KR101513792B1 - Method for preparing capsule and sorbent using the capusle - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a capsule manufacturing method in which a functional material is contained on the surface or inside to improve the recoverability of valuable metal and the selectivity to a specific metal, and a capsule for an adsorbent therefrom.
Unlike conventional beads, the adsorption capsules of the present invention can contain a desired functional material in the capsule, and they can hold the shape while retaining them for a long period of time.
According to the present invention, the metal recovery performance can be improved by providing a polymer capsule in which a functional material such as a metal extractant is granulated, and only a specific metal can be selectively recovered.
The method according to the present invention can simplify the process as compared with the conventional wet smelting method because solid-liquid separation can be performed in the recovery of valuable metals, and since the secondary sludge does not occur, the process can be operated more environmentally friendly.

Description

TECHNICAL FIELD The present invention relates to a method for preparing a capsule,

TECHNICAL FIELD The present invention relates to a capsule manufacturing method and a capsule for an adsorbent therefrom, and more particularly, to a capsule manufacturing method in which a functional material is contained on the surface or inside to improve the recoverability of valuable metal and the selectivity to a specific metal, .

As the demand for electronic products surges, various kinds of waste electronic products are discharged as garbage together with industrial wastewater generated in electronic manufacturing process. Industrial wastewater and waste electronic products are the main cause of polluting the environment, but they also contain valuable metals such as gold, silver, and copper, which is also a high value for recycling. For example, the average price of a valuable metal in a mobile phone is 0.024 g of gold, 0.14 g of gold, 10.5 g of copper, etc. It is worth about 1,500 won or more. If you collect 500,000 mobile phones and recycle them, A resource conservation effect of KRW 150 million is generated.

Recently, recycling of resources is a global issue in order to cope with resource depletion crisis. The discovery of new resources is reaching its limit, and it is necessary to seek fundamental solutions such as alternative materials and waste resource utilization in order to cope with resource depletion crisis.

In order to obtain the resource conservation effect through industrial wastewater or waste electronic products, the most important thing is to recover valuable metals. Currently commonly used methods for the recovery of valuable metals from wastewater are those using metal extractants. However, in the case of using a metal extracting agent, a large-scale process is continuously required and secondary pollutants are generated. To solve this problem, studies for recovering valuable metals using environmentally friendly materials have been actively conducted. Typical methods include hydrogels such as alginate, chitosan, and cellulose.

For example, Korean Patent Laid-Open Publication No. 10-2012-87678 discloses a method for removing a bromate-removing heterogeneous metal oxide adsorbent using a hydrogel. This method is characterized in that the metal oxide adsorbent containing two metals is characterized in that the adsorption performance is improved because the surface charge is higher than that of one kind of the iron oxide adsorbent. However, the metal oxide adsorbent can not contain a reducing agent or the like in the hydrogel, It is difficult to selectively recover.

Figure 1 shows the mechanism for manufacturing beads in a conventional manner. Referring to FIG. 1, conventionally, capsules were prepared by dropping polymer beads on a coagulant (such as calcium chloride). 1, the coagulant is diffused into the beads, and the polymer in the solution is cured from the outside to the inside to form beads. However, the method has limitations on the content of the functional material, and it is difficult to contain the hydrophobic functional material , Functional materials may leak, and so on.

The present invention provides a capsule for an adsorbent having improved recoverability of a valuable metal.

The present invention provides an adsorbent capsule capable of selectively recovering a specific metal and a method for producing the same.

The present invention provides a new capsule manufacturing method which can easily contain a desired functional substance in a capsule, unlike a conventional bead manufacturing method.

The present invention provides a new capsule capable of retaining a functional material therein for a long period of time while maintaining its shape, and a method for producing the same.

One aspect of the present invention is directed to a method of making a coagulant, comprising: mixing a functional material and a coagulant;

The step of dripping the mixed solution into the polymer solution, wherein the step of curing the mixed solution from the outside of the droplet mixed solution into which the polymer is dripped forms a film having a predetermined thickness, and the functional material is contained in the membrane Capsule manufacturing method.

In another aspect, the present invention relates to a capsule for an adsorbent produced by the above method.

