JPH0662971B2 - Inhibitor for increasing water content of open-field coal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water content increase inhibitor for open-field coal.

(Prior Art) In recent years, energy saving and resource saving have been screamed by the oil shock, and at the same time, the amount of coal used as an energy source has been gradually increasing as its status has been restored.

Along with this, various problems related to coal storage have been highlighted. For example, various measures such as prevention of scattering of coal dust, prevention of heat generation, prevention of deterioration, prevention of permeation of rainwater, etc. are considered.

However, no serious measures have been taken to prevent rainwater infiltration of open-field coal. The increase in water content due to the infiltration of rainwater into open-field coal consumes extra energy due to water content during combustion, resulting in a large economical loss. Have an adverse effect. Therefore, even if the increase in the water content of coal due to rainwater is suppressed by 1%, a great profit will be produced.

Even in the past, various proposals have been made for such means for suppressing an increase in the water content of coal. For example, JP-A-55-43133
No. 59, No. 82203, No. 58-117270, No. 58-117271.
No. 59-89391, 59-147089, 59-174695.
No. 60-40305, No. 60-40306, etc.

As described above, all of the conventionally proposed methods are practical methods and methods that can be carried out immediately, but on the other hand, they have the following drawbacks.

1) A resin film alone must be used for practical purposes together with a reinforcing agent that is the same as or similar to the open-air deposit, or that is made of an organic or inorganic substance.

2) When using the resin film alone, a pre-process such as mechanically pressurizing and increasing the density of the surface layer portion of the open pile coal pile before forming the resin film is required.

3) When using the resin film alone without pretreatment,
A cationic resin or a resin emulsion having a small amount of emulsifier (or no emulsifier) is used in order to increase the adhesive strength with coal, but the waterproofing and water repellency are weak, and the effect of suppressing an increase in water content due to rainwater is not good.

Therefore, when performing rainwater permeation waterproofing of open pile coal piles without pretreatment with the resin film alone, in practice,
This is a two-liquid spray method in which a resin emulsion is sprayed as a curing agent in advance and then dried, and then a resin emulsion made of a hydrophobic monomer is sprayed as a penetration inhibitor to form a resin film. Often.
However, although such a two-liquid method can obtain a rainwater permeation-preventing effect for a while, it must be sprayed with the first liquid after the first liquid is sprayed and then sprayed with the resin emulsion of the second liquid. Unless it is expected that the sunny days will continue, the resin emulsion cannot be sprayed and there is a problem in work. In particular, it is difficult to carry out waterproofing when it is necessary, such as in the rainy season.

In addition, in JP-A-58-117271, it was formed by specifying the compounding ratio with the filler of the solute which is a film-forming component in the paint and adding a water-repellent agent such as silicone, paraffin or low molecular weight polyethylene. It is disclosed to impart water repellency and moisture permeability to the film formation. However, in this case, since a considerably large amount of the filler is used, the film-forming property is considerably poor, a continuous film cannot be obtained, and there are some difficulties such as difficulty in uniform blending in the preparation of the paint.

(Problems to be Solved by the Invention) An object of the present invention is to provide an excellent water content increase inhibitor for open-field coal that is inexpensive and has good workability under such circumstances.

(Means for Solving Problems) The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned drawbacks of the conventional method, and as a result, have shown that water after drying having a glass transition temperature in the range of 5 to −50 ° C. Knowing that the above-mentioned drawbacks can be improved by using a resin liquid containing 3 to 15 parts by weight of a water repellent agent to 100 parts by weight of a solute of a resin emulsion forming an insoluble film, the present invention was developed. Is a successful one.

Here, the gist of the present invention is that the water repellency-imparting agent 3 is added to 100 parts by weight of a solute of a resin emulsion which forms a water-insoluble film after drying having a glass transition temperature in the range of 5 ° C to -50 ° C. It is a suppressor for increasing the water content of open-field coal, characterized by containing up to 15 parts by weight.

