JP2022027532A - Dust scattering inhibitor for solid fuel and/or steel raw material, and dust scattering inhibiting method for solid fuel and/or steel raw material - Google Patents

Abstract

To provide a dust scattering inhibitor for hydrophobic solid fuels and/or steel raw materials and a dust scattering inhibiting method for hydrophobic solid fuels and/or steel raw materials, for inhibiting scattering of dust from hydrophobic solid fuels and/or steel raw materials.SOLUTION: There is provided a dust scattering inhibitor containing glycerin and a nonionic surfactant represented by the general formula (I), for hydrophobic solid fuels and/or steel raw materials. R1-O-(EO)m(PO)n-H (I) (In the formula, R1 represents an alkyl group having 10-14 carbons, (EO)m(PO)n is an addition product of ethylene oxide (EO) and propylene oxide (PO), m/n is from 9/1 to 1/1, and the EO and the PO may be added in a blocked or random manner).SELECTED DRAWING: None

Description

The present invention relates to a dust scattering inhibitor for solid fuel and / or steel raw materials and a method for suppressing dust scattering from solid fuel and / or steel raw materials. More specifically, the present invention relates to a dust scattering inhibitor for a hydrophobic solid fuel and / or a steel raw material and a dust scattering suppressing method for a hydrophobic solid fuel and / or a steel raw material.

Normally, in steel mills, etc., lumpy iron ore as a raw material, coal on lumps, powdery iron ore, powdery limestone, and sintered ore processed to have a particle size and strength suitable for charging into a blast furnace. , Iron mill dust discharged from blast furnaces, converters, electric furnaces, etc. are piled up, accumulated and stored.
In addition, in power plants, steel mills, mines, etc., a large amount of coal is often piled up in a coal yard (coal yard), and is deposited and stored. In addition, coke, which is a porous solid mainly composed of carbon produced by carbonizing coal at a high temperature of 1,200 ° C., is used for iron making, casting, fuel, etc. Coke is also often piled up, carbonized and stored in the coke storage area (coke yard).
Further, in biomass power plants and the like, wood chips, wood pellets, RDF (Refuse Delivered Fuel), and RPF (Refuse Paper & Plastic Fuel), which are fuels, may be piled up, accumulated, and stored.
Belts for transport lines of iron ore, limestone, sintered ore, steel mill dust, coal, coke, wood chips, wood pellets, RDF, RPF, etc. (hereinafter referred to as solid fuel and / or steel raw materials) as described above. Although a conveyor is used, there is a place where there is a difference in height at the connecting portion of the belt conveyor, and when the solid fuel and / or the steel raw material falls, the impact causes the falling dust to scatter. Measures such as sprinkling have been taken to suppress the scattering of dust from the solid fuel and / or the steel raw material, but the solid fuel and / or the steel raw material should efficiently suppress the scattering of the dust only by sprinkling water. Was difficult. In addition, it is not recommended to spray a large amount of water because water adheres to solid fuel and / or steel raw material, and it is desirable to reduce the amount of water sprayed as much as possible to suppress dust scattering. ing. Therefore, a dust scattering inhibitor has been conventionally used to suppress dust scattering.

Examples of such a dust scattering inhibitor include polyhydric alcohols such as glycerin, surfactants, and the like, as described in Patent Document 1 and Patent Document 2.

However, when the solid fuel and / or the steel raw material is hydrophobic, even if the conventional dust scattering inhibitor is used to suppress the dust, the conventional dust scattering inhibitor is the hydrophobic solid fuel and / or the steel. In some cases, it did not sufficiently penetrate into the raw material and the effect of suppressing dust scattering could not be sufficiently obtained. In addition, the hydrophobic solid fuel and / or the steel raw material, which is a mixture of the hydrophobic solid fuel and / or the steel raw material and the hydrophobic binder and processed into a property and shape suitable for the usage situation, is more hydrophobic. There is a problem that it becomes stronger and it becomes more difficult for water to penetrate. In addition, in steelworks, weakly adhesive or non-adhesive pulverized coal may be used as coking coal for coke production from an economic point of view, and tar content is added to enhance the cohesiveness. There is. The surface of coal is usually hydrophobic and water does not easily permeate, but coal containing tar becomes more hydrophobic, which causes a problem that water becomes more difficult to permeate.

