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DESCRIPTION
WEATHERED REEF-BUILDING CORAL MATERIAL
TECHNICAL FIELD
This invention relates to a process for manufacturing
a weathered reef-building coral material suitable for food
materials, filter mediums and so forth, by removing organic
substances originating from marine algae, microorganism and
so forth held in porous tissue of weathered reef-building coral,
and also relates to a weathered reef-building coral material
obtained by this process and an immersion treating apparatus
suitable for carrying out this process.
BACKGROUND ART
Coral insects inhabiting sea areas in the temperate zone,
the subtropical zone and the tropical zone form coral reefs.
The coral reefs weather and one after another turn into spalls
or particles with lapse of thousands to tens of thousands of
years after the death of coral insects living in the coral reefs.
Such spalls or particles are carried by ocean currents, and
they settle on the sea bed according to particle size by the
action of the levigation in ocean currents and accumulate there.
The weathered reef-building coral is an accumulation of such
spalls ar particles.
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The weathered reef-building coral have a very porous fine
structure. This porous fine structure is a dwelling site of
the inhabitation of coral insects, and organic substances
originating from various marine algae and microorganisms ( a . g. ,
Vibrio bacteria) inhabiting the ocean are held therein while
the weathered reef-building coral exists at the sea bed for
many years.
The weathered reef-building coral is utilized as food
materials for supplementing calcium, or as filter mediums for
water purifiers, agricultural soil conditioners and so forth.
When it is used in food materials and filter mediums for water
purifiers, it is required to remove the above organic
substances from the viewpoint of safety, and is also required
to take measures for disinfection or sterilization so that
microbiological safety can be ensured.
As a conventional process by which weathered reef-
building' coral materials used as food materials are
manufactured from the weathered reef-building coral, the
following steps are taken, as schematically shown in Fig. 4.
That is, first, the weathered reef-building coral is
collected from the sea bed by a pumping boat, and is classified
according to manufacture purposes into portions with
predetermined particle or grain size [e.g. , passing a 10-mesh
sieve (particle diameters of 2.0 mm or smaller) and leaving
on a 80-mesh sieve (particle diameters of 0. 18 mm or larger) ] .
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The weathered reef-building coral thus classified is landed
and thereafter stored in a stockyard, and the greater part of
sea water salt is removed therefrom by spraying city water over
the whole, followed by air-drying. This is then brought into
a factory, and is sieved in the factory yard by a vibrating
sifter according to the predetermined particle or grain size,
which is again washed with water using a washing machine,
followed by dehydration and drying and further followed by dry
heat disinfection or dry sterilization usually at 100 to 200~C .
The resultant material is pulverized and sifted to adjust their
particle or grain size to a predetermined particle or grain
size, and then packaged for commercialization. Alternatively,
the material brought into a factory, sieved, and washed with
water followed by dehydration and drying is then roasted at
a temperature within the rage where calcium carbonate , the main
component of the weathered reef-building coral, is not
decomposed ( 250 to 600~C ) , and this is pulverized and sifted
to adjust their particle or grain size to a predetermined
particle or grain size and then packaged for commercialization.
The weathered reef-building coral material for food thus
obtained is made to have particle diameters small enough to
pass a 300-mesh sieve, i.e. particle diameters of 45 ,cam or
smaller.
As a conventional process for manufacturing ffilter
mediums for water purifiers, like the above process for
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manufacturing weathered reef-building coral materials for
food, the weathered reef-building coral is collected, sieved
in the factory yard by a vibrating sifter to sift grains to
have a predetermined size to thereby uniform their grain size
to a size suitable for the filter mediums for water purifiers,
followed by washing with water, dehydration and drying.
Subsequently, the resultant weathered reef-building coral is
roasted ( 250 to 600~C ) so as to be activated to enhance mineral
elution quantity, which is then sifted to adjust the grain size
to a predetermined size, and packaged for commercialization.
Silver-added materialsprepared by coatingthe weathered
reef-building coral with silver are known to be improved in
sterilizing ability(Japanese Patent Application Laid-open No.
51-179107, etc.). As the silver-added materials, those having
grain diameters of 0.71 mm or larger which are used chiefly
as filter mediums for water purifiers and those having grain
diameters smaller than 0 . 71 mm which are used for other purposes
are manufactured. As a process for manufacturing such
silver-added materials, the filter mediums for water purifiers
described above, the weathered reef-building coral is roasted
in the same manner as in the case of the filter mediums for
water purifiers described above. Thereafter, it is immersed
in an aqueous silver solution, immersed in a reducing agent
solution such as an ascorbic acid solution, and heated at 400~C
for about 30 minutes to cause silver to deposit, followed by
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washing with water, drying and packaging for
commercialization.
However, in the conventional process for manufacturing
weathered reef-building coral materials for food or filter
mediums, various marine algae having grown for many years,
various microorganisms including Vibrio bacteria inhabiting
the ocean and other organic substances can not be removed from
the inside of the porous fine structure of the weathered
reef-building coral. Hence, the conventional process is
insufficient in view of the ensuring of safety required for
food materials.
In general, as well known, in water purifiers in which
the weathered reef-building coral having been subjected to the
step of heating by dry heat disinfection or dry sterilization,
or by roasting is set as a filter medium, minerals flow out
in a small quantity when water is run, so that the taste of
water can be improved. However, the weathered reef-building
coral materials obtained by the conventional process can not
elute minerals so much as to greatly enhance total hardness
elution quantity. Also, it has not a sufficient degree of
activation and hence can not be said to have a good adsorptivity
for impurities or the like.
In the case when the silver-added weathered reef-
building coral material is manufactured, there is also the
problem that the silver is coated only on the surface of the
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weathered reef-building coral and is not coated throughout the
porous inner fine structure.
