JPS63112306A - Prevention for permeation of rainwater into piled coal substance in field - Google Patents

Abstract

PURPOSE:To prevent the permeation of rainwater into the piled coal substance in a field by forming a resin protecting film onto the surface layer of the piled substance. CONSTITUTION:The nonion group surfactant which is represented by the general formula of (I): R-O-(CH2CH2O)n-H is dispersed in the dispersion quantity of 0.5-15g/m<2> uniformly onto the highly water repelling piled coal substance in a field. Then, SBR group or acrylic group emulsion latex as solid portion is dispersed uniformly in the dispersion quantity of 8-500g/m<2>. Thus, a resin protecting film can be formed onto the surface layer of the piled substance, and the permeation of rainwater into the coal piled substance in a field can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing rainwater infiltration into open coal deposits. In general, coal powder and lumps are often piled up and stored in steel mills, gas plants, paper mills, and the like. If such deposits are left alone for a long time, rainwater will permeate into the coal deposits, causing moisture to accumulate in the coal deposits and resulting in a loss of heat energy during the next process of providing it for use, such as combustion. This may cause some inconvenience. By the way, 1 ton of coal
The amount of heat lost due to a 1% increase in water content is approximately 5,300 kcal, resulting in a large economic loss. (Conventional Method) In this regard, a method has been known in the past in which emulsion latex such as SBR (styrene-butadiene rubber), polyvinyl acetate, polyacrylic acid, etc. is sprayed onto the deposit to form a resin film on the surface layer. ing. Also, recently,
The inventors of this invention discovered that after spraying an SBR emulsion as a solid content on open coal deposits at a rate of 8 to 500 g/m, and after drying, an acrylic emulsion as a solid content of 8 to soo/= We have applied for a patent on a method for forming a resin protective film on the surface layer of deposits by spraying at a spraying rate of . (Patent Application No. 1987-287247, Application: 1985
(February 20) (Problems with conventional technology) In recent years, in order to make the form of coal import more stable, measures have been taken to further disperse supply sources and prepare as much as possible for situations that may occur in various regions. It is being As a result, coal with various properties has been supplied, and high-18 water-based coal has been supplied. When this highly water-repellent coal is piled up in the open, rainwater does not penetrate at all, and moisture accumulates in the coal, so measures to prevent rainwater penetration are required. However, the conventional technology of protective film forming agents (emulsion,
latex, etc.) on the high IB aqueous coal,
Because the surface is sloped, most of the protective film-forming agent flows out from the coal surface, making the protective film thinner and weaker, making it impossible to protect coal from rainwater for a long period of time. It was recognized that there was a problem. This invention was made in view of such problems. The inventors of this invention completed the present invention as a result of intensive research on this high ↑B aqueous coal. (Means for Solving the Problems) Thus, according to the present invention, on a highly water-repellent open coal deposit, the general formula CI>: R-0-(CBICthO), 1-1
1 ・・−・−・(I) (However, R has 10 to 10 carbon atoms
22 saturated or unsaturated alkyl groups; n is an integer from 5 to 20; ) After uniformly spraying a nonionic surfactant represented by 0.5 to 15 g/%, apply SBR and/or acrylic emulsion latex as a solid content at a rate of 8 to 500 g/m. Provided is a method for preventing rainwater infiltration into open coal deposits, which comprises uniformly dispersing the resin to form a protective resin film on the surface layer of the deposit. In this invention, high water repellency means that the water penetration rate is O.
lae/sec. Refers to the following properties. In this invention, the water penetration rate refers to the coal particle size of 16
~32 mesh, moisture content 1%, bulk specific gravity 0
．． When 0.5 - of water is dropped on the surface of coal with a weight of 73 g/-, the time until the water drop is completely absorbed inside the coal is measured, and it is defined as the ratio of the amount of water drop to the measurement time. That is, it is a value that indicates the ease with which coal gets wet with water; coal with a low permeation rate is highly water repellent, and vice versa, it is low tΩ aqueous. According to experiments conducted by the inventors, the penetration rate was 0, 1
ml/sec. Even if conventional technology such as emulsion latex is applied to the following high-18 water-based coals, if the surface of the applied coal is inclined at an angle of approximately 45 degrees, approximately 70% or more of the applied amount will flow out. It was confirmed that the coating was not able to protect coal from rainwater for a long time because the coating became thinner and the membrane strength became weaker. Therefore, in this invention, the water permeation rate is Q, l ml/
sec. The following coals are targeted. In general, what is the wettability of water and the coal band of coal (expressed as a binary index of the number of hydrogen atoms (H) per 100 carbon atoms in coal and the number of oxygen atoms [0] per 100 carbon atoms in coal)? , it is known that there is a correlation. [Fuel Association Journal Vol. 65 No. 6 pp. 408-41.6 (19
86) ) The water permeation rate of this invention also has a correlation with the coal band, and can be used as a guideline when using this invention (see Reference Example 1). The permeation rate of water in this invention is 0, 1 w=l/se
c. The following coals are normal coals whose coal bands are (H).