Japanese Unexamined Patent Publication No. 56-067385 Japanese Patent No. 4569172

INDUSTRIAL APPLICABILITY The present invention relates to a hydrophobic solid fuel and / or a dust scattering inhibitor for a steel raw material and a hydrophobic solid fuel and / or a steel raw material for suppressing dust scattering from a hydrophobic solid fuel and / or a steel raw material. It is an object to provide a method for suppressing dust scattering.

As a result of diligent studies to solve the above problems, the present inventors have studied to suppress dust scattering of hydrophobic solid fuels and / or steel raw materials, in which dust scattering is suppressed by containing glycerin and a specific nonionic surfactant. It has been found that the use of the agent effectively improves the permeability of water into the hydrophobic solid fuel and / or the steel raw material, and has completed the present invention.
The term "hydrophobic solid fuel and / or steel raw material" as used herein refers to solid fuel and / or steel raw material (iron ore, limestone, cemented ore, steel mill dust, coal, etc.) whose grain size has been adjusted by crushing. Coke, wood chips, wood pellets, RDF, RPF, etc.) are mixed with hydrophobic components such as cement (Portorand cement, blast furnace cement), blast furnace slag fine powder, gypsum, coal tar, etc. as a binder, and then into the obtained mixture. It also includes those that have been subjected to processing such as granulation, agglomeration or molding. Examples of such hydrophobic solid fuel and / or steel raw material include lump ore obtained by mixing Portland cement with powdered iron ore, coal containing tar, and the like. However, the hydrophobic solid fuel and / or the steel raw material in the present specification is not limited to the one in which the hydrophobic component is mixed as the binder as described above.

That is, the present invention is a hydrophobic solid fuel containing glycerin and a nonionic surfactant represented by the general formula (I) and / or a dust scattering inhibitor for steel raw materials.
R ₁ -O- (EO) _m (PO) _n -H (I)
(In the formula, R ₁ represents an alkyl group having 10 to 14 carbon atoms, (EO) _m (PO) _n is an adduct of ethylene oxide (EO) and propylene oxide (PO), and m / n is 9 It is 1/1 to 1/1, and the EO and the PO may be added in a block shape or randomly.)
The scattering inhibitor has a weight ratio of glycerin to a nonionic surfactant represented by the general formula (I) (glycerin: a nonionic surfactant represented by the general formula (I)) of 50:50. It is preferably ~ 90:10.
Further, the weight of glycerin contained in the scattering inhibitor is preferably 15 to 30% by weight.

Further, in the present invention, the aqueous solution having a weight content of the dust scattering inhibitor of 0.05 to 5% by weight is 0.3 to 8% by weight with respect to the weight of the hydrophobic solid fuel and / or the steel raw material. It is also a method for suppressing dust scattering of hydrophobic solid fuel and / or steel raw material to be contacted.

According to the present invention, a hydrophobic solid fuel and / or a steel raw material dust scattering inhibitor and a hydrophobic solid fuel for suppressing dust scattering with respect to a hydrophobic solid fuel and / or a steel raw material and / Or a method for suppressing dust scattering of a steel raw material can be provided.

It is a schematic diagram when the dust evaluation (desktop test) of Test Example 2 was performed using the pulverized coal mixed with the chemicals of Examples and Comparative Examples.

The hydrophobic solid fuel of the present invention and / or the dust scattering inhibitor for steel raw materials (hereinafter, also simply referred to as “scattering inhibitor of the present invention”) is glycerin and a nonionic system represented by the general formula (I). Contains a surfactant.
R ₁ -O- (EO) _m (PO) _n -H (I)
(In the formula, R ₁ represents an alkyl group having 10 to 14 carbon atoms, (EO) _m (PO) _n is an adduct of ethylene oxide (EO) and propylene oxide (PO), and m / n is 9 It is 1/1 to 1/1, and the EO and the PO may be added in a block shape or randomly.)

The nonionic surfactant represented by the general formula (I) includes ethylene oxide (EO), propylene oxide (PO) or a mixture thereof. m and n are the average number of added moles, and m is preferably 5 to 10 and n is preferably 1 to 9 from the viewpoint of further suppressing dust of the hydrophobic solid fuel and / or steel raw material.