The present invention addresses the above referenced
problems in the prior art. Accordingly, it is desirable to
provide a weathered reef-building coral material from which
various marine algae, various microorganisms including Vibrio
bacteria inhabiting the ocean and other various organic
substances held in the inner fine structure of weathered reef-
building coral have been removed and thereby its safety
required as food materials has been ensured, and also to
provide a process for manufacturing such a weathered reef-
building coral material.
It is also desirable to provide food materials and filter
mediums comprised of such a weathered reef-building coral
material.
It is also desirable to provide a silver-added weathered
reef-building coral material coated with silver on its surface
and also throughout its fine structure inside the porous
tissue, and also to provide a process for manufacturing such a
weathered reef-building coral material.
It is also desirable to provide an apparatus useful for
manufacturing such a weathered reef-building coral material.
DISCLOSURE OF THE INVENTION
According to one aspect of the present invention there is
provided a process for manufacturing a weathered reef-building
coral material, comprising the steps of immersing weathered
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reef-building coral in an aqueous O.1N to 6N alkali solution
under reduced pressure to carry out alkali washing to make the
aqueous alkali solution penetrate into the weathered reef-
building coral throughout its fine structure inside the porous
tissue; and washing it with water until a washing from the
inside of the porous tissue is neutralized, wherein said alkali
washing is carried out by forcibly passing the aqueous alkali
solution through the weathered reef-building coral immersed in
the aqueous alkali solution, or is carried out by agitating the
weathered reef-building coral in the aqueous alkali solution,
and wherein said alkali washing is carried out while heating
the aqueous alkali solution.
A weathered reef-building coral material can be obtained
by the above process for manufacturing a weathered reef-
building coral material.
A food material can comprise powdery weathered reef-
building coral having a particle size of 500 meshes or greater
(diameters of 27.28 ~m or smaller), obtained by the above
process for manufacturing a weathered reef-building coral
material in which, after the washing with water, the weathered
reef-building coral is further pulverized and sifted into it.
A filter medium can comprise weathered reef-building coral
obtained by the above process for manufacturing a weathered
reef-building coral material in which, after the washing with
water, the weathered reef-building coral is roasted at 100 to
750°C.
According to another aspect of the invention there is
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provided a process for manufacturing a silver-added weathered
reef-building coral material, comprising, after the washing
with water in the above process for manufacturing a weathered
reef-building coral material; subjecting the weathered reef-
building coral to dry heat disinfection or dry sterilization,
or roasting, followed by immersion in an aqueous silver
solution under reduced pressure to make the aqueous silver
solution penetrate into the weathered reef-building coral
throughout its fine structure inside the porous tissue; and
reducing the silver with a reducing agent to coat the weathered
reef-building coral with silver throughout its find structure
inside the porous tissue.
A silver-added weathered reef-building coral material can
be obtained by this manufacturing process.
According to another aspect of the invention there is
provided an immersion treating apparatus, preferably for
carrying out the above process for manufacturing a weathered
reef-building coral material, comprising an enclosed container
whose interior can be evacuated; a hollow cylindrical basket
for holding weathered reef-building coral provided in the
container; a heating unit at the bottom of the container; a
feed pipe for introducing a washing solution or a treating
solution with said interior of said enclosed container; a
liquid discharge pipe for discharging an effluent from the
enclosed container; and an agitator blade which rotates within
the hollow space to form a vertical liquid flow in the basket.
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According to the process of the present invention for
manufacturing a weathered reef-building coral material, the
weathered reef-building coral is immersed in an aqueous alkali
solution under reduced pressure to carry out alkali washing to
make the aqueous alkali solution penetrate into the weathered
reef-building coral throughout its fine structure inside the
porous tissue. Hence, the various marine algae, various
microorganisms including Vibrio bacteria inhabiting the ocean
and other various organic substances held in the inner fine
structure of weathered reef-building coral can be removed.
Thus, a weathered reef-building coral material can be obtained
whose safety required as food materials has been ensured.
In particular, its powdery material can be obtained by
subjecting the weathered reef-building coral to dry heat
disinfection or dry sterilization, or roasting so as to have a
particle size of 500 meshes or greater (diameters of 27.28 um
or smaller) can ensure the safety required for food, and is
preferable as food materials as being free from rough feeling
when eaten.
The product that can be obtained by roasting this
_ _ _ _ i L _ _ _ _ ~
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reef-building coral material at 100 to 750~C is highly
activated and is improved in adsorptivity of impurities, and
hence can be a good filter medium.
The weathered reef-building coral may be subjected to
dry heat disinfection or dry sterilization, or roasting,
followed by immersion in an aqueous silver solution under
reduced pressure to make the aqueous silver solution penetrate
into the weathered reef-building coral throughout its fine
structure inside the porous tissue, and subsequently the silver
is reduced with a reducing agent, whereby a silver-added
weathered reef-building coral material can be obtained which
has been coated with silver also throughout its fine structure
inside the porous tissue.
According to the immersion treating apparatus of the
present invention, the weathered reef-building coral is put
into the basket , and the aqueous alkali solution or water can
be forcibly passed through the weathered reef-building coral
held in the basket. Hence, the weathered reef-building coral
can be completely immersed in the aqueous alkali solution or
water throughout the former~s inside of the porous tissue,
so that the weathered reef-building coral can be washed in a
good efficiency. In this instance, the weathered reef-
building coral itself can also be washed without agitating it ,
and hence the weathered reef -building coral can be prevented
from turning into fine powder after washing, so that the desired
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particle or grain diameter can be retained.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a flow chart of a process for manufacturing
the weathered reef-building coral material and silver-added
weathered reef-building coral material of the present
invention.
Fig. 2 illustrates the immersion treating apparatus of
the present invention.
Fig. 3 show the relationship between mesh size and
particle or grain size.
Fig. 4 is a flow chart of a conventional process for
manufacturing weathered reef-building coral materials.
BEST MODE FOR WORKING THE INVENTION
The present invention wi7_1 be described below in detail.
