JP3792583B2 - Granulation treatment agent for iron making and granulation treatment method using the same - Google Patents

Description

【００８６】
上記の焼結原料７００００部をドラムミキサーに投入し、回転速度２４ｍｉｎ^-1で１分間、予備攪拌した。その後、同回転速度で攪拌しながら、該焼結原料に、予め調製した本発明にかかる製鉄用造粒処理剤（１）５２５０部を霧吹きを用いて約１．５分間かけて噴霧した。焼結原料に対する高分子化合物の割合、すなわち、本発明の製鉄用造粒処理剤（１）に含有される高分子化合物の割合は０．０３％であった。噴霧後、さらに同回転速度で３分間攪拌することにより、造粒操作を行った。
【００８７】
得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【００８８】
〔実施例２〕
攪拌機およびコンデンサを備えた容量５Ｌのセパラブルフラスコ（ＳＵＳ３１６製）に、イオン交換水８０５．５部を仕込み、攪拌下、系の沸点（１００℃）まで昇温した。
【００８９】
続いて、上記セパラブルフラスコ内に、カルボキシル基含有単量体としての８０％アクリル酸水溶液２１２６．１部、並びに、重合開始剤としての１５％過硫酸ナトリウム水溶液１１２．４部および連鎖移動剤としての４５％次亜リン酸ナトリウム一水和物水溶液８８．５部を滴下した。上記８０％アクリル酸水溶液、１５％過硫酸ナトリウム水溶液、４５％次亜リン酸ナトリウム一水和物水溶液は、それぞれ別々の滴下口より滴下した。８０％アクリル酸水溶液は１８０分間で滴下した。１５％過硫酸ナトリウム水溶液は１８５分間で滴下した。４５％次亜リン酸ナトリウム一水和物水溶液は１８０分間で滴下した。滴下時間中、反応温度は系の沸点を維持した。滴下終了後、同温度に５分間保持した後、中和剤としての４８％水酸化ナトリウム水溶液１８８９．０部を６０分間かけて滴下することにより、重合体水溶液を得た。このようにして得られた重合体水溶液中の重合体（高分子化合物）の数平均分子量、多分散度、酸価、クレー分散能を測定、算出したところ、数平均分子量は２９００、多分散度は４．２１、酸価は１１．１ｍｍｏｌ／ｇ、クレー分散能は１．３０であった。
【００９０】
また、得られた重合体水溶液を固形分換算で２１部となるように採取し、これをイオン交換水で希釈し、５２５０部にすることにより本発明にかかる製鉄用造粒処理剤（２）を得た。
【００９１】
その後、実施例１において、製鉄用造粒処理剤（１）に代えてこの製鉄用造粒処理剤（２）を用いて実施例１と同様の操作により造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【００９２】
〔実施例３〕
攪拌機およびコンデンサを備えた容量５Ｌのセパラブルフラスコ（ＳＵＳ３１６製）に、イオン交換水８０５．５部および連鎖移動剤としての４５％次亜リン酸ナトリウム一水和物水溶液４０．１部を仕込み、攪拌下、系の沸点（１００℃）まで昇温した。
【００９３】
続いて、上記セパラブルフラスコ内に、カルボキシル基含有単量体としての８０％メタクリル酸水溶液２１２６．１部、並びに、重合開始剤としての１５％過硫酸ナトリウム水溶液１１２．４部および４５％次亜リン酸ナトリウム一水和物水溶液１６０．２部を滴下した。上記８０％メタクリル酸水溶液、１５％過硫酸ナトリウム水溶液、４５％次亜リン酸ナトリウム一水和物水溶液は、それぞれ別々の滴下口より滴下した。８０％アクリル酸水溶液は１８０分間で滴下した。１５％過硫酸ナトリウム水溶液は１８５分間で滴下した。４５％次亜リン酸ナトリウム一水和物水溶液は１８０分間で滴下した。滴下時間中、反応温度は系の沸点を維持した。滴下終了後、同温度に１０分間保持した後、中和剤としての４８％水酸化ナトリウム水溶液１５９５．１部を６０分間かけて滴下することにより、重合体水溶液を得た。このようにして得られた重合体水溶液中の重合体（高分子化合物）の数平均分子量、多分散度、クレー分散能を測定、算出したところ、数平均分子量は１９００、多分散度は３．３１、クレー分散能は１．１１であった。
【００９４】
また、得られた重合体水溶液を固形分換算で２１部となるように採取し、これをイオン交換水で希釈し、５２５０部にすることにより本発明にかかる製鉄用造粒処理剤（３）を得た。
【００９５】
その後、実施例１において、製鉄用造粒処理剤（１）に代えてこの製鉄用造粒処理剤（３）を用いて実施例１と同様の操作により造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【００９６】
〔実施例４〕
攪拌機およびコンデンサを備えた容量１Ｌのセパラブルフラスコ（ＳＵＳ３１６製）に、イオン交換水３５５部、カルボキシル基含有単量体としての無水マレイン酸９８部および中和剤としての水酸化ナトリウム８０部を仕込んで中和させ、攪拌下、系の沸点（１００℃）まで昇温した。
【００９７】
続いて、上記セパラブルフラスコ内に、カルボキシル基含有単量体としての４０％アクリル酸水溶液１８０部、並びに、重合開始剤としての１０％過硫酸ナトリウム水溶液１００部および１４％過酸化水素水溶液１００部を滴下した。上記４０％アクリル酸水溶液、１０％過硫酸ナトリウム水溶液１００部、１４％過酸化水素水溶液は、それぞれ別々の滴下口より４時間かけて滴下した。滴下時間中、反応温度は系の沸点を維持した。滴下終了後、同温度に６０分間保持した後、中和剤としての４９％水酸化ナトリウム水溶液５７部を６０分間かけて滴下することにより、重合体水溶液を得た。このようにして得られた重合体水溶液中の重合体（高分子化合物）の数平均分子量、多分散度、クレー分散能を測定、算出したところ、数平均分子量は１２００、多分散度は４．９４、クレー分散能は０．９８であった。
【００９８】
また、得られた重合体水溶液を固形分換算で２１部となるように採取し、これをイオン交換水で希釈し、５２５０部にすることにより本発明にかかる製鉄用造粒処理剤（４）を得た。
【００９９】
その後、実施例１において、製鉄用造粒処理剤（１）に代えてこの製鉄用造粒処理剤（４）を用いて実施例１と同様の操作により造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【０１００】
〔実施例５〕
攪拌機およびコンデンサを備えた容量１Ｌのセパラブルフラスコ（ＳＵＳ３１６製）に、イオン交換水１４００部を仕込み、攪拌下、系の沸点（１００℃）まで昇温した。
【０１０１】
続いて、上記セパラブルフラスコ内に、カルボキシル基含有化合物としての８０％アクリル酸水溶液５７８．５部および重合開始剤としての１５％過硫酸アンモニウム水溶液６２．５部をそれぞれ別々の滴下口より２時間かけて滴下した。滴下時間中、反応温度は系の沸点を維持した。滴下終了後、同温度に１２０分間保持した後、中和剤としての４８％水酸化ナトリウム水溶液３５３部を６０分間かけて滴下することにより、重合体水溶液を得た。このようにして得られた重合体水溶液中の重合体（高分子化合物）の数平均分子量、多分散度、酸価、クレー分散能を測定、算出したところ、数平均分子量は４９００、多分散度は９．８４、酸価は１０．７ｍｍｏｌ／ｇ、クレー分散能は０．６５であった。