In the nonionic surfactant represented by the general formula (I), R ₁ may be a linear, branched or unsaturated alkyl group, and is preferably isodecyl, n-decyl or tridecylic.

The m / n in the nonionic surfactant represented by the general formula (I) may be 9/1 to 1/1, preferably 8/1 to 1/1, and 6/1. It is more preferably to 1/1.

In the present disclosure, the weight average molecular weight of the nonionic surfactant represented by the general formula (I) is preferably 1500 or less. When the weight average molecular weight exceeds 1500, the permeability of the nonionic surfactant represented by the general formula (I) decreases, and the nonionic surfactant may not be sufficiently dispersed in the scattering inhibitor of the present invention. This is because

Examples of the nonionic surfactant represented by the general formula (I) include polyoxyethylene polyoxypropylene alkyl ether and the like.
The nonionic surfactant represented by the general formula (I) is preferably a polyoxyethylene polyoxypropylene alkyl ether, and the polyoxyethylene polyoxypropylene alkyl ether has an alkyl group having 10 to 14 carbon atoms. Ethylene oxide and propylene oxide are added to the higher alcohol having, and commercially available ones can be used. Further, the higher alcohol may be a natural alcohol such as coconut oil reduced alcohol or a synthetic alcohol, and in the case of the synthetic alcohol, a cheegler alcohol, an oxo alcohol or the like can be used. The polyoxyethylene polyoxypropylene alkyl ether of the general formula (I) may be used alone, or may be used as a mixture of two or more kinds of polyoxyethylene and polyoxypropylene having different numbers of added moles.

The glycerin used in the shatter inhibitor of the present invention may be glycerin and / or diglycerin.

The scattering inhibitor of the present invention has a weight ratio of glycerin to a nonionic surfactant represented by the above general formula (I) (glycerin: a nonionic surfactant represented by the general formula (I)). It is preferably 50:50 to 90:10. When the content weight ratio of glycerin and the nonionic surfactant represented by the above general formula (I) is within the above range, the effect of suppressing dust scattering of the hydrophobic solid fuel and / or the steel raw material can be sufficiently obtained. This is because it can be done. The content weight ratio of glycerin to the nonionic surfactant represented by the above general formula (I) is more preferably 50:50 to 85:15.

Further, the weight of glycerin contained in the scattering inhibitor of the present invention is preferably 15 to 30% by weight. This is because when the content of glycerin is within the above range, glycerin is suitably dispersed in the scattering inhibitor, and the effect of suppressing dust scattering of the hydrophobic solid fuel and / or the steel raw material can be sufficiently obtained.

In one or more embodiments, the shatter-inhibiting agent of the present invention contains components other than glycerin and the nonionic surfactant represented by the above general formula (I) as long as the effects of the present disclosure are exhibited. However, it may or may not be included. As components other than glycerin and the nonionic surfactant represented by the general formula (I), in order to improve the handleability of glycerin and / or the nonionic surfactant represented by the general formula (I). Examples include the solvent used. Specific examples thereof include water and solvents such as hydrophilic organic solvents and alcohols other than the components used in the scattering inhibitor of the present invention as long as the effects of the present invention are not impaired.

The scattering inhibitor of the present invention may contain a surfactant as a component other than the nonionic surfactant represented by the above general formula (I). The blending amount of the surfactant in the shatter inhibitor is preferably 0.01 to 20%.