(Function) As the main chain monomer constituting the water-insoluble resin emulsion after drying applied to the present invention, acrylic acid ester such as methyl acrylate, ethyl acrylate, butyl acrylate, 2 ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, Methacrylic acid esters such as butyl methacrylate, 2 ethylhexyl methacrylate; acrylonitrile; methacrylonitrile; vinyl acetate; styrene; ethylene; butadiene; vinyl chloride; vinylidene chloride. Other,
Acrylic acid, methacrylic acid, glycidyl methacrylate, acrylamide, N-methylol acrylamide,
A polymerizable functional monomer such as 2-hydroxyethyl methacrylate may be used in combination. The copolymerization ratio of these monomers is appropriately selected such that the glass transition temperature of the produced copolymer resin is in the range of 5 to -50 ° C, preferably 0 to -30 ° C according to the following formula (1).

Where Tg is the transition temperature expressed in ° C, Tg ₁ , Tg ₂ ...
Tgn is Tg of a homopolymer of each composition monomer, W ₁ , W ₂ ·
-Wn shows the weight fraction of composition 1, 2 ... n.

If the glass transition temperature Tg exceeds 5 ° C, the rubber elasticity of the film formed on the surface layer of the open pile coal mountain is poor, and therefore strain due to subsidence of the coal mountain itself or strain due to mechanical vibration cannot be absorbed. , The resin film is easily cracked. Furthermore, the film-forming property is poor at low temperatures (in winter), and a film-forming aid must be used in combination, which results in secondary pollution such as bad odor and deterioration in drying property. On the other hand, glass transition When the temperature Tg is less than -50 ° C, the film forming property at low temperature is good, but the film strength at high temperature (summer) is lowered.

Since the glass transition temperature has an additive property as described above, necessary knowledge can be obtained by appropriately changing the type and amount of each composition monomer.

Examples of the water repellency-imparting agent include wax-based, wax / aluminum salt-based, wax, zirconium salt-based, quaternary pyridinium-based, fatty acid amide resin-based, silicone-based, fluororesin-based, low molecular weight polyethylene, and fatty acid ester. There is. These are appropriately used in an emulsion form with an emulsifier or the like. Silicone type and fluororesin type have good water repellency but are not economical and are not suitable for practical use. Quaternary pyridinium-based, fatty acid amide resin-based, low-molecular-weight polyethylene, and fatty acid ester have low water repellent effect, and wax-based, wax-aluminum-salt-based,
Using a wax-zirconium salt emulsion,
It is preferable in terms of water repellency and economy.

This water repellency-imparting agent is used by mixing it with the resin emulsion just before being sprayed on the open pile coal pile, but it may be added when the resin emulsion is synthesized.

The resin emulsion used here has a difference in water absorbency of the formed resin film depending on the kind and amount of the emulsifier used in the synthesis step. Therefore, the water repellent is at least 100 parts by weight of the solute of the resin emulsion. 3 parts by weight or more is necessary, and if less than this, the water repellency is extremely poor,
Infiltration of rainwater cannot be prevented. On the other hand, if it exceeds 15 parts by weight, the strength of the resin film decreases. Therefore, it is necessary to use 3 to 15 parts by weight, preferably 5 to 12 parts by weight, of the water repellent agent with respect to 100 parts by weight of the solute of the resin emulsion.

In addition, as already known in the art, in the water emulsion system, a film-forming aid (eg: butyl cellosolve), a thickener (eg: methyl cellulose), an antifoaming agent (eg: cetyl alcohol), etc. are appropriately used. You may add.

By the way, in order to apply the water content increase inhibitor for open-field coal of the present invention, generally, a spraying solution adjusted to a concentration of solid content of 5 to 10% by weight is applied to a solid content per 1 m ^{2 of} open-field coal pile surface. As 50
~ 300g, preferably 150-300g, sprayed evenly over the entire surface of the coal pile by a sprayer. In addition, although the water content increase inhibitor of the present invention exerts a sufficient effect by spraying once, it does not impede spraying several times.

The spraying method may be any of the following.

1) After forming the coal pile, spray it on the surface layer.

2) It is sprayed on the belt conveyer, which is the surface layer of coal when it is being formed, which is being transferred.

3) When the coal pile is formed, all the coal being transferred is sprayed on the belt conveyor.