Unlike conventional beads, the adsorption capsules of the present invention can contain a desired functional material in the capsule, and they can hold the shape while retaining them for a long period of time.

According to the present invention, the metal recovery performance can be improved by providing a polymer capsule in which a functional material such as a metal extractant is granulated, and only a specific metal can be selectively recovered.

The method according to the present invention can simplify the process as compared with the conventional wet smelting method because solid-liquid separation can be performed in the recovery of valuable metals, and since the secondary sludge does not occur, the process can be operated more environmentally friendly.

1 is a schematic view showing a conventional bead manufacturing method.
Fig. 2 shows a schematic view of a capsule for an adsorbent according to the present invention.
3 is a schematic view of an apparatus for producing capsules of the present invention.
FIG. 4 shows a process of forming a capsule in the capsule forming machine 130.
FIG. 5 is a schematic diagram showing that the coagulant diffuses from the outside to the inside of the capsule when the capsule prepared in FIG. 4 is injected into a separate coagulant solution.
6 is an electron micrograph of the capsules or beads obtained in Example 1, Example 4 and Comparative Example 1. Fig.
FIG. 7 is a graph showing the adsorption test performed using the capsule of Example 1. FIG.
FIG. 8 is a graph showing the adsorption test performed using the capsule of Example 2. FIG.
FIG. 9 is a graph showing the adsorption test performed using the capsule of Example 3. FIG.

Hereinafter, the present invention will be described in more detail.

One embodiment of the present invention relates to a method for preparing capsules by injecting a mixed solution of a functional material and a coagulant into a polymer solution.

In the present invention, capsules are prepared by first mixing a functional material and a coagulant, and then dropping the mixture into a polymer solution.

It is preferable that the mixed solution is dropped into a polymer solution in a bead form. In the dropping step, the polymer surrounds the dripped mixed solution to form a wall having a predetermined thickness, and the coagulant maintains the shape of the polymer wall by applying pressure to the outside from the inside of the formed polymer wall.

Through the dropping step, the functional material is contained in the formed polymer wall. The term "containing" means that the functional material is carried or contained in the inside of the capsule, and the term " containing " means that the functional material is deposited or adsorbed on the surface of the capsule, . Furthermore, the expression "containing" does not exclude that the functional material together with the polymer forms an outer layer (shell) of the capsule or is carried in the outer layer.

Fig. 2 shows a schematic view of a capsule for an adsorbent according to the present invention. 3 is a schematic view of an apparatus for producing capsules of the present invention. Referring to FIG. 2, the capsule 100 of the present invention includes an inner region 10 and a wall 20.

The functional material and the coagulant are contained in the inner region (10). The wall 20 forms a wall by surrounding the mixed solution while solidifying the polymer.

The thickness of the wall 20 may be 1 to 5,000 mu m, preferably 10 to 1,000 mu m.

Referring to FIG. 3, the manufacturing apparatus of the present invention includes a mixer 110, an injector 120, and an encapsulator 130.

In the mixer 110, a mixed solution is prepared by mixing a functional solution and a coagulant. The mixer may be further mixed with a high viscosity material.

The injector 120 drops the mixed solution supplied from the mixer 110 to the capsule shaper 130. The injection unit 120 may include a nozzle capable of dropping the mixed solution at predetermined intervals.

The manufacturing apparatus of the present invention may include a transfer unit 140 for providing the mixed solution to the injection unit.

The capsule forming machine 130 is filled with a polymer solution. In the capsule forming machine 130, when the mixed solution is dropped into the polymer solution in a bead form, the polymer in contact with the bead interface is cured to form a wall having a predetermined thickness.

The capsule shaper 130 may include an agitator.

FIG. 4 shows a process of forming a capsule in the capsule forming machine 130. In Fig. 4, CaCl2 is used as a coagulant. The ionized Ca ^{2 +} inside the bead diffuses into the polymer solution surrounding the bead, whereby the polymer in solution is cured from the bead surface.

Method and manufacturing apparatus of the present invention, for the internal bead coagulant, for example, by controlling the polymer concentration in the Ca ^{2 +} concentrations and capsule manufacturing machine 130, it is possible to adjust the curing speed and the wall thickness of the polymer as desired.