The object to which the shatter suppressor of the present invention is used may be a hydrophobic solid fuel and / or a steel raw material, but a solid fuel and / or a steel raw material mixed with a hydrophobic component as a binder is preferable. The hydrophobicity of the solid fuel and / or the steel raw material containing the hydrophobic binder becomes stronger than the hydrophobicity of the solid fuel and / or the steel raw material containing no hydrophobic binder, and the effect of the scattering inhibitor of the present invention becomes more effective. This is because it can be obtained remarkably. The content of the hydrophobic binder is preferably 0.5% by weight or more, more preferably 0.5 to 15% by weight, based on the solid fuel and / or the steel raw material.
For example, when the hydrophobic solid fuel and / or the steel raw material is coal containing tar, generally, when fine granular coal is used as agglomerated coal, 3 to 15% tar is added. (Reference Patent Document 1: Japanese Patent Application Laid-Open No. 52-071504, Reference Patent Document 2: Japanese Patent Application Laid-Open No. 09-003458, Reference Patent Document 3: Japanese Patent Application Laid-Open No. 08-239669). Therefore, the target to which the shatter-inhibiting agent of the present invention is used may be coal containing 3 to 15% of tar.
Further, the object to which the shatter-inhibiting agent of the present invention is used may be a solid fuel such as petroleum coke, or may be a solid fuel such as waste of agricultural crop residues such as palm coconut shells. Petroleum coke is a residue obtained by thermally decomposing heavy oil such as asphalt in petroleum refining, is a solid containing carbon as a main component, and is used as a fuel. And, like coal, it is a substance that causes deterioration of the working environment and surrounding environment by scattering fine dust during storage and transportation. In addition, palm coconut shell (Palm Kernel Shell = PKS) is a waste of agricultural residue generated in the process of producing palm oil. PKS is used as a biomass fuel because it has a low water content and a high calorific value. PKS is a substance in which fine dust is scattered during storage and transportation, but since the surface is hydrophobic, it is difficult to suppress the scattering only with water, which may lead to deterioration of the working environment and the surrounding environment.

In the present invention, an aqueous solution having a weight content of the shatter suppressor of the present invention of 0.05 to 5% by weight is 0.3 to 8% by weight based on the weight of the hydrophobic solid fuel and / or the steel raw material. It is also a method for suppressing dust scattering of hydrophobic solid fuel and / or steel raw material to be brought into contact (hereinafter, also simply referred to as “method for suppressing scattering of the present invention”). In one or more embodiments, the shatterproof method of the present invention is a hydrophobic solid, such as a field storage yard, a storage tank, and a transport pipe, belt conveyor, etc., where hydrophobic solid fuel and / or steel raw materials are stored. It comprises contacting the shatter-inhibiting agent of the present invention at at least one place in the transportation route of the fuel and / or the steel raw material. In the shatter-suppressing method of the present invention, the shatter-suppressing agent of the present invention is preferably added to and mixed with the hydrophobic solid fuel and / or the steel raw material. In the method of the present invention, from the viewpoint of improving the permeability of the aqueous solution containing the scattering inhibitor to the hydrophobic solid fuel and / or the steel raw material, the weight content of the scattering inhibitor in the aqueous solution is 0. It is preferably 1 to 5% by weight, more preferably 0.2 to 5% by weight, and even more preferably 0.4 to 5% by weight. Further, in the method of the present invention, it is preferable that the aqueous solution containing the scattering inhibitor of the present invention is brought into contact with the weight of the hydrophobic solid fuel and / or the steel raw material in an amount of 0.3 to 5% by weight, preferably 0. It is more preferable to bring them into contact with each other in an amount of 5 to 5% by weight.

In the scattering suppression method of the present invention, glycerin contained in the dust scattering inhibitor of the hydrophobic solid fuel and / or the steel raw material of the present invention is 0. It is preferable to bring the aqueous solution into contact with the hydrophobic solid fuel and / or the steel raw material so as to be 3 mg to 750 mg / kg.
If the contact amount of glycerin with respect to 1 kg of the hydrophobic solid fuel and / or the steel raw material is less than 0.3 mg, a sufficient effect of suppressing dust scattering of the hydrophobic solid fuel and / or the steel raw material may not be obtained. On the other hand, when the contact amount of glycerin with respect to 1 kg of the hydrophobic solid fuel and / or the steel raw material exceeds 750 mg, the glycerin becomes uniform, depending on the means for contacting the hydrophobic solid fuel and / or the steel raw material with glycerin. It becomes difficult to disperse, and a sufficient dust scattering suppressing effect may not be obtained. Even if the contact can be made uniformly, the dust scattering suppressing effect corresponding to the contact amount may not be obtained.
The contact amount of glycerin with respect to 1 kg of a preferable hydrophobic solid fuel and / or steel raw material is 0.3 mg to 750 mg.
The contact amount of glycerin may be appropriately set in consideration of the situation and economic efficiency, depending on the type of the hydrophobic solid fuel and / or the steel raw material, the dust generation state from the glycerin, the dust generation amount, and the like.

