JP2018127709A - Method for preventing the leakage of water and/or mineral material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing the leakage of water and/or mineral material from a storage facility.SOLUTION: The present invention provides a method for preventing the leakage of water and/or mineral material, wherein, a mixture material containing a wet mineral material and a superabsorbent resin and/or water-soluble polymer compound is stored in a storage facility, and the leakage of water and/or mineral material from the storage facility is prevented.SELECTED DRAWING: None

Description

  The present invention relates to a method for preventing leakage of water and / or mineral raw materials, and in particular, in a storage facility for temporarily storing mineral raw materials transported from an outdoor raw material yard, water and / or mineral raw materials contained in the mineral raw materials. However, it is related with the leak prevention method for preventing leaking outside the storage equipment.

  In thermal power plants, steelworks, etc., mineral raw materials for 30 to 60 days are usually stocked in a raw material yard as stock. Since the mineral raw material in the raw material yard is impregnated with water or rainwater sprayed as a measure against dust, the mineral raw material carried out from the raw material yard tends to have a high water content.

The mineral raw material carried out from the raw material yard is temporarily stored in a storage facility and then supplied to various facilities such as a boiler and a coke oven. The mineral raw material is transferred from the raw material yard to each facility by transferring the belt conveyor.
In the raw material yard, when the water content of the mineral raw material is greatly increased to become a mud-like fluid (hereinafter referred to as slurry), it becomes difficult to convey it on the belt conveyor. In response to this problem, the present inventor has proposed a conveying method in which the polymer absorbent is brought into contact with the slurry to improve handling as a solidified body (see Patent Document 1).

  On the other hand, when the moisture content of the mineral raw material rises and becomes wet until it becomes slurry, the moisture contained in the mineral raw material moves to the lower part of the storage facility during storage in the storage facility, A phenomenon in which the water content of the lower mineral raw material is further increased is observed. Thus, if the moisture content of the mineral raw material further increases in the lower part of the storage facility during the storage, it is not preferable because the mineral raw material being stored easily leaks from the storage facility due to a decrease in frictional force.

  In addition, when water contained in the mineral raw material is accumulated in the lower part of the storage facility, the water may fall on the belt conveyor disposed below the storage facility to form a water reservoir in the central portion of the belt conveyor. If the mineral raw material in the storage facility is discharged onto the water pool during the transfer of the mineral raw material, the mineral raw material cannot be slid and transported with water, and the mineral raw material staying there is moved downward from the side of the belt conveyor. There was a risk of falling and damaging the return surface of the belt conveyor.

JP2013-256710A

  The present invention solves the above-described problem and prevents the mineral raw material being stored in the storage facility from leaking out of the storage facility, and / or water leaks from the storage facility while storing the mineral raw material in the storage facility. It is an object of the present invention to provide a method for preventing this.

  When the wet mineral raw material is stored in the storage facility, the present inventors suppress leakage of the mineral raw material and water from the storage facility by bringing the superabsorbent resin and / or the water-soluble polymer compound into contact with each other. I found out that I can do it. The present invention is based on this finding.

That is, the present invention provides the following [1] to [7].
[1] A raw material mixture containing a wet mineral raw material and a superabsorbent resin and / or a water-soluble polymer compound is stored in a storage facility to prevent leakage of water from the storage facility and / or leakage of a mineral raw material. Water leakage and / or mineral raw material leakage prevention method.
[2] The water and / or mineral raw material leakage prevention method according to [1], wherein the storage facility is at least one of a compounding tank, a hopper, a silo, and a bunker.
[3] The water according to the above [1] or [2], including a step of adding and mixing the superabsorbent resin and / or the water-soluble polymer compound with the mineral raw material before being stored in the storage facility. / Or prevention method of leakage of mineral raw materials.
[4] In the above [1] or [2], the method includes a step of charging the superabsorbent resin and / or water-soluble polymer compound and the mineral raw material into the storage facility alternately and in layers. The water and / or mineral raw material leakage prevention method described.
[5] The above [1] or [2], which includes a step of adding the superabsorbent resin and / or water-soluble polymer compound to the storage facility, and a step of adding the mineral raw material. To prevent leakage of water and / or mineral raw materials.
[6] The method for preventing leakage of water and / or mineral raw material according to any one of [1] to [5] above, wherein the superabsorbent resin is sodium polyacrylate.
[7] The method for preventing leakage of water and / or mineral raw materials according to any one of [1] to [5] above, wherein the water-soluble polymer compound is an acrylamide / ammonium acrylate copolymer.

