JP7587102B2 - How iron ore is processed - Google Patents
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- JP7587102B2 JP7587102B2 JP2020048004A JP2020048004A JP7587102B2 JP 7587102 B2 JP7587102 B2 JP 7587102B2 JP 2020048004 A JP2020048004 A JP 2020048004A JP 2020048004 A JP2020048004 A JP 2020048004A JP 7587102 B2 JP7587102 B2 JP 7587102B2
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- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims description 212
- 229910052742 iron Inorganic materials 0.000 title claims description 106
- 239000002562 thickening agent Substances 0.000 claims description 57
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 44
- 229920002845 Poly(methacrylic acid) Polymers 0.000 claims description 43
- 229920000642 polymer Polymers 0.000 claims description 37
- 239000000839 emulsion Substances 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 21
- 229920002125 Sokalan® Polymers 0.000 claims description 20
- 239000002245 particle Substances 0.000 claims description 17
- 239000004584 polyacrylic acid Substances 0.000 claims description 14
- 230000003311 flocculating effect Effects 0.000 claims 1
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 22
- 229920002401 polyacrylamide Polymers 0.000 description 20
- 239000002002 slurry Substances 0.000 description 18
- 239000007787 solid Substances 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 16
- 239000003795 chemical substances by application Substances 0.000 description 15
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 14
- 230000015572 biosynthetic process Effects 0.000 description 10
- 239000000178 monomer Substances 0.000 description 9
- 239000000126 substance Substances 0.000 description 8
- 238000011156 evaluation Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 6
- 238000003672 processing method Methods 0.000 description 6
- 239000008394 flocculating agent Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000003245 coal Substances 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- -1 2-ethylhexyl Chemical group 0.000 description 2
- SOGAXMICEFXMKE-UHFFFAOYSA-N Butylmethacrylate Chemical compound CCCCOC(=O)C(C)=C SOGAXMICEFXMKE-UHFFFAOYSA-N 0.000 description 2
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 238000012790 confirmation Methods 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 238000005227 gel permeation chromatography Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- GOXQRTZXKQZDDN-UHFFFAOYSA-N 2-Ethylhexyl acrylate Chemical compound CCCCC(CC)COC(=O)C=C GOXQRTZXKQZDDN-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- SNRUBQQJIBEYMU-UHFFFAOYSA-N Dodecane Natural products CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000003368 amide group Chemical group 0.000 description 1
- 125000001204 arachidyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000002511 behenyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 125000004093 cyano group Chemical group *C#N 0.000 description 1
- 125000006165 cyclic alkyl group Chemical group 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- 125000001511 cyclopentyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C1([H])[H] 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 125000002704 decyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 125000003438 dodecyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 125000000755 henicosyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000004051 hexyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 125000001421 myristyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 239000007764 o/w emulsion Substances 0.000 description 1
- 125000005064 octadecenyl group Chemical group C(=CCCCCCCCCCCCCCCCC)* 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 125000000913 palmityl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 125000002914 sec-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
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- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 230000009974 thixotropic effect Effects 0.000 description 1
- 239000007762 w/o emulsion Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Description
本発明は、鉄鉱石の処理方法に関する。 The present invention relates to a method for processing iron ore.
鉄鉱石は、鉱山で採掘された後、搬送手段（貨物船、貨物列車、トラック等）によって搬送される。
鉄鉱石の内、保水力が低い鉄鉱石は、例えば、船から荷揚げ時に、含まれる水によりスラリー化し、ベルトコンベアに付着して搬送が困難になったり、ヤードの積山が降雨で崩れたりする問題が起こっている。
After being extracted from a mine, iron ore is transported by transportation means (cargo ships, freight trains, trucks, etc.).
Iron ore has a low water retention capacity, and when it is unloaded from a ship, the water in it causes it to turn into a slurry, which can stick to conveyor belts and make transportation difficult, or the piles in the yard can collapse due to rain.
上記問題を解決する方法として、薬剤を鉄鉱石に付与し、鉄鉱石粒子を凝集させる方法が知られている。 A known method to solve the above problem is to apply a chemical to the iron ore to cause the iron ore particles to agglomerate.
例えば、特許文献１には、「石炭及び／又は鉄鉱石スラリーに、Ｗ／Ｏ型エマルジョン状のアクリル酸系及び／又はアクリルアミド系ポリマーを添加し、混合することを特徴とする、石炭及び／又は鉄鉱石スラリーの造粒方法。」が開示されている。 For example, Patent Document 1 discloses a method for granulating coal and/or iron ore slurry, which is characterized by adding and mixing a W/O type emulsion of an acrylic acid-based and/or acrylamide-based polymer to a coal and/or iron ore slurry.
また、特許文献２には、「鉱石や石炭の如き含水バラ物を貨物船から橋形クレーンやアンローダのグラブバケットを使って荷揚げするに当たり、荷揚げ作業時に、湧水中に粉体が懸濁した状態の懸濁湧水が生成した場合に、その懸濁湧水発生位置に対し高分子凝集剤を添加して粒子の凝結、凝集を起こさせると共に、この部位の近傍あるいはその他の部位にあるバラ物を混ぜて、荷揚げを行なうことを特徴とする含水バラ物の荷揚げ方法。」が開示されている。 Patent Document 2 also discloses a method for unloading moist bulk materials such as ore and coal from a cargo ship using a bridge crane or a grab bucket of an unloader, which, if spring water containing suspended particles is generated during the unloading operation, adds a polymer flocculant to the location where the suspended water is generated to cause the particles to coagulate and aggregate, and mixes with the bulk materials in the vicinity of this location or in other locations before unloading.
また、特許文献３には、「水分を含む鉱石や石炭等の含水バラ物を、ベルトコンベアで船舶に積み込むに際し、前記ベルトコンベア上および／または前記ベルトコンベアのジャンクション部で、前記含水バラ物に、質量比（水／凝集剤）で２０～２００に希釈した凝集剤を添加し、該含水バラ物に凝集剤を付着させる含水バラ物処理方法。」が開示されている。 Patent Document 3 also discloses a method for treating moist bulk materials, such as ores and coals, which are loaded onto a ship using a belt conveyor, by adding a flocculant diluted to a mass ratio (water/flocculant) of 20 to 200 to the moist bulk materials on the belt conveyor and/or at the junction of the belt conveyor, thereby adhering the flocculant to the moist bulk materials.