In the scattering suppressing method of the present invention, the general formula (I) contained in the hydrophobic solid fuel and / or the dust scattering suppressing agent of the steel raw material of the present invention with respect to the weight of the hydrophobic solid fuel and / or the steel raw material. ) Is preferably brought into contact with the hydrophobic solid fuel and / or the steel raw material so that the nonionic surfactant is 0.05 to 500 mg / kg.
If the contact amount of the nonionic surfactant with respect to 1 kg of coal containing a tar content is less than 0.05 mg, the effect of suppressing dust scattering of a sufficiently hydrophobic solid fuel and / or a steel raw material may not be obtained. On the other hand, when the contact amount of the nonionic surfactant with respect to 1 kg of the hydrophobic solid fuel and / or the steel raw material exceeds 500 mg, the means for bringing the nonionic surfactant into contact with the hydrophobic solid fuel and / or the steel raw material. However, it may be difficult to uniformly disperse the above-mentioned nonionic surfactant, and a sufficient effect of suppressing dust scattering may not be obtained. The effect of suppressing dust scattering may not be obtained.
The contact amount of the nonionic surfactant with respect to 1 kg of a preferable hydrophobic solid fuel and / or steel raw material is 0.05 to 500 mg.
The contact amount of the nonionic surfactant should be appropriately set in consideration of the situation and economy, depending on the type of hydrophobic solid fuel and / or steel raw material, the dust generation state from the nonionic surfactant, the dust generation amount, and the like. Just do it.

In the method of the present invention, an aqueous solution containing the scattering inhibitor of the present invention containing glycerin and a nonionic surfactant represented by the above general formula (I) in a hydrophobic solid fuel and / or a steel raw material. However, the method is not particularly limited and may be appropriately selected depending on the state of the hydrophobic solid fuel and / or the steel raw material and the surrounding conditions. It is preferable to spray the aqueous solution on the hydrophobic solid fuel and / or the steel raw material in terms of obtaining a uniform dust scattering suppressing effect and workability, and the solution is sprayed or dropped so as to be uniformly sprayed. Is preferable, and spraying is particularly preferable in terms of uniform application of the above aqueous solution to a hydrophobic solid fuel and / or a steel raw material.
Further, depending on the form of the hydrophobic solid fuel and / or the steel raw material, even if the aqueous solution is applied to the hydrophobic solid fuel and / or the steel raw material, the hydrophobic solid fuel and / or is contained in the aqueous solution. The steel raw material may be immersed and passed through.

The object to which the scattering inhibitor of the present invention is used may be a hydrophobic solid fuel and / or a steel raw material as in the subject to which the scattering inhibitor of the present invention is used, and a suitable hydrophobic solid fuel and / Alternatively, the aspect of the steel raw material is the same as that of the object in which the scattering inhibitor of the present invention is used.

In the present specification, the expression of the numerical range of "X to Y" indicates a numerical range of X or more and Y or less. For example, the expression "1 to 10" is an expression indicating a numerical range of "1 or more and 10 or less".

The present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. In the following test example, Osaka city water was used as water. All "%" are "% by weight". Further, in the following Examples and Comparative Examples, the test was carried out using coal containing tar, which is a hydrophobic binder, as a hydrophobic solid fuel and / or a steel raw material, but the present invention is limited thereto. It's not something.

<Examples 1 to 7, Comparative Examples 1 to 8>
In order to suppress falling dust of coal during transportation by a belt conveyor, it is necessary to infiltrate a scattering inhibitor (hereinafter, also simply referred to as “drug”) into the coal containing tar. In addition, in the evaluation of the effect of suppressing falling dust, in addition to confirming the permeability of the chemical into coal containing tar, a test involving actual falling was conducted to evaluate the effect of suppressing dust scattering. Specifically, the permeability of the chemical to coal containing tar was confirmed by Test Example 1 below, and the falling dust of coal containing tar was evaluated by Test Example 2.