<70 and (0)<8 are included. These include K-9 (produced in the Soviet Union) and GOONYELLA (produced in Australia).
Examples include coal called B Creek CB, CREEK (produced domestically in the United States) and QUINTETTE (produced in Canada). In this invention, the nonionic surfactant represented by the general formula (1) that is sprayed onto the open coal deposit is used to impart wettability (penetration) to the surface of the coal deposit. This surfactant is called a higher alcohol ethylene oxide adduct or an alkylphenol ethylene oxide adduct, and natural and synthetic alcohols having 10 to 22 carbon atoms are used as the higher alcohol. In addition, as alkylphenol, nonylphenol,
Dodecylphenol, octylphenol, octylcresol, etc. are used. The number of moles of ethylene oxide added is 5 to 20. If the number of moles of ethylene oxide added is 5 or less, wetting (permeability) cannot be imparted to the surface of the deposit. Moreover, if the number of added moles is 20 or more, although wettability (penetration) can be imparted, the effect of preventing rainwater penetration of the protective film and/or its strength is impaired, which is not preferable. This surfactant is applied on open coal deposits from 0.5 to 15
Spread evenly with an application rate of g/rd. If the amount of spraying is less than 0.5 g/rd, sufficient wettability (penetration) cannot be imparted to the sediment surface, and 15 g/rd
If it is more than d, wettability (permeability) can be imparted, but the rainwater permeation prevention effect and/or strength of the protective film will be impaired, which is not preferable. In order to uniformly spread this surfactant on open coal deposits, a spraying rate of 1 to 32/d is usually appropriate;
．． It is preferable to use it as a 01-1.5% aqueous solution. If a surfactant other than the surfactant of this invention is used for the purpose of imparting wettability (penetration) to the coal surface, it will certainly be possible to obtain the wetting (penetration) property if the required amount is applied. However, as a side effect, the effect of preventing rainwater penetration and/or the strength of the protective film is significantly impaired, making it impossible to achieve the intended purpose (see Test Example 2). In this sense, this invention can be said to be particularly selected. In this invention, after uniformly dispersing the specific nonionic surfactant, 8 to 500 g of SBR-based and/or acrylic-based emulsion latex is added as a solid content to form a resin protective film on the surface layer of the open coal pile. Spread evenly at a spray rate of /m. Spread amount of each emulsion is 8 g as solid content
If it is less than /rd, it will be difficult to obtain a resin protective film with a large film thickness and film strength, and a good effect of preventing rainwater penetration will not be exhibited. The upper limit of the amount of each emulsion to be sprayed is 500 g/m as a solid content from an economical point of view, but it is usually 250 g/I.
It is sufficient to use a solid content of 150 g/m or less, and if a particularly preferred emulsion is used, the desired effect can be sufficiently achieved with a solid content of 150 g/m or less. As the SBR emulsion latex used in this invention, a styrene-bucc diene rubber emulsion latex with a styrene content of 60% by weight or less is particularly preferable from the viewpoint of preventing rainwater penetration, and usually has a solid content of 0.5 to 50% by weight. Concentrations are suitable. The acrylic emulsion/latex used in this invention includes homopolymer emulsions and copolymer emulsions of acrylic acid esters and meccrylic acid esters, and combinations of these monomers with one or more of vinyl acetate, styrene, acrylonitrile, acrylamide, acrylic acid, etc. Examples include copolymer emulsions with monomers, but copolymer emulsions with acrylic esters and styrene are particularly preferred because they form a strong resin protective film and exhibit a remarkable rainwater penetration prevention effect. Further, for both the SBR emulsion and the acrylic emulsion, those having a glass transition point of 0° C. or lower are particularly preferable from the viewpoint of the above-mentioned effects. Further, it is also preferable to mix and use a wax emulsion with each emulsion/latex from the viewpoint of the above-mentioned effects. In the method of this invention, a nonionic surfactant represented by the general formula (T) is first added, and then an SBR-based and/or acrylic-based emulsion latex is sprayed. Even if this order is reversed or the surfactant and each umaldigon are used simultaneously or in a mixture, a sufficient effect of preventing rainwater penetration will not be exhibited, which is not preferable. It is practically convenient to spray the aqueous surfactant solution or emulsion latex using a known water sprinkler, water truck, or the like. It is also a preferred embodiment to spray a surfactant on the coal forming the surface layer in advance. The effects of this invention will be illustrated by the following test examples and examples. (Test Example 1) The following six types of coal were used to test the rate of water penetration and the effect of preventing rainwater penetration when spraying SBR-based or Ac IJ-based emulsion latex. □ Type of coal □ A K-9 (Caking coal from the Soviet Union) □ Method for preparing test specimens □ Dry the above various coals in a constant temperature bath at 100°C for 16 hours, and use a sieve to reduce the particle size to 16~ 32 meshes. After that, water was added to adjust the water content to 1%, and the test coal was prepared in a zero-order petri dish (bottom area 63.6 cd, height 1.5 cd).