Fig. 1 is a flow chart of a process for manufacturing
the weathered reef-building coral material and silver-added
weathered reef-building coral material of the present
invention. This flow chart shows steps subsequent to the
factory yard step in the conventional process for manufacturing
weathered reef-building coral materials as shown in Fig. 4.
Steps prior to the factory yard step are the same as those
shown in Fig. 4 as the flow chart of the conventional process.
Thus, the weathered reef-building coral collected from the sea
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bed, which is then classified according to particle or grain
size, and sprinkled with water to remove sea water salt,
followed by air-drying, can be used as the weathered reef-
building coral to be washed in the manufacturing process of
the present invention.
As shown in Fig. 1, in the manufacturing process of the
present invention, the weathered reef-building coral to be
washed is first immersed in an aqueous alkali solution under
reduced pressure to carry out alkali washing to make the aqueous
alkali solution penetrate into the weathered reef-building
coral throughout its fine strucaure inside the porous tissue.
Optimum pressure in the system at the time of alkali washing
depends on the particle or grain size of weathered reef-
building coral having the shape of fragments , granules or
powder. For example, when it is in the shape of fragments with
an average grain diameter of from 0.18 mm to 0.71 mm, the
pressure may preferably be controlled to be 70 mmHg or below.
When it is in the shape of granules with an average grain
diameter of from 8.0 mm to 16.0 mm, the pressure may preferably
be controlled to be 30 mmHg or below.
As the aqueous alkali solution, an aqueous solution of
NaOH, KOH, Na2C03, KZC03 or the like may preferably be used. A
solution of a single alkali or a two or more, mixed alkali
solution may also be used. There are no particular limitations
on the concentration of the alkali. The aqueous alkali solution
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may be preferably in a concentration of from O.O1N to 6N, and
more preferably from 0. 1N to 1N. If the aqueous alkali solution
has a concentration lower than O.O1N, it is difficult to
completely elute organic substances such as the marine algae
or proteins originating from microorganisms and so forth held
in the fine structure inside the porous tissue. If on the other
hand the aqueous alkali solution has a concentration higher
than 6N, in the water washing in the later stage, the washing
until the pH of the effluent becomes neutral must be carried
out in a greatly larger number of times , bringing about a
possibility of a decrease in operating efficiency.
The aqueous alkali solution in which the weathered
reef-building coral has been immersed may preferably be heated
to 80 to 100~C for about 30 to 60 minutes. This enables
acceleration of the alkali decomposition of the organic
substances such as proteins held in the weathered reef-building
coral.
It is also preferable to forcibly pass the aqueous alkali
solut ion through the weathered reef -building coral ( i . a . , to
form liquid flows so as to forcibly pass liquid flows of the
aqueous alkali solution through the weathered reef-building
coral immersed in the aqueous alkali solution) so that the
aqueous alkali solution can effectively act on the weathered
reef-building coral immersed therein, or to agitate the
weathered reef-building coral immersed in the aqueous alkali
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solution. Agitation of the weathered reef-building coral
causes the weathered reef-building coral to collide against
each other during the agitation to make it ready to be formed
into fine powder. Accordingly, in instances where the
weathered reef-building coral may be finely powdered, it is
preferable to agitate the weathered reef-building coral in the
aqueous alkali solution. Also, in instances where it is
intended to maintain the original grain size after the alkali
washing, it is preferable to forcibly pass the aqueous alkali
solution through the weathered reef-building coral.
After the alkali washing thus carried out, the inside
of the system is restored to normal pressure to discharge the
washing solution, and the next step is taken. Before the next
step is taken, the alkali washing carried out under reduced
pressure as described above may be repeated several times.
The water washing is, like the above alkali washing,
carried out by immersing the weathered reef-building coral
under reduced pressure in water. In this instance, city water
may be used as the water, and hot water with a temperature of
from about 40 to 60~C may preferably be used. In this step of
water washing, it is preferable to forcibly pass the water
through the weathered reef-building coral or to agitate the
weathered reef-building coral immersed in the water.
After the water washing, the inside of the system is
restored to normal pressure to discharge the water, where the
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water washing is repeatedly operated until the pH of the
effluent turn neutral. Hence, in usual instances, the step
of water washing may be enough when carried out twice . In some
instances, it must be carried out three to five times.
It is not preferable to use acid in place of the water
in the step of water washing, because the use of acid may cause
the decomposition of calcium carbonate, the main component of
the weathered reef-building coral, and also a salt ascribable
to the reaction to neutralize acid with alkali may be unwantedly
formed inside the weathered reef-building coral.
The washing step comprising the alkali washing and the
water washing may be completed usually in 30 to 60 minutes in
total.
After the water washing, the weathered reef-building
coral is dehydrated by means of a dehydrator (centrifugal
separator) or the like, followed by drying.
The weathered reef-building coral thus obtained can be
a weathered reef-building coral material usable in various
purposes such as food materials, filter mediums
and soil conditioners. Thus, the weathered reef-building
coral is adjusted in particle or grain size according to such
purposes , and then packaged so as to be sent to market as food
materials, ffilter mediums or soil conditioners.
When, however, the weathered reef-building coral
material is used as food materials, it may preferably be
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subjected to dry heat disinfec;tion or dry sterilization, or
roasting in order to ensure the microbiological safety.
Here , the dry heat disi.nfection is to make dry heat
treatment to control bacteria concentration so as to be not
more than 100 cells/10 g. The dry sterilization is to make
dry heat treatment to control bacteria concentration so as to
be not more than 10 cells/10 g. As this dry heat disinfection
or dry sterilization , heat treatment may be made , a . g . , at 120
to 300 ~ for 30 to 60 minutes. As for the roasting, the
weathered reef-building coral may preferably be roasted at 100
to 750~C , and may more preferably be roasted at at 250 to 750~C .