(Test Example 1: Confirmation of permeability to coal containing tar)
(Procedure of test)
1) Tar was added to the coal collected at a certain coal storage yard, dried at 105 ° C. for 24 hours, and then crushed using a hand crusher. The pulverized coal that passed through a sieve with an opening of 106 μm was prepared.
2) Add the chemicals according to Examples and Comparative Examples shown in Table 2 to a 300 ml beaker so as to have a predetermined weight percent concentration (0.2%, 0.4%, 0.8%), and tap water (Osaka City). Water) to make the total amount 300 g. The surfactant shown in Table 2 below is the surfactant shown in Table 1 below.
3) 0.5 g of the pulverized coal prepared earlier was gently floated on the water surface of each chemical aqueous solution according to this Example and Comparative Example.
4) The total amount of pulverized coal floating on the water surface of the chemical aqueous solution and the time required for the pulverized coal to settle from the water surface of the chemical aqueous solution into the chemical aqueous solution were measured and evaluated in five stages. Since the surface of coal containing tar is hydrophobic and repels water, it did not settle in the water of Blank to which no chemical was added for 24 hours.

(Evaluation criteria)
Less than 1: 1 minute 2: 1 minute or more and less than 2 minutes 3: 2 minutes or more and less than 3 minutes 4: 3 minutes or more and less than 5 minutes 5: 5 minutes or more The faster the sedimentation speed, the higher the permeability, so the evaluation standard is 1. Is most preferable. The obtained results are shown in Table 3 below.

<Test Example 2: Dust evaluation (desktop test)>
(Procedure of test)
1) 30 g of pulverized coal prepared in the test procedure 1) of Test Example 1 was weighed.
2) An aqueous solution of the chemicals according to the examples and the comparative examples (water is Osaka city water) containing the chemicals according to the examples and the comparative examples shown in Table 2 above at a concentration of 2% by weight was prepared, and the weight of the prepared pulverized coal was adjusted. On the other hand, 3% of the aqueous chemical solution according to Examples and Comparative Examples was added and mixed, and then the solution was dropped from a height of 50 cm. The pulverized coal mixed with the chemicals was dropped in a transparent cylinder as shown in FIG. 1, and the pulverized coal was dropped in the center of the cylinder.
3) The dust scattered by the fall was measured with a light scattering type digital dust meter (LD-5D type manufactured by Shibata Scientific Technology), and the relative concentration of the dust (CPM = count value per minute) was determined.
4) The dust scattering suppression rate (%) was calculated based on the following formula.
(a formula)
Dust scattering suppression rate (%) = [Relative concentration of dust generated from pulverized coal to which only water is added (CPM) -Relative concentration of dust generated from pulverized coal to which an aqueous chemical solution is added (CPM)] / Add only water Relative concentration of dust generated from pulverized coal (CPM) x 100
The obtained results are shown in Table 3 below.

From the results of Test Example 1 in Table 3 above, it was confirmed that when the chemicals according to Examples 1 to 7 were used, the aqueous chemical solution effectively permeated into the pulverized coal of coal containing tar. Further, when the chemicals according to Examples 1 to 7 are used, when the concentration of the chemical in the aqueous chemical solution is 0.4% by weight or more, the fine powder of coal containing tar content is more effectively compared with Example 1. It was confirmed that the drugs related to 7 permeate.
From the results of Test Example 2 in Table 3 above, the chemical aqueous solutions according to Examples 1 to 7 have a dust scattering suppression rate of 50% or more for coal pulverized coal containing tar, and have an excellent dust scattering suppression effect. It was confirmed that
On the other hand, from the results of Test Example 1 in Table 3 above, the aqueous chemical solution according to Comparative Example 7 showed excellent permeability similar to the aqueous chemical solution according to Examples 1 to 7, but dust scattering in Test Example 2 was observed. The suppression rate was less than 10%, and the effect of suppressing dust scattering was not shown. Since the drug according to Comparative Example 7 does not contain glycerin, it is considered that it did not show the desired dust scattering suppressing effect.

<Test Example 3: Example 2, Comparative Example 1: Dust evaluation using an actual machine>
A test was conducted around a belt conveyor that transfers coal containing tar in a coal storage yard.
(Procedure of test)
1) After preparing a diluted solution containing 0.5% of the chemicals according to Example 2 and Comparative Example 1 shown in Table 2 above, coal containing tar content (from pulverized coal of 0.3 mm or less) in the coal transportation line. Each of the obtained diluents was sprayed onto (containing various sizes such as fist size). The spray amount was 0.5% by weight with respect to the weight of the coal containing the tar content.
2) A white sheet plate was installed at the place where the dust was evaluated, and the dust accumulated in a certain period of time (5 minutes) was visually confirmed.
3) In addition, a digital dust meter (LD-5D type manufactured by Shibata Scientific Technology) was installed in the same place where the white sheet was installed, and the relative concentration (CPM) of the dust was determined.
The obtained results are shown in Table 4 below.