【０１０２】
また、得られた重合体水溶液を固形分換算で２１部となるように採取し、これをイオン交換水で希釈し、５２５０部にすることにより本発明にかかる製鉄用造粒処理剤（５）を得た。
【０１０３】
その後、実施例１において、製鉄用造粒処理剤（１）に代えてこの製鉄用造粒処理剤（５）を用いて実施例１と同様の操作により造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【０１０４】
〔実施例６〕
攪拌機およびコンデンサを備えた容量５Ｌのセパラブルフラスコ（ＳＵＳ３１６製）に、イオン交換水３００部を仕込み、攪拌下、沸点まで昇温した。
【０１０５】
そこに、カルボキシル基含有化合物としての８０％アクリル酸水溶液７２０部、重合開始剤としての１５％過硫酸ナトリウム水溶液１０６．７部および重亜硫酸ナトリウム水溶液１８２．９部、イオン交換水１２６．５部、並びに中和剤としての４８％水酸化ナトリウム水溶液６００部をそれぞれ別々の滴下口より１２０分間かけて滴下した。滴下時間中、反応温度は沸点を維持した。滴下終了後、沸点に３０分間保持した。このようにして得られた重合体水溶液中の重合体（高分子化合物）の数平均分子量、多分散度、酸価、クレー分散能を測定、算出したところ、数平均分子量は５２００、多分散度は１１．８、酸価は８．７、クレー分散能は０．５１であった。
【０１０６】
また、得られた重合体水溶液を固形分換算で２１部となるように採取し、これをイオン交換水で希釈し、５２５０部にすることにより本発明にかかる製鉄用造粒処理剤（６）を得た。
【０１０７】
その後、実施例１において、製鉄用造粒処理剤（１）に代えてこの製鉄用造粒処理剤（６）を用いて実施例１と同様の操作により造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。この結果を、用いた高分子化合物の前記物性と併せて表２に示す。
【０１０８】
〔比較例１〕
数平均分子量２１０００、多分散度７．５７のポリアクリル酸ナトリウムを固形分換算で２１部となるように採取し、これをイオン交換水で希釈して５２５０部に調整した比較用の製鉄用造粒処理剤（Ｉ）を実施例５の製鉄用造粒処理剤（５）の代わりに用いた以外は実施例５と同様にして造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。ＧＩ指数は８７．２であった。また、上記ポリアクリル酸ナトリウムのクレー分散能は０．３２、酸価は１０．８ｍｍｏｌ／ｇであった。この結果を、上記ポリアクリル酸ナトリウムの前記物性と併せて表２に示す。
【０１０９】
〔比較例２〕
アクリル酸−マレイン酸共重合体のナトリウム塩（アクリル酸：マレイン酸の組成比５０：５０）を固形分換算で２１部となるように採取し、これをイオン交換水で希釈して５２５０部に調整した比較用の製鉄用造粒処理剤（II）を実施例５の製鉄用造粒処理剤（５）の代わりに用いる他は実施例５と同様にして造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。ＧＩ指数は８８．１であった。上記アクリル酸−マレイン酸共重合体のナトリウム塩としては、数平均分子量が７４００、多分散度が１３．５、クレー分散能が０．２９のものを使用した。
【０１１０】
〔比較例３〕
生石灰１４００部と水５２５０部とを併用し、これを比較用の製鉄用造粒処理剤（III）として、実施例５の製鉄用造粒処理剤（５）５２５０部の代わりに用いる他は実施例５と同様にして造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を測定した。ＧＩ指数は７６．２であった。
【０１１１】
〔比較例４〕
アクリル酸−マレイン酸共重合体のナトリウム塩（アクリル酸：マレイン酸の組成比７０：３０）を固形分換算で２１部となるように採取し、これをイオン交換水で希釈して５２５０部に調整した比較用の製鉄用造粒処理剤（IV）を実施例５の製鉄用造粒処理剤（５）の代わりに用いる他は実施例５と同様にして造粒を行い、得られた擬似粒子を乾燥後、ふるいを用いて分級することにより、造粒後の粒径が０．２５ｍｍ以下の擬似粒子のＧＩ指数を求めた。ＧＩ指数は８８．４であった。上記アクリル酸−マレイン酸共重合体のナトリウム塩としては、数平均分子量が３０００、多分散度が１６．５、クレー分散能が０．４４のものを使用した。
【０１１２】
【表２】

【０１１３】
表２に示す結果から明らかなように、本発明にかかる高分子化合物を含む製鉄用造粒処理剤を少量用いることにより、ＧＩ指数、すなわち、鉄鉱石の造粒性を大きく増加させることができることが判る。
【０１１４】
また、この結果から、本発明にかかる高分子化合物を含む製鉄用造粒処理剤を少量用いることにより、擬似粒子を焼結してなる焼結機の生産率、成品歩留、焼結鉱強度を向上させることができることが推察される。焼結鉱強度が弱い焼結鉱は微粉が発生し易くなるので、返鉱が多くなり成品歩留が低下し、その生産効率が低下する。
【０１１５】
【発明の効果】
本発明にかかる製鉄用造粒処理剤は、以上のように、微粉の鉄鉱石を含む製鉄用原料を造粒処理するのに用いる処理剤であって、カルボキシル基および／またはその塩を含有し、数平均分子量が５００以上、２００００以下の範囲内であり、かつ、重量平均分子量／数平均分子量で表される多分散度が１．２以上、１２．０以下の範囲内である高分子化合物を含む構成である。
【０１１６】
また、本発明にかかる製鉄用造粒処理剤では、以上のように、上記高分子化合物は、クレー分散能が０．５以上である水溶性の高分子化合物であることが好ましい。
【０１１７】
本発明にかかる上記各高分子化合物は、微粉の鉄鉱石を含む製鉄用原料（焼結原料またはペレット原料）を造粒処理（擬似粒化またはペレット化）する際に、微粉粒子を核粒子の周りに付着させる効果に優れ、焼結機の生産効率を向上させることができ、それゆえ、製鉄用造粒処理剤を安価に提供することができるという効果を奏する。
【０１１８】
本発明にかかる造粒処理方法は、以上のように、本発明にかかる上記製鉄用造粒処理剤を上記製鉄用原料に添加する構成である。
【０１１９】
これにより、焼結鉱を得るべく微粉の鉄鉱石を含む製鉄用原料（焼結原料またはペレット原料）を造粒処理（擬似粒化またはペレット化）するのに好適な造粒処理方法を提供することができるという効果を奏する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a sintered ore or a pellet producing method as a raw material for iron making, and when granulating the raw material for iron making, in particular, adjusting the moisture of the raw material for iron making, The present invention relates to a granulating agent for iron making suitably used for pelletization and a granulating method using the same.