When the water content increase inhibitor for open pile coal according to the present invention is sprayed on open pile coal, a flexible film having a good water repellent effect is formed on the surface of the pile. Therefore, the soft resin film absorbs the strain caused by the subsidence of the open-field coal itself, and it has fewer cracks than a hard resin that emphasizes strength. By using the agent together, since spraying only once is required, the film has moisture permeability as compared with the method of spraying twice, which facilitates evaporation of internal moisture and suppresses an increase in water content of coal.

Next, the present invention will be described in more detail with reference to examples.

Example 1 5 mm sieve (concrete aggregate standard sieve JIS No. 5,
2 kg of B-Cleef charcoal that has passed through an aperture of 4.760 mm and a wire diameter of 1.290 mm) is piled up in a cone shape with a diameter of 30 cm on a flat plate (which does not absorb water) that is inclined at 5 degrees. Resin emulsions and water repellents shown in Table 1 (melting point 135 ° F
Paraffin wax) was mixed and prepared, and then uniformly dispersed. The water repellency-imparting agent was emulsified and dispersed at a concentration of 50% to prepare a water emulsion, and the spray amount was 3 / m ² .
After air-drying at room temperature for 3 days, it was exposed to artificial rainfall with a rainfall intensity of 50 mm / hr for 1 hour, and then the increase in water content and the state of film formation were examined. The results are summarized in Table 2. The water content was calculated from the equation (2).

Here, Wt: weight at sampling, W: weight at constant temperature of 110 ° C.

In Test Nos. 1 to 4, there was no permeation of rainwater due to rainfall and the evaporation of moisture inside was good. In the test No. 5 of the comparative example, the water content was as high as 9.0% because the water repellent was small. Also, the test No.
Sample No. 6 contained many water repellents and had a low water content, which was good, but there was a problem that cracking occurred in the film formation.

In Test Nos. 7 and 8, the glass transition temperature was out of the limited numerical value, and neither crack nor deformation was good.

Incidentally, in accordance with JP-A-58-117271, the resin composition ratio, E
100 parts of 50% emulsion consisting of A: BA: AN = 75: 20: 5 was used as a solute, and 2000 parts of coal powder of 5 mesh pass and melting point
20 parts of a 50% water emulsion of 135 ° F paraffin wax was mixed, but it was not in a state of being sprayed with a spray gun or the like, and a uniform continuous film could not be obtained even if it was forcedly sprayed.

Example 2 A resin emulsion having a resin composition of EA: BA: AN = 75: 20: 5 was adjusted to a solute concentration of 9% on a coal pile (Quintet Canadian coal) having a width of 30 mm, a length of 110 m, and a total amount of 17,000 tons, and the repellent property was adjusted to 9%. As a water-based agent, a melting point of 135 ° F paraffin wax was mixed with 11 parts by weight of 100 parts by weight of the solute of the resin emulsion and 1 part by weight of the same, and 3 / per surface area of the open pile coal pile was prepared. A comparative test was conducted by spraying an amount of m ² equivalent to half of the coal pile. 50 for water repellency
A water emulsion was used which was emulsified and dispersed to a concentration of%.

This coal mountain was good even after 3 weeks, but the mountain treated with spray liquid showed a decrease in water content despite the rain (30 mm) at 3 weeks, but it was treated with spray liquid. The mountain showed an increase in water content in the third week due to rainfall of 30 mm.

Continued front page (72) Inventor Noboru Saito 1850 Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Steel Works (72) Inventor Shogo Watanabe 687, Arimoto, Wakayama, Shinagawa Naka Kagaku Kogyo Co., Ltd. (72) Kenji Kawamura, 687 Arimoto, Wakayama, Wakayama Shin-Nakamura Kagaku Kogyo Co., Ltd. (56) Reference JP-A-60-120763 (JP, A)

Claims (1)

[Claims] 1. A water repellent agent is contained in an amount of 3 to 15 parts by weight based on 100 parts by weight of a solute of a resin emulsion which forms a water-insoluble film after drying having a glass transition temperature in the range of 5 ° C. to −50 ° C. A water content increase inhibitor for open-field coal.