  According to the present invention, the phenomenon that moisture contained in the mineral raw material moves to the lower part of the storage facility during storage in the storage facility is suppressed, and leakage of water from the storage facility and / or leakage of the mineral raw material can be easily performed. Can be prevented.

Hereinafter, the leakage prevention method of the present invention will be described.
In the present invention, “leakage prevention” is used to mean not only a case where no leakage occurs, but also a case where some leakage occurs.

  The method for preventing leakage of water and / or leakage of mineral raw material according to the present invention includes storing a raw material mixture containing a wet mineral raw material and a superabsorbent resin and / or a water-soluble polymer compound in the storage facility. This suppresses the phenomenon that moisture contained in the mineral raw material moves to the lower part of the storage facility during storage in the water, and prevents leakage of water and / or leakage of the mineral raw material from the storage facility.

  When the wet mineral raw material comes into contact with the highly water-absorbing resin and / or the water-soluble polymer compound, the highly water-absorbing resin and / or the water-soluble polymer compound absorbs moisture in the mineral material. Thereby, it is possible to prevent leakage of water and / or leakage of mineral raw material that has occurred in the past when the wet mineral raw material is stored in the storage facility.

(Mineral raw materials)
The kind of mineral raw material is not particularly limited, and examples thereof include iron ore, sintered ore, coal, dust, coke, and limestone. These may be one kind alone or a mixture of two or more kinds.
Further, the shape, size, etc. of the mineral raw material are not particularly limited, but one of the objects of the present invention is to prevent the leakage of the mineral raw material in the storage facility. For example, it is suitably applied to mineral raw materials such as granular or powdery particles having a particle diameter of 2 mm or less.

The “wet mineral raw material” referred to in the present invention is a mineral raw material which is not in a slurry state but contains water and can be conveyed as a solid matter by a belt conveyor. That is, it is distinguished from a slurry which is a muddy or liquid fluid with much moisture, which is difficult to convey with a belt conveyor. The moisture content of the mineral raw material in a wet state varies depending on the type and properties of the mineral raw material and cannot be determined generally. For example, in the case of coal, the moisture content is about 1 to 30% by mass. It can be said that it is a state, and when it exceeds about 30 mass%, it can be said that it is a slurry state.
The moisture content in the mineral raw material is not particularly limited, it may be derived from the raw material itself, or it may be water such as rain water or water spray to prevent dust contacted during transportation or storage. Good.

(High water absorption resin)
The highly water-absorbent resin is defined by JIS K7223 (1996) and JIS K7224 (1996). “It is a resin that highly absorbs water and swells, and absorbs water by contact with water with a hydrophilic substance having a crosslinked structure. And once it absorbs water, it has the characteristic that it is difficult to remove water even when pressure is applied. That is, the resin has a large amount of water absorption and excellent water retention.
The type of the superabsorbent resin may be either a synthetic resin type or a natural product-derived type, and is not particularly limited. For example, poly (meth) acrylic acid, poly (meth) acrylate, poly (meta) ) Acrylic acid ester, poly (meth) acrylamide, polyalkyleneimine, polyoxyalkylene, polymaleic acid, and copolymers containing any of the monomers constituting these. In the present invention, “(meth) acryl” means acryl or methacryl.

Examples of the monomer constituting the poly (meth) acrylate include sodium (meth) acrylate, potassium (meth) acrylate, ammonium (meth) acrylate, and the like.
Examples of monomers constituting the poly (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) Isobutyl acrylate, hydroxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like.
Examples of the monomer constituting the polyalkyleneimine include ethyleneimine and methylethyleneimine.
Examples of the monomer constituting polyoxyalkylene include ethylene oxide and propylene oxide.
Examples of other monomers constituting the copolymer include vinyl sulfonic acid, styrene sulfonic acid, (meth) acrylamide, N-ethyl (meth) acrylamide, and vinyl pyridine.

A super absorbent polymer may be used individually by 1 type, and may use 2 or more types together. Polyacrylic acid or polyacrylic acid sodium salt is preferably used, and polyacrylic acid sodium salt is particularly preferred from the viewpoints of availability and high water absorption.
Further, the highly water-absorbing resin may be used in combination with other water-absorbing agents. Examples of other water absorbing agents include silica gel, zeolite, activated carbon and the like.
The properties of the superabsorbent resin are preferably in the form of particles or powder having a particle size equal to or smaller than that of the mineral raw material from the viewpoint of uniformly contacting the surface of the mineral raw material and ease of handling.