特許文献１～３では、薬剤として、ポリアクリルアミド系凝集剤として（ポリアクリルアミド系のＷ／Ｏ型エマルジョン）を用いることが示されている。
ポリアクリルアミド系凝集剤は、薬剤の高分子成分が静電気力又は水素結合により粒子表面に吸着し、高分子同士が絡まり合い粒子を凝集させる。薬剤は、ベルトコンベア又はそのジャンクション部などで付与されるが、付与量が微量（鉱石に対し、０．０５～０．５質量％程度）であるため、均一に混合するためには、薬剤を希釈して粘度を下げておくことが有効と考えられる。
Patent Documents 1 to 3 disclose the use of a polyacrylamide-based flocculant (a polyacrylamide-based W/O type emulsion) as a chemical agent.
In polyacrylamide flocculants, the polymer components of the agent are adsorbed to the particle surface by electrostatic forces or hydrogen bonds, and the polymers become entangled and cause the particles to flocculate. The agent is applied on the belt conveyor or at its junction, but since the amount applied is very small (about 0.05 to 0.5% by mass of the ore), it is considered effective to dilute the agent to lower its viscosity in order to mix it uniformly.
しかし、実際には、ポリアクリルアミド系凝集剤は、ポリアクリルアミド系高分子が油に分散したＷ／Ｏ型エマルジョンであり、水を添加するとゲル化し、混合することが困難になる。そのため、凝集剤に水を加えて粘度を下げるためには質量比で５０倍以上に希釈する必要がある。この場合、希釈に使用した水が加わることにより、鉱石に対する水の含有量が増えて、薬剤の付与効果が低下する問題がある。 However, in reality, polyacrylamide-based flocculants are W/O emulsions in which polyacrylamide-based polymers are dispersed in oil, and when water is added, they gel, making mixing difficult. Therefore, in order to add water to the flocculant to reduce its viscosity, it is necessary to dilute it by 50 times or more by mass. In this case, the addition of water used for dilution increases the water content relative to the ore, which creates the problem of reducing the effectiveness of the agent.
また、ポリアクリルアミド系凝集剤は、鉄鉱石に含まれる水分に接触した瞬間にゲル化して内部に浸透し難いため、このことも均一混合が困難な一因となる。 In addition, polyacrylamide-based flocculants gel the moment they come into contact with the moisture contained in the iron ore, making it difficult for them to penetrate into the interior, which is another reason why uniform mixing is difficult.
そのため、ポリアクリルアミド系凝集剤による鉄鉱石のスラリー化抑制効果は、十分でないのが現状である。 As a result, the effectiveness of polyacrylamide-based flocculants in preventing iron ore from turning into a slurry is currently insufficient.
そこで、本発明の課題は、鉄鉱石のスラリー化抑制効果が高い鉄鉱石の処理方法を提供することである。 The objective of the present invention is to provide a method for treating iron ore that is highly effective in suppressing the formation of a slurry of iron ore.
課題を解決するための手段は、次の態様を含む。
＜１＞
水分を含む鉄鉱石に、ポリ（メタ）アクリル酸系高分子が水に分散したＯ／Ｗ型エマルジョンであるポリ（メタ）アクリル酸系増粘剤を付与し、前記鉄鉱石中の鉄鉱石粒子を凝集させる鉄鉱石の処理方法。
＜２＞
前記鉄鉱石を船舶に積み込む前に、前記鉄鉱石に前記ポリ（メタ）アクリル酸系増粘剤を付与する＜１＞に記載の鉄鉱石の処理方法。
＜３＞
前記ポリ（メタ）アクリル酸系増粘剤の付与量は、前記ポリ（メタ）アクリル酸系高分子が前記鉄鉱石１００質量部に対し、０．００２～０．０２質量部となる量である＜１＞又は＜２＞に記載の鉄鉱石の処理方法。
＜４＞
前記ポリ（メタ）アクリル酸系増粘剤において、前記水と前記ポリ（メタ）アクリル酸系高分子との質量比（水／ポリ（メタ）アクリル酸系高分子）が５以上２０未満である＜１＞～＜３＞のいずれか１項に記載の鉄鉱石の処理方法。
The means for solving the problems include the following aspects.
＜1＞
A method for treating iron ore, comprising adding a poly(meth)acrylic acid-based thickener, which is an O/W emulsion in which a poly(meth)acrylic acid-based polymer is dispersed in water, to iron ore containing moisture, thereby agglomerating iron ore particles in the iron ore.
＜2＞
The method for treating iron ore according to <1>, wherein the poly(meth)acrylic acid-based thickener is applied to the iron ore before the iron ore is loaded onto a ship.
＜3＞
The method for treating iron ore according to <1> or <2>, wherein the amount of the poly(meth)acrylic acid-based thickener added is an amount in which the poly(meth)acrylic acid-based polymer is 0.002 to 0.02 parts by mass per 100 parts by mass of the iron ore.
＜4＞
The method for treating iron ore according to any one of <1> to <3>, wherein in the poly(meth)acrylic acid-based thickener, a mass ratio of the water to the poly(meth)acrylic acid-based polymer (water/poly(meth)acrylic acid-based polymer) is 5 or more and less than 20.
本発明によれば、鉄鉱石のスラリー化抑制効果が高い鉄鉱石の処理方法を提供できる。 The present invention provides a method for treating iron ore that is highly effective in suppressing the formation of a slurry of iron ore.
以下、本発明の一例である実施形態について説明する。
なお、本明細書において、「～」を用いて表される数値範囲は、特に指定しない限り、「～」の前後に記載される数値を下限値及び上限値として含む範囲を意味する。よって、例えば、０．６５～１．５０％は０．６５％以上１．５０％以下の範囲を意味する。
成分組成における「％」は、特に断らない限り、質量％を意味するものとする。
Hereinafter, an embodiment of the present invention will be described as an example.
In this specification, unless otherwise specified, a numerical range expressed using "to" means a range including the numerical values written before and after "to" as the lower and upper limits. Thus, for example, 0.65 to 1.50% means a range of 0.65% or more and 1.50% or less.