The capsule manufacturing method of the present invention can contain a large amount of functional material in comparison with the conventional bead or hydrogel manufacturing method and it is difficult to contain a hydrophobic functional material in the prior art. ≪ / RTI >

In addition, according to the present invention, there is no deformation of the polymer material due to the inclusion of the functional substance, leakage of the functional material contained therein, and easy adjustment of the capsule thickness.

The capsule manufacturing method and apparatus of the present invention may further include a step of injecting the capsule formed by the dropping step into a separate coagulant solution and an apparatus. FIG. 5 shows the action of the coagulant after the capsule prepared in FIG. 4 is injected into the coagulant solution. In FIG. 4, the coagulant is present only in the interior, but in the case of FIG. 5, the coagulant is also present on the outer wall of the polymer, so that the coagulant diffuses from the outer wall to the inner wall to more firmly form the polymer outer wall.

The functional material may be at least one of a metal reducing agent, a metal extracting agent, and a chelating compound.

The metal reducing agent may be selected from natural antioxidants such as tocopherols, flavone derivatives, phyllozurcines, gallic acid derivatives, catechin, nordihydroguaiaretic acid, gossypol, lignan glycosides, plant extracts and polymers having metal reducing power, glutaraldehyde, sodium borohydride _{4), Hydrazine (N 2 H} 4), Borohydride, Dimethylamine borane [(CH 3) 2 NH.HBH 3], Formaldehyde [CH 2 O], Sodium dithionite [Na 2 S 2 O 4], Ascorbic acid [C 6 H ₂ O ₆ ], Ethylene glycol, Sodium alkoxide, Hydroquinone (C ₆ H ₆ O ₂ ), Sodium oxalate (Na ₂ C ₂ H ₂ O ₄ ), Formic acid, Dimethylamine borane, Dithiothreitol and Tris (2-carboxyethyl) phosphine. < / RTI >

The metal extractant may be selected from organic phosphorus derivatives (for example, triisobutylphosphine sulfide, trioctylphosphine oxide, trialkylphosphine oxide), trioctylamine, methyl isobutyl ketone, trioctylmethylammonium chloride, Dibutyl sulfoxide, tris-iso-octylamine, LIX 84I (triphenylphosphine, 2-hydroxyl-5-nonylacetophenoneoxime), phosphonic acid di (2-ethylhexyl) ester, (4-ethyl-1-methyloctyl) -8-hydroxyquinoline, alkyl sulfides, phosphine sulfide, hydroxyoximes, secondary amines, tertiary amines, ammonium salts, tri-n-butyl phosphate, quinolinol derivatives, polymeric amines (trialkylmethylamine, n-dodecylalkylmethylamine, trioctylamine) , Trioctylphosphine oxide and ethylenediamine And a set acid.

Examples of the chelating agent include polyphosphates (for example, sodium tripolyphosphate, hexametaphosphoric acid, sodium pyrophosphate, sodium pyrophosphate, sodium pyrophosphate, sodium hexametaphosphate, sodium metaphosphate); (EDTA), 1,2-bis (2-amino-phenoxy) ethane-N, N, N'N'-tetraacetic acid (EGTA), ethylenebis (HETTA), diethylenetriaminepentaacetic acid (DTPA), N-dihydroxyethylglycine (2-HxG (2-hydroxyethyl) ), Ethylenebis (hydroxyphenyl-glycine) (EHPG), glutamic acid, aspartic acid, glycine, lysine); 1,3-diketones (e.g., acetylacetone, trifluoroacetylacetone, decanoyl trifluoroacetone, ascorbic acid); Hydroxycarboxylic acids (e.g., tartaric acid, citric acid, malic acid, gluconic acid, ferulic acid, lactic acid, glucuronic acid); Polyamines (e. G., Diethylenetriamine, triethylenetriamine); Amino alcohols (e.g., triethanolamine, N-hydroxyethylethylenediamine, aminoethylethanolamine (AEEA), phenol (e.g., disulfo pyrocatechol, chromotropic acid) (Such as, for example, oxydisulfonic acid), Schiff bases (e.g., disalicylaldehyde 1,2-propylenedimine), tetrapyrroles (e.g., tetraphenylporphine, phthalocyanine ), Silicates (such as calcium silicate aluminum, calcium silicate, sodium aluminosilicate, sodium aluminosilicate (hydrate), calcium silicate), sulfur compounds (such as potassium ethylenzonate, sodium diethyldithiocarbamate, Diethyldithiophosphoric acid, thiourea, magnesium sulfate), synthetic macrocyclic compounds (e.g., hexamethyl- [14] -4,11-diene N4,2.2.2-cryptate) For example, polyethyleneimine, polymethacryloyl acetone, poly (p-vinylbenzyl L-cystein, Phosphatidylcholone, < / RTI > < RTI ID = 0.0 > lauryldithiocarbamate) Min.