The amount of the superabsorbent resin to be brought into contact with the mineral raw material is appropriately adjusted according to the kind and properties of the mineral raw material and the superabsorbent resin. From the viewpoint of sufficiently reducing the moisture content on the surface of the mineral raw material without impairing the desired physical properties in the use of the mineral raw material, and from the viewpoint of cost and the like, for example, 0.1 parts by weight with respect to 100 parts by weight of the wet mineral raw material. It is preferable that it is 001-2 mass parts, More preferably, it is 0.01-2 mass parts, More preferably, it is 0.1-1 mass part.
By setting the amount of the highly water-absorbent resin to 0.001 part by mass or more with respect to 100 parts by mass of the mineral raw material, it is possible to sufficiently absorb the water caused by the mineral raw material.
If the amount of the superabsorbent resin becomes excessive, a large amount of ash is generated in the subsequent combustion process, which is not preferable from the viewpoint of environment and economy, but the amount of superabsorbent resin is 2 parts by mass or less with respect to 100 parts by mass of the mineral raw material. By doing so, the amount of ash in the combustion process can be suppressed.

(Water-soluble polymer compound)
The water-soluble polymer compound also has a characteristic that it has a large water absorption amount and excellent water retention, like the above-described highly water-absorbent resin. In the present invention, “water-soluble” means that 0.01 g or more is dissolved in 100 g of water at 25 ° C.
The water-soluble polymer compound may be an artificially produced synthetic polymer compound or a naturally-occurring natural polymer compound, such as a synthetic water-soluble polymer compound, a semi-synthetic water-soluble polymer compound, and a natural water-soluble polymer compound. Examples thereof include molecular compounds.

  Synthetic water-soluble polymer compounds include polyvinyl alcohol, polyvinyl pyrrolidone or salts thereof, polyethylene oxide, polyvinyl methyl ether; (meth) acrylic acid, (meth) acrylamide, maleic anhydride, maleic acid, maleic amide, maleic imide , Copolymers of itaconic acid, crotonic acid, fumaric acid, etc., or salts thereof. Examples of the salt include alkali metal salts such as sodium and potassium.

  Semisynthetic water-soluble polymer compounds include cellulose derivatives such as viscose, methylcellulose, cationized cellulose, ethylcellulose, carboxymethylcellulose, hydroxypropylcellulose; pregelatinized starch, carboxyl starch, dialdehyde starch, cationized starch, dextrin, British Examples include starch derivatives such as rubber; cationized guar gum, anionized guar gum, methyl glycol chitosan and the like.

  Examples of natural water-soluble polymer compounds include starch, mannan, guar gum, xanthan gum, sodium alginate, locust bean gum, pectin, dextran, gelatin, lambzan gum, gellan gum and the like.

  The water-soluble polymer compound may be any of anionic, cationic, nonionic, and amphoteric. Of these, anionic and nonionic, which are less toxic to fish, are preferred, and anionic is more preferred.

The water-soluble polymer compound is preferably a synthetic water-soluble polymer compound. As the synthetic water-soluble polymer compound, a homopolymer or a copolymer having one or more of an anionic monomer and a nonionic monomer as a constituent component is preferable. Examples of the anionic group (anionic monomer) include carboxylic acids (monomers) such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid; styrene sulfonic acid, vinyl sulfonic acid, and 3-allyloxy-2- Examples thereof include sulfonic acids (monomers) such as hydroxypropane sulfonic acid. Examples of nonionic groups (nonionic monomers) include acrylamide (monomer) and methacrylamide (monomer). As the synthetic water-soluble polymer compound, acrylic acid-based and / or acrylamide-based polymers are more preferable. Examples of acrylic acid-based and / or acrylamide-based polymers include acrylic acid homopolymers, acrylamide homopolymers, acrylic acid / acrylamide copolymers, polyacrylamide partial hydrolysates, acrylic acid / acrylamide / 2-acrylamide- Examples thereof include 2-methylpropanesulfonic acid, acrylic acid / maleic acid copolymer or a salt thereof, and these may be used alone or in combination of two or more. Among these, acrylic acid / acrylamide copolymer, acrylamide homopolymer, and polyacrylamide partial hydrolyzate all have high molecular weight and are preferably used for the application of the present invention.
The average molecular weight of the acrylamide-based or acrylic acid-based polymer is preferably 1,000,000 to 10,000,000, more preferably 5,000,000 to 9,000,000 (inherent viscosity method). Is preferred.
In the case of an anionic polymer, the content of acrylic acid units in producing the acrylic acid-based and / or acrylamide-based polymer is based on the total amount (100 mol%) of the monomers used. Preferably it is 5 mol% or more, more preferably 20-100 mol%.
The state when the water-soluble polymer compound is used is not particularly limited, and it is preferable to use the water-soluble polymer compound in the form of powder, liquid or emulsion. In particular, it is preferable to use in the form of powder and emulsion that can be used without increasing the water to be treated. The water-soluble polymer compound in the form of a W / O emulsion can be produced by a known method (for example, Japanese Patent Publication No. 52-039417 and Japanese Patent Publication No. 51-41090).

