulverisation claimed in claim 1, wherein the following parameters are maintained for the formation of an increased percentage of flake shaped particles as compared to the percentage formed when the conditions claimed in claim 3 are maintained -
i. Whizzer and beater distance of 70 mm.
ii. Speed of crushing motor maintained at 1900 rpm.
iii. Speed of suction blower maintained at 3000 rpm.

6. The parameters claimed in claim 5, wherein 8 hours of crushing under these parameters produces 180-200 kg of 10 µm particles (also known as CM10 grade powder) and 1000- 1200 Kg of particles greater than 45 µm (also known as -325# particles).
, Description:FIELD OF THE INVENTION:
The present invention describes a novel process of pulverization used for the production of iron powder consisting of needle shaped and/or flake shaped iron particles.

DEFINITIONS:
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used, indicate otherwise.
The expression “electro-deposits” used hereinafter in this specification refers to, but is not limited to, pure, soft iron obtained electrolytically using impure iron as the starting material.
The expression “-325# particles”, used hereinafter in this specification refers to, but is not limited to, iron powder particles with size less than 45 microns.
The expression “CM10 grade powder”, used hereinafter in this specification refers to, but is not limited to, iron powder particles with size less than 10 microns.

BACKGROUND
High Purity irregular shape Iron powder is required for many high end industrial applications, including but not limited to, the manufacture of especially electro-magnetic applications, magnetorheological fluids, food applications, etc. With the increasing number of industrial applications of iron powder in the current day, there is a need for the production of iron powder suitable for use in all these varied applications. The shape of the particles in the iron powder plays an important role in the usefulness of the powder for any application (for instance, iron powder consisting of flaky shapes has a larger surface area and better dispersion in fluids, flaky, leafy shape iron powder has good electo-magnetic properties).
Currently, research has been done on the optimization of the electrolytic process for the production of iron deposits, but there is relatively very less research on the actual processes of pulverization and production of iron powder; especially with emphasis on the shape and size of the particles in the powder produced. The present invention elaborates on a novel process of pulverization that allows for the production of iron powder wherein the particles are of two unique shapes – namely needle shaped and flake shaped.
Currently used instruments for the production of iron powder include, but are not restricted to, ball mills, attritor mills, mechanicals pulverizers and jet pulverizers. None of the current pulverization processes allow for the production of iron powder in which the shape of the particles is needle shaped or flake shaped.

PRIOR ART:
The prior art cited in the present invention is -
1. European patents EP0556645 B1, discloses “An impact pulveriser for grinding material to be ground, having an impact pulveriser housing (2) which delimits a grinding space (10) and in which a vertically extending rotor (4) is disposed which is provided with impact tools (6), wherein at least one inlet opening (15) is provided above the impact tools (6) on the top face of the impact pulveriser housing (2), having groups of impact tools consisting of impact tools (6) which in the direction of the axis of rotation (5) are situated substantially in the same plane extending perpendicularly to the axis of rotation (5), and having a screen (7) disposed radially outwardly of the impact tools (6) for separating a fine fraction from a coarse fraction of the material to be ground which is fed to the impact pulveriser and is processed by the impact tools (6), and having an outlet opening (12) provided on the bottom face of the impact pulveriser housing (2), characterised in that at least one downwardly extending projection in the form of blades (16) for the axial deflection of the material to be ground which is driven in rotation is provided in an annular region of the impact pulveriser housing (2) which is situated above the impact tools (6) and in which the at least one inlet opening (15) is situated, wherein the blades (16) are aligned substantially radially along lines through the axis of rotation (5) and are preferably each disposed on both sides of the inlet opening (15) in the direction of rotation.”
2. US patent US5839670 A, discloses “A pneumatic pulverizer comprises an accelerating tube for carrying and accelerating powder to be pulverized with high-pressure gas and a pulverizing chamber for pulverizing the powder to be pulverized. The back end of the accelerating tube is provided with a pulverization powder feed port for feeding powder to be pulverized to the accelerating tube, the pulverizing chamber has an impact member having an impact surface opposed to the opening plane of the outlet of the accelerating tube, and a side wall against which the powder to be pulverized that has been pulverized by the impact member collides to further pulverize. The closest distance from the side wall to a margin of the impact member is shorter than the closest distance from the front wall of the pulverizing chamber opposed to the impact surface to the margin of the impact member to prevent pulverized powder from fusing, coagulating, and getting coarser, and prevent localized abrasion of an impact surface the impact member and the accelerating tube.”
The aforementioned prior art is used for the production of iron powder, but it has one major drawback – neither of the processes gives any emphasis on the shape and size of the particles of iron powder produced. This means that the particles of iron powder thus produced are of random, arbitrary shapes and sizes. As elucidated in the background of invention, in many industrial applications, the specific shape of the iron powder plays a significant and important role. Two shapes of iron powder that are essential in the industry, but not relevant literature on the production of needle shaped and flake shaped by any of the prior art. The present invention overcomes this drawback of the prior art. The present invention discloses a process specifically tuned for the production of these unique particle shapes.