Unless otherwise specified, "%" in the composition of a component means % by mass.
本実施形態に係る鉄鉱石の処理方法は、水分を含む鉄鉱石に、ポリ（メタ）アクリル酸系高分子が水に分散したＯ／Ｗ型エマルジョンであるポリ（メタ）アクリル酸系増粘剤を付与し、前記鉄鉱石中の鉄鉱石粒子を凝集させる鉄鉱石の処理方法である。 The iron ore processing method according to this embodiment is a method for processing iron ore in which a poly(meth)acrylic acid-based thickener, which is an O/W emulsion in which a poly(meth)acrylic acid-based polymer is dispersed in water, is added to iron ore containing moisture, thereby agglomerating iron ore particles in the iron ore.
本実施形態に係る鉄鉱石の処理方法は、鉄鉱石のスラリー化抑制効果が高い鉄鉱石の処理方法である。その理由は、次の通りである。 The iron ore processing method according to this embodiment is highly effective in suppressing the formation of a slurry in the iron ore. The reasons for this are as follows:
ポリ（メタ）アクリル酸系増粘剤を鉄鉱石に付与すると、ポリアクリル酸系高分子が鉄鉱石粒子表面に吸着又は含水中に遊離し、中性～アルカリ性でポリアクリル酸系高分子が会合することにより、鉄鉱石粒子を凝集させる。つまり、鉄鉱石に含まれる水のｐＨは中性～弱アルカリであるため、ポリ（メタ）アクリル酸系増粘剤を鉄鉱石に付与しただけで、鉄鉱石粒子が凝集する。そして、鉄鉱石粒子が凝集することで、鉄鉱石が増粘し、スラリー化が抑制される。 When a poly(meth)acrylic acid-based thickener is applied to iron ore, the polyacrylic acid-based polymer is adsorbed onto the surface of the iron ore particles or released when it is hydrated, and the polyacrylic acid-based polymer associates with the iron ore particles in a neutral to alkaline condition, causing the iron ore particles to aggregate. In other words, since the pH of the water contained in the iron ore is neutral to slightly alkaline, simply applying a poly(meth)acrylic acid-based thickener to the iron ore causes the iron ore particles to aggregate. The aggregation of the iron ore particles then causes the iron ore to thicken, suppressing the formation of a slurry.
しかも、ポリ（メタ）アクリル酸系増粘剤は、Ｏ／Ｗ型エマルジョンであるため、鉄鉱石に含有する水と接触してもゲル化し難い。粘度を下げるために、ポリ（メタ）アクリル酸系増粘剤を水で希釈してもゲル化し難い。そのため、ポリ（メタ）アクリル酸系増粘剤を鉄鉱石に均一に付与され易い In addition, since poly(meth)acrylic acid-based thickeners are O/W emulsions, they are unlikely to gel when they come into contact with the water contained in iron ore. Even if the poly(meth)acrylic acid-based thickener is diluted with water to reduce the viscosity, it is unlikely to gel. Therefore, the poly(meth)acrylic acid-based thickener can be applied uniformly to the iron ore.
以上から、本実施形態に係る鉄鉱石の処理方法は、鉄鉱石のスラリー化抑制効果が高くなる。
そして、鉄鉱石のスラリー化が抑制されることで、例えば、鉄鉱石がヤードで積上げられた後、降雨があっても崩れることが抑制される。また、ベルトコンベアの搬送が困難になることも抑制される。
From the above, the iron ore processing method according to this embodiment has a high effect of suppressing the slurrying of the iron ore.
By suppressing the formation of a slurry in the iron ore, the iron ore is prevented from collapsing even if it rains after it is piled up in a yard, and the belt conveyor is also prevented from becoming difficult to transport.
また、ポリアクリルアミド系凝集剤は、ライフタイムが短く（１～６ヶ月程度でゲル化）、窒素を含むため、鉄鉱石の焼結時にＮＯｘを発生するのに対して、ポリ（メタ）アクリル酸系増粘剤は、ライフタイムも長く（２年程度）、窒素を含まないため鉄鉱石の焼結時にＮＯｘ発生もない。
さらに、ポリアクリルアミド系凝集剤がＷ／Ｏ型エマルジョンであるのに対して、ポリ（メタ）アクリル酸系増粘剤は、Ｏ／Ｗ型エマルジョンであり、溶媒が水である。
そのため、本実施形態に係る鉄鉱石の処理方法は、環境にも優しい処理方法となる。
In addition, polyacrylamide-based flocculants have a short lifetime (gelling in about 1 to 6 months) and contain nitrogen, which generates NOx when iron ore is sintered, whereas poly(meth)acrylic acid-based thickeners have a long lifetime (about 2 years) and do not contain nitrogen, so no NOx is generated when iron ore is sintered.
Furthermore, while the polyacrylamide-based flocculant is a W/O type emulsion, the poly(meth)acrylic acid-based thickener is an O/W type emulsion, and the solvent is water.
Therefore, the iron ore processing method according to this embodiment is an environmentally friendly processing method.
また、ポリ（メタ）アクリル酸系増粘剤は、Ｏ／Ｗ型エマルジョンであるため、Ｗ／Ｏ型エマルジョンに比べ、粘性が低い。具体的には、例えば、通常、Ｗ／Ｏエマルジョンが５００～２０００ｍＰａ・ｓに対し、Ｏ／Ｗ型エマルジョンは５００ｍＰａ・ｓ以下である。加えて、ポリ（メタ）アクリル酸系増粘剤は、チクソトロピックな粘性を示すため、水による希釈時に粘度が低下しやすく、水と均一混合しやすい。
そのため、ポリ（メタ）アクリル酸系増粘剤中のポリ（メタ）アクリル酸系高分子が少量でも、スラリー化抑制効果が高く、コスト面で有利である。
In addition, since the poly(meth)acrylic acid-based thickener is an O/W type emulsion, it has a lower viscosity than a W/O type emulsion. Specifically, for example, a W/O emulsion usually has a viscosity of 500 to 2000 mPa·s, whereas an O/W type emulsion has a viscosity of 500 mPa·s or less. In addition, since the poly(meth)acrylic acid-based thickener exhibits thixotropic viscosity, the viscosity is likely to decrease when diluted with water, and it is easy to mix uniformly with water.
