JPH0617164B2 - Rainwater infiltration prevention method for Nozumi coal deposit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for preventing rainwater infiltration of open-field coal deposits.

Generally, in iron mills, gas mills, paper mills, etc., coal powder and lumps are often accumulated and stored in piles.

When such a deposit is left as it is for a long time, rainwater permeates into the coal deposit, whereby moisture is accumulated in the coal deposit, and heat energy is lost in the process of providing the next use such as combustion. Inconvenience occurs. By the way, 1t of coal
As a result, the amount of heat lost by increasing the water content by 1% is approximately 5,300 kcal, which is a large economic loss.

(Conventional method) In this regard, a method of forming a resin film on the surface layer by spraying an emulsion / latex of SBR (styrene-butadiene rubber), polyvinyl acetate, polyacrylic acid or the like on the above deposit has been known. Has been. Also recently
The inventors of the present invention applied SBR emulsion as a solid content on Nozumi coal deposits at a spraying amount of 8 to 500 g / m ² and then dried acrylic emulsion as a solid content of 8 to 500 / m ² Patent application was made for a method of forming a resin protective film on the surface layer of the deposit by spraying at a spray amount of.

(Japanese Patent Application No. 60-287247, filing date: December 20, 1985) (Problems of the prior art) In order to make the coal import form more stable in recent years, we have further dispersed the suppliers, Measures are taken to prepare for situations that can occur in various regions as much as possible. As a result, coal with various properties has been supplied, and highly water-repellent coal has been supplied. When this highly water-repellent coal is piled up, rainwater does not infiltrate at all, and since water still accumulates in the coal, it is necessary to take rainwater infiltration prevention measures.

However, the protective film forming agent (emulsion
Even if the latex) is sprayed on the highly water-repellent coal, the surface of the coal is inclined, so most of the protective film forming agent flows out from the coal surface, the protective film becomes thin, and its strength is also high. It was recognized that there is a problem that coal cannot be protected from rainwater for a long time because it becomes weak.

The present invention has been made in view of such problems. The inventors of the present invention have completed the present invention as a result of earnest research on this highly water-repellent coal.

(Means for Solving the Problems) Thus, according to the present invention, the general formula (I): RO- (CH ₂ CH ₂ O) _n -H ... …… ( I) (wherein R is a saturated or unsaturated alkyl group or alkylaryl group having 10 to 22 carbon atoms, and n is 5 to 5).
It is an integer of 20. ) After uniformly spraying the nonionic surfactant represented by the formula (5) at a spraying rate of 0.5 to 15 g / m ² , the SBR and / or acrylic emulsion / latex as a solid content at a spraying rate of 8 to 500 g / m ² Provided is a method for preventing rainwater permeation of a Nozomi coal deposit, which is characterized by forming a resin protective film on the surface layer of the deposit by uniformly spraying.

In this invention, high water repellency means that the water penetration rate is 0.1 ml.
/ Sec. The following properties.

In the present invention, the water permeation rate means a coal particle size of 16 to
32 mesh, water content 1%, bulk specific gravity 0.73g
When 0.5 ml of water is dropped on the surface of coal, the time taken for the water droplets to be completely absorbed inside the coal is measured, and it is defined as the ratio of the amount of water droplets to the measurement time. That is, it is a value indicating the wettability of coal to water. Coal having a low permeation rate has high water repellency, and vice versa.

According to the experiments by the inventors, the permeation rate is 0.1 ml /
Even if the emulsion / latex, which is the conventional technology, is sprayed on highly water-repellent coal of sec. or less, if the sprayed coal surface is inclined at about 45 °, the sprayed amount will be about 70%.
It was confirmed that the coal could not be protected from rainwater for a long time because more than 100% of it would flow out, the film thickness would be thin and the film strength would be weak.

Therefore, the present invention is intended for coal having a water permeation rate of 0.1 ml / sec. Or less.

Generally, water wettability and coal coal band (number of hydrogen atoms [H] per 100 carbon atoms in coal and carbon atom 1
It is known to have a correlation with the number of oxygen atoms [00] represented by a binary index of 0). [Fuel Association Magazine Vol. 65, No. 6, pp. 408-416 (1986)] The water permeation rate of the present invention also correlates with the Coal band, and is a standard for using the present invention (see Reference Example 1).

Coal having a water permeation rate of 0.1 ml / sec. Or less according to the present invention means that the coal band of normal coal is [H] <70 and [O] <8.
Included.

Corresponding to these, K-9 (Soviet Union), Guniera [GOONYELLA] (Australia) B Creek [
B.CREEK], (from the United States), quintet [QUI
Examples include coal called NTETTE] (produced in Canada).