[0002]
[Prior art]
In the production of sintered ore, iron ore as a raw material for sintering, auxiliary materials, fuel, etc. are first mixed and granulated while adjusting moisture with a granulator such as a drum mixer, pelletizer, Eirich mixer, etc. Build particles. Pseudo particles are particles in which fine particles of 0.5 mm or less are generally attached to 1 to 3 mm core particles. At this time, the action required for granulation is to improve the quasi-granulating property that fine powder particles adhere around the core particles, and that the quasi-particles are difficult to disintegrate in a wet zone, a dry zone, etc. in the sintering process. is there. By making the sintering raw material into pseudo particles in this way, the air permeability in the sintering raw material packed layer (sintering bed) on the sintering machine can be improved, and the productivity of the sintering machine can be improved. .
[0003]
The sintering machine that sinters the sintering raw material adopts the downward suction type, and by sucking from the lower side of the sintering raw material, the air necessary for the sintering is circulated and the upper side of the sintering raw material from the lower side The sintering raw material is sintered by burning the fuel toward the head. For this reason, if the sintering raw material contains a large amount of fine powder, the air permeability decreases due to clogging and the like, and the combustion rate of coke as a fuel becomes slow, so the production efficiency of the sintering machine decreases. Therefore, in order to improve the air permeability, a pretreatment such as granulating (pseudo-granulating) the sintered raw material is necessary. As the pretreatment, for example, a granulation operation such as adding a small amount of water to the sintered raw material and stirring it is performed. However, in the granulation operation using only water, since the effect of improving the pseudo-granulating property is poor, the amount of fine powder contained in the sintered raw material cannot be reduced so much.
[0004]
For this reason, conventionally, as a countermeasure for improving the pseudo-granulating property, a method of adding various granulating additives as a binder to the sintered raw material has been proposed. Many are known as granulation additives. For example, bentonite, lignin sulfite (pulp waste liquor), starch, sugar, molasses, water glass, cement, gelatin, corn starch and the like have been studied for use as binders or thickeners.
[0005]
JP-A-59-50129 discloses a pretreatment method of a sintering raw material using water containing a specific concentration of a dispersant and / or a specific concentration of a surfactant. Describes an acrylic acid polymer, a maleic acid polymer, a styrene sulfonic acid polymer, and the like having an average molecular weight of 2000 to 20000.
[0006]
JP-A-61-61630 describes a binder for producing sintered ore containing a water-soluble polymer compound such as a maleic acid polymer having an average molecular weight of 500 to 300,000.
[0007]
However, both of these have the problem that the pseudo-granulating property is insufficient in the production of sintered ore, and although the amount of fine particles contained in the sintered raw material can be reduced, In addition to the inadequate amount, collapse in the water condensation zone during transportation and in the sintering bed is inevitable, so the added amount is relatively high and the cost is high, and the amount to be used is secured. However, it is not used industrially.
[0008]
In addition to this, Japanese Patent Application Laid-Open No. 52-117820 and Japanese Patent Application Laid-Open No. 3-183729 have a description of what is characterized by adding fine powders such as iron ore and calcium carbonate. There are problems such as insufficient properties, and it is not used industrially.
[0009]
As a granulating additive currently in practical use, for example, quicklime disclosed in Steel Manufacturing Research No. 288 (1976), page 9, is widely used. According to this, the effect of quicklime is shown as follows. First, it is possible to promote pseudo-granulation in the mixer. Secondly, in the sintering process after filling the sintering raw material consisting of pseudo particles at a specific height and igniting the surface layer after forming the sintering bed, the pseudo particles collapse in the process of drying and heating It is said that a uniform air flow in the sintered layer can be maintained.
[0010]
On the other hand, in the manufacture of pellets, iron ore, dust, carbonaceous materials, and the like, which are raw materials, are mixed and then granulated while adjusting moisture with a granulator such as a pelletizer. A pellet generally refers to a particle having particles of 1.0 mm or less solidified into a spherical shape of 6.0 to 50 mm. Under the present circumstances, the effect | action calculated | required by granulation is that the intensity | strength in the state of the raw pellet before drying is high, it is destroyed during a drying process or a transport process, and is not pulverized. Conventionally, in order to improve the strength of the pellets, 1% by weight or more of bentonite as a granulation additive is added to the fine powder material and kneaded, and granulation is performed while sprinkling an appropriate amount of water to produce pellets. A method has been proposed. In addition, the pellet described here becomes a blast furnace raw material, a sintering raw material, a converter raw material, or the like, and a manufacturing method thereof is not particularly limited.
[0011]
[Problems to be solved by the invention]
However, in the production of sintered ore, the use of binders such as quick lime and molasses is generally expensive, leading to an increase in production cost. Moreover, although the granulation method using quick lime has been put into practical use, quick lime is easy to absorb moisture, and since it generates heat at this time, there is a problem that care is required. Moreover, since the quick lime currently used cannot obtain a sufficient effect unless the usage-amount is comparatively increased, cost becomes high. Therefore, the current situation is that the amount of use is reduced as much as possible. And even if it adds 2 weight% or more of quicklime, the improvement effect of the pseudo-granulation property tends to reach a peak. In addition, recently, with the depletion of high-quality ores, the deterioration of fine ore is also severe, and there is a problem that the granulation property of the sintered raw material is worse than before. For this reason, even if granulation is performed by adding quicklime, the effect is smaller than before. Furthermore, binders other than quicklime are insufficient in the effect of reducing the amount of fine powder contained in the sintering raw material, and are less effective in improving the air permeability of the sintering bed and shortening the sintering time. The strength of the sinter is low. A sinter with weak sinter strength, for example, is likely to generate fine powder during crushing after sintering, so that the amount of returned ore is increased, the product yield is lowered, and the production efficiency is lowered. For this reason, the granulation method using binders other than quicklime has not been put into practical use.
[0012]
Even when quicklime is used, the effect of reducing the amount of fine powder contained in the sintered raw material is still not sufficient. On the other hand, although there is an idea that a binder other than quicklime and quicklime are used together, a known binder other than quicklime has the effect of reducing the amount of fine powder contained in the sintered raw material even when used in combination with quicklime. The expensive one is not known.
[0013]
Therefore, an inexpensive binder that is excellent in the effect of improving the pseudo-granulating property and can improve the production efficiency of the sintering machine, that is, a binder that can be suitably used for granulating a sintered raw material, and There is a need for a granulation method using this.
