JPH05179149A - Water absorbent and method for decreasing water content of powdered or particulate material - Google Patents

Abstract

PURPOSE:To prepare a water absorbent which is not broken into pieces even when used repeatedly and decreases effectively the water content of a powdered or particulate material contg. water by combining a highly water-absorbing resin, a magnetic material, and a rubberlike polymer. CONSTITUTION:A highly water-absorbing resin (e.g. a hydrolysis product of a starch-acrylonitrile copolymer), a magnetic material (e.g. Fe-Ni or Fe3O4), and a rubberlike polymer (e.g. a polybutadiene rubber) are combined to give a water absorbent, which is used to effectively decrease the water content of a powdered or particulate material contg. water without being broken into pieces even when used repeatedly. When added to coal for coke, the absorbent not only decreases the water content of the coal but also increases the packing density in a coke oven and thus improves the quality of the resulting coke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-absorbing agent and a method for reducing the water content of a granular material containing water using the water-absorbing agent.

[0002]

2. Description of the Related Art Conventionally, the water content in a powder or granular material such as coke raw coal is reduced by a method of heating and drying a large amount of raw coal using an indirect heating type dryer (JP-A-58-58).
5389, JP-A-58-37082, JP-A-58
-37083 gazette etc.). In this case, a huge amount of heat and a huge drying facility are required, and the water content in the coking coal is 5
When it was less than%, dust was generated and problems such as deterioration of working environment occurred. On the other hand, in order to reduce the water content of the raw coal without heating and drying, the raw coal and water-absorbent resin are mixed, the water is absorbed by the water-absorbent resin, and then the water-absorbent resin is collected, dried and reused. Is used (Japanese Patent Laid-Open No. 61-
151,294). In this method, the water-absorbent resin is filled as it is or, if necessary, in a container such as a sintered iron ball and mixed with the raw coal, and then separated and recovered by sieving or using a magnet. However, when the water-absorbent resin and the raw coal are directly mixed, the water-absorbent resin is subdivided during the mixing, which causes a problem such as difficulty in separation by sieving, and also in a suitable container. When the resin is filled and mixed with the raw coal, the ratio of direct contact between the resin and the raw coal is small, so that problems such as inefficient water absorption occur.

[0003]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above problems, the present inventors have found that by combining a highly water-absorbent resin, a magnetic substance and a rubber-like polymer, The inventors have found that even if the operations such as mixing are repeated, they can be reused efficiently without fragmentation, and the present invention has been completed.

[0004]

Thus, according to the present invention, there is provided (1) a water-absorbing agent comprising a highly water-absorbent resin, a magnetic substance and a rubber-like polymer. Further, according to the present invention,
(2) A feature that a water absorbing agent composed of a highly water-absorbent resin, a magnetic substance and a rubber-like polymer is brought into contact with a powdery particle containing water, and then the water absorbing agent is separated from the powdery particle using magnetic force. And a method for reducing water content of a powder or granular material containing water.

The superabsorbent resin used in the present invention is an organic polymer compound which forms a hydrogel, and is a water-insoluble resin having a polymer network which is physically or chemically three-dimensionally crosslinked. is there. Water is adsorbed in the polymer network of this resin to form a hydrogel. The water-absorbing capacity of the superabsorbent resin is not particularly limited as long as it can absorb 5 to 1000 times its own weight of distilled water, but examples thereof include a water-soluble polymer compound that is physically or chemically Examples thereof include a compound having a crosslinked structure introduced therein, or a compound obtained by crosslinking a water-insoluble polymer compound and then imparting a hydrophilic portion by hydrolysis.

As the water-soluble polymer compound capable of introducing cross-linking, those synthesized by a known method can be used and are not particularly limited. For example, starch-acrylonitrile copolymer hydrolyzate and polyacrylonitrile hydrolyzate. Substance, polyethylene oxide, vinyl acetate-acrylic acid salt copolymer hydrolyzate, vinyl acetate-acrylic acid ester copolymer hydrolyzate, vinyl alcohol-acrylic acid salt copolymer, polyacrylic acid salt, or olefin-anhydrous Examples thereof include maleic acid copolymer hydrolyzate. These water-soluble polymer compounds can be made into a highly water-absorbent resin by cross-linking by a suitable method.

As a method of introducing a crosslink into a water-soluble polymer compound, a method of introducing a polar group into the polymer compound to cause a hydrogen bond in the molecule or between the molecules; polyfunctional at the time of synthesizing the polymer compound Examples thereof include a method using a cross-linking agent; a method by a reaction between functional groups contained in the polymer compound; a method of crosslinking by radiation; or a method of introducing a hydrophobic group or a crystal structure into the polymer compound.