OBJECTS:
The objects of present disclosure are aimed at ameliorating one or more problems of the prior art or to at least provide useful alternatives as listed herein below.
The object of the present invention is to provide a novel process of pulverization that allows for the production of iron powder consisting of different sized particles with two unique shapes – namely, needle shaped and flake shaped.

SUMMARY:
Before the present invention is described, it is to be understood that present invention is not limited to particular methodologies and materials described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention.
The present invention describes a novel process of a pulverization. A customized impact pulverizer is used for the production of iron powder from iron electro-deposits which are obtained by electrolysis of impure iron. Optimized pulverizer settings allow for the formation of iron powder consisting of particles of a specific and unique shape and size. The shapes of particles that can be produced from this novel process of pulverization cannot be produced by any other pulverization technique in current use. These two unique shapes that the pulverizer described in the present invention can produce are flaky shaped particles and needle shaped particles. These particular shapes of particles have specific importance in several industries.

BRIEF DESCRIPTION OF DRAWINGS:

Figure I: Schematic diagram of impact pulverizer
Numeral 1 – Pulverizer motor
Numeral 2 – Crushing Chamber
Numeral 3 – Cyclone-I
Numeral 4 – Cyclone-II and Cyclone-III
Numeral 5 – Blower
Numeral 6 – Baghouse

Figure II: Schematic diagram of crushing chamber component of impact pulverizer
Numeral 1 – Raw material input opening
Numeral 2 – Rotating shaft
Numeral 3 – Hammering beaters
Numeral 4 – Whizzer
Numeral 5 – Distance between beaters and whizzer
Numeral 6 – Output opening

Figure III: Stages of pulverization and classification of different shapes and sizes of electrolytic iron particles.
Figure IV: SEM micrographs of electrolytic iron powder of grade -325# depicting needle shaped particles.

Figure V: 2: SEM micrographs electrolytic iron powder of grade CM10 depicting flaky shaped particles.

DETAILED DESCRIPTION:
Before the present invention is described, it is to be understood that this invention is not limited to particular methodologies described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention. Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.

The main components of the impact pulverizer are:
1. Pulverizer Motor
2. Pulverizer Crushing Chamber
3. Cyclone-I
4. Cyclone-II and Cyclone-III
5. Blower
6. Baghouse

The arrangement and function of each of these components is described through the attached drawings and the following paragraphs.

1. Pulverizer motor (Figure I, Numeral 1):
i. This is a motor with a power of 30 HP.
ii. The motor has a variable frequency drive (VFD). The function of this drive is to adjust the speed of the motor as per requirement.
iii. The rotating speed of the motor is maintained at an optimum of 1800-1900 rpm. This optimized speed of the motor allows for the maximum production of needle shaped iron powder (approximately 70%).
iv. The shaft of the motor is connected to the shaft of the crushing chamber using roller bearings.