[0014]
On the other hand, when bentonite is used in the production of pellets, a large amount of water needs to be added during granulation because of its high swelling property. For this reason, since raw pellets are soft, they are easily deformed, the gas permeability deteriorates during the drying process, and there is a problem that it takes a long time to perform sufficient drying and the strength decreases. Further, bentonite contains a large amount of impurity components such as silicon, and there is a problem that the hot metal and slag in the molten steel are increased.
[0015]
The present invention has been made in view of the above-described conventional problems, and the object thereof is an inexpensive iron-making granulating agent that is suitably used for granulating and pseudo-granulating or pelletizing iron-making raw materials. And it is providing the granulation processing method using the same.
[0016]
[Means for Solving the Problems]
  The inventors of the present application, when granulating a steelmaking raw material containing fine iron ore, have a better granulation effect than conventional granulation treatment agents for ironmaking, that is, an improvement effect of pseudo graininess. Intensive study to provide a granulating agent and a granulating methodResults containing carboxyl groups and / or salts thereof,Combines a specific number average molecular weight with a specific polydispersityHigh molecular compounds as essential componentsThe present invention was completed by finding that a granulation effect significantly improved over the prior art can be obtained by granulating a raw material for iron making containing fine iron ore using a granulating agent for iron making. It was.
[0017]
  That is, the iron granulation treatment agent of the present invention is a treatment agent used for granulating a steelmaking raw material containing fine iron ore in order to solve the above problems,11. It contains a carboxyl group and / or a salt thereof, has a number average molecular weight in the range of 500 or more and 20000 or less, and a polydispersity expressed by weight average molecular weight / number average molecular weight is 1.2 or more, and 12. Within 0 or lessIt is characterized by containing a polymer compound.
[0018]
  Granulation treatment agent for iron making of the present inventionThen,the aboveThe polymer compound is preferably a water-soluble polymer compound having a clay dispersibility of 0.5 or more. In addition, in this invention, clay dispersibility means the value of the light absorbency (ABS) measured about a polymer (polymer compound) with the method shown in the Example.
[0019]
In order to solve the above problems, the granulating agent for iron making according to the present invention is such that the polymer compound has (a) polyacrylic acid, (b) part or all of the carboxyl groups contained in polyacrylic acid. It is characterized by being at least one compound selected from the group consisting of at least one neutralized polyacrylate selected from the group consisting of sodium, potassium, calcium and ammonia.
[0020]
In order to solve the above problems, the granulation treatment method of the present invention is a method of granulating a raw material for iron making containing fine iron ore, and the granulation treatment agent for iron making is added to the raw material for iron making. It is characterized by that.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The granulating agent for iron making according to the present invention is a treating agent used for granulating a raw material for iron making (sintered raw material or pellet raw material) containing fine iron ore,
(A) Water-soluble polymer compound having a clay dispersibility of 0.5 or more
(B) containing a carboxyl group and / or a salt thereof, having a number average molecular weight in the range of 500 or more and 20000 or less, and a polydispersity expressed by weight average molecular weight / number average molecular weight of 1.2 or more It is the structure which contains at least one of the high molecular compound which exists in the range of 12.0 or less as an essential component.
[0022]
Further, the granulation treatment method according to the present invention is a method for mixing and humidity-regulating an iron-making raw material containing fine iron ore, wherein the iron-making granulation treatment agent is used as the iron-making raw material. It is a method of adding. In particular, the granulation treatment method of the present invention preferably includes a step of adding the above-mentioned granulation treatment agent for iron making to a raw material for iron making containing fine iron ore of 0.5 mm or less.
[0023]
In the above granulation treatment, the role of the polymer compound (A) and the polymer compound (B) is that fine iron ore and / or clay adhering to the iron ore contained in the raw material for iron making are used. It is to disperse in the water for granulation. That is, in the present invention, the polymer compound (A) and the polymer compound (B) are used as a dispersant.
[0024]
The reason why the polymer compound (A) and the polymer compound (B) exhibit high granulation properties in the granulation of iron ore is not clear, but is considered as follows.
That is, the iron ore contains clay, and by adding the polymer compound (A) and / or the polymer compound (B) to the raw material for iron making, fine iron ore and / or the The clay adhering to the iron ore is finely dispersed in the water for granulation. Finely dispersed fine iron ore and clay act as a binder between the iron ore and fine iron ore.
At this time, by using a water-soluble polymer compound having a clay dispersibility of 0.5 or more as a dispersant, the clay contained in the iron ore is finely dispersed on a submicron order, and the finely dispersed clay is obtained. It acts as a binder between iron ore and fine iron ore. Using iron ore powder of the order of micron or more as a core particle, iron ore powder of the order of micron or more and fine iron ore of milli order By splicing, pseudo particles are made. As a result, high granulation property is obtained, and it is considered that the fine powder of iron ore is reduced (granulation property is improved).
[0025]
Therefore, if a polymer compound having higher clay dispersibility is added to the raw material for iron making, the amount of clay dispersed is increased (binding force is increased), and the granulation property is improved.
[0026]
The polymer compound (A) according to the present invention is characterized by being water-soluble and having a clay dispersibility of 0.5 or more in order to exhibit the above-described effects. In the present invention, the polymer compound means a compound having a number average molecular weight of 500 or more. Therefore, the polymer compound (A) used in the present invention is a water-soluble compound having a number average molecular weight of 500 or more and a clay dispersibility of 0.5 or more.
[0027]
As described above, the clay dispersibility increases as the clay dispersibility increases. For this reason, the clay dispersibility is preferably 0.6 or more, more preferably 0.9 or more, and most preferably 1.1 or more. A water-soluble polymer compound having a clay dispersibility of 0.5 or more is remarkably excellent in pseudo-granulating property, and can greatly increase the granulating property of iron ore.
[0028]
The number average molecular weight of the polymer compound (A) is not particularly limited as long as it is 500 or more, but its lower limit (number average molecular weight) is preferably 800, and preferably 1000. More preferred. Moreover, the upper limit (number average molecular weight) is preferably 100,000, and more preferably 30,000. When the number average molecular weight is less than 500, the pseudo-granulating property tends to be lowered, and the above-described clay dispersibility cannot be obtained. On the other hand, when the number average molecular weight exceeds 100,000, the viscosity becomes too high, the polymer compound (A) does not sufficiently turn around the iron ore, and there is a possibility that the pseudo-granulating property is lowered.
[0029]
The polymer compound (A) used in the present invention is not particularly limited as long as the above-described conditions are satisfied. As long as the polymer compound (A) satisfies the above-mentioned conditions, any known water-soluble polymer compound; a polymer obtained by making a known water-insoluble polymer compound water-soluble by a known hydrophilization technique A known monomer is selected from known polymerization techniques such as radical polymerization, cationic polymerization, anionic polymerization, coordination anionic polymerization, polycondensation and the like (co) polymer; be able to.