Therefore, even if the poly(meth)acrylic acid-based thickener contains a small amount of poly(meth)acrylic acid-based polymer, the slurry formation suppression effect is high, which is advantageous in terms of cost.
以下、本実施形態に係る鉄鉱石の処理方法の詳細について説明する。 The details of the iron ore processing method according to this embodiment are described below.
（鉄鉱石）
増粘剤を付与する鉄鉱石は、水分を含む鉄鉱石である。鉄鉱石としては、ＰＦＦＴ（ブラジル産微粉鉱石）、ミナスリオ、ＡＭＭＣ（カナダ産微粉鉱石）、サンマルコ、メタロインベスト、ノースランド等の微粉鉱石；カラジャスなどの鉱石が挙げられる。
これら鉄鉱石は、比表面積が小さいため、保水力が低く、含浸した水によるスラリー化が生じやすい。
(Iron ore)
The iron ore to which the thickener is applied is iron ore containing moisture. Examples of the iron ore include fine ores such as PFFT (Brazilian fine ore), Minas Rio, AMMC (Canadian fine ore), San Marco, Metalloinvest, and Northland, and ores such as Carajas.
These iron ores have a small specific surface area, so they have low water retention and are prone to forming a slurry due to the impregnated water.
ここで、水分を含む鉄鉱石は、例えば、鉄鉱石に対して、１０～２０質量％の水分を含む鉄鉱石である。なお、（メタ）アクリル酸系増粘剤を、水の含有量が２０質量％を超える鉄鉱石に適用した場合には、鉄鉱石の凝集が不充分で、充分な効果が得られない場合がある。そのため、増粘剤は、水の含有量が１２～１８質量％の鉄鉱石に適用することがより好ましい。 Here, the iron ore containing moisture is, for example, iron ore containing 10 to 20% by mass of moisture. If a (meth)acrylic acid-based thickener is applied to iron ore with a water content of more than 20% by mass, the iron ore may not be sufficiently coagulated, and sufficient effects may not be obtained. For this reason, it is more preferable to apply the thickener to iron ore with a water content of 12 to 18% by mass.
（ポリ（メタ）アクリル酸系増粘剤）
ポリ（メタ）アクリル酸系増粘剤は、ポリ（メタ）アクリル酸系高分子が水に分散したＯ／Ｗ型エマルジョンである。
(Poly(meth)acrylic acid-based thickener)
The poly(meth)acrylic acid-based thickener is an O/W type emulsion in which a poly(meth)acrylic acid-based polymer is dispersed in water.
ポリ（メタ）アクリル酸系高分子は、（メタ）アクリル酸及び／又は（メタ）アクリル酸エステルのモノマーに由来する構造単位を含む共重合体である。ここで、(メタ)アクリル酸とはアクリル酸及び／またはメタクリル酸を指す。
（メタ）アクリル酸エステルとしては、炭素数１～２４の、直鎖、分岐、又は環状のアルキル基を有する（メタ）アクリル酸エステルが挙げられる。
具体的には、（メタ）アクリル酸エステルとしては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓｅｃ－ブチル、（メタ）アクリル酸ｔｅｒｔ－ブチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸ｎ－オクチル、（メタ）アクリル酸デシル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸テトラデシル、（メタ）アクリル酸ヘキサデシル、（メタ）アクリル酸オクタデシル、（メタ）アクリル酸イコシル、（メタ）アクリル酸ヘンイコシル、（メタ）アクリル酸ドコシル、（メタ）アクリル酸オクタデセニル、（メタ）アクリル酸シクロぺンチル、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸べンジル等が挙げられる。
これらの中でも、鉄鉱石のスラリー化抑制の観点から、（メタ）アクリル酸エステルとしては、炭素数１～１２の直鎖又は分岐アルキル基を有する（メタ）アクリル酸エステル（アクリル酸エチル、アクリル酸ブチル、アクリル酸２－エチルヘキシル、メタクリル酸メチル、メタクリル酸ブチル等）が好ましく、アクリル酸エチルが特に好ましい。
A poly(meth)acrylic acid polymer is a copolymer containing structural units derived from (meth)acrylic acid and/or (meth)acrylic acid ester monomers, where (meth)acrylic acid refers to acrylic acid and/or methacrylic acid.
Examples of the (meth)acrylic acid ester include (meth)acrylic acid esters having a linear, branched, or cyclic alkyl group having 1 to 24 carbon atoms.
Specific examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, icosyl (meth)acrylate, henicosyl (meth)acrylate, docosyl (meth)acrylate, octadecenyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and benzyl (meth)acrylate.
Among these, from the viewpoint of suppressing the formation of a slurry of iron ore, the (meth)acrylic acid ester is preferably a (meth)acrylic acid ester having a linear or branched alkyl group having 1 to 12 carbon atoms (e.g., ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, butyl methacrylate, etc.), and particularly preferably ethyl acrylate.
ポリ（メタ）アクリル酸系高分子の構成単位は、（メタ）アクリル酸及び／または（メタ）アクリル酸エステルのモノマー由来の構成単位以外に、カルボン酸ビニル系モノマー、スチレン系モノマー、ヒドロキシル基含有モノマー、アミド基含有モノマー、シアノ基含有モノマーなどの共重合可能なモノマー由来の構成単位を有していてもよい。
ただし、ポリ（メタ）アクリル酸系高分子は、（メタ）アクリル酸及び／または（メタ）アクリル酸エステルのモノマー由来の構成単位を７０質量％（８０質量％以上、又は９０質量％以上）を有することがよい。
The constituent units of the poly(meth)acrylic acid-based polymer may have constituent units derived from copolymerizable monomers such as vinyl carboxylate-based monomers, styrene-based monomers, hydroxyl group-containing monomers, amide group-containing monomers, and cyano group-containing monomers, in addition to constituent units derived from (meth)acrylic acid and/or (meth)acrylic acid ester monomers.
However, it is preferable that the poly(meth)acrylic acid-based polymer contains 70% by mass (80% by mass or more, or 90% by mass or more) of structural units derived from (meth)acrylic acid and/or (meth)acrylic acid ester monomers.