In the present invention, the nonionic surfactant represented by the general formula (I), which is sprayed on the Nozomi coal deposit, is used to impart wettability (permeability) to the surface of the coal deposit.
This surfactant is called a so-called higher alcohol ethylene oxide adduct and an alkylphenol ethylene oxide adduct, and as the higher alcohol, natural and synthetic alcohols having 10 to 22 carbon atoms are used.

Further, as the alkylphenol, nonylphenol,
Dodecylphenol, octylphenol and octylcresol are used.

The number of moles of ethylene oxide added is 5 to 20. The number of moles of ethylene oxide added is 5
If it is below, wettability (permeability) cannot be imparted to the surface of the deposit.

When the number of added moles is 20 or more, wettability (permeability) can be imparted, but the rainwater permeation preventive effect of the protective film and / or its strength are impaired, which is not preferable.

This surfactant is 0.5-15g / m ² on Nozumi coal deposit.
Evenly distributed with the application amount of.

If the spray amount is 0.5 g / m ² or less, sufficient wettability (permeability) cannot be imparted to the surface of the deposit, and if it is 15 g / m ² or higher, wettability (permeability) can be imparted, but a protective film Is not preferable because it impairs the rainwater penetration preventing effect and / or its strength.

Since a spraying amount of 1 to 3 / m ² is usually suitable for uniformly spraying this surfactant on the Nozumi coal deposit,
It is preferably used as an 01 to 1.5% aqueous solution.

When a surfactant other than the surfactant of the present invention is used for the purpose of imparting wettability (permeability) to the surface of coal, wettability (permeability) is certainly obtained if the necessary addition amount is sprayed. However, as a side effect, the rainwater penetration preventing effect of the protective film and / or the strength thereof are significantly impaired, so that the intended purpose cannot be achieved (see Test Example 2). In this sense, the present invention is particularly selected.

In the present invention, after uniformly spraying the specific nonionic surfactant, SBR-based and / or acrylic emulsion-latex as solid content is 8 to 500 g to form a resin protective film on the surface layer of the Nozumi coal deposit. Dispersed evenly at a spray rate of / m ² .

The amount of each emulsion sprayed is 8 g / solid
When it is less than m ² , it becomes difficult to obtain a resin protective film having a large film thickness and film strength, and a good rainwater permeation prevention effect is not exhibited.

The upper limit of the amount of each emulsion sprayed is 500 g / m ^{2 in} terms of solids from the economical viewpoint, but usually 250 g / m ² or less is sufficient, and when a particularly preferred emulsion is used, the solid content is 150 g / m ² or less. The desired effect is fully achieved with.

As the SBR emulsion / latex used in the present invention, a styrene-butadiene rubber emulsion / latex having a styrene content of 60% by weight or less is particularly preferable from the viewpoint of the rainwater permeation-preventing effect, and usually has a solid content of 0.5 to 50% by weight. Is suitable. The acrylic emulsion / latex used in the present invention includes homopolymer emulsions and copolymer emulsions of acrylic acid esters and methacrylic acid esters, and vinyl acetate, styrene, acrylonitrile, acrylamide, and these monomers.
A copolymer emulsion with one or more monomers such as acrylic acid may be mentioned. However, a copolymer emulsion of acrylic ester and styrene forms a strong resin protective film and exerts a remarkable effect of preventing rainwater penetration. Particularly preferred.

Further, both of the SBR type and acrylic type emulsions, those having a glass transition point of 0 ° C. or lower are particularly preferable in view of the above effects. It is also preferable to use a wax emulsion mixed with each emulsion / latex in terms of the above effects.

In the method of the present invention, the nonionic surfactant represented by the general formula (I) is first added, and then the SBR and / or acrylic emulsion / latex is sprinkled. Even if this order is reversed or a surfactant is used simultaneously or in a mixture with each emulsion, a sufficient rainwater penetration preventing effect is not exhibited, which is not preferable.

It is practically convenient to spray the aqueous surfactant solution or emulsion / latex by using a known water sprayer, water sprayer or the like. Further, it is also one of the preferred embodiments to spray a surfactant in advance on the coal forming the surface layer portion.

The effects of the present invention will be illustrated by the following test examples and examples.

(Test Example 1) The following 6 types of coal were used to test the permeation rate of water and the effect of preventing rainwater permeation during SBR or acrylic emulsion / latex spraying.

-Type of coal- AK-9 (Soviet Union, coking coal) B Guniera (Australia, coking coal) [GOONYELLA] CB. Creek (United States, coking coal) [B.OREEK] D Quintet (Canada, coking coal) [QUINTETTE] E Optimum (South Africa, non-caking coal) [OPTIMUM] F Daillon (Australia, coking coal) ) [DUIYON] -Preparation method of test sample body-Dry each of the above coals in a constant temperature bath at 100 ° C for 16 hours, and use a sieve to make the particle size 16-32 mesh. After that, water is added to adjust the water content to 1% to obtain the test coal. Next, put the test coal in a petri dish (bottom area 63.6 cm ² , height 1.5 cm, columnar shape) with a bulk specific gravity of 0.73 g / ml, make a sample body with its surface as a flat surface, and use it as a test piece. Use as a sample body.

i) Measurement of water permeation rate <Test method> Using a pipette, 0.5 ml of water droplets was dropped on the coal surface of each test sample body, and the time until the water droplets were completely absorbed inside the coal was measured.