The magnetic material used in the present invention is not particularly limited as long as it is a powder of a substance having magnetism. For example, pure iron powder, Fe-Ni, Fe-Si, Fe.
-Al, powder of iron alloy such as Fe-Co, or α-
Examples include powders of oxide magnetic materials such as Fe ₂ O ₃ and Fe ₃ 0 ₄ , and a ferromagnetic substance is preferable to a weak magnetic substance.

The rubber-like polymer used in the present invention is in a rubber state at room temperature and has a number average molecular weight of 1
The polymer is not particularly limited as long as it is a polymer of 0000 or more, but examples thereof include a conjugated diene polymer and a rubbery polymer of an unsaturated carboxylic acid and an unsaturated carboxylic acid ester. Specific examples of the conjugated diene polymer include polybutadiene rubber, polyisoprene rubber, polychloroprene rubber, poly (2,3-dimethylbutadiene), poly (1,3-pentadiene), acrylonitrile-butadiene rubber, and styrene. -Butadiene rubber, styrene-isoprene rubber,
Poly (α-methylstyrene / butadiene) rubbery copolymer and the like; Examples of the rubbery polymer of unsaturated carboxylic acid and unsaturated carboxylic acid ester include acrylic rubber and the like. Furthermore, examples of other rubber-like polymers include silicone rubber and epichlorohydrin rubber. Also,
It is also possible to use thermoplastic elastomers such as styrene-butadiene block copolymer rubber and styrene-isoprene block copolymer rubber, and also natural rubber.

Among the rubber-like polymers, the rubber-like polymers having a glass transition temperature of -20 ° C. or lower are preferable and can form a good mixture with the super absorbent polymer and the magnetic substance.
Further, in the case of a block copolymer having two or more glass transition temperatures, it is preferable that at least one of them has a glass transition temperature of -20 ° C or lower.

The amount of the rubber-like polymer used in the present invention is not particularly limited, but usually it is a super absorbent resin 10.
Rubber-like polymer is 0.1 parts by weight or more to 0 parts by weight 25
It is used in the range of not more than 1 part by weight, preferably 1 to 10 parts by weight.

The water absorbing agent of the present invention produces a hydrogel comprising a magnetic substance, a rubber-like polymer and a superabsorbent resin, and water,
Then, the hydrogel can be produced by drying. The method for producing a water-containing gel is a method of adsorbing an appropriate amount of water to the polymer network of the super absorbent polymer, and then mixing the magnetic substance and the rubber-like polymer; the super absorbent resin, water, the magnetic substance and the rubber. A polymer and a polymer in a batch; or a magnetic substance and a rubber polymer are added to an aqueous solution of a water-soluble polymer compound and mixed, and then the water-soluble polymer compound is crosslinked by an appropriate method. A method of mixing a polymerizable monomer with a magnetic substance and a rubber-like polymer, then polymerizing the monomer to synthesize a water-soluble polymer compound, and then crosslinking the water-soluble polymer compound Etc. In addition, in these production methods, when the rubber-like polymer is used in the state of a rubber-based latex, a water-absorbing agent having a particularly good mixed state with the highly water-absorbent resin and the magnetic substance can be obtained.

The hydrogel containing the magnetic substance and the rubber-like polymer is appropriately dried to reduce or remove water in the hydrogel. As a method for reducing or removing water in the hydrogel, the water is evaporated in a temperature range in which the hydrogel is not decomposed, preferably at 100 ° C to 180 ° C for at least 30 minutes using a dryer or the like. Although the method is mentioned, it is also possible to dry by other methods.

The water-absorbing agent of the present invention is crushed if necessary,
Adjust to an appropriate size before use. The size of the water absorbent is
The size is not particularly limited as long as the powder and the water absorbing agent can sufficiently contact with each other, but the particle size is usually 0.5 to 5 mm, preferably 1 to 3 mm. If the particle size of the water absorbing agent is too small, it becomes impossible to contain a sufficient amount of the magnetic substance, and it becomes impossible to magnetically separate the water absorbing agent that has adsorbed water from the granular material. On the other hand, if it is too large, the contact efficiency between the powder and the water-absorbing agent decreases, which is not preferable.

The amount of the magnetic substance used in the water-absorbing agent of the present invention is not particularly limited as long as it can magnetically separate the water-absorbing agent that has adsorbed water from the granular material, but usually the water-absorbing agent is used. The magnetic substance is contained in an amount of 5 parts by weight or more and 1000 parts by weight or less, preferably 50 to 600 parts by weight, based on 100 parts by weight of the highly water-absorbent resin. When the amount of the magnetic substance used is less than 5 parts by weight, it becomes difficult to separate the water-absorbing agent having adsorbed water from the granular material by the magnet.
If the amount exceeds 1,000 parts by weight, the amount of the magnetic material that falls off increases, which is not preferable.