The weathered reef-building coral material of the
present invention requires no particular limitations on its
shape and size, and may have the form of , e. g. , blocks, granules
or powder. When, however, the weathered reef-building coral
material is used as food materials, it may preferably be
prepared in the form of a powder with a particle size of 500
meshes or greater (particle diameter of 27.28 ,c.(,m or smaller)
so that its texture as a food can be improved. This makes the
food have a roughness-free, very smooth texture. Conventional
weathered reef-building coral powders have been prepared in
the form of powders with a particle size ranging from 150 meshes
to 500 meshes (particle diameter of from 103 I~m to 27.28 ,t.c
m). Those having such a particle size give rough feeling in
mouths when eaten, having a poor texture.
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The "mesh" used in the present invention with regard to
the prescription of this particle or grain size is a unit
according to the ASTM sieve, called Tyler or Tyler sieve, which
is widely used not only in The United States of America but
also in other countries including Japan. For reference, the
relationship between "mesh" and "particle or grain size
m)" is shown in Fig. 3.
Meanwhile, when the weathered reef-building coral
material is used as filter mediums , it may preferably be roasted
at a temperature of from 100 to 750~C , and may more preferably
be roasted at a temperature of from 250 to 750~C . This makes
it possible to activate various properties such as smell
adsorptivity, mineral elution performance and coloring-matter
adsorptivity and to more improve the usefulness as filter
mediums for water purifiers.
The weathered reef -building coral material can also be
useful as materials for silver-added materials. More
specifically, since in the weathered reef-building coral
material of the present invention the material from which
organic substances originating from the marine algae,
microorganisms and so forth have been removed from all the fine
structure inside the porous tissue, it is possible to coat the
weathered reef-building coral with silver on its particle or
grain surfaces and also throughout its fine structure inside
the porous tissue. Hence, the silver-added material obtained
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by coating the weathered reef-building coral with silver
according to the present invention can have a longer lifetime
as filter mediums than conventional silver-added materials.
It can also be improved in sterilization effect , and can have
a superior sterilization effect against bacteria belonging to
the genus of Escherichia coli, such as colon bacteria and
pathogenic colon bacteria; diatopathogenic bacteria
(sitotoxic or food poisoning bacteria) such as Salmonella,
Vibrio parahaemoliticus and Staphilococcus aureus; Bacillus
anthracis (anthrax bacilli); and Enterococcus.
As a process for manufacturing the silver-added material
from the weathered reef-building coral material, like the above
process for manufacturing food materials or filter mediums ,
the weathered reef-building coral washed with water after the
alkali washing and then dried is further subjected to dry heat
disinfection or dry sterilization, or roasting. In this
instance, as the weathered reef-building coral used, it is
preferable to use those sifted according to the purposes for
which the silver-added material is used. For example, when
the silver-added material is used as filter mediums, it is
preferable to use those having a grain size of 0. 71 mm or larger.
After the dry heat disinfection or dry sterilization,
or roasting, the weathered reef.-building coral is immersed in
an aqueous silver solution under reduced pressure, whereby the
aqueous silver solution is penetrated into the weathered
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reef-building coral throughout its fine structure inside the
porous tissue. In this instance, as the aqueous silver
solution, an aqueous silver nitrate solution or the like may
preferably be used. Its concentration may be appropriately
determined in accordance with the amount silver to be coated.
Usually it may be controlled to be from 4 to 6~ by weight . The
degree of vacuum to be set when the weathered reef-building
coral is immersed in the aqueous silver solution may be the
same as the one in the case of the alkali washing or water washing
described above.
After the weathered reef-building coral has been thus
immersed in the aqueous silver solution, the aqueous silver
solution is discharged, and a reducing agent is introduced so
that the silver in the aqueous silver solution adhering to the
weathered reef-building coral is reduced and deposited. As
the reducing agent , an aqueous solution of reducing agent such
as an ascorbic acid solution, an erysovine solution or a glucose
solution may be used. In order :for the weathered reef-building
coral to be well coated with silver, it must be immersed in
the reducing agent solution usually for a time of from about
30 to 60 minutes. Thereafter, any excess reducing agent
solution is discharged, followed by heating, e.g., at about
400~C for 30 to 60 minutes to complete the reduction of silver.
In this instance, the heating may preferably be carried out
after the weathered reef-building coral is moved from the
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reactor in which the reducing agent has been introduced, to
an electric furnace or the like separately provided.
Thereafter, according to conventional methods , the steps
of cooling, water washing, drying and packaging are taken up
to commercialization.
When the silver-added material is thus manufactured, the
time for which the weathered reef-building coral is immersed
in the aqueous silver solution., which has had to be done for
about 96 hours in conventional processes for manufacturing
silver-added materials, can be shortened to about 30 to 60
minutes , and hence it becomes possible to dramatically improve
the productivity of silver-added materials.
The immersion treating apparatus of the present
invention, which is preferable for carrying out the process
for manufacturing the weathered reef-building coral material
of the present invention will be described below.
Fig. 2 illustrates an embodiment of the immersion
treating apparatus for treating the weathered reef-building
coral according to the present invention. The apparatus shown
in Fig. 2 comprises an enclosed container 2 for internally
holding weathered reef-building coral 1 to be treated; a hollow
cylindrical basket 3 made of stainless steel, into which the
weathered reef-building coral 1 is put inside the enclosed
container; an agitator blade 4 positioned at the central hollow
space of the basket 3 ; and a motor 5 for rotating the agitator
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blade 4. An aqueous alkali solution storage vessel 6 is also
juxtaposed with the enclosed container 2. The enclosed
container 2 is provided with a :feed pipe 7 for introducing the
aqueous alkali solution into the enclosed container 2 from the
storage vessel 6. The enclosed container 2 is also provided
with a feed pipe 8 for introducing the water or aqueous silver
solution into the enclosed container 2, a feed pipe 9 for
introducing the reducing agent into the enclosed container 2
and a liquid discharge pipe 10 for discharging the effluent
from the enclosed container 2. These feed pipes 7, 8 and 9
and liquid discharge pipe 10 are further provided with valves
for controlling the quantity of liquid to be introduced or
discharged. At the bottom of the enclosed container 2, a
heating pipe 11 for heating the inside of the enclosed container
2 is internally provided. To the enclosed container 2 a vacuum
pump 12 for evacuating its inside is connected. Inside the
enclosed container 2 , the basket 3 is supported by four to six
supports 13.