The permeation rate was calculated by the following formula.

ii) Measurement of rainwater permeation prevention effect The following shall be applied to the coal surface of each sample specimen tilted at approximately 45 °.
The SBR or acrylic emulsion / latex was diluted with water so that the solid content was 6 W / W%, and 120 g / m ^{2 was} sprayed as the solid content using a sprayer. At that time, the outflow rate was calculated by the following formula from the amount of each emulsion flowing out from the coal surface.

After that, test specimens with each emulsion sprayed at 48 ℃
After drying for 16 hours, the film thickness, strength and water repellency of the obtained resin protective film were measured. Good marks for all properties are marked with a circle, and other properties are marked with a cross for a comprehensive evaluation.

a Measurement of film thickness of resin protective film The resin protective film was taken out from the petri dish and the film thickness was measured.

A film thickness of 2.5 mm or more is considered good and is indicated by a circle. A film thickness of less than 2.5 mm is marked as defective and indicated by a cross.

b Strength of Resin Protective Film Remove the resin protective film from the petri dish and leave it outdoors for one month. If the original shape after being left unattended is indicated as good, it is indicated by a circle. If the original shape is not stopped and the original shape is broken or cracked, it is indicated by X as a defect.

c Water repellency of the resin protective film 0.5 ml of water droplets was dropped on the surface of the resin protective film using a pipette, and the time until completely absorbed into the coal was measured. The state in which water droplets are not absorbed even after 1 hour has passed is indicated as good and is indicated by a circle. Those that are absorbed within 1 hour are marked as defective and indicated by x.

The test emulsions are as follows.

(a) SBR emulsion styrene-butadiene rubber emulsion / latex Amount of polymerized styrene 60% by weight or less Solid concentration 40% by weight pH 7.2, specific gravity 1.027, viscosity (20 ° C) 25cp (b) Acrylic emulsion Acrylic ester-styrene copolymer emulsion / latex Solid content concentration ………… 45% by weight pH 7.5, Specific gravity 1.022, Viscosity (20 ℃) ……… 90cp <Test Results> The test results are summarized in Table 1.

<Consideration> From the test results, for coals of A, B, C, and D whose water permeation rate is 0.1 ml / sec. It can be seen that the coal cannot be protected from rainwater for a long time because it flows out, the film thickness becomes thin, and the film strength becomes weak.

Further, it can be seen that for the E and F coals having a water permeation rate of 0.5 ml / sec. Or more, a good effect of preventing rainwater permeation can be obtained by spraying the emulsion / latex which is a conventional technique. (Incidentally, coal with a water permeation rate of 0.5 ml / sec. Or higher is a coal that has the property that when 0.5 ml of water drops are dropped onto the surface of the coal according to the test method, the water drops are instantaneously absorbed on the surface of the coal. .) As described above, it can be seen that, with respect to highly water-repellent coal having a water permeation rate of 0.1 ml / sec. Or less, a good effect of preventing rainwater permeation cannot be obtained only by spraying emulsion / latex, which is a conventional technique. .

(Test Example 2) <Test method> Moisture content 1%, Particle size 16-32 mesh, Bulk specific gravity 0.73 g / ml
Of coal (K-9) was used to measure the permeation rate of water at the time of spraying various amounts of various surfactants.
The amount of the surface active agent (in terms of solid content) required to achieve 0.1 ml / sec. Or more was measured.

Next, after adding the above-mentioned surfactant, the SBR or acrylic emulsion / latex is diluted with water so that the solid content is 6 w / w%, and the solid content is 120% by using a sprayer.
The effect of preventing rainwater permeation when sprayed with g / m ² was tested.

The test sample preparation method, water permeation rate measurement method, rainwater permeation prevention effect measurement method, and test emulsion were the same as in Test Example 1.

<Test Results> Table 2 shows the test results.

<Consideration> As is apparent from the test results, the alkylphenol ethylene oxide adduct and the higher alcohol ethylene oxide adduct represented by Test Nos. 1 to 5, which are examples of the present invention, were added in an amount of 0.5 to 15 g / m ² as a solid content. By doing so, the permeation rate of water on the coal surface can be increased to 0.1 ml / sec. Or more [to impart wettability (permeability) to the coal surface], and the SBR system,
It is understood that the rainwater permeation preventive effect can be obtained for the highly water-repellent coal without impairing the rainwater permeation preventive effect of the acrylic emulsion / latex protective film.