Preferably, as the chelating agent, any one of melamine, L-cystein, phosphatidylcholone, and alumin may be used.

The coagulant may be sodium polyphosphate, calcium chloride, or caustic soda aqueous solution.

The polymer may be selected from the group consisting of chitosan, alginate, dextran, oxidized dextran, heparan, heparin, hyaluronic acid, agarose, carrageenan carageenan, amylopectin, amylose, glycogen, starch, cellulose, chitin, heparan sulfate, chondroitin sulfate, dextran sulfate, And may be at least one selected from the group consisting of dermatan sulfate, keratan sulfate, pectins, xanthan Gum and carboxymethylcellulose.
The polymer may be used by dissolving it in a suitable hydrophilic solvent. For example, water, alcohol, and the like may be used as the hydrophilic solvent.

delete

The polymer is cured from the outside of the dropped bead-shaped mixed solution to form a film having a predetermined thickness.

The concentration of the polymer solution is 0.01 to 80% (w / v), and 0.01 to 50% (w / v) of the functional substance and 0.01 to 40% (w / v) of the coagulant can be used have.

The method may further comprise a high viscosity material in the mixed solution, and the functional material may be granulated by the high viscosity material.

More specifically, the physically mixed emulsion state of the highly viscous substance, the functional substance, and the coagulant may be added to the polymer solution. When the bead of the emulsion mixture is added to the polymer solution, The capsule can be formed in such a form that the mixture bead is coated from the outside while being cured.

According to the present invention, since the functional material and the high viscosity material are mixed to form an emulsion state having a predetermined viscosity, the functional material can be stably contained in the capsule.

The high viscosity material may be added in an amount of 0.01 to 50 parts by weight, preferably 1 to 20 parts by weight based on 100 parts by weight of the functional material so that the functional material does not dissolve out of the capsule. When the amount is less than 0.01 part by weight, it is difficult to block the granulation of the functional material and the elution out of the capsule, and when the amount is more than 50 parts by weight, it is difficult to drop the solution in an excessive viscosity.

The highly viscous material may have a viscosity of 2 to 10,000 mPa s.

The highly viscous material may be selected from the group consisting of Carboxymethyl Cellulose, Hydroxyethyl Cellulose, Xanthan Gum, Hycel, Carbomer, Gelatin, Pectin, Guargum, Sodium Alginate, Calcium Glycerophosphate, Carrageenan, Tragacanth Gum, Propylene Glycol Alginate, Methyl Ethyl Cellulose, Methylethylcellulose, potassium alginate, and calcium carboxymethylcellulose.

In another aspect, the present invention relates to a capsule for an adsorbent produced by the method.

The adsorbent capsules according to the present invention may contain at least one functional material selected from the group consisting of melamine, L-cystein, phosphatidylcholone, dibutyl sulfoxide, LIX 84I (triphenylphosphine, 2-hydroxyl-5-nonylacetophenone oxime), trioctylphosphine oxide , Trialkylphosphine oxide, and the like. The capsule may have a selective adsorption ability to gold, including alamine and methyl isobutyl ketone as a functional material.

When the adsorbent capsule having an oil component among the above-mentioned functional materials is used, the replacement cycle of the capsule can be visually determined. The oil component may be an alumin, melamine, or the like.

The specific gravity of the capsule increases with the adsorption of the valuable metal and precipitates to the bottom of the solution. In addition, if the capsules that are settled on the bottom are collected and placed in the desorption solution, they float to the upper part of the solution as the adsorbed metal is desorbed.