ポリ（メタ）アクリル酸系高分子の重量平均分子量は、鉄鉱石のスラリー化抑制の観点から、５０万～１０００万が好ましく、１００万～５００がより好ましい。
なお、重量平均分子量は、ゲルパーミエーションクロマトグラフィ（ＧＰＣ）により測定される値である。
The weight average molecular weight of the poly(meth)acrylic acid-based polymer is preferably from 500,000 to 10,000,000, and more preferably from 1,000,000 to 500, from the viewpoint of suppressing the formation of a slurry of iron ore.
The weight average molecular weight is a value measured by gel permeation chromatography (GPC).
ポリ（メタ）アクリル酸系増粘剤の粘度は、鉄鉱石のスラリー化抑制の観点から、１～５００ｍＰａ・ｓが好ましく、１～１００ｍＰａ・ｓがより好ましい。
なお、粘度は、２５℃で測定される値である。
The viscosity of the poly(meth)acrylic acid-based thickener is preferably from 1 to 500 mPa·s, and more preferably from 1 to 100 mPa·s, from the viewpoint of suppressing the formation of a slurry of the iron ore.
The viscosity is a value measured at 25°C.
（ポリ（メタ）アクリル酸系増粘剤の付与場所）
ポリ（メタ）アクリル酸系増粘剤の付与場所は、特に限定されないが、例えば、鉄鉱石の原料ヤード、貯蔵保管場（積地等）、船やトラック等の運送時、船からの荷揚げ時、ベルトコンベアの搬送時などが挙げられる。
特に、鉄鉱石のスラリー化抑制効果をより引き出すためには、国内の荷揚げ時に増粘剤を付与するよりも、あらかじめ海外の積地で、例えば、鉱山、港でのベルトコンベア輸送時や積み付け時、払い出し時など、船舶に積込む前に、増粘剤を付与しておく方が有効である。つまり、鉄鉱石を船舶に積み込む前に、鉄鉱石に前記ポリ（メタ）アクリル酸系増粘剤を付与することが好ましい。その理由は、次の通りである。
(Position of poly(meth)acrylic acid-based thickener)
The location where the poly(meth)acrylic acid-based thickener is applied is not particularly limited, but examples thereof include a raw material yard for iron ore, a storage facility (loading point, etc.), during transportation by ship or truck, when unloading from a ship, and during transport on a conveyor belt.
In particular, in order to further suppress the formation of a slurry in iron ore, it is more effective to add a thickener at a loading port overseas, for example, during belt conveyor transport at a mine or port, during loading or unloading, before loading onto a ship, rather than adding the thickener at the time of unloading domestically. In other words, it is preferable to add the poly(meth)acrylic acid-based thickener to the iron ore before loading onto a ship. The reasons are as follows.
水分を含有する鉄鉱石は、海上輸送中に水分が船底の方向に移動して溜まりスラリー化する。荷揚げ時、スラリーとなっている部分の鉄鉱石を採取するためには、水を汲み上げる作業が必要となり、作業効率が悪くなる（つまり荷揚げ障害）。スラリー化した鉄鉱石は、搬送中、ベルトコンベアからも落下しやすい。そのため、あらかじめ積地で、増粘剤を付与して鉄鉱石のスラリー化を抑制する方が有利である。また、船内でスラリー化した鉄鉱石は流動しやすく、船倉の片側により易くなって、船のバランスが崩れ、最悪船が転覆することもある。積地で、鉄鉱石に増粘剤を付与して鉄鉱石のスラリー化を抑制しておくことにより、このような事態も回避することができる。 When iron ore contains moisture, the moisture moves toward the bottom of the ship during sea transport and accumulates, turning it into a slurry. When unloading, the water must be pumped up to extract the slurried iron ore, which reduces work efficiency (i.e., it causes unloading problems). Slurried iron ore also tends to fall off the conveyor belt during transportation. For this reason, it is more advantageous to apply a thickening agent to the ore at the loading port in advance to prevent the iron ore from turning into a slurry. In addition, slurried iron ore on board the ship tends to flow and accumulate on one side of the ship's hold, causing the ship to lose its balance and, in the worst case, capsize. By applying a thickening agent to the iron ore at the loading port to prevent the iron ore from turning into a slurry, this type of situation can be avoided.
（ポリ（メタ）アクリル酸系増粘剤の付与方法）
ポリ（メタ）アクリル酸系増粘剤の付与方法は、特に限定されないが、積地での積込み時又は揚地での荷揚げ時に、ベルトコンベア上又はベルトコンベアのジャンクション部で、シャワー状に散布する方式、又は蛇口からストレート棒状に流す方式等が挙げられる。
可能ならば、保管・貯蔵等の際に機械的に鉄鉱石を攪拌しつつ、増粘剤を鉄鉱石と混合することが望ましい。
(Method of adding poly(meth)acrylic acid-based thickener)
The method of applying the poly(meth)acrylic acid-based thickener is not particularly limited, but examples thereof include a method of spraying the thickener in a shower-like manner on a belt conveyor or at a junction of a belt conveyor when loading at a loading port or unloading at a discharging port, or a method of pouring the thickener in a straight rod-like manner from a faucet.
If possible, it is desirable to mix the thickener with the iron ore while mechanically stirring the iron ore during storage or preservation.
（ポリ（メタ）アクリル酸系増粘剤の付与量）
ポリ（メタ）アクリル酸系増粘剤の付与量は、鉄鉱石のスラリー化抑制の観点から、ポリ（メタ）アクリル酸系高分子が鉄鉱石１００質量部に対し、０．０００５～０．０４質量部となる量が好ましく、０．００２～０．０２質量部となる量がより好ましい。
(Amount of poly(meth)acrylic acid-based thickener added)
From the viewpoint of suppressing the slurrying of the iron ore, the amount of the poly(meth)acrylic acid-based thickener added is preferably 0.0005 to 0.04 parts by mass, and more preferably 0.002 to 0.02 parts by mass, of the poly(meth)acrylic acid-based polymer per 100 parts by mass of the iron ore, from the viewpoint of suppressing the slurrying of the iron ore.