2. Pulverizer crushing chamber (Figure I, Numeral 2) :
i. The crushing chamber is the most important component of the pulverizer.
ii. It has one input opening (Figure 2, Numeral 1) through which the raw material (soft iron electro-deposit) is fed into the chamber and an output opening (Figure 2, Numeral 6) through which the crushed material is conveyed into the cyclones (i.e., the classifying systems) and then into the baghouse. The particles are transported as a result of the suction force created by the blower (described later in this specification).
iii. The grinding of the electro-deposit in the chamber is done with the help of beaters. A beater (Figure 2, Numeral 2) is a rectangular structure cast out of grade 3 manganese steel. Eight beaters are mounted circular on a rotating shaft (Figure 2, Numeral 3). The said shaft is connected to the aforementioned motor with the help of roller bearings.
iv. On the same shaft, at a distance of 70-100 mm from the beaters, is mounted another structure known as a whizzer (Figure 2, Numeral 4). The whizzer is a cone flat shaped structure, the role of which is to control the flow of particles to the classifying systems from crushing chamber. The whizzer controls the dimensions of outlet provided for flow of particles from chamber to classifying. The dimensions of this outlet are depending upon distance between the beater and the whizzer on the shaft. A change in this distance results in a corresponding change in the size of the aforementioned output opening (previously referenced in point 2(ii)).
v. If the gap between the beaters and whizzers (Figure 2, Numeral 5) is on the lower side (~70 mm), the size of the output opening is large. Thus, the particles remain in the crushing chamber for a relatively shorter period of time and as a result, a coarse powder is produced. On the other hand, the distance between the beaters and whizzer is higher (~100 mm), the size of the output opening is correspondingly smaller. These particles of the electro-deposit to remain inside the beater for a longer period of time, resulting in a finer powder.
vi. The ground particles leave the crushing chamber through the aforementioned output opening and enter into the classifying systems.
vii. The crushing chamber is connected to cyclone-I by mild steel pipes.

3. Blower (Figure I, Numeral 5):
i. The purpose of the blower is to create a suction in the pulverizer system. This suction acts as a force to transport the crushed particles.
ii. The optimized speed of blower motor is 2500 rpm to 3000 rpm to create required suction for conveying crushed powder from crushing chamber to cyclones and bags house.
iii. The blower suction is directed into the baghouse through filters. This consequently results in the creation of a suction pressure in the crushing chamber and cyclones.
iv. The baghouse is linked to the cyclones through mild steel pipes.
v. One end of the blower is an opening that is open to atmosphere and to another opening which is on the upper side of the filter unit of the baghouse (described later in this specification).
vi. The baghouse is further linked to cyclones II, II and I through mild steel pipes. The ground material from the crushing chamber gets transported to the cyclone-I, cyclone-II and then cyclone-III through these pipes. The heavier particles settle down in the cyclone-I, II and III and the very lighter ones settle in the filter unit of the baghouse.

4. Cyclone-I (Figure I, Numeral 3):
i. The heavier particles of = 45µm and >45 µm settle down in cyclone-I. These particles are needle in shape (Fig.IV). Below cyclone-I, a mesh of -325# is kept through which particles of = 45µm sieved and particles >45 µm size recollected separately. These particles (>45 µm) again taken for crushing.

5. Cyclone-II and Cyclone-III (Figure I, Numeral 4) :
i. The lighter particles (= 10 µm) which are flaky in shape (Fig.V) enter cyclones-II and III and get collected in drum.

6. Baghouse (Figure I, Numeral 6) :
i. This is the unit in which the particles are filtered according to size. Particles that are greater than 5 µm cannot pass through the bag filters. Bag filters has filters made of non-woven fabric with a size of 157 mm diameter and 3200 mm length. The filter unit has 45-50 bags.
ii. The baghouse is connected to cyclone-III through a piping system at the base of the baghouse.
iii. Due to the suction created by the blower in the filter bags, the lighter particles (= 5 µm) collect on the outer surface of the aforementioned filters. An additional unit of pulse jet is provided on baghouse to provide a compressed air for cleaning filters. These pulse jets provide a jet of pressurized air (~5 bar pressure), said jet of air is directed onto the filters. The purpose of the pulse jets is to remove the particles stuck on the filter so as to clean the filters.
iv. Due to the blower, the internal conditions of the baghouse are highly pressurized. To slightly relieve the pressure (to prevent bursting of the baghouse vessel), two small openings are provided on the baghouse. These openings are covered with aluminum foil of 25-35 µm thickness (at a pressure greater than 1200 mm water column, aluminum foil bursts; thus, if the pressure in the baghouse exceeds this level, it will be released through these two openings).

