JPH0353356B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an agent for suppressing an increase in moisture content of open piled coal, and more particularly, to an agent for suppressing an increase in moisture content of open piled coal by making the surface of the open piled coal hydrophobic and preventing rainwater from penetrating into the inside of the piled coal. This invention relates to a moisture content increase inhibitor. In recent years, energy and resource conservation have been called for in the wake of oil shocks, and at the same time, as coal has regained its position as an energy source, its usage has also been on the rise. Along with this, various issues related to coal storage have also been brought into focus. For example, various countermeasures are being considered, such as preventing coal dust from scattering, preventing heat generation, and preventing deterioration. However, no serious measures have yet been taken to prevent rainwater from seeping into open coal piles. The increase in water content due to the infiltration of rainwater in open piled coal not only consumes extra energy for water evaporation, resulting in large economic losses, but also has various negative effects on the coke manufacturing process in the case of coking coal. Therefore, even if the increase in moisture content of coal due to rainwater is suppressed by 1%, it will bring about great benefits. Under such circumstances, it is an object of the present invention to provide an inexpensive and excellent inhibitor of increase in moisture content of open coal. That is, the present invention provides a moisture content increase inhibitor for open piled coal for hydrophobicizing the surface of the piled coal to prevent internal penetration of rainwater and suppressing the increase in moisture content. An oil-in-water resin emulsion of a resin consisting of a polymer, which does not contain an emulsifier or contains 1 emulsifier per 100 parts by weight of the resin in the resin emulsion.
This is an agent for suppressing an increase in the water content of piled coal, characterized in that the active ingredient is an oil-in-water resin emulsion containing not more than parts by weight. The moisture content increase inhibitor of open piled coal is an agent that hydrophobicizes at least the surface of open piled coal, prevents rainwater from penetrating into the inside, and suppresses an increase in moisture content.
It is required to form a hydrophobic film on the surface of the coal, and penetration into the interior is not necessarily required. On the other hand, dust scattering prevention agents are agents that penetrate resin over a considerable thickness and aggregate or solidify fine particles in order to prevent dust from scattering due to wind, etc. hydrophobicity is not necessarily required. Generally, resin emulsions use a considerable amount of emulsifier in order to provide emulsion stability, but especially in the case of dust scattering prevention agents, a large amount of emulsifier is used because internal penetration is required. The anti-heat generation and anti-deterioration agent also needs to be solidified to a considerable thickness in order to block air from entering, and similarly it is necessary to use a large amount of emulsifier to penetrate into the inside. However, when a large amount of emulsifier is blended, hydrophilicity is imparted to the composition, making it easy for water to penetrate, making it impossible to use it as a moisture content inhibitor. The present invention utilizes the phenomenon that by making at least the surface of piled coal hydrophobic, it is possible to prevent rainwater from penetrating into the interior.For this reason, the emulsifier is reduced at the cost of sacrificing the penetrability of the resin into the interior. Reduce the amount and make the surface hydrophobic. Open piled coal treated with such moisture content inhibitors cannot prevent air from entering, so it is less effective in preventing dust scattering, heat generation, deterioration, etc., but with a small amount of the agent used, rainwater can be effectively removed. It is possible to prevent water from penetrating into the interior and suppress an increase in moisture content. The oil-in-water resin emulsion, which is the active ingredient of the present invention, can be obtained by emulsion polymerization of hydrophobic monomers without using an emulsifier, or even if an emulsifier is used, the amount is 1% or less of the weight of the hydrophobic monomer. Examples of the hydrophobic monomer used in the present invention include vinyl acetate, acrylic ester, methacrylic ester, styrene, ethylene, butadiene, vinyl chloride, vinylidene chloride, etc. One type or a mixture of two or more of these monomers can be used. is subjected to emulsion polymerization. Further, these hydrophobic monomers may be copolymerized with a cationic monomer, and in this case, the cationic monomer is preferably about 10 wt% or less of the total monomers. As the cationic monomer, methacryloyloxyethyltrimethylammonium chloride, methacrylamide propyltrimethylammonium chloride, vinylpyridine, etc. can be used. As the emulsifier, any cationic, anionic or nonionic surfactant may be used. As the cationic surfactant, primary amine salts, secondary amine salts, tertiary amine salts, and quaternary ammonium salts having an aliphatic hydrocarbon group having 12 or more carbon atoms are used, and among these, , quaternary ammonium salt type is preferred. Examples of the quaternary ammonium salt type cationic surfactant include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride,