The method for recovering valuable metals according to the present invention can selectively recover a specific valuable metal. Further, since the method according to the present invention can perform solid-liquid separation in recovering valuable metals, an eco-friendly process can be operated.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Example  One

50 ml of 1.5% CaCl2 solution (solvent: water) and 1.5% of carboxymethyl cellulose (CMC) (solvent: water) solution were mixed and 4 g of melamine was added and mixed well to prepare a mixed solution. The above mixed solution was dropped in a 0.6% w / v Na-alginate solution (solvent: water) and stirred for 5 minutes to obtain capsules.

The capsule thus obtained was washed and then added to 100 mL of 2% CaCl 2 solution (solvent: water) and stirred for about 30 minutes. After completion of the reaction, the capsules were washed several times with deionized water.

Example  2

A capsule was prepared in the same manner as in Example 1, except that 4 g of L-Cystein was added instead of melamine.

Example  3

A capsule was prepared in the same manner as in Example 1, except that 4 g of phosphatidylcholone was added instead of melamine.

Example  4

A mixed solution was prepared by adding 10 ml of alumina to a 50 ml solution (containing 1.5% CaCl 2 solution and 1.5% carboxymethyl cellulose (CMC)). The mixed solution was dropped into a 0.6% w / v Na-alginate solution and stirred for 5 minutes to obtain capsules.

The capsule thus obtained was washed and then placed in 100 mL of 2% CaCl2 solution and stirred for about 30 minutes. After completion of the reaction, the capsules were washed several times with deionized water.

Comparative Example  One

0.6% w / v Na-alginate solution was injected into 1000 ml of 2% CaCl2 solution and reacted at room temperature for about 30 minutes to obtain beads, which were washed several times.

Adsorption test

A mixed solution of Au (III), Pd (II), and Pt (IV) (containing 100 mg / L of each metal ion in 0.1 M HCl solution) was used to evaluate adsorption selectivity of the prepared materials. 0.05 g of the capsules obtained in Examples 1 to 3 were added to the mixed solution, and the adsorption was performed while adjusting the pH to 2 to 12 by using 1 M NaOH and 1 M HCl.

Fig. 6 is an electron micrograph of the capsule or bead obtained in Example 1 and Example 4, Comparative Example 1. Fig.

6, the outer wall of the capsule of the present invention is formed to have a predetermined thickness, but the bead of Comparative Example 1 does not have a wall having a predetermined thickness as in the present invention.

Also, FIG. 6 shows that the functional material is mixed with a high-viscosity material and granulated into an emulsion state.

FIG. 7 is a graph showing the adsorption test performed using the capsule of Example 1, FIG. 8 is a graph showing the adsorption test performed using the capsule of Example 2, and FIG. The results of the adsorption test are shown in Fig.

Referring to FIG. 7, when the capsules of Example 1 were used, the adsorption performance was increased at pH 2 to 4, the adsorption performance was decreased gently at pH 4 to 10, and the adsorption performance was drastically decreased at pH 10. On the other hand, in case of Pt, the adsorption performance was increased at pH 10 or higher, and Pd showed the highest adsorption selectivity in the entire pH range. The capsules containing melamine selectively adsorb palladium in the range of pH 4 to pH 12 compared to platinum and the capsules containing melamine are highly selective for palladium compared to platinum and gold at pH 2 or near pH 12 .

Referring to FIG. 8, when the capsule of Example 2 is used, palladium and gold are selectively adsorbed rather than platinum. That is, when the pH is 3 to 6 or more than 9, the selectivity to palladium and gold is superior to that of platinum.

Referring to FIG. 9, it can be seen that when the capsules of Example 3 were used, the selectivity to gold was superior to platinum and palladium over the entire pH range.