Here, with regard to the inner faces of at least the
enclosed container 2 , the feed pipes 7 , 8 and 9 and the liquid
discharge pipe 10, it is necessary for them to be formed of
a metal having corrosion resistance to the aqueous alkali
solution. As the vacuum pump .L2, a vacuum pump is used which
can evacuate the inside of the enclosed container 2 to a vacuum
of 70 mmHg or below, and preferably 30 mmHg or below.
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As a method for the alkali washing of the weathered
reef-building coral 1 using this apparatus , first the weathered
reef-building coral 1 is put in the basket 3 inside the enclosed
container 2 . Next , the aqueou:~ alkali solution is introduced
through the feed pipe 7. Then the vacuum pump 12 is operated
to evacuate the inside of the enclosed container 2 to a vacuum
of 70 mmHg or below, and preferably 30 mmHg or below.
Concurrently with this evacuai~ion, the motor 5 is driven to
rotate the agitator blade 4 , to thereby form liquid flows moving
in the up and down vertical directions inside the basket 3,
as shown by the arrow in Fig.3,thus the aqueous alkali solution
is forcibly passed through the weathered reef-building coral
1 put in the basket 3. Hot water is also passed through the
heating pipe 11 to heat the enclosed container 2 to 80 to 100~C .
Such alkali washing is usually carried out for 30 to 60 minutes .
Thus, the marine algae, organic substances originating from
microorganisms and so forth present on the surface and in the
fine structure inside the porous tissue of the weathered
reef-building coral 1 can be dissolved in the aqueous alkali
solution and removed.
As the method for the alkali washing of the weathered
reef-building coral 1 using the apparatus of Fig. 2, the step
of immersing the weathered reef -building coral 1 in the aqueous
alkali solution and the step of evacuating the inside of the
enclosed container 2 may be replaced with each other so that
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the inside of the enclosed container 2 is evacuated by means
of the vacuum pump 12 and thereafter the aqueous alkali solution
is introduced to immerse the weathered reef-building coral 1
in the aqueous alkali solution. When the inside of the enclosed
container 2 is evacuated after the weathered reef-building
coral 1 has been immersed in the aqueous alkali solution, the
alkali washing of the weathered reef-building coral 1 can be
carried out in a good operability. In reverse, when the
weathered reef-building coral 1 is immersed in the aqueous
alkali solution after the inside of the enclosed container 2
has been evacuated, the aqueous alkali solution can be spread
also throughout the fine stru<aure inside the porous tissue
in a short time.
After the alkali washing, the aqueous alkali solution
having been used is discharged through the liquid discharge
pipe 10.
As a method for washing the weathered reef-building coral
with water after the above alkali washing, using the apparatus
of Fig. 2, the aqueous alkali solution used in the alkali
washing may be replaced with water, and the same operation as
the above may be repeated. More specifically, the water is
introduced into the enclosed container 2 through the feed pipe
8 to immerse the weathered reef-building coral 1 in the water,
and then the inside of the enclosed container 2 is evacuated.
Alternatively, the inside of the enclosed container 2 holding
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the weathered reef-building coral 1 is previously evacuated
and thereafter the water is introduced into it through the feed
pipe 8 to immerse the weathered reef-building coral 1 in the
water. Then the agitator blade 4 is rotated to forcibly pass
the water through the weathered reef-building coral 1 put in
the basket 3. Thereafter, the washing water having been used
is discharged through the liquid discharge pipe 10. This water
washing is repeated until the pH of the washing water having
been used from the liquid discharge pipe 10 turns neutral.
The apparatus shown in Fig. 2 may be used also for
manufacturing the silver-added weathered reef-building coral
material. In such an instance, the weathered reef-building
coral 1 to be coated with silver is preferably subjected to
the alkali washing and water washing described above, followed
by drying, and is further subjected to dry heat disinfection
or dry sterilization, or roasting. The resultant weathered
reef-building coral 1 is put in the basket 3. Then the aqueous
silver solution is introduced into the enclosed container 2
through the feed pipe 8 to well immerse the weathered
reef-building coral in this aqueous silver solution under
reduced pressure. Subsequent:Ly, the excess aqueous silver
solution is discharged through the liquid discharge pipe 10,
and thereafter the reducing agent solution such as an ascorbic
acid solution is introduced through the feed pipe 9 under
reduced pressure to reduce the aqueous silver solution having
CA 02229055 1998-02-09
adhered to the surface and fine structure inside the porous
tissue of the weathered reef-building coral 1. Subsequently,
the remaining reducing agent solution is discharged through
the liquid discharge pipe 10. Then, the resultant weathered
reef-building coral is moved to a heating means such as an
electric furnace separately provided, and is heated there at
about 400~C for 30 to 60 minutes. Thus, it becomes possible
to obtain a silver-added material whose weathered reef-
building coral has been coated with silver on its surface and
also throughout its fine structure inside the porous tissue,
and improved in sterilization effect.
The immersion treating apparatus of the present
invention is useful for the alkali washing of the weathered
reef-building coral and for manufacturing the silver-added
material as described above. Besides, it can also be useful
for any treatment accompanied by immers ion , a . g . , f or washing ,
coating or extracting various materials to be treated. Stated
specifically, it can be used as, e.g., an appratus for
extracting useful intended substances or physiologically
active substances by immersing spices , plant roots or bark and
dried products thereof, fruits or seeds, or other starting
materials for food or medicine in an extraction solvent to
extract such substances contained in the respective starting
materials.