Examples include stearyltrimethylammonium chloride. Examples of anionic surfactants include sodium alkyl sulfonate, sodium alkylbenzene sulfonate, sodium salt of polyoxyethylene alkyl ether sulfate, sodium salt of polyoxyethylene phenyl ether sulfate, sodium salt of higher alcohol sulfate, and Examples include oil. As the nonionic surfactant, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene ether, etc. are used, but those having an HLB of 16 or more are preferred. In emulsion polymerization, hydrophobic monomers are stirred and dispersed in water together with an emulsifier if necessary, heated while blowing nitrogen gas, and a catalyst such as benzoyl peroxide, persulfate, hydrogen peroxide, etc. This is carried out using a redox catalyst that combines a chemical agent and a reducing agent such as sodium thiosulfate or sodium bisulfite. Further, it is preferable to use a polymerization accelerator such as copper sulfate in addition to the catalyst because the resin particles of the resulting emulsion become smaller and the emulsion stability becomes better. Emulsifiers are preferably not used, but if used, they should be used in an amount of 1% or less of the weight of the hydrophobic monomer. Further, in order to generally improve emulsion stability during or after emulsion polymerization, a protective colloid such as polyvinyl alcohol or carboxymethyl cellulose may be used, but in the present invention it is preferable not to use an emulsifier or a protective colloid. This is because when an oil-in-water emulsion containing large amounts of emulsifiers and protective colloids is sprayed onto coal, these substances interpose between the emulsion particles, preventing the particles from coalescing and making it take a long time to form a resin film. This is because it is necessary and causes an increase in the water permeability of the formed film. The moisture content increase inhibitor for open piled coal of the present invention is usually used at a concentration of 5 to 10% resin content, and for open pile coal, the resin content is 25 to 25% per square ^meter of coal pile surface.
Spread 200g, preferably 50-100g. that time,
It is best to use a spreader to spread it evenly over the entire surface of the coal pile. Note that the chemical may be sprayed only once, or may be sprayed multiple times. It may also be used as follows. When a coal pile is formed, it is spread on the conveyor belt to the coal that is being transported and forms the surface layer of the pile. When the coal pile is formed, all of the coal being transported is spread on the conveyor belt. After forming a coal pile by performing the spraying described in or, further spraying is performed on the surface layer of the coal pile. When the moisture content increase inhibitor for open piled coal of the present invention is sprayed on open piled coal, the formation of a resin film is promoted, and the resin film and coal are strongly bonded to strengthen the surface of the coal pile. Hydrophobizes the coal on the surface. Therefore, internal infiltration of rainwater can be prevented, and an increase in the moisture content of coal can be suppressed. Furthermore, since the film is strong, it can also be expected to prevent coal piles from collapsing due to heavy rainfall. Next, the present invention will be explained in detail with reference to Examples. Example 4 Goonyera charcoal 3 passed through mesh sieve
Kg is piled up in a conical shape on a circular container (diameter 30 cm) that can separate surface water and permeated water, and various resin emulsions shown in Table 1 are added to this at a resin concentration of 5%.
After adjusting the amount, it was evenly spread and air-dried indoors for 3 days. Next, after exposing this to artificial rain with a rainfall intensity of 10 mm/hr for 20 hours, the amount of surface water, amount of permeated water, and change in weight of the piled coal (difference in weight before and after rain) were measured to determine total moisture and permeation rate. . The results are shown in Table 2. The total moisture after rain was calculated from the total moisture before rain and weight change using the following formula. Total moisture after rain (%) = Coal weight before rain (g) x Total moisture before rain (%) x 10 ^-2 + Weight change (Δg) / Coal weight before rain (g) + Weight change (Δg) x 100 The penetration rate was calculated using the following formula. Permeation rate (%) = Permeated water amount (g) + Weight change (Δg) / Surface water amount (g) + Permeated water amount (g) + Weight change (Δg) × 100

【table】

【table】

[Table] Table 2 shows that resin emulsions that do not contain an emulsifier or that contain less than 1% emulsifier based on the resin content are more effective in suppressing increases in the moisture content of coal than those that contain a large amount of emulsifier. Recognize. Example 2 Using the resin emulsions shown in Table 3, tests were conducted in the same manner as in Example 1 to determine the total water content and permeability. The results are shown in Table 4.

【table】

[Table] From Table 4, it can be seen that the resin emulsion is more effective when it does not contain a protective colloid.

Claims (1)

[Claims] 1. An agent for suppressing the increase in moisture content of open coal, which hydrophobicizes the surface of open coal, prevents rainwater from penetrating inside, and suppresses an increase in moisture content, which comprises a hydrophobic monomer. The active ingredient is an oil-in-water resin emulsion of a resin made of a polymer of A moisture content increase inhibitor for open piled coal, characterized by: 2. The inhibitor for moisture content increase in open coal as claimed in claim 1, wherein the resin emulsion does not contain a protective colloid.