Hereinafter, specific embodiments of the present invention have been described. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: inner area 20: (outer) wall
100: Capsule
110: mixer 120: injector
130: capsule forming device 140:

Claims (13)

Preparing a mixed solution by adding a functional substance, a high viscosity substance and a coagulant into water; And
And dropping the mixed solution into a hydrophilic polymer solution,
The hydrophilic polymer in the hydrophilic polymer solution is cured from the surface of the bead to form a wall having a predetermined thickness as the coagulant is diffused from the bead to the hydrophilic polymer solution surrounding the bead by the dropping step,
Wherein the functional material is at least one of a metal reducing agent, a metal extracting agent, and a chelating compound,
Wherein the coagulant is sodium polyphosphate, calcium chloride, or caustic soda aqueous solution,
Wherein the high viscosity material has a viscosity ranging from 2 to 10,000 mPa · s,
The hydrophilic polymer solution may be added to a hydrophilic solvent such as chitosan, alginate, dextran, oxidized dextran, heparan, heparin, hyaluronic acid, agarose carrageenan, amylopectin, amylose, glycogen, starch, chitin, heparan sulfate, chondroitin sulfate, dextran sulfate, dextran sulfate, Wherein the hydrophilic polymer is selected from the group consisting of dermatan sulfate, keratan sulfate, pectins, and xanthan gum. The method of claim 1, wherein the method further comprises adding the capsules formed in the loading step to a coagulant, wherein the coagulant is sodium polyphosphate, calcium chloride, or a caustic soda aqueous solution. Gt; delete The method of claim 1, wherein the metal reducing agent is selected from the group consisting of natural antioxidants such as tocopherols, flavone derivatives, phyllozurcin, gallic acid, catechin, nordihydroguaiaretic acid, glutaric acid, It is also possible to use a catalyst such as aldehyde, sodium borohydride (NaBH ₄ ), hydrazine (N ₂ H ₄ ), borohydride, dimethylamine borane, [(CH ₃ ) ₂ NH.HBH ₃ ], sodium dithionite [Na ₂ S ₂ O ₄ ], ascorbic acid [C ₆ H ₈ O ₆ ], ethylene glycol, sodium alkoxide, hydroquinone (C ₆ H ₆ O ₂ )), sodium oxalate (Na ₂ C ₂ H ₂ O ₄ ), formic acid, dimethylamine borane, and Tris (2-carboxyethyl) phosphine ≪ RTI ID = 0.0 > 1, < / RTI > The method of claim 1, wherein the chelating compound is selected from the group consisting of melamine, L-cystein, phosphatidylcholone, alumin, polyphosphate, aminocarboxylic acid. 1,3-diketone, a hydroxycarboxylic acid, a polyamine, and an amino alcohol. The method of claim 1, wherein the metal extractant is selected from the group consisting of triisobutylphosphine sulfide, trialkylphosphine oxide, trioctylamine, methyl isobutyl ketone, Trioctylmethylammonium chloride, dibutyl sulfoxide, tris-iso-octylamine, phosphonic acid di (2-ethylhexyl) ester, tributyl phosphate, Alkyl sulfides, phosphine sulfides, hydroxyoximes, secondary amines, tertiary amines, ammonium salts, tri-n-butyl And at least one selected from the group consisting of tri-n-butyl phosphate, quinoline derivative, trialkylmethylamine, n-dodecylalkylmethylamine, trioctylamine, and ethylenediamine acetic acid . ≪ / RTI > delete The method of claim 1, wherein the functional material is granulated by the high viscosity material. The method of claim 1, wherein the high viscosity material is selected from the group consisting of Carboxymethyl Cellulose, Hydroxyethyl Cellulose, Xanthan Gum, Hycel, Carbomer, Gelatin Pectin, Guargum, Sodium Alginate, Calcium Glycerophosphate, Carrageenan, Tragacanth gum, Propylene Glycol, Wherein the capsule is any one selected from the group consisting of alginate, methylethylcellulose, potassium alginate, and calcium carboxymethylcellulose. delete A capsule produced according to any one of claims 1, 2, 4, 6, 8, and 9. The capsule according to claim 11, wherein the capsule comprises a functional material selected from the group consisting of melamine, L-cystein, phosphatidylcholine, dibutyl sulfoxide, triphenylphosphine, 2- hydroxyl-5-nonylacetophenone oxime, and trialkylphosphine oxide, and has a selective adsorption ability to palladium. The capsule according to claim 11, wherein the capsule has a selective adsorption ability to gold, including alamine or methyl isobutyl ketone as a functional substance.

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