The immersion treating apparatus of the present
CA 02229055 1998-02-09
26
invention may be modified in various forms in accordance with
the purposes for which the apparatus is used, so long as it
has the enclosed container whose interior can be evacuated;
the hollow cylindrical basket for holding the material to be
processed, provided in the container; and the agitator blade
which rotates within the hollow space to form a vertical liquid
flow in the basket. For example, the basket may be made of
a material appropriately selected from those which are not
attacked by the washing solution or treating solution used on
the materials to be treated. Also, the net material
constituting the basket may have any mesh size which may be
appropriately determined in accordance with the size of the
materials to be treated. The :Feed pipes for introducing the
washing solution or treating solution and the liquid discharge
pipe may also not necessarily be provided on the enclosed
container.
The present invention will be described below in greater
detail by giving Examples . The present invention is by no means
limited to these Examples.
Example 1
Parent material weathered reef-building coral was set
on a vibratory screen to sif t it , and 20 kg of weathered
reef-building coral with a grain size of 2 mm to 1 mm was put
in the basket 3 in the enclosed container 2 of the apparatus
CA 02229055 1998-02-09
27
shown in Fig. 2. To pre-wash this weathered reef-building
coral , city water was introduced through the feed pipe 8 , the
agitator blade 4 was rotated to forcibly pass the water through
the weathered reef-building coral for 30 minutes. The washing
solution was sent as an effluent to an effluent treating tank
through the liquid discharge pipe 10.
Next, as the operation of alkali washing, first the
vacuum pump 12 was driven to evacuate the inside of the enclosed
container 2 to a vacuum of 10 mmH20, and 25 liters of an aqueous
O.1N sodium hydroxide solution beforehand prepared in the
storage vessel 6 was introducE:d into the enclosed container
2 through the feed pipe 7. Thereafter, hot water with a
temperature of 80~C was passed through the heating pipe 11 to
heat for 30 minutes the inside of the enclosed container 2 in
which the aqueous sodium hydroxide solution was being forcibly
passed through the weathered reef-building coral. After this
alkali washing was completed, the hot water was stopped being
fed to the heating pipe 11 and also the vacuum state of the
inside of the enclosed container 2 was restored to normal
pressure. Then, the aqueous sodium hydroxide solution in the
enclosed container 2 was completely discharged through the
liquid discharge pipe 10.
City water was again ini:roduced through the feed pipe
8 , and the same operation as the above was repeated except for
using the city water in placE: of the above aqueous alkali
CA 02229055 1998-02-09
28
solution, to carry out water washing. This water washing was
repeatedly carried out twice. More specifically, after the
first-time water washing, the water discharged through the
liquid discharge pipe 10 was collected to measure its pH to
find that it was 8.1. The pH of the effluent after the
second-time water washing turned to 7Ø Accordingly, the
water washing was stopped after that.
This alkali washing and water washing took 30 minutes
in total time.
A sample obtained after the water washing followed by
dehydration and drying was used as a specimen, and its crude
protein content and the number of general bacteria (cells/g)
were measured. Here, the crude protein content was calculated
from the total nitrogen by the semimicro-Kjeldahl method, and
the number of general bacteria (cells/g) was measured by a
microbiological test (the standard agar medium method). For
comparison, the crude protein content and the number of general
bacteria were also measured on the parent material weathered
reef-building coral. Results obtained are shown in Table 1.
Example 2
Alkali washing was carried out in the same manner as in
Example 1 except that the weathered reef -building coral with
a grain size of 2 mm to 1 mm used in Example 1 was replaced
with 20 kg of weathered reef-building coral with a grain size
CA 02229055 1998-02-09
29
of 5 mm to 4 mm and 25 liters of the aqueous 0 . 1N sodium hydroxide
solution was replaced with an aqueous 1.ON sodium hydroxide
solution. Then the aqueous sodium hydroxide solution in the
tank was completely discharged.
Thereafter, water washing was repeated in the same manner
as in Example 1 , and the pH of t:he effluent was measured every
time the water washing was completed. As the result, the pH
values of the effluent at the first to third times were 8.8,
8.1 and 7.4, respectively, an<i the pH value of the effluent
at the fourth time turned to 7Ø Accordingly, the water
washing was stopped after that.
This alkali washing and water washing took 55 minutes
in total time.
A sample obtained after the water washing followed by
dehydration and drying was used as a specimen, and its crude
protein content and the number of general bacteria were
measured in the same manner as in Example 1. For comparison,
the crude protein content and the number of general bacteria
were also measured on the parent material weathered reef-
building coral. Results obtained are shown in Table 1.
CA 02229055 1998-02-09
Table 1
Example Example 2
1
f
Manu
acturing process
Parent material:
Grain diameter: (mm) 2-1 5-4
Sampling weight: (kg) 20 20
Pre-washing:
Degree of vacuum : ( mmHzO ) 10 10
Time: (min) 30 30
Alkali washing:
Alkali concentration: O.1N 1. ON
Degree of vacuum : ( mmH20 ) 10 10
Heating : ( C ) 80 80
(min) 30 30
Water washing:
Degree of vacuum : ( mmH20 ) 10 10
Washing times: 2 4
Evaluation
Crude protein content:
Parent material: (g) 0.9/100 0.9/100
After washing: (g) 0.04/100 0.03/100
Number of general bacteria:
Parent material: (cells/g) 3.1x102 3.1x102
After washing: (cells/g) <30 <30
CA 02229055 1998-02-09
31
Example 3
Alkali washing was carried out in the same manner as in
Example 1 except that the weathered reef-building coral with
a grain size of 2 mm to 1 mm used in Example 1 was replaced
with weathered reef-building coral with a grain size of 8 mm
to 5 mm. Then the aqueous sodium hydroxide solution in the
tank was completely discharged. Subsequently, the water
washing was repeatedly carried out twice in the same manner
as in Example 1, and the pH of the effluent was confirmed to
have turned to 7Ø
Thereafter, the water washing, dehydration and drying
were carried out, further followed by roasting (500~C, 60
minutes ) , cooling and grain sizE: adjustment ( sifting ) to obtain
a filter medium for water purifiers.