  A water-soluble high molecular compound may be used individually by 1 type, and may use 2 or more types together. The acrylic acid / acrylamide copolymer, acrylamide homopolymer, and polyacrylamide partial hydrolyzate all have a high molecular weight and are preferably used in the application of the present invention.

(Storage facility)
The storage equipment referred to in the present invention means equipment for transferring raw materials to other equipment and equipment for storing raw materials. For example, a mixing tank, a hopper, a silo, a bunker and the like can be mentioned.
When wet mineral raw materials are stored in these storage facilities, the moisture contained in the mineral raw materials moves to the lower part of the storage facilities during storage. As a result, moisture leaked from the storage facility, or the moisture content of the lower mineral raw material increased, and the mineral raw material being stored easily leaked from the storage facility.
On the other hand, according to the present invention, the phenomenon that the moisture contained in the mineral raw material moves to the lower part of the storage facility during storage in the storage facility is suppressed, the leakage of water from the storage facility and / or the mineral raw material Can be easily prevented.

(Raw material mixture)
The raw material mixture is a mixture of a wet mineral raw material and a superabsorbent resin and / or a water-soluble polymer compound.
When the superabsorbent resin and / or the water-soluble polymer compound comes into contact with the wet mineral raw material, at least a part of the moisture content in the mineral raw material is absorbed by the superabsorbent resin, and the moisture content on the surface of the mineral raw material is reduced. It reduces and the phenomenon in which the water | moisture content contained in a mineral raw material moves to the lower part of storage equipment during storage is suppressed. Note that it is only necessary to suppress the adhesion to the contact surface of the transfer facility, and it is not necessary that the total amount of water content in the mineral raw material is absorbed by the superabsorbent resin and / or the water-soluble polymer compound.

  The method for obtaining the raw material mixture is not particularly limited, but the raw material mixture in a state where the wet mineral raw material and the superabsorbent resin and / or water-soluble polymer compound are uniformly mixed and in contact with each other. Is preferably obtained.

  For example, a method of adding a superabsorbent resin and / or a water-soluble polymer compound to a mineral raw material and stirring and mixing it before the mineral raw material is put into the storage facility; A method of adding water-soluble polymer compounds, a method of adding a superabsorbent resin and / or a water-soluble polymer compound with some mineral raw material remaining in the storage facility, and a mineral raw material entering the storage facility at the same time Examples thereof include a method of adding a highly water-absorbing resin and / or a water-soluble polymer compound, and a method of alternately adding a mineral raw material and a highly water-absorbing resin and / or a water-soluble polymer compound.

  Although the effect of the present invention can be exhibited only by adding the superabsorbent resin and / or water-soluble polymer compound without mixing with the mineral raw material, the superabsorbent resin and / or the water-soluble polymer compound is When added to the mineral raw material and then stirred and mixed, an overall uniform raw material mixture is obtained in which the superabsorbent resin and / or the water-soluble polymer compound are uniformly attached to the surface of the mineral raw material.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following Example.

