EP-4626997-B1 - METHOD FOR PREVENTING DUST GENERATION FROM AND/OR MOISTURE INCREASE IN OPEN-AIR PILE

Inventors

• TANIYAMA, Natsumi
• KIKKAWA, TAKASHI

Dates

Publication Date

20260513

Application Date

20240321

Claims (2)

1. A method for preventing dust generation from and/or moisture increase in an open-air pile, comprising spraying an O/W emulsion comprising acrylic-based resin and polyvinyl alcohol-based resin onto the open-air pile, wherein the polyvinyl alcohol -based resin content of the O/W emulsion is 0.1 to 5.0 parts by mass relative to 100 parts by mass of the acrylic-based resin.
2. The method for preventing dust generation from and/or moisture increase in an open-air pile according to claim 1, wherein the acrylic-based resin is a styrene acrylic resin and/ or a vinyl acetate acrylic resin.

Description

Technical Field The present invention relates to a method for preventing dust generation from and/or moisture increase in an open-air pile. Background Art Powders such as coal, iron ore, slag, dust, chips, wood shavings, sludge paper, and the like are piled in the open air at steel mills, power plants, pulp and paper mills, and other facilities. The open-air piled powder generates dust, which causes environmental problems. In addition, heavy rains or the like can cause landslides, coal flows (a phenomenon in which coal piled in the open air flows and collapses due to an increased moisture content of the coal that causes the coal to become slurry), or the like. Also, when, for example, it rains, rainwater permeates the powder and increases the moisture content of the powder. The increase in moisture content of open-air piled powder causes the powder to consume extra energy to evaporate the moisture when the powder is used as fuel, resulting in a large economic loss and increased CO2 emissions. Additionally, when open-air piled powder is raw material coal, it has various adverse effects on the coke manufacturing process. Thus, techniques to suppress the increase in moisture content of open-air piled powder are demanded. PTL 1 discloses the use of an acrylic-based emulsion resin as a hydrophobic treatment agent for an open-air pile. The hydrophobic treatment agent is sprayed onto, applied to, or kneaded with the pile to form hydrophobic portions on the surface of the particles of the pile. PTL 2 discloses spraying an emulsion resin solution containing polymer particles having particle sizes of 0.3 µm to 3 µm in average particle diameter and 0.2 µm or more in standard deviation onto an open-air pile. The use of an emulsion resin solution whose polymer particles are large in particle diameter and wide in particle size distribution, as above, forms thick and strong coating films that are difficult to crack on the pile, preventing dust generation from or moisture increase in the open-air pile. CN 106 939 154 B describes an anti-mite dust suppressant agent that is sprayed to prevent dust generation. Citation List Patent Literature PTL 1: JP 01-38723 BPTL 2: JP 2013-203525 A Summary of Invention Technical Problem For the hydrophobic treatment agent disclosed in PTL 1, the resultant film is weak in strength and fragile and may crack, undesirably allowing rainwater or the like to penetrate. The method disclosed in PTL 2 is also insufficient in terms of film strength, and the film cracks in some cases. An object of the present invention is to provide a method for preventing dust generation from and/or moisture increase in an open-air pile, which can increase the strength of the coating film made of a coating agent to coat particles of the open-air pile and reliably prevent moisture increase in the open-air pile. Solution to Problem After earnest examination, the present inventors have found that an emulsion containing acrylic-based resin and polyvinyl alcohol-based resin can provide a coating film improved in film strength and reliably prevent moisture increase in an open-air pile. The present invention is based on such findings. The present invention is defined by the apended claims. In an embodient, the method is characterized in that the styrene acrylic resin is a polymer of monomers including a styrene-based monomer and one or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters, the styrene-based monomer being styrene, the one or two or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters being one or more selected from the group consisting of 2-ethylhexyl acrylate, methyl methacrylate, butyl acrylate, and acrylic acid. In an embodiment, the method is characterized in that in the total amount of raw material monomers of the styrene acrylic resin, the blended amount of the styrene-based monomer is 5% to 70% by mass, and the blended amount of the one or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters is 30% to 95% by mass. In another embodiment, the method is characterized in that the vinyl acetate acrylic resin is a polymer of monomers including vinyl acetate and one or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters, the one or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters being one or more selected from the group consisting of 2-ethylhexyl acrylate, methyl methacrylate, butyl acrylate, and acrylic acid. In a further embodiment, the method is characterized in that in the total amount of raw material monomers of the vinyl acetate acrylic resin, the blended amount of the vinyl acetate is 10% to 95% by mass, and the blended amount of the one or more selected from the group consisting of (meth)acrylic acids and (meth)acrylic acid esters is 5% to 90% by mass. In yet another embodiment, the method is charac