[0030]
Specifically, as the polymer compound (A), for example, (a) polyacrylic acid, (b) part or all of the carboxyl groups contained in polyacrylic acid are composed of sodium, potassium, calcium, and ammonia. And at least one compound selected from the group consisting of polyacrylates neutralized with at least one selected from the group.
[0031]
The above compounds (a) and (b) include a copolymer containing acrylic acid as a main component. The copolymerization component (copolymerizable monomer) in the case where polyacrylic acid is a copolymer is not particularly limited. The compound (b) is not particularly limited as long as at least a part of polyacrylic acid is neutralized with a neutralizing agent. Polyacrylic acid is dissolved in water by neutralizing at least a part thereof with a basic neutralizing agent or as it is (without neutralization). As a result, the granulating agent for iron making containing the compound (a) and / or (b) as a polymer compound according to the present invention has sufficient performance even with a small amount of use.
(Effect) can be exhibited. Specific examples of the neutralizing agent include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; basic carbonates such as sodium carbonate, sodium hydrogen carbonate, ammonium carbonate, and ammonium hydrogen carbonate; Nitrogen-containing bases such as aqueous ammonia and monoethanolamine are mentioned, but are not particularly limited.
[0032]
In addition, the compound (b) can be easily obtained, for example, by polymerizing acrylate or copolymerizing acrylic acid and acrylate. Specific examples of the acrylate include alkali metal salts such as sodium salt and potassium salt of acrylic acid; alkaline earth metal salts such as calcium salt; ammonium salts; amine salts and the like. Is not to be done.
[0033]
Further, as an example of the polymer compound (A), specifically, for example, it contains a carboxyl group and / or a salt thereof, the number average molecular weight is in the range of 500 or more and 20000 or less, and the weight. Examples thereof include a polymer compound having a polydispersity represented by average molecular weight / number average molecular weight within a range of 1.2 or more and 12.0 or less. Among the polymer compounds (A), a polymer compound satisfying the condition (B), that is, the polymer compound (B) is preferable.
[0034]
In the present invention, the polydispersity is calculated using the weight average molecular weight and the number average molecular weight.
Polydispersity = weight average molecular weight / number average molecular weight
Defined by As the weight average molecular weight and the number average molecular weight used in the present invention, values obtained by the measurement method described in detail in Examples described later are used.
[0035]
The polydispersity in the polymer compound (B) is not particularly limited as long as it is in the range of 1.2 or more and 12.0 or less, but the lower limit is preferably 1.3. 1.5 is more preferable, and 1.7 is particularly preferable. On the other hand, the upper limit is preferably 10, more preferably 7.0, and most preferably 5.0. If the polydispersity is less than 1.2, the strength of the raw material for ironmaking after granulation tends to be reduced. On the other hand, even if the polydispersity is greater than 12.0, a sufficient granulation effect cannot be obtained. The closer the polydispersity is to 1, the smaller the molecular weight distribution.
[0036]
The number average molecular weight of the polymer compound (B) is not particularly limited as long as it is in the range of 500 or more and 20000 or less, but the lower limit is preferably 800, and 1000. More preferably, 1200 is particularly preferable. On the other hand, the upper limit is preferably 10,000, more preferably 7000, and particularly preferably 5000. When the number average molecular weight is less than 500 or more than 20000, a sufficient granulation effect cannot be obtained.
[0037]
The combination of the number average molecular weight and the polydispersity in the polymer compound (B) used in the present invention is not particularly limited as long as both satisfy the above conditions.
[0038]
The polymer compound (B) used in the present invention is, for example, a carboxyl group-containing monomer alone, or other monomers copolymerizable with the carboxyl group-containing monomer, It can be obtained by (co) polymerization in the presence of a polymerization initiator.
[0039]
Specific examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, crotonic acid, acrylamide glycolic acid, and salts thereof. However, it is not particularly limited. These carboxyl group-containing monomers may be used alone or in appropriate combination of two or more. Among the carboxyl group-containing monomers exemplified above, (meth) acrylic acid is preferable, and acrylic acid is particularly preferable.
[0040]
When a salt of a carboxylic acid group-containing monomer is used as the carboxyl group-containing monomer, the neutralizing base is not particularly limited, but alkali metal ions such as potassium ion and sodium ion; calcium Examples include alkaline earth metal ions such as ions; nitrogen-containing bases such as ammonium and primary to quaternary amines.
[0041]
Among the polymer compounds of (B), those obtained by (co) polymerizing acrylic acid are preferable, and the polymer compound contains (a) polyacrylic acid and (b) polyacrylic acid. Preferably, at least one compound selected from the group consisting of at least one neutralized polyacrylic acid salt selected from the group consisting of sodium, potassium, calcium and ammonia is used.
[0042]
The polymer compound (B) according to the present invention includes a unit derived from the carboxyl group-containing monomer and, if necessary, other monomer capable of copolymerization with the carboxyl group-containing monomer. It may contain a body-derived unit. That is, in the present invention, when obtaining the polymer compound of the above (B), in addition to the carboxyl group-containing monomer, any monomer copolymerizable with the carboxyl group-containing monomer It is also possible to carry out copolymerization in such a range that the proportion of the carboxyl group-containing monomer in the body (monomer component) is 45 mol% or more. A more preferable ratio of the carboxyl group-containing monomer in all monomers is in the range of 75 mol% to 100 mol%, and the most preferable range is in the range of 90 mol% to 100 mol%. If the ratio of the carboxyl group-containing monomer is less than 45 mol%, a sufficient granulation effect may not be obtained, which is not preferable.
[0043]
Specific examples of monomers constituting the units derived from the other monomers (hereinafter referred to as copolymerizable monomers) include, for example, vinyl sulfonic acid, styrene sulfonic acid, sulfoethyl (meth) acrylate. Sulfo group-containing monomers such as 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxypropyl acid phosphate, 2- (meth) acryloyloxy-3-chloropropyl acid phosphate, 2- (meth) ) Acid phosphate group-containing monomers such as acryloyloxyethylphenyl phosphate; Carbonate monomers such as vinylphenol; Acid group-containing monomers such as salts, and salts thereof
Polyalkylene glycol (meth) acrylic acid esters such as polyethylene glycol monomethacrylic acid ester, methoxypolyethylene glycol monomethacrylic acid ester, methoxypolyethylene glycol monoacrylic acid ester; ethylene oxide on 3-methyl-3-buten-1-ol A polyalkylene glycol monoalkenyl ether monomer formed by addition; a polyethylene glycol monoethenyl ether monomer formed by adding ethylene oxide to allyl alcohol; a polyethylene glycol half ester of maleic acid obtained by adding polyethylene glycol to maleic anhydride; And a polyalkylene glycol chain-containing monomer. Among the above polyalkylene glycol chain-containing monomers, a monomer containing a polyalkylene glycol chain having a chain length of 5 mol or more and 100 mol or less, preferably 10 mol or more and 100 mol or less in terms of ethylene oxide is easily available. In addition, it is preferable for improving the pseudo-granulating property, and is preferable in terms of polymerizability. One kind of these copolymerizable monomers may be used as needed, or two or more kinds may be used.