ここで、ポリ（メタ）アクリル酸系増粘剤は、固形分濃度（つまり、ポリ（メタ）アクリル酸系高分子濃度）が２０～４０質量％の原液のまま使用することも可能である。
しかし、鉄鉱石に増粘剤を均一に付与する観点から、水で希釈して、水とポリ（メタ）アクリル酸系高分子との質量比（水／ポリ（メタ）アクリル酸系増粘剤）を５以上２０未満（好ましくは５以上１０以下）とすることがよい。なお、質量比が２０以上の場合には、鉄鉱石に含有される水分が多くなりすぎ、鉄鉱石のスラリー化抑制効果が小さくなる場合がある。
Here, the poly(meth)acrylic acid-based thickener can be used as is in the form of a stock solution having a solids concentration (that is, poly(meth)acrylic acid-based polymer concentration) of 20 to 40% by mass.
However, from the viewpoint of uniformly applying the thickener to the iron ore, it is preferable to dilute with water so that the mass ratio of water to the poly(meth)acrylic acid-based polymer (water/poly(meth)acrylic acid-based thickener) is 5 or more and less than 20 (preferably 5 or more and 10 or less). If the mass ratio is 20 or more, the iron ore may contain too much water, which may reduce the effect of suppressing the slurrying of the iron ore.
以下、本発明を、実施例を挙げてさらに具体的に説明する。ただし、これら各実施例は、本発明を制限するものではない。 The present invention will be described in more detail below with reference to examples. However, these examples do not limit the present invention.
（実施例１）
凝集性の評価をコンクリート等の流動性を評価するスランプフロー試験を模擬した方法（以下、崩れやすさ確認試験と呼ぶ）により行った。
鉄鉱石として、微粉鉱石であるＰＦＦＴを用い、薬剤として、水中にポリアクリル酸系高分子が分散したＯ／Ｗ型エマルジョン型増粘剤（（株）日本触媒製アクリセット）を用いた。薬剤の固形分濃度（ポリアクリル酸系高分子濃度）は３０質量％であった（水／ポリアクリル酸系高分子（固形分）の質量比が２．３３）。
Example 1
The cohesiveness was evaluated by a method simulating a slump flow test for evaluating the fluidity of concrete, etc. (hereinafter, referred to as a crumbling property confirmation test).
As the iron ore, PFFT, which is a finely powdered ore, was used, and as the chemical, an O/W type emulsion type thickener in which a polyacrylic acid-based polymer is dispersed in water (Acryset manufactured by Nippon Shokubai Co., Ltd.) was used. The solid content concentration (polyacrylic acid-based polymer concentration) of the chemical was 30% by mass (water/polyacrylic acid-based polymer (solid content) mass ratio was 2.33).
最初に、乾燥したＰＦＦＴに、水分含有量が１５質量％になるように水を加えて混合した。水分調整後の鉄鉱石２００ｇを２５０ｃｃのポリ瓶に入れた。鉄鉱石１００質量部に対し、増粘剤を固形分濃度（ポリアクリル酸系高分子濃度）として０．００８質量％添加後、蓋をし、ポリ瓶ごと上下に５回転転倒撹拌して混合した。内径２５ｍｍ、高さ５０ｍｍのアクリル製の管をステンレス製の平板に立て、混合後の試料をすりきりまで充填した後、管を引き抜いた。１分間放置した後、試料の高さを測定した。管を引き抜いた後の高さが高いものほど、凝集性が高く、元の形状を保持する能力が高い優れた薬剤であると評価される。本試験の結果、アクリル管を引き抜いても形状の崩れは僅かで、高さは４９ｍｍであり、良好な結果であった。 First, water was added to the dried PFFT to a moisture content of 15% by mass and mixed. 200 g of iron ore after moisture adjustment was placed in a 250 cc plastic bottle. 0.008% by mass of thickener was added as a solid concentration (polyacrylic acid-based polymer concentration) to 100 parts by mass of iron ore, and then the bottle was covered and mixed by rotating up and down 5 times. An acrylic tube with an inner diameter of 25 mm and a height of 50 mm was placed on a stainless steel flat plate, and the mixed sample was filled to the top, and then the tube was removed. After leaving it for 1 minute, the height of the sample was measured. The higher the height after the tube was removed, the higher the cohesiveness and the better the agent was evaluated to be, with a high ability to retain its original shape. As a result of this test, even when the acrylic tube was removed, there was only a slight deformation of the shape, and the height was 49 mm, which was a good result.
（比較例１）
薬剤として、炭化水素系溶媒中にポリアクリルアミド系高分子が分散したＷ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター）を用いて、実施例１と同じ方法で崩れやすさ確認試験を行った。凝集剤の固形分濃度（ポリアクリルアミド系高分子濃度）は４０質量％であった、そして、凝集剤を、鉄鉱石１００質量部に対し、固形分濃度（ポリアクリルアミド系高分子濃度）として０．００８質量％付与した。管を引き抜いた後、形状は崩れ、高さが低下して３５ｍｍとなって、凝集性は弱かった。
(Comparative Example 1)
A test to confirm the ease of crumbling was carried out in the same manner as in Example 1, using as the chemical a W/O emulsion type flocculant (Lockmaster, manufactured by Hymo Co., Ltd.) in which a polyacrylamide polymer is dispersed in a hydrocarbon solvent. The solids concentration (polyacrylamide polymer concentration) of the flocculant was 40 mass %, and the flocculant was added at a solids concentration (polyacrylamide polymer concentration) of 0.008 mass % per 100 mass parts of iron ore. After the tube was pulled out, the shape collapsed, the height decreased to 35 mm, and the coagulation properties were weak.