Using the above novel design of impact pulverizer, iron powder of different size and two unique shapes (namely, flake shaped and needle shaped) can be produced. The general process for the production iron powder using the pulverizer described above is elaborated in the following section:
1. Raw material (iron electro-deposit) is fed into the crushing chamber of the pulverizer.
2. The raw material falls inside crushing chamber where the beaters (rotating at a speed of 1800-1900 rpm).
3. Due to the hammering action of the beaters, the raw material gets crushed. As electro deposits granules gets in contact with beads at high speed and force, small chips get removed from surface of granules and such chips formed are flaky or leafy shape (10 µm,) and remained hammered particles of needle like shape (= 45 µm).
4. As stated in the description of components, the blower creates a suction force in the crushing chamber, cyclones and baghouse. This suction force facilitates the movement of the crushed particles towards the classifying systems. The movement of the particles into the classifying systems is controlled by the whizzer, as explained earlier.
5. Under the optimum distance of 70-100 mm between the beaters and whizzer (as described previously), 70% of the crushed iron particles of size less than or equal to 45 µm enter the classifying systems. The remaining some coarse particles (i.e., particles of size greater than 45 µm) remain in the crushing chamber and few enters in cyclone-I which is separated and then recrushed again.
6. All the particles enter cyclone system. Particles of size = 45 µm settles down in cyclone-I, from which they are collected and particles of > 45 µm taken back to the crushing chamber for another round of crushing.
The particles of size = 45 µm may be of the following sizes - 10 µm, 25 µm, 37 µm and 45 µ. These particles are subjected to a further separation according to size (by sieving). The particles = 10 µm proceed ahead to cyclone-II and cyclone-III where they are collected directly in the drums. The separation and collection of particles of size = 10 µm is due to unique design of size cyclone and its piping system. Overall it is due to design of pulverizing system and its operating parameters.
7. The very fine dust particles (= 5 µm) are taken ahead to the baghouse.
8. The typical process flow of powder crushing to classifying with its shape are demonstrated in the Fig. III.

The following section details on the specific conditions to be maintained for the production of needle shaped and flake shaped particles.

1. Example I:
i. The conditions that the pulverizer must be set to in order to obtain these results are enlisted below -
a) Period of crushing of 8 hours.
b) Whizzer and blower distance of 100 mm.
c) Speed of crushing motor maintained at 1800 rpm.
d) Speed of suction blower maintained at 2500 rpm.
ii. Results in the production of 110-140 kg of 10 µm particles (also known as CM10 grade powder) and 800-900 kg of particles = 45 µm (also known as -325# particles).
iii. Ratio of flake shaped: needle shaped particles of ~ 1 : 6.5.
iv. The characteristics of particles formed under the above conditions are tabulated below:
Grade of Powder
Electro-deposit +325#
-325# CM10 Baghouse
Characteristics

Granules/Powder (kg) 3900-5800 2910-4585 800-900 110-140 7-10
Purity, Fe % > 99.8 > 99.8 > 99.5 > 98.5 > 95.5
Average Particle Size
(µm) Granules of large shape >45 =45 =10 <10
Particle Shape Irregular Needle like Needle like Flaky, Leaf like Flaky, Leaf like

2. Example II :
i. The conditions that the pulverizer must be set to in order to obtain these particles are enlisted below -
a) Period of crushing of 8 hours.
b) Whizzer and blower distance of 70 mm.
c) Speed of crushing motor maintained at 1900 rpm.
d) Speed of suction blower maintained at 3000 rpm.
ii. 8 hours of crushing time produces 180-200 kg of 10 µm particles (also known as CM10 grade powder) and 800-1000 kg of -325# particles.
iii. Results in the production of 180-200 kg of 10 µm particles (also known as CM10 grade powder) and 1000-1200 kg of -325# particles.
iv. Ratio of flake shaped: needle shaped particles of ~ 1: 6.
v. The characteristics of the particles formed under the above conditions are tabulated below:
Grade of Powder
Electro-deposit +325#
-325# CM10 Baghouse
Characteristics

Granules/Powder (kg) 4500 - 6500 3290-4900 1000-1200 180-200 10-15
Purity, Fe % > 99.8 > 99.8 > 99.5 > 98.5 > 95.5
Average Particle Size
(µm) Granules of large shape >45 =45 =10 <10
Particle Shape Irregular Needle like Needle like Flaky, Leaf like Flaky, Leaf like

To summarize, as the speed of the crushing motor is increased, the overall fineness of the particles increases. Also, a smaller distance between the beater and whizzer indicates that the size of the output opening of the crushing chamber is smaller. This results in an increased proportion of fine particles. Furthermore, an increase in the speed of the blower creates an enhanced suction force, which consequently results in an increased overall production of both -325# and CM10 particles.

TECHNICAL ADVANCEMENTS:
The technical advancements of the system and method envisaged by the present disclosure include the realization of:
1. A novel process of pulverisation that allows for the production of iron powder with uniquely shaped particles (needle shaped and flake shaped).
The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein above and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification, specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.