The number of general bacteria (cells/g) of the filter
medium for water purifiers thus obtained were measured in the
same manner as in Example 1 by a microbiological test (the
standard agar medium method). In order to judge the
adsorptivity of this filter medium, 50 g of this filter medium
was put into a column of 130 mm in inner diameter and 130 mm
in height to make a decoloring test using 100 ml of 0.002
methylene blue. Then the rate of adsorption of methylene blue
present in the methylene blue solution having passed through
the column was determined according to the following
expression:
CA 02229055 1998-02-09
32
Rate of adsorption (~)
(transmittance of methylene blue solution
after passing through column)
- X 100
(transmittance of methylene blue solution
before passing through column).
The activity of this filter medium was also calculated
according to:
Activity (~) - 100 - rate of adsorption.
Results obtained on these are shown in Table 2.
Example 4
Alkali washing was carried out in the same manner as in
Example 2 except that the weathered reef-building coral with
a grain size of 5 mm to 4 mm used in Example 2 was replaced
with 20 kg of weathered reef-building coral with a grain size
of 8 mm to 5 mm. Subsequently, the water washing was carried
out four times, and the pH of the effluent was confirmed to
have turned to 7Ø
Thereafter, the water washing, dehydration and drying
were carried out, further followed by roasting (500~C, 60
minutes ) , cooling and grain size adjustment ( sifting ) to obtain
a filter medium for water purifiers .
The number of general bacteria (cells/g) of the filter
medium for water purifiers thus obtained were measured in the
CA 02229055 1998-02-09
33
same manner as in Example 3. In order to judge the adsorptivity
of this filter medium, the deco:Loring test was made in the same
manner as in Example 3, to determine the rate of adsorption
of methylene blue and the activity.
Results obtained on these are shown in Table 2.
Examples 5 and 6
Filter mediums for water purifiers were obtained in the
same manner as in Example 4 except that the concentration of
the aqueous sodium hydroxide solution used in the alkali
washing was changed. In respect of the filter mediums thus
obtained, the decoloring test was carried out to determine the
rate of adsorption of methylene blue and the activity.
As can be seen from comparison of Examples 3 to 6, the
activity increases with an increase in the concentration of
the aqueous sodium hydroxide solution, and the microorganisms
and other organic substances in the water can be adsorbed to
purify the water .
Comparative Example 1
The parent material weathered reef-building coral used
in Example 3 was only pre-washed. Then, in respect of the
weathered reef-building coral thus obtained, in the same manner
as in Example 3 , the number of general bacteria ( cells /g ) was
measured and the decoloring test was carried out to determine
CA 02229055 1998-02-09
34
the rate of adsorption of methylene blue and the activity.
Results obtained on these are shown in Table 2.
Comparative Example 2
The parent material weathered reef-building coral used
in Example 3 was pre-washed, and the resultant weathered
reef-building coral was roasted in the same manner as in Example
3. Then, in respect of the weathered reef-building coral thus
obtained, in the same manner as in Example 3, the number of
general bacteria (cells/g) was measured and the decoloring test
was carried out to determine the rate of adsorption of methylene
blue and the activity. Results obtained on these are shown
in Table 2.
CA 02229055 1998-02-09
Table 2
Example Comparative
Example
3 4 1 2
5
6
Manufacturing' process
Parent material:
Grain diameter: (mm) 8-5 8-5 8-5 8-5 8-5 5-4
Sampling weight: (kg) 20 20 20 20 20 20
Pre-washing:
Degree of vacuum : ( mmHZO ) 10 10 10 10 10 10
Time: (min) 30 30 30 30 30 30
Alkali washing:
Alkali concentration: O.1N 1. 2. 6.
ON ON ON
Degree of vacuum : ( mmH20 ) 10 10 10 10
Heating : ( ~ ) 80 80 80 80
(min) 30 30 30 30
i
Water washing:
I
i 10 10 10 10
Degree of vacuum: (mmH20)
Washing times: 2 4 4 4
Roasting:
Temperature: (~C) 500 500 500 500 500
Time: (min) 60 60 60 60 60
Evaluation
Number of general bacteria:
(cells/g) <30 <30 <30 <30 6.9 1.7
X 102 X 102
Decoloring test:
Rate of adsorption: (~) 58.9 14.2 10.8 9.1 98.9 82.7
Activity: (~) 41.4 85.8 89.2 90.9 1.1 17.3
CA 02229055 1998-02-09
36
Example 7
Using the filter medium for water purifiers obtained in
Example 3 , this was put in the basket 3 in the enclosed container
2 of the apparatus shown in Fig . 2 , the inside of the enclosed
container 2 was evacuated, 2C1 liters of an aqueous silver
nitrate solution with 5~ silvE:r was introduced into it, and
the agitator blade 4 was rotated for 30 minutes to forcibly
pass the aqueous silver nitrai~e solution through the filter
medium.
After the aqueous silver nitrate solution was discharged,
20 liters of an aqueous 1.5-~ ascorbic acid solution was
introduced through the feed pipe 9 , and the agitator blade 4
was rotated for 30 minutes to forcibly pass the aqueous silver
nitrate solution through the filter medium. Subsequently, the
ascorbic acid solution was discharged through the liquid
discharge pipe 10 , and the resultant weathered reef -building
coral was taken out of the enclosed container 2 and put into
a 400~C electric furnace to heat it for 50 minutes . After the
heating was completed, cooling, water washing, drying and grain
size adjustment were successively carried out, followed by
packaging to obtain a product o:f a silver-added material. The
silver-added material thus obtained had a silver coating weight
as shown in Table 3.