（実施例２～１２、比較例２～１０）
鉄鉱石としてＰＦＦＴ、薬剤として、実施例１で使用したＯ／Ｗ型エマルジョン型増粘剤（日本触媒（株）製アクリセット、固形分濃度（ポリアクリル酸系高分子濃度）３０質量％）又は比較例１で使用したＷ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター、固形分濃度（ポリアクリルアミド系高分子濃度）４０質量％）を用いた。
そして、鉄鉱石中に含有される水分量、薬剤の固形分濃度を変えて、実施例１及び比較例１と同じ方法で崩れやすさ確認試験を行い、高さを測定した。
結果を表１の実施例２～１２および比較例２～１０に示す。
表中の薬剤の種類には、Ｏ／Ｗ型エマルジョン型増粘剤（（株）日本触媒製アクリセット）を「増粘剤」、Ｗ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター）を「凝集剤」と記入した。
評価は高さが４７ｍｍ以上を〇（優）、高さが４７ｍｍ未満、４２ｍｍ以上を△（可）、４２ｍｍ未満を×（不可）とした。ポリ（メタ）アクリル酸系増粘剤を用いた実施例２～１２では、比較的少量の付与でも△または〇の評価結果が得られたのに対し、薬剤を付与しなった、又はポリアクリルアミド系凝集剤を用いた比較例２、３、５～１０では、鉄鉱石粒子の凝集が弱く、形状が崩れて、×の評価となった。また、ポリアクリルアミド系凝集剤を用いて良好な結果を得るには、比較例４に例示したように薬剤付与量をかなり増やす必要があり、コストが高くなるとともに、有機溶剤の量が増えるという環境上の問題も生じる。
(Examples 2 to 12, Comparative Examples 2 to 10)
The iron ore used was PFFT, and the chemical used was the O/W emulsion thickener used in Example 1 (Acryset manufactured by Nippon Shokubai Co., Ltd., solids concentration (polyacrylic acid-based polymer concentration) 30% by mass) or the W/O emulsion flocculant used in Comparative Example 1 (Lockmaster manufactured by Hymo Co., Ltd., solids concentration (polyacrylamide-based polymer concentration) 40% by mass).
Then, the moisture content in the iron ore and the solids concentration of the agent were changed, and a crumbling confirmation test was carried out in the same manner as in Example 1 and Comparative Example 1, and the height was measured.
The results are shown in Table 1 for Examples 2 to 12 and Comparative Examples 2 to 10.
In the table, the type of chemical is recorded as "thickener" for the O/W emulsion type thickener (Acryset, manufactured by Nippon Shokubai Co., Ltd.) and "flocculant" for the W/O emulsion type flocculant (Lockmaster, manufactured by Hymo Co., Ltd.).
The evaluation was ◯ (excellent) for heights of 47 mm or more, △ (passable) for heights less than 47 mm or 42 mm or more, and × (unacceptable) for heights less than 42 mm. In Examples 2 to 12, which used poly(meth)acrylic acid-based thickeners, evaluation results of △ or ◯ were obtained even with relatively small amounts applied, whereas in Comparative Examples 2, 3, and 5 to 10, which did not apply any agent or used a polyacrylamide-based flocculant, the iron ore particles were weakly aggregated and the shape was distorted, resulting in an evaluation of ×. In addition, in order to obtain good results using a polyacrylamide-based flocculant, it is necessary to significantly increase the amount of agent applied, as exemplified in Comparative Example 4, which increases costs and also creates environmental problems such as an increase in the amount of organic solvent.
（実施例１３～１５、比較例１６～１９）
鉄鉱石として、カラジャス鉄鉱石を用い、篩分けにより粒径を５ｍｍ以下とした後、水を加えて含水率１４％に調整し、崩れやすさ確認試験を行った。
薬剤は、実施例１で使用したＯ／Ｗ型エマルジョン型増粘剤（（株）日本触媒製アクリセット、固形分濃度（ポリアクリル酸系高分子濃度）３０質量％）又は比較例１で使用したＷ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター、固形分濃度（ポリアクリルアミド系高分子濃度）４０質量％）を用いた。
(Examples 13 to 15, Comparative Examples 16 to 19)
Carajas iron ore was used as the iron ore, and was sieved to reduce the particle size to 5 mm or less. Water was then added to adjust the moisture content to 14%, and a test was conducted to confirm the ease of crumbling.
The chemicals used were the O/W emulsion thickener used in Example 1 (Acryset, manufactured by Nippon Shokubai Co., Ltd.; solids concentration (polyacrylic acid-based polymer concentration) 30% by mass) or the W/O emulsion flocculant used in Comparative Example 1 (Lockmaster, manufactured by Hymo Co., Ltd.; solids concentration (polyacrylamide-based polymer concentration) 40% by mass).
水分調整済みの鉄鉱石５００ｇを５００ｃｃのポリ瓶に入れた。薬剤を所定量付与後、蓋をし、ポリ瓶ごと上下に５回転転倒撹拌して混合した。内径６０ｍｍ、高さ１００ｍｍのアクリル製の管をステンレス製の平板に立て、混合後の試料をすりきりまで充填した後、管を引き抜いた。１分間放置した後、試料の高さを測定した。管を引き抜いた後の高さが低いものほど、凝集性が高く、元の形状を保持する能力が高い優れた薬剤であると評価される。
結果を表２の実施例１３～１５および比較例１６～１９に示す。
表中の薬剤の種類には、Ｏ／Ｗ型エマルジョン型増粘剤（（株）日本触媒製アクリセット）を「増粘剤」、Ｗ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター）を「凝集剤」と記入した。
評価は高さが９０ｍｍ以上を〇（優）、高さが９０ｍｍ未満、８０ｍｍ以上を△（可）、８０ｍｍ未満を×（不可）とした。ポリアクリル酸系増粘剤を用いた実施例１３～１５では、比較的少量の付与でも△または〇の評価結果が得られたのに対し、薬剤を付与しなかった、又は、ポリアクリルアミド系凝集剤を用いた比較例１６～１９では、薬剤が均一に混合されず、粒子の凝集が弱くなり、形状が崩れて、×の評価となった。
500g of iron ore with adjusted moisture was placed in a 500cc plastic bottle. After adding a prescribed amount of the agent, the bottle was covered and mixed by rotating the bottle upside down 5 times. An acrylic tube with an inner diameter of 60mm and a height of 100mm was placed on a stainless steel flat plate, and the mixed sample was filled to the top, and then the tube was removed. After leaving it for 1 minute, the height of the sample was measured. The lower the height after removing the tube, the higher the cohesiveness and the better the agent was evaluated to be, with a high ability to retain the original shape.
The results are shown in Table 2 for Examples 13 to 15 and Comparative Examples 16 to 19.