[0044]
Examples of copolymerizable monomers other than the above include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylic acid (N, N-dimethylamino). Ethyl), (meth) acrylic acid (N, N-diethylaminoethyl), aminoethyl (meth) acrylate, (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms; (meth) acrylamide, N-methyl (meta) ) Acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and other (meth) acrylamides and derivatives thereof; vinyl acetate; (meth) acrylonitrile; N-vinyl-2-pyrrolidone, vinylpyridine, Base-containing monomers such as vinylimidazole; N-methylol (meth) acrylamide, N-butyl (Meth) acrylamide monomers having crosslinkability such as xylmethyl (meth) acrylamide; vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloylpropyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane Silane monomers in which a hydrolyzable group is directly bonded to a silicon atom, such as allyltriethoxysilane; Epoxy group-containing monomers such as glycidyl (meth) acrylate and glycidyl ether (meth) acrylate; 2 -Oxazoline group-containing monomers such as isopropenyl-2-oxazoline and 2-vinyl-2-oxazoline; Aziridine group-containing monomers such as 2-aziridinylethyl (meth) acrylate and (meth) acryloylaziridine; Vinyl chloride, vinylidene fluoride, vinyl chloride, chloride Halogen group-containing monomers such as vinylidene; (meth) acrylic acid, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, Multifunctional (meth) acrylic acid ester having a plurality of unsaturated groups in the molecule, such as an esterified product with a polyhydric alcohol such as dipentaerythritol, etc .; having a plurality of unsaturated groups in the molecule such as methylenebis (meth) acrylamide Polyfunctional (meth) acrylamides; polyfunctional allyl compounds having a plurality of unsaturated groups in the molecule, such as diallyl phthalate, diallyl maleate, diallyl fumarate; allyl (meth) acrylate; divinylbenzene; In limited There. These copolymerizable monomers may also be used alone or in combination of two or more as required.
[0045]
In addition to these copolymerizable monomers, a chain transfer agent may be used for the purpose of adjusting the molecular weight. Specific examples of the chain transfer agent include compounds having a high chain transfer coefficient such as mercapto group-containing compounds such as mercaptoethanol, mercaptopropionic acid, and t-dodecyl mercaptan; carbon tetrachloride; isopropyl alcohol; toluene; Can be mentioned. These chain transfer agents may also be used alone or in combination of two or more as required. The amount of these chain transfer agents to be used is not particularly limited, but is suitably within a range of 0.005 to 0.15 mol with respect to 1 mol of the monomer, that is, a carboxyl group-containing monomer and a copolymerizable monomer. is there.
[0046]
The production method of the polymer compound (B), that is, the polymerization method of the monomer component is not particularly limited, and various conventionally known polymerization methods such as oil-in-water emulsion polymerization, oil A water-in-water emulsion polymerization method, suspension polymerization method, dispersion polymerization method, precipitation polymerization method, solution polymerization method, aqueous solution polymerization method, bulk polymerization method and the like can be employed. Among the polymerization methods exemplified above, the aqueous solution polymerization method is preferable from the viewpoints of reduction in polymerization cost (production cost) and safety.
[0047]
The polymerization initiator used in the above polymerization method may be a compound that decomposes by heat or a redox reaction to generate radical molecules. In the case of employing an aqueous solution polymerization method, a polymerization initiator having water solubility is preferable. Specific examples of the polymerization initiator include persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; 2,2′-azobis- (2-amidinopropane) dihydrochloride, 4,4 Water-soluble azo compounds such as' -azobis- (4-cyanopentanoic acid); thermal decomposable initiators such as hydrogen peroxide; hydrogen peroxide and ascorbic acid, t-butyl hydroperoxide and Rongalite, potassium persulfate and metals Examples thereof include, but are not particularly limited to, a redox polymerization initiator composed of a combination of a salt, ammonium persulfate, sodium hydrogensulfite, and the like. These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator used may be appropriately set according to the composition of the monomer component, the polymerization conditions, and the like.
[0048]
The polymerization conditions such as reaction temperature and reaction time may be appropriately set according to the monomer component, that is, the composition of the monomer composition, the kind of the polymerization initiator, etc., but the reaction temperature is 0 to 150 ° C. It is more preferable to be within the range, and it is further preferable to be within the range of 40 to 105 ° C. The reaction time is preferably about 3 to 15 hours. As a method for supplying the monomer component to the reaction system in the case of employing the aqueous solution polymerization method, for example, a batch addition method, a divided addition method, a component dropping method, a power feed method, a multistage dropping method, and the like can be performed. There is no particular limitation. The polymerization may be performed under normal pressure, reduced pressure, or increased pressure.
[0049]
In the production of the polymer compound (B), the concentration of the non-volatile component containing the polymer compound (B) contained in the polymer aqueous solution obtained when the aqueous solution polymerization method is adopted is particularly limited. However, it is preferably 60% by weight or less. A polymer aqueous solution having a non-volatile concentration exceeding 60% by weight has a viscosity that is too high, and dispersion stability cannot be maintained, which may cause aggregation.
[0050]
Examples of the polymer compound (B) used in the present invention include, for example, a carboxyl group-containing monomer alone or another monomer copolymerizable with the carboxyl group-containing monomer. It can obtain by carrying out addition reaction in presence of the high molecular compound. Examples of the known polymer compound include polyethylene glycol and polyvinyl pyrrolidone having a number average molecular weight of 500 to 20,000.
[0051]
The polymer compound (B) used in the present invention can be obtained, for example, by subjecting a known polymer compound to any one of hydrolysis, oxidation, and reduction reaction. Examples of the known polymer compound used in this case include polyacrylamide and polymethyl acrylate having a number average molecular weight of 500 to 20,000.
[0052]
When the polymer compound (B) is a homopolymer of acrylic acid or a polymer in which a part or all of the polymer is neutralized, the acid value measured by colloid titration is 9 mmol / g or more. It is preferable. The acid value measured by the colloid titration method indicates the amount of carboxylic acid contained in the polymer compound. In addition, the low acid value measured by colloid titration indicates that the polymer compound contains a large amount of impurities derived from the polymerization initiator, by-products during polymerization, and unreacted products. In addition, not only a larger amount than usual is required, but also the granulation property may be significantly inhibited by impurities.
[0053]
The acid value of the polymer compound measured by the colloid titration method is more preferably 9.5 mmol / g or more, and particularly preferably 10.5 mmol / g or more. In addition, the measuring method of the acid value by the colloid titration method will be described in detail in Examples described later.