CA 02229055 1998-02-09
37
Example 8
A silver-added material was obtained in the same manner
as in Example 7 except that the weathered reef-building coral
material obtained in Example 4 was used.
The silver-added material thus obtained had a silver
coating weight as shown in Table 3.
Comparative Example 3
A silver-added material was obtained in the same manner
as in Example 7 except for using one obtained by only pre-
washing the parent material weathered reef-building coral used
in Example 3.
The silver-added material thus obtained had a silver
coating weight as shown in Table 3.
CA 02229055 1998-02-09
38
Table 3
Example Comparative
7 8 Example 3
Manufacturi ng~ Drocess
Parent material:
Grain diameter: (mm) 8-5 8-5 8-5
Sampling weight: (kg) 20 20 20
Pre-washing:
Degree of vacuum: (mmH20) 10 10
Time: (min) 30 30
Alkali washing:
Alkali concentration: O.1N 1. ON
Degree of vacuum: (mmHzO) 10 10
Heating : ( C ) 80 80
(min) 30 30
Water washing:
Degree of vacuum: (mmHzO) 10 10
Washing times: 2 4
Roasting:
Temperature : ( C ) 500 500
Time: (min) 60 60
Silver coating:
Silver solution concentration: 5 5 5
(wt.~)
Reducing agent concentration: 1.5 1.5 1.5
(wt.~)
Evaluation
Silver coating weight:(mg/g) 15 20 10
CA 02229055 1998-02-09
39
Example 9
Weathered reef-building coral materials obtained in
Examples 1 and 2 were each pulverized by means of a pulverizer
WONDER BLENDER (manufactured by Osaka Chemical Co. , Ltd. ) , and
a portion with a particle size of 500 meshes or greater
(particle diameter of 27.28 ,u m or smaller) was separate and
collected. This was used as a food material comprised of the
weathered reef-building coral material (i.e., coral calcium
powder for food, or weathered reef-building coral powder for
food).
31.0 by weight of this food material comprised of the
weathered reef-building coral material, 23.8 by weight of
lactose, 12. 5~ by weight of maltitol, 6 . 5~ by weight of sucrose,
2.7~ by weight of vitamin C, 4.7~ by weight of CPP (casein
phosphopeptide) and 18.8 by weight of dextrin were mixed, and
prepared into granules. The texture of the granules was
evaluated by five panelists. As the result, all the panelists
evaluated that the granules have a smooth texture free of
roughness.
The particle size of this weathered reef-building coral
material was also analyzed using a laser diffraction type
particle size distribution measuring apparatus (SALD-2000
manufactured by SHIMAZU SEISAKUSHO) in the following way.
First, a small quantity of sample was collected in a 200 mL
beaker, and methanol (first grade) was added thereto as a
CA 02229055 1998-02-09
dispersant, followed by dispersion for about 2 minutes by
ultrasonic irradiation to obtain a measurement sample. Next,
methanol was previously put in a circulatory agitating tank,
and the above measurement sample was introduced into it while
applying propeller agitation, in such an extent that the
diffracted/scattered light intensity came to be 30 to 40~,
further followed by ultrasonic irradiation for about 1 minute
to measure the particle size distribution.
Results obtained are shown in Table 4.
CA 02229055 1998-02-09
41
Table 4
Particle Inte- Particle Inte- Particle Inte-
diameter grated diameter grated diameter grated
( Vim) jalue(~ ( Vim) value() ( Vim) value()
(1)700.00 100 (18)22.91 99 (35) 0.75 4
(2)572.45 100 (19)18.73 98 (36) 0.61 2
(3)468.14 100 (20)15.32 95 (37) 0.50 1
(4)382.84 100 (21)12.53 90 (38) 0.41 0
(5)313.08 100 (22)10.25 83 (39) 0.34 0
(6)256.04 100 (23) 8.38 75 (40) 0.27 0
(7)209.38 100 (24) 6.85 65 (41) 0.22 0
(8)171.23 100 (25) 5.60 56 (42) 0.18 0
(9)140.03 100 (26) 4.58 48 (43) 0.15 0
(10)114.51 100 (27) 3.75 40 (44) 0.12 0
(11) 93.65 100 (28) 3.07 34 (45) 0.10 0
(12) 76.58 100 (29) 2.51 28 (46) 0.082 0
(13) 62.63 100 (30) 2.05 23 (47) 0.067 0
(14) 51.22 100 (31) 1.68 18 (48) 0.055 0
(15) 41.89 100 (32) 1.37 14 (49) 0.045 0
(16) 34.25 100 (33) 1.12 10 (50) 0.037 0
(17) 28.01 100 (34) 0.92 7 (51) 0.030 0
10.0~D: 1.127
50.O~D:
4.810 90.O~D:
12.394
Median diameter:
4.810 Mode
diameter:
7.577
Average value:
4.222 Standard
deviation:
0.391
CA 02229055 1998-02-09
42
POSSIBILITY OF INDUSTRIAL UTILIZATION
According to the process of the present invention for
manufacturing a weathered reE:f-building coral material, a
weathered reef-building coral material can be obtained from
which the various marine a:Lgae, various microorganisms
including Vibrio bacteria inhabiting the ocean and other
various organic substances held in the inner fine structure
of weathered reef-building coral have been removed and whose
safety has been ensured. This weathered reef-building coral
material can be used in various purposes. In particular, it
is suitable for food materials. According to the present
invention, a filter medium for water purifiers can also be
obtained which has a high mineral elution quantity and a high
activity.
According to the present invention, a silver-added
material can also be obtained whose weathered reef-building
coral has been coated with silver on its surface and also
throughout its fine structure inside the porous tissue.
According to the immersion treating apparatus of the
present invention, the process of the present invention for
manufacturing a weathered reef -building coral material can be
carried out with ease. The immersion treating apparatus of
the present invention can also be useful not only for the
treatment of the weathered reef-building coral but also for
the treatment of, e.g. , washing, coating or extraction of
43
various materials to be treated.