In the table, the type of chemical is recorded as "thickener" for the O/W emulsion type thickener (Acryset, manufactured by Nippon Shokubai Co., Ltd.) and "flocculant" for the W/O emulsion type flocculant (Lockmaster, manufactured by Hymo Co., Ltd.).
The evaluation was made as follows: ◯ (excellent) for a height of 90 mm or more, △ (passable) for a height of less than 90 mm or 80 mm or more, and × (unacceptable) for a height of less than 80 mm. In Examples 13 to 15, in which a polyacrylic acid-based thickener was used, an evaluation result of △ or ◯ was obtained even with a relatively small amount of agent applied, whereas in Comparative Examples 16 to 19, in which no agent was applied or a polyacrylamide-based flocculant was used, the agent was not mixed uniformly, the particle aggregation was weakened, and the shape was lost, resulting in an evaluation of ×.
（実施例１６～２０、比較例２０～２５）
鉄鉱石として粒径５ｍｍ以下に篩分けし、水分含有量を１４質量％に調整したカラジャス鉱石を用い、実施例１４と同様の崩れやすさ確認試験を行った。
薬剤は、実施例１で使用したＯ／Ｗ型エマルジョン型増粘剤（（株）日本触媒製アクリセット、固形分濃度（ポリアクリル酸系高分子濃度）３０質量％）を用い、増粘剤の拡散性をより向上させるため、水とポリアクリル酸系高分子との質量比（水／ポリアクリル酸系高分子＝固形分質量比（水／固形分））が所定の比率となるように、水で増粘剤を希釈してから鉄鉱石に加えた。
その結果を表３の実施例１６～２０に示す。評価は高さが９０ｍｍ以上を〇（優）、高さが９０ｍｍ未満、８０ｍｍ以上を△（可）、８０ｍｍ未満を×（不可）とした。増粘剤を希釈することにより、増粘剤をより均一に混合することができ、形状の崩れがより小さくすることができたが、希釈倍率が高くなり過ぎると、鉄鉱石に含有される水分量が多くなり、若干形状の崩れが大きくなり、高さが低くなった。
比較のため、比較例１で使用したＷ／Ｏエマルジョン型凝集剤（ハイモ（株）製ロックマスター、固形分濃度（ポリアクリルアミド系高分子濃度）４０質量％）を用い、水とポリアクリルアミド系高分子との質量比（水／ポリアクリルアミド系高分子＝固形分質量比（水／固形分））が所定の比率となるように、水で凝集剤を希釈してから鉄鉱石に加えた。
その結果を表３の比較例２０～２５に示す。比較例２０～２４では、凝集剤に水を加えると凝集剤がゲル化し、均一に混合することができず、凝集性が悪化した。比較例２５では、薬剤が流動するようにはなったが、粘性は高く、混合状態の不均一性が改善されなかったとともに、鉄鉱石に含有される水分量が多くなり、形状の崩れが大きく、高さ低くなり、不適であった。
(Examples 16 to 20, Comparative Examples 20 to 25)
Carajas ore was used as the iron ore, which had been sieved to a particle size of 5 mm or less and had a moisture content adjusted to 14 mass%, and a crumbling test similar to that of Example 14 was conducted.
The agent used was the O/W emulsion thickener used in Example 1 (Acryset, manufactured by Nippon Shokubai Co., Ltd., solids concentration (polyacrylic acid polymer concentration) 30% by mass). In order to further improve the diffusibility of the thickener, the thickener was diluted with water and then added to the iron ore so that the mass ratio of water to polyacrylic acid polymer (water/polyacrylic acid polymer=solids mass ratio (water/solids)) was a predetermined ratio.
The results are shown in Table 3 for Examples 16 to 20. The evaluation was made as follows: ◯ (excellent) for a height of 90 mm or more, △ (passable) for a height of less than 90 mm and 80 mm or more, and × (unacceptable) for a height of less than 80 mm. By diluting the thickener, it was possible to mix the thickener more uniformly and reduce deformation, but if the dilution rate was too high, the moisture content in the iron ore increased, causing some deformation and a decrease in height.
For comparison, the W/O emulsion type flocculant used in Comparative Example 1 (Lockmaster manufactured by Hymo Co., Ltd., solids concentration (polyacrylamide polymer concentration) 40% by mass) was used and was diluted with water and then added to the iron ore so that the mass ratio of water to polyacrylamide polymer (water/polyacrylamide polymer=solids mass ratio (water/solids)) became a predetermined ratio.
The results are shown in Table 3 for Comparative Examples 20 to 25. In Comparative Examples 20 to 24, when water was added to the flocculant, the flocculant gelled, making it impossible to mix uniformly, and the flocculation properties deteriorated. In Comparative Example 25, the agent became fluid, but the viscosity was high, and the non-uniformity of the mixed state was not improved. In addition, the water content in the iron ore increased, causing significant deformation and a small height, making it unsuitable.
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| JP2002088418A (en) | 2000-09-11 | 2002-03-27 | Nippon Steel Corp | Granulating agent for iron making and granulating method using the same |
| JP2009280849A (en) | 2008-05-21 | 2009-12-03 | Nippon Shokubai Co Ltd | Pelletizing agent for iron-making raw material and pelletization method using the same |
| WO2015151524A1 (en) | 2014-04-01 | 2015-10-08 | Ｊｆｅスチール株式会社 | Water-containing bulk material treatment method, and device for adding flocculant to water-containing bulk material |
| JP2018058017A (en) | 2016-10-04 | 2018-04-12 | 栗田工業株式会社 | Method for preventing adhesion and clogging of mineral raw materials |
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| JP2002088418A (en) | 2000-09-11 | 2002-03-27 | Nippon Steel Corp | Granulating agent for iron making and granulating method using the same |
| JP2009280849A (en) | 2008-05-21 | 2009-12-03 | Nippon Shokubai Co Ltd | Pelletizing agent for iron-making raw material and pelletization method using the same |
| WO2015151524A1 (en) | 2014-04-01 | 2015-10-08 | Ｊｆｅスチール株式会社 | Water-containing bulk material treatment method, and device for adding flocculant to water-containing bulk material |
| JP2018058017A (en) | 2016-10-04 | 2018-04-12 | 栗田工業株式会社 | Method for preventing adhesion and clogging of mineral raw materials |
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