[0054]
According to the present invention, when the raw material for iron making (sintered raw material or pellet raw material) containing fine iron ore is granulated (pseudo granulated or pelletized), the above-described polymer compound (A) and ( The raw material for iron making containing fine iron ore is granulated by using a granulating agent for iron making containing at least one of the polymer compounds of B) as an essential component, thereby attaching fine powder particles around the core particles. The effect is excellent and the production efficiency of the sintering machine can be improved.
[0055]
The content (ratio) of the polymer compound (A) and the polymer compound (B) contained in the granulating agent for iron making according to the present invention is the granulation of ore (iron ore) as a sintering raw material. May be appropriately set according to the property (type), the type of the polymer compound (A) and the type of the polymer compound (B), the granulator used, and the like. In the production of the ore, the total addition of the polymer compound (A) and the polymer compound (B) in the granulating agent for iron making to the sintering raw materials (iron ore, auxiliary materials, fuel, etc.) The lower limit of the ratio (however, the polymer compound (A) and the polymer compound (B) may be used alone or in combination of two or more) is preferably 0. 0.001% by weight, more preferably 0.005% by weight, and an upper limit is preferable. A 2% by weight, is preferably set as more preferably is 1% by weight. When the total addition ratio of the polymer compound (A) and the polymer compound (B) to the sintering raw material exceeds 2% by weight, the amount of the granulating agent for iron making to the sintering raw material increases. Therefore, there is a possibility that a large mass of the sintered raw material may be formed, and a problem such that the inside of the mass of the sintered raw material is not sintered may occur.
[0056]
On the other hand, when the total addition ratio of the polymer compound (A) and the polymer compound (B) to the sintering raw material is less than 0.001% by weight, the polymer compound (A) and (B) There is a possibility that the effect of improving the pseudo-granulating property when the performance of the polymer compound, particularly when these polymer compounds are used for granulation of a raw material for iron making containing fine iron ore, may not be exhibited sufficiently.
[0057]
Further, the ratio of the polymer compound (A) and the polymer compound (B) contained in the granulating agent for iron making in the production of pellets is not particularly limited. The total addition ratio of the polymer compound (A) and the polymer compound (B) in the granulating agent for iron making to the stone, dust, charcoal, etc. (however, the polymer compound (A) above) As for the polymer compound (B), only one kind may be used, or two or more kinds may be used in combination. The lower limit value is preferably 0.005% by weight, more preferably 0.8%. The upper limit is preferably 5% by weight, and more preferably 1% by weight. When the total addition ratio of the polymer compound (A) to the pellet raw material and the polymer compound (B) exceeds 5% by weight, the amount of addition of the granulating agent for iron making to the pellet raw material is too large. Due to excessive granulation, the pellet raw material may be largely agglomerated, which may cause adverse effects such as a large variation in particle size of the pellet raw material.
[0058]
Further, the amount of the granulating agent for iron making relative to the sintered raw material (iron ore, auxiliary raw material, fuel, etc.) is not particularly limited, but the lower limit is preferably 0.001% by weight, More preferably, it is 0.005% by weight, and the upper limit is preferably 15% by weight, more preferably 10% by weight. By making the addition ratio of the granulating agent for iron making to the sintering raw material within 15% by weight, the sintering raw material becomes difficult to be agglomerated and the inside of the mass of the sintering raw material is not sintered. It becomes difficult to occur. In addition, the lower limit of the amount (addition ratio) of the above granulating agent for iron making depends on the granulation property of the ore as the sintering raw material, the amount of water added, the granulator used, etc., but as small as possible It is desirable to design so that
[0059]
On the other hand, the amount of the granulating agent for iron making relative to the pellet raw material (iron ore, dust, charcoal, etc.) is not particularly limited, but the lower limit is preferably 0.01% by weight, The upper limit is preferably 50% by weight, and more preferably 10% by weight. If the amount of the granulating agent for iron making exceeds 50% by weight, the pellet raw material is excessively granulated and a large amount of the pellet raw material is formed, resulting in adverse effects such as an increase in the particle size variation of the pellet raw material. . In addition, the lower limit of the amount of addition of the above granulating agent for iron making depends on the granulation properties of the pellet raw material, the amount of water added, the granulator used, etc., but it should be designed to be as small as possible. Is desirable.
[0060]
That is, the above-mentioned granulating agent for iron making is used for the purpose of suppressing the viscosity of the granulating agent for iron making and maintaining the dispersion stability depending on the viscosity of the polymer compound used, that is, the type of the polymer compound used. If necessary, it may further contain a diluent such as water, and was obtained by the aqueous solution polymerization method by adding water or the like to the iron-making raw material such as the sintering raw material or pellet raw material (B The polymer aqueous solution containing the polymer compound (1) or the polymer compound (A) and / or the polymer compound (B) may be used as the granulating agent for iron making according to the present invention.
[0061]
Therefore, the content (ratio) of the polymer compound (A) and the polymer compound (B) contained in the granulating agent for iron making according to the present invention is the same as that of the ore (iron ore) of the sintering raw material. What is necessary is just to set suitably according to granulation property (kind), the polymer compound of said (A), the kind of polymer compound of (B), the granulator to be used, etc., It does not specifically limit.
[0062]
Moreover, when the said granulation processing agent for iron manufacture contains water, content (ratio) of the high molecular compound of said (A) in this granulation processing agent for iron manufacture and the high molecular compound of (B) was mentioned above. What is necessary is just to set so that conditions may be satisfy | filled, Although it does not specifically limit, It is preferable that it is 0.1 to 80 weight%, and it is 0.2 to 70 weight% Is more preferably 0.3% by weight or more and 60% by weight or less. In addition, the blending ratio of each polymer compound when the polymer compound (A) and the polymer compound (B) are used in combination is not particularly limited.
[0063]
Furthermore, the above-mentioned granulating agent for iron making has the performance of the polymer compound (A) and the polymer compound (B), in particular, granulation of a raw material for iron making containing fine iron ore containing these polymer compounds. For the purpose of further improving the pseudo-granulating property within the range that does not hinder the effect of improving the pseudo-granulating property when used for other components, for example, other conventionally known other structures such as quick lime are used as necessary. You may use a grain additive etc. together.
[0064]
The polymer compound (A) and the polymer compound (B) according to the present invention are effective in improving the pseudo-granulating property when granulating the raw material for iron making, even if the amount used is considerably small. It is excellent and can improve the production efficiency of the sintering machine. That is, the iron-making granulation agent acts as a binder for granulating (pseudo-granulating or pelletizing) the iron-making raw material. Thereby, the granulating agent for iron manufacture suitably used for granulating the raw material for iron manufacture in order to obtain a sintered ore can be provided at low cost.