In the method of reducing the water content of a powder or granular material using the water absorbing agent of the present invention, first, the powder or granular material and the water absorbing agent are mixed and brought into contact with each other for a time sufficient for the water to be absorbed by the water absorbing agent. The contact time is not particularly limited, but is usually 3 minutes or more and 4 hours or less, preferably 30 minutes to 2 hours. The water absorbent is then separated from the granules using magnetism. The separated and collected water-absorbing agent can be used repeatedly by removing water using a heating dryer or the like.

The amount of the water-absorbing agent to be brought into contact with the granular material is not particularly limited as long as the amount of the super absorbent resin in the water-absorbing agent is at least an amount capable of sufficiently adsorbing the moisture in the granular material. Highly water-absorbent resin in water-absorbent agent 0.0 to 100 parts by weight of granules
05 parts by weight or more and 25 parts by weight or less, preferably 1
10 to 10 parts by weight.

The magnetism used in the present invention is determined by the amount of powder and granules,
Although it is arbitrarily selected depending on the shape, etc., normally, magnets for commonly used magnetic separators such as an electromagnetic suspension magnetic separator, a permanent magnetic suspension magnetic separator, an electromagnetic drum, an electromagnetic pulley, a magnet conveyor, and an electromagnetic round shape are used. Can be used. Using the present invention,
Examples of the granular material capable of reducing the water content include alumina, silica, crushed stone, clay, talc, cement, carbon black, activated sludge, coal, and wood chips, and the magnetic granular particles. Although not applicable to the field of body, it can be applied to a wide range of fields such as food, chemistry, paper manufacturing, metal mining, casting, and ceramic industry.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Parts and% in the examples are by weight. The residual water content of the pulverized coal, the bulk density of the pulverized coal, the water absorbing agent recovery rate, the magnet, the magnetic substance, the superabsorbent resin, and the crosslinking agent in the examples are as follows. (Residual water content of pulverized coal) Pulverized coal in an oven at 107 ° C for 1
After drying for an hour, the ratio of the weight reduction amount at this time and the weight before drying was determined. (Bulk density of pulverized coal) It was determined by measuring the weight of 500 cc of pulverized coal at room temperature. (Recovery rate of water absorbing agent) Obtained by elemental analysis. (Magnet) Magnetic base MB-BV (manufactured by Kanetsu Kogyo Co., Ltd.) (Magnetic material) Iron powder (200 mesh transmittance 90% or more) (Super absorbent polymer) Isobutylene-maleic anhydride (1: 1) co-weigh Coalescence (Molecular weight 100,000) (Crosslinking agent) Polyethylene glycol diglycidyl ether (Molecular weight 529)

(Examples 1 to 4 and Comparative Examples 1 to 4) 100 parts of the super absorbent polymer and 1000 parts of water were mixed to form a hydrogel, and 110 parts of the magnetic material, 1 part of the rubber-like polymer and the crosslinked material were crosslinked. Add 1 part of the agent, knead, and dry for 3 hours at 107 ° C.
It was pulverized to prepare a water absorbing agent having a particle size of 1 to 3 mm. Pulverized coal containing 10 parts of this water absorbing agent and 9% of water (bulk density 0.71
200 parts of g / cc) was mixed by stirring with a mixer. After standing still for 1 hour, the water absorbing agent that adsorbed water was collected using a magnet, and the residual water content of the pulverized coal was measured. Further, the collected water absorbing agent was dried at 107 ° C. for 3 hours and then repeatedly used. In addition, as a comparative example, a water absorbing agent composed of a highly water-absorbent resin and a magnetic material was prepared by the same method, mixed with pulverized coal and then collected, and the residual water content of the pulverized coal was measured. The results are shown in Table 1.

[0021]

[Table 1]

From Table 1, the water absorbing agent of the present invention is prevented from being fragmented even if the number of times of repeated use is increased, the recovery rate of the water absorbing agent is not lowered, and the residual water content in the pulverized coal is efficient. It can be seen that it is well reduced and further improves the bulk density of pulverized coal.

[0023]

As described above, according to the present invention, a novel water-absorbing agent which can be reused efficiently without fragmentation even if it is repeatedly used is obtained, and the moisture content of the powdery granules is improved. A method is provided for reducing further,
When applied to coking coal, in addition to the effect of efficiently reducing water content, the packing density in the coke oven is improved, and the quality of coke can be further improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C10B 57/10 8018-4H

Claims (2)

[Claims] 1. A water absorbing agent comprising a highly water-absorbent resin, a magnetic substance and a rubber-like polymer. 2. A powder containing water, comprising contacting the water absorbing agent according to claim 1 with a powdery particle containing water, and then separating the water absorbing agent from the powdery particle using magnetism. Method of reducing water content in granules.