From the results in Table 4, even in the actual machine, when the chemical according to Example 2 is used, the dust scattering of the coal containing the tar content is clearly small, and the dust scattering of the coal containing the tar content can be remarkably suppressed. did it. On the other hand, when the agent according to Comparative Example 1 containing only glycerin was used, the scattering of dust of coal containing a tar content was not so suppressed. From this result, not only the chemicals according to Example 2, but also the chemicals according to Examples 1 to 7, which showed the same dust scattering suppressing effect as Example 2 in the tabletop test, were effectively coal containing tar. It was confirmed that the dust of the coal can be suppressed.

<Test Example 4: Confirmation of permeability to petroleum coke>
(Procedure of test)
1) Petroleum coke collected at a certain refinery was dried at 105 ° C. for 24 hours and then crushed using a hand crusher. Fine petroleum coke that passed through a sieve with an opening of 500 μm was prepared.
2) In a 300 ml beaker, the chemicals (Examples 1, 3, 5 and 6 and Comparative Examples 1, 5 and 6) according to Examples and Comparative Examples shown in Table 2 were placed in a predetermined weight percent concentration (1.0), respectively. %, 1.5%, 2.0%), and the total amount of tap water (Osaka city water) was set to 300 g. The surfactant shown in Table 2 is the surfactant shown in Table 1.
3) 0.5 g of the finely divided petroleum coke prepared earlier was gently floated on the water surface of each chemical aqueous solution according to this Example and Comparative Example.
4) The total amount of fine petroleum coke floating on the surface of the aqueous solution of the drug was measured and the time until it settled in the solution of the drug from the surface of the solution of the drug was evaluated on a 5-point scale. The evaluation criteria are the same as the evaluation criteria in Test Example 1.
The obtained results are shown in Table 5 below. Since the fine petroleum coke is derived from petroleum and its surface is hydrophobic and repels water, it did not settle in the water of Blank to which no chemical was added for 24 hours.

<Test Example 5: Dust evaluation (desktop test)>
(Procedure of test)
1) 30 g of fine petroleum coke prepared in the test procedure 1) of Test Example 4 above was weighed.
2) Examples and Comparative Examples containing the agents (Examples 1, 3, 5 and 6 and Comparative Examples 1, 5 and 6) shown in Table 2 above in a concentration of 4% by weight. Such a chemical aqueous solution (water is Osaka city water) is prepared, 5% by weight of the chemical aqueous solution according to Examples and Comparative Examples is added to the weight of the prepared fine petroleum coke, mixed, and then dropped from a height of 50 cm. rice field. The pulverized coal mixed with the chemicals was dropped in a transparent cylinder as shown in FIG. 1, and the pulverized coal was dropped in the center of the cylinder.
3) The dust scattered by the fall was measured with a light scattering type digital dust meter (LD-5D type manufactured by Shibata Scientific Technology), and the relative concentration of the dust (CPM = count value per minute) was determined.
4) The dust scattering suppression rate (%) was calculated based on the following formula.
(a formula)
Dust scattering suppression rate (%) = [Relative concentration of dust generated from pulverized coal to which only water is added (CPM) -Relative concentration of dust generated from pulverized coal to which an aqueous chemical solution is added (CPM)] / Add only water Relative concentration of dust generated from pulverized coal (CPM) x 100
The obtained results are shown in Table 5 below.

From the results of Test Example 4 in Table 5 above, it was confirmed that when the chemicals according to Examples 1, 3, 5 and 6 were used, the aqueous chemical solution effectively permeated the fine petroleum coke. Further, when the chemicals according to Examples 1, 3, 5 and 6 are used, when the concentration of the chemical in the aqueous chemical solution is 1.0% by weight or more, the fine petroleum coke is effectively compared with Examples 1, 3 It was confirmed that the drugs related to 5 and 6 penetrated.
From the results of Test Example 5 in Table 5 above, the aqueous chemical solutions according to Examples 1, 3, 5 and 6 have a dust scattering suppression rate of 50% or more for fine petroleum coke powder, and have an excellent dust scattering suppression effect. Confirmed to show.
On the other hand, from the results of Test Example 4 in Table 5 above, the aqueous chemical solutions according to Comparative Examples 1, 5 and 6 have poor permeability to fine petroleum coke, and the dust scattering suppression rate in Test Example 5 is 15% or less. It did not show the effect of suppressing dust scattering.