11, cylindrical) with a bulk specific gravity of 0.73 g/-1
A sample body is prepared with the surface as a flat surface, and this is used as the test sample body. i) Measurement of water penetration rate <Test method> Using a pipette, drop a 0.5-water droplet onto the coal surface of each test specimen, and measure the time until the water droplet is completely absorbed into the coal. did. The penetration rate was calculated using the following formula. Water absorption time (see) Measurement of rainwater infiltration prevention effect The following SBR or acrylic emulsion latex with a solid content of 61% was applied to the coal surface of each test specimen tilted at an angle of about 45°. It was diluted with water to give a solid content of 120 g/m using a sprayer. At that time, the outflow rate was calculated from the amount of each emulsion flowing out from the coal surface using the following formula. Amount of emulsion sprayed (1) × 100 After that, 48 test samples were
It was dried at ℃ for 16 hours, and the film thickness, strength, and ta aqueous property of the obtained resin protective film were measured. Those with good properties in all respects are marked with a circle, and those with other properties are marked with an x, giving an overall evaluation. a. Measurement of film thickness of resin protective film The resin protective film was taken out from the petri dish and its film thickness was measured. A film thickness of 2.511+I or more is considered good and is indicated by an O mark, 2
．． A film thickness of less than 51 m11 is considered defective and is represented by an x mark. b Strength of resin protective film Remove the resin protective film from the Petri dish and leave it outdoors for one month. Items that retain their original shape after being left unused are marked as good and are marked with an O mark. Items that do not retain their original shape and are deformed or have cracks are marked as defective and are marked with an X mark. c A 0.5-droplet of water was dropped onto the surface of the water-repellent resin protective film of the #A fat protective film using a pipette, and the time until it was completely absorbed into the coal was measured. A state in which water droplets are not absorbed even after one hour has passed is considered good and is indicated by an O mark. Those that are absorbed within one hour are marked as defective and are marked with an X. The sample emulsions are as follows. FalsBR emulsion styrene-butadiene rubber emulsion latex Polymerized styrene amount ・・−・−・・・−・・−60% by weight or less Solid content concentration ・・−・・・・・・・−
...40% by weight pH 7.2, specific gravity 1.027. Viscosity (20℃)...--25Cp
Medium) Acrylic emulsion acrylic acid ester-styrene copolymer emulcillin latex solid content concentration ・・・・・・・・・・・・・・・・−45% by weight
p) (7.5, specific gravity 1.022. Viscosity (20°C)...---------90
cp test results> The test results are summarized in Table 1. (The following margin continues on the next page) <Consideration> From the test results, the water penetration rate is Q, 1+a//sec,
For the following coals A, B, C, and D, even if emulsion latex is sprayed, more than 70% of the sprayed amount will flow out, and the film thickness will become thin (and the film strength will also weaken). , it can be seen that coal cannot be protected from rainwater for a long period of time.Also, for coal of E.F, where the water penetration rate is 0.5 wJ/sec or more, the conventional technique of spraying emulsion latex , it can be seen that a good rainwater infiltration prevention effect can be obtained.(Incidentally, the water infiltration rate is 0.5a
c. The above coal is a coal that has a property that when a 0.5-water droplet is dropped on the coal surface according to the test method, the water droplet is instantly absorbed by the coal surface. ) Thus, it can be seen that for high-18 water-based coal with a water permeation speed of 0.1 m/156c or less, a good rainwater permeation prevention effect cannot be obtained only by applying emulsion latex, which is the conventional technology. . (Test Example 2) <Test method> Moisture content 1%, particle size 16-32 mesh, bulk specific gravity 0.7
Using 3 g/- of coal (K-9>), the water permeation rate was measured when various amounts of surfactants were sprayed. The amount of the surfactant (in terms of solid content) was measured. Next, after adding the above surfactant, the SBR-based or acrylic emulsion latex was mixed with a solid content of 6 w/w.