When nonionic surfactants represented by test numbers 6 to 10 (comparative examples) other than the surfactant of the present invention are used, the permeation rate of water on the coal surface should be 0.1 ml / sec. Or more. It is necessary to add a large amount, and it can be seen that the required amount of SBR-based or acrylic-based emulsion / latex protective film significantly impairs the rainwater permeation preventive performance and fails to achieve the initial purpose.

(Example 1) ^Two coal piles having a weight of about 20,000 tons and a surface area of about 4000 m ² (water seepage rate 0.008 ml / sec. Or less, coal type K-9) were created,
On the one hand, the SBR emulsion described in Test Example 1
The latex was diluted with water so that the solid content was 3.2 w / w%, and was uniformly sprayed on the coal pile to a solid content of 96 g / m ² using a known spraying machine. On the other hand, an aqueous solution of polyoxyethylene nonyl phenyl ether (10 moles of EO added: 10) was sprayed uniformly so as to have a solid content of 3 g / m ^2, and the above SBR emulsion / latex was added in the same manner as above. Sprayed on coal mine. Rainy season (7
From the 3rd of July to the 31st of July, the state of both coal piles was observed by leaving it outdoors in the natural environment at a rainfall of about 110 mm).

In the former case (SBR emulsion alone spraying), most of the SBR emulsion / latex aqueous solution flowed out from the coal surface during spraying, causing slight landslides during rainfall on the 3rd day after the start of the test, and rainwater in some places. Penetrated On the 7th day, landslides and depressions occurred everywhere. One month later, the water content of the coal mine had risen to 11%. The latter (after adding a specific surfactant solution, SB
In the case of spraying R emulsion), landslides and depressions did not occur even after 1 month, and the water content of the coal mine after 1 month was 8%, which was the same as before the test and showed a good rainwater permeation prevention effect. .

Note) The water permeation rate is measured in the same manner as in Test Example 1, including the method for adjusting the sample body under test.

(Reference Example 1) [Relationship between water permeation rate and call band] The composition analysis of the following six types of overseas coal was performed, and the number of hydrogen atoms (indicated by [H]) relative to 100 carbon atoms in the coal was shown. Number of oxygen atoms per 100 carbon atoms (represented by [O])
Was calculated.

Further, the water penetration rate of the above coal was tested in the same manner as in Test Example 1.

(The method for adjusting the sample body to be tested is also the same as in Test Example 1.) Table 3 collectively shows the test results of both.

<Consideration> From the test results, there is a correlation between the water permeation rate and the call band, and coal with a small call band [H] [O] (eg [H] <70, [O] <5). It can be seen that the water penetration rate is as low as 0.1 ml / sec. On the contrary, coal having a large call band [H] [O] (eg [H]> 70, [O]> 9) has a water penetration rate of
It can be seen that the water repellency is low, as high as 0.1 ml / sec. Or higher.

(Effect of the Invention) As described above, according to the present invention, a strong resin protective film is formed even in highly water-repellent coal, and a remarkable effect of preventing rainwater penetration is exhibited.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Osamu Umekawa, Inventor Osamu Umekawa 2-10-15 Higashi-Awaji, Higashiyodogawa-ku, Osaka-shi, Katayama Institute of Chemical Research, Ltd. 2-10-15 Awaji, Katayama Chemical Industry Research Institute Co., Ltd. (56) Reference JP-A-62-146804 (JP, A) JP-B 61-16681 (JP, B2) JP-B-58-53037 (JP, B2) Japanese Patent Sho 58-53679 (JP, B2)

Claims (4)

[Claims] 1. A highly water-repellent Nozumi coal deposit, on the general formula (I): RO- (CH ₂ CH ₂ O) _n -H (I) (where R is 10 to 22 carbon atoms). A saturated or unsaturated alkyl group or alkylaryl group, wherein n is 5 to
It is an integer of 20. ) After uniformly spraying the nonionic surfactant represented by the formula (5) at a spraying rate of 0.5 to 15 g / m ² , the SBR and / or acrylic emulsion / latex as a solid content at a spraying rate of 8 to 500 g / m ² A method for preventing permeation of rainwater into Nozomi coal deposits, which comprises uniformly spraying and forming a resin protective film on the surface layer of the deposits. 2. The rainwater permeation prevention method according to claim 1, wherein the highly water-repellent Nozomi coal deposit is a Nozomi coal deposit having a water permeation rate of 0.1 ml / sec. Or less. 3. The rainwater permeation prevention method according to claim 1, wherein the SBR emulsion / latex is a styrene / butadiene copolymer emulsion / latex having a styrene content of 60% by weight or less. 4. Acrylic emulsion latex is a copolymer emulsion of acrylic acid ester and styrene.
The method for preventing permeation of rainwater according to claim 1, wherein the method is latex.