<Test Example 6: Dust evaluation of agricultural residue waste (PKS)>
(Procedure of test)
1) Palm kernel shell (PKS) collected at a certain power plant was dried at 105 ° C. for 24 hours and then crushed using a hand crusher. Then, a fine powder PKS was prepared by passing through a sieve having an opening of 500 μm.
2) 30 g of the obtained fine powder PKS was weighed.
3) Examples and Comparative Examples containing the agents (Examples 1, 3, 5 and 6 and Comparative Examples 1, 5 and 6) shown in Table 2 above in a concentration of 4% by weight. Such a chemical aqueous solution (water is Osaka city water) was prepared, 5% by weight of the chemical aqueous solution according to Examples and Comparative Examples was added to the weight of the prepared fine powder PKS, mixed, and then dropped from a height of 50 cm. .. The pulverized coal mixed with the chemicals was dropped in a transparent cylinder as shown in FIG. 1, and the pulverized coal was dropped in the center of the cylinder.
4) The dust scattered by the fall was measured with a light scattering type digital dust meter (LD-5D type manufactured by Shibata Scientific Technology), and the relative concentration of the dust (CPM = count value per minute) was determined.
5) The dust scattering suppression rate (%) was calculated based on the following formula.
(a formula)
Dust scattering suppression rate (%) = [Relative concentration of dust generated from pulverized coal to which only water is added (CPM) -Relative concentration of dust generated from pulverized coal to which an aqueous chemical solution is added (CPM)] / Add only water Relative concentration of dust generated from pulverized coal (CPM) x 100
The obtained results are shown in Table 6 below. Since the fine powder PKS contains a large amount of fiber, the permeability confirmation test of the aqueous chemical solution to the fine powder PKS could not be performed.

From the results of Test Example 6 in Table 6 above, the aqueous chemical solution according to Examples 1, 3, 5 and 6 has a dust scattering suppression rate of 50% or more for the fine powder PKS, and exhibits an excellent dust scattering suppression effect. It was confirmed.
On the other hand, from the results of Test Example 6 in Table 6 above, the aqueous chemical solution according to Comparative Examples 1, 5 and 6 had a dust scattering suppression rate of 20% or less with respect to the fine powder PKS, and did not show a dust scattering suppression effect.

1 Microcharcoal mixed with chemicals 2 Rohto 3 Transparent cylinder 4 Sample dish 5 Dust meter

Claims (4)

A hydrophobic solid fuel and / or a dust scattering inhibitor for steel raw materials, which contains glycerin and a nonionic surfactant represented by the general formula (I).
R ₁ -O- (EO) _m (PO) _n -H (I)
(In the formula, R ₁ represents an alkyl group having 10 to 14 carbon atoms, (EO) _m (PO) _n is an adduct of ethylene oxide (EO) and propylene oxide (PO), and m / n is 9 It is 1/1 to 1/1, and the EO and the PO may be added in a block shape or randomly.) The content weight ratio of glycerin to the nonionic surfactant represented by the general formula (I) (glycerin: the nonionic surfactant represented by the general formula (I)) is 50:50 to 90:10. The hydrophobic solid fuel and / or a steel raw material dust scattering inhibitor according to claim 1. The hydrophobic solid fuel and / or a steel raw material dust scattering inhibitor according to claim 1 or 2, wherein the content weight of glycerin in the scattering inhibitor is 15 to 30% by weight. The aqueous solution having a weight content of 0.05 to 5% by weight of the dust scattering inhibitor according to claim 1, 2 or 3 is applied to the hydrophobic solid fuel and / or the weight of the steel raw material at 0. A method for suppressing dust scattering of a hydrophobic solid fuel and / or a steel raw material to be brought into contact with 3 to 8% by weight.

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