[Leakage test]
Example 1
For 1000 g of wet coal (water content 26 mass%, particle size 2 mm or less), 0.01% by mass of “Kuriline S-200” (manufactured by Kurita Kogyo Co., Ltd .; sodium polyacrylate) as a highly water-absorbent resin. The mixture was added and stirred and mixed uniformly to prepare a raw material mixture sample. The superabsorbent resin was added by a method of adding the superabsorbent resin to the coal using a powder spraying device (BRES, Breslide 40). Using a vibration test apparatus in which a simulated hopper (input port: 200 mm × 200 mm, discharge port: 30 mm × 50 mm, inverted square frustum-shaped outer shape; made of steel) is attached to the upper part of the product) A leakage test of the raw material mixture sample was performed.
In the leak test, put the prepared raw material mixture sample into the simulated hopper of the vibration test device, let it stand for 15 minutes, and measure the amount of water dripping from the lower part of the hopper (leakage amount) within the standing time. It went by.
In addition, the moisture content of coal measured the mass (A) about about 20 g of coal, measured the mass (B) after drying this with a 105 degreeC dryer for 2 hours, and reduced the weight (A -B) was regarded as the water content and calculated from the following formula.
Moisture content [%] = (A−B) / A × 100

(Examples 2-3)
The additive concentration of the superabsorbent resin was changed as shown in Table 1 below, and the discharging time of the raw material mixture sample was measured in the same manner as in Example 1 except that.

Example 4
The superabsorbent resin was changed to a water-soluble polymer compound (acrylamide / ammonium acrylate copolymer (molecular weight: 8 million (in terms of intrinsic viscosity), ammonium acrylate monomer: 35 mol%)). In the same manner as described above, the discharge time of the raw material mixture sample was measured.

(Example 5)
1000 g of wet coal (moisture content 26 mass%, particle size 2 mm or less) was divided into 5 parts, and the raw material mixture sample was prepared by charging the vibration test apparatus hopper with layers of coal, chemicals, coal, chemicals in this order. Other than that was carried out similarly to Example 3, and measured the discharge time of the raw material mixture sample.

(Example 6)
After the superabsorbent resin was put into the vibration test apparatus hopper, 1000 g of wet coal (water content 26 mass%, particle size 2 mm or less) was added to prepare a raw material mixture sample. Other than that was carried out similarly to Example 3, and measured the discharge time of the raw material mixture sample.

(Comparative Example 1)
In Example 1, the amount of water dripped from the hopper was measured in the same manner as in Example 1 except that neither the superabsorbent resin nor the water-soluble polymer compound was added.

(Comparative Example 2)
The superabsorbent resin was changed to silica gel, and the discharge time of the raw material mixture sample was measured in the same manner as in Example 3 except that.

(Comparative Example 3)
The superabsorbent resin was changed to sodium alkanesulfonate, and the discharge time of the raw material mixture sample was measured in the same manner as in Example 3 except that.

  Table 1 summarizes the results of evaluating the amount of water leakage (water leakage) in each of the above Examples and Comparative Examples.

  As can be seen from the results shown in Table 1, water leakage from the vibration test apparatus hopper is eliminated by adding sodium polyacrylate or acrylamide / ammonium acrylate copolymer to wet coal (Example 2). 4, 5-6) or 30% or less compared to the blank (Example 1) was confirmed.

Claims (7)

  A raw material mixture containing a wet mineral raw material and a superabsorbent resin and / or a water-soluble polymer compound is stored in a storage facility, and water and / or a mineral raw material are prevented from leaking from the storage facility. / Or prevention method of leakage of mineral raw materials.   The water and / or mineral raw material leakage prevention method according to claim 1, wherein the storage facility is at least one of a compounding tank, a hopper, a silo, and a bunker.   The leakage of water and / or mineral raw material according to claim 1 or 2, comprising a step of adding and mixing the superabsorbent resin and / or water-soluble polymer compound with the mineral raw material before being stored in the storage facility. Prevention method.   The water and / or according to claim 1 or 2, comprising a step of charging the superabsorbent resin and / or water-soluble polymer compound and the mineral raw material alternately and in layers into the storage facility. How to prevent leakage of mineral raw materials.   The water and / or mineral according to claim 1, comprising a step of adding the superabsorbent resin and / or water-soluble polymer compound to the storage facility, and a step of adding the mineral raw material. Raw material leakage prevention method.   The method for preventing leakage of water and / or mineral raw materials according to any one of claims 1 to 5, wherein the superabsorbent resin is polyacrylic acid sodium salt.   The method for preventing leakage of water and / or mineral raw material according to any one of claims 1 to 5, wherein the water-soluble polymer compound is an acrylamide / ammonium acrylate copolymer.