The effect of preventing rainwater infiltration was tested by diluting with water to give a solid content of 120 g/n (120 g/n) using a sprayer. Preparation method of test sample, measurement of water infiltration rate Method: The method for measuring the rainwater penetration prevention effect and the test emulsion are the same as in Test Example 1. Test results> The test results are shown in Table 2. (The following margin continues on the next page) Discussion> It is clear from the test results. As shown in FIG. The permeation rate is Q, 1 ml/s
ec, or above [imparts moisture (penetration) properties on the coal surface]
It can be seen that the rainwater permeation prevention effect can be obtained for high T8 aqueous coal without impairing the rainwater permeation prevention effect of the , SBR type, and acrylic emulsion latex protective film. In addition, when nonionic surfactants represented by test numbers 6 to 10 (comparative examples) other than the surfactant of this invention are used, the permeation rate of water on the coal surface is 0.1ml/5IB.
In order to achieve C6 or higher, a large amount of addition is required, and it can be seen that the required addition amount significantly impedes the rainwater penetration prevention performance of SBR-based and acrylic-based emulsion latex protective films, making it impossible to achieve the initial purpose. . (Example 1) Two coal piles with a weight of about 20,000 t and a surface area of about 4000 RL (water infiltration rate 0.008 wJ/sec, hereinafter referred to as -9 for coal type) were created, and one of them had a test example. Dilute the SBR emulsion latex described in 1 with water to a solid content of 3.2 w/w%, and use a known sprayer to uniformly distribute the solid content to 96 g/n. On the other hand, an aqueous solution of polyoxyethylene nonylphenyl ether (EO added mole number: 10) was uniformly sprayed to a solid content of 3 g/rd, and then the above SBR emulsion
The latex was spread on the coal pile in the same manner as above. Rainy season 3L
IJ (July 3rd to July 31st precipitation: approx. 110m+a
), and the conditions of both coal mines were observed. In the former case (single spraying of SBR emulsion), most of the SBR emulsion/latex aqueous solution flowed out from the coal surface during spraying, and a slight landslide occurred during the rain on the third day after the start of the test, causing rainwater to leak in places. It penetrated. On the seventh day, landslides and cave-ins occurred everywhere. One month later, the moisture content of the coal mine had risen to 11%. In the latter case (spraying SBR emulsion after adding a specific surfactant solution), no landslides or cave-ins occurred even after one month, and the moisture content of the coal pile after one month was 8.
%, which was unchanged from before the test, showing good rainwater infiltration prevention effect. Note: The measurement of the water permeation rate was the same as in Test Example 1, including the method of preparing the test specimen. (Reference Example 1) [Relationship between water permeation rate and coal band] The following six types of overseas coal were analyzed for composition, and the number of hydrogen atoms (indicated by [H]) per 100 carbon atoms in the coal was determined.
The number of oxygen atoms (expressed as [0]) per 100 carbon atoms was calculated. Further, the water permeation rate of the coal was tested in the same manner as in Test Example 1. (The method for preparing the test specimen is also the same as in Test Example 1.) The results of both tests are summarized in Table 3. <Discussion> From the test results, there is a correlation between water penetration rate and coal band, and coal with small coal band [H] [0] (for example, (H) < 70, [0] × 5) It can be seen that the water permeation rate is as low as Q, 1 wJ/sec or less, resulting in high water repellency. Conversely, in coals with a large coal band (H) (0) (for example, (H)>70, (0)>9), the water penetration rate is 0.1. f/sec, high and low IQ
It can be seen that it is water-based. (The following margin continues on the next page) (Table 3) (Effects of the invention) As described above, this invention forms a strong resin protective film even on highly water-repellent coal, and exhibits a remarkable rainwater infiltration prevention effect. .

Claims (1)

[Claims] 1. General formula (I): R-O-(CH_2CH_2O)n-H on highly water-repellent open coal deposits
・・・・・・・・・(I) (However, R has 10 to 2 carbon atoms
2 saturated or unsaturated alkyl or alkylaryl groups, and n is an integer of 5 to 20. ) 0.5 to 15 g/m^2 of a nonionic surfactant represented by
After uniformly spreading the SBR-based and/or acrylic emulsion latex at a solid content of 8.
A method for preventing rainwater infiltration into open coal deposits, comprising uniformly spraying at a spraying rate of ~500 g/m^2 to form a resin protective film on the surface layer of the deposit. 2. Highly water-repellent open coal deposits have a water penetration rate of 0.
．． 1ml/sec. The method for preventing rainwater infiltration according to claim 1, which is the following open coal deposits. 3. SBR emulsion latex has a styrene content of 6
The method for preventing rainwater infiltration according to claim 1, which is a styrene-butadiene copolymer emulsion latex containing 0% by weight or less. 4. The method for preventing rainwater penetration according to claim 1, wherein the acrylic emulsion latex is a copolymer emulsion latex of acrylic acid ester and styrene.