[0065]
According to the present invention, when a raw material for iron making containing fine iron ore is granulated, in particular, a polymer compound satisfying the above conditions (A) and (B), that is, a carboxyl group and / or a salt thereof. The number average molecular weight is in the range of 500 or more and 20000 or less, and the polydispersity represented by the weight average molecular weight / number average molecular weight is in the range of 1.2 or more and 12.0 or less. By using a water-soluble polymer compound having a clay dispersibility of 0.5 or more, even if the amount of the granulating agent for iron making is 0.1% by weight or less based on iron ore, As a GI index of iron ore (pseudo particles), a very high GI index can be obtained as compared with a conventional binder.
[0066]
The GI index is an index indicating how much the fine powder content has decreased after granulation as compared with that before granulation, and indicates the ratio of fine powder particles adhering around the core particles. That is, it is shown that the higher the GI index, the smaller the fine powder content (that is, the granulation property is improved). In particular, it is considered that the raw materials for iron making with poor granulation properties will increase with the depletion of high-quality iron ore. When the fine powder content is increased (when the granulation property is deteriorated), the air permeability during sintering is deteriorated, the productivity is lowered, and in some cases, the production is impossible. For this reason, providing a granulating agent for iron making that provides a high GI index is a very important theme in producing sintered ore and pellets. The clay dispersibility and the method for measuring the GI index will be described in detail in Examples described later.
[0067]
The method for adding the iron-making granulating agent to the iron-making raw material is not particularly limited, but the method for mixing the iron-making granulating agent in an aqueous solution and mixing it with the added water of the granulator, or The method of spraying on the stirring raw material for iron making is particularly preferred. By adopting these methods, the granulating agent for iron making can be added easily and uniformly, and since it is pseudo-granulated without spots, fine powder can be further reduced.
[0068]
Also, after mixing, kneading, and granulating a part of the ironmaking raw material according to the particle size distribution, granulation property, composition, etc. of each brand of ironmaking raw material including auxiliary raw materials and fuel, the remaining iron making The processing method of mixing and granulating the raw material can be pseudo-granulated by adding the iron-making granulating agent according to the present invention to the iron-making raw material. For example, when a part of the raw material for iron making shows difficult granulation, it can be pseudo-granulated by adding a granulating agent for iron making to this hardly granulated raw material for iron making. Therefore, the raw material for iron making can be efficiently granulated with a small amount of the granulating agent for iron making.
[0069]
As described above, the granulation treatment agent for iron making according to the present invention can freely select a combination of raw materials for iron making, a granulator, timing and place of addition, and the combination is particularly limited. It is not a thing. That is, having a plurality of treatment steps, and for the granulation treatment method combining the granulation treatment agent for iron making and each treatment method, by adding the granulation treatment agent for iron making according to the present invention to the raw material for iron making, Can be pseudo-granulated. Of course, the granulating agent for iron making according to the present invention can be used for a known pseudo-granulating method (means).
[0070]
As described above, the granulation treatment method of the present invention is configured to add the above-mentioned granulation treatment agent for iron making according to the present invention to a raw material for iron making, and thereby, fine iron ore is obtained to obtain a sintered ore. It is possible to provide a granulation treatment method suitable for granulating (including pseudo-granulation or pelletizing) a raw material for iron making (sintered raw material or pellet raw material).
[0071]
In addition, as described above, the granulation treatment method of the present invention preferably has a configuration in which the above-mentioned granulation treatment agent for iron making is added in the form of an aqueous solution, whereby a raw material for iron making containing fine iron ore ( A granulation method that is superior in the effect of reducing the amount of fine powder and can improve the production efficiency of the sintering machine when granulating (pseudo granulation or pelletizing) the sintering raw material or pellet raw material) Can be provided.
[0072]
Furthermore, as described above, the granulation treatment method of the present invention may be configured to add the above-mentioned granulation treatment agent for iron making within a range of 0.001 wt% to 50 wt% with respect to the raw material for iron making. Preferably, this is excellent in the effect of reducing the amount of fine powder when granulating (pseudo granulation or pelletizing) a raw material for iron making (sintering raw material or pellet raw material) containing fine iron ore. It is possible to provide a granulation method that can further improve the production efficiency of the machine.
[0073]
Furthermore, the granulation treatment method of the present invention preferably has a plurality of treatment steps as described above, and is preferably configured to combine the above-mentioned granulation treatment agent for iron making and each treatment method. When granulating (pseudo-granulated or pelletized) raw materials for iron making containing iron ore (pseudo-granulated or pelletized), the effect of reducing the amount of fine powder is further improved, further improving the production efficiency of the sintering machine A granulation treatment method that can be further improved can be provided.
[0074]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these. In the examples and comparative examples, “part” indicates “part by weight”, and “%” indicates “% by weight”. Moreover, all the sintering raw materials and pellet raw materials in the examples and comparative examples described below were used in an absolutely dry state.
[0075]
The number average molecular weight, weight average molecular weight, polydispersity, clay dispersibility, acid value, average particle diameter, and GI index in the present invention were measured by the following methods.
[0076]
(Number average molecular weight, weight average molecular weight, polydispersity)
The number average molecular weight and the weight average molecular weight of the polymer compound were measured by GPC (gel permeation chromatography). The measurement conditions are as follows.
Pump: “L-7110” (manufactured by Hitachi, Ltd.)
Carrier solution: an aqueous solution in which ultrapure water was added to 34.5 g of disodium hydrogen phosphate dodecahydrate and 46.2 g of sodium dihydrogen phosphate dihydrate to a total amount of 5000 g
Flow rate: 0.5 ml / min
Column: One aqueous GPC column “GF-7MHQ” (manufactured by Showa Denko KK)
Detector: Ultraviolet (UV) detector “L-7400” (manufactured by Hitachi, Ltd.), wavelength 214 nm
Molecular weight standard sample: Sodium polyacrylate (manufactured by Soka Kagaku Co., Ltd.)
The analytical sample was prepared by diluting with the carrier liquid so that the polymer compound had a solid content of 0.1 weight.
[0077]
Further, the polydispersity of the polymer compound is calculated based on the weight average molecular weight and number average molecular weight measured under the above measurement conditions.
(Polydispersity) = (weight average molecular weight) / (number average molecular weight)
Calculated by
[0078]
However, when the polymer compound is not dissolved in (1) the carrier, (2) the measurement is performed under the following conditions only when the change in the molecular weight with time is significantly large due to decomposition in the carrier. Carrier liquid: Add pure water to 27.22 g of sodium acetate trihydrate to make 2000 g. After sodium acetate trihydrate is dissolved in pure water, 670 g of acetonitrile is added to make uniform.
Column: “TOSOH TSK-GEL α-2500, α-3000” (manufactured by Tosoh Corporation)
The other conditions are the same as the measurement conditions.
[0079]
(Clay dispersibility)
The clay dispersibility was measured by the following method. First, (1) 66.56 g of glycine, 52.6 g of sodium chloride, and 60 ml of 1 mol / L sodium hydroxide aqueous solution were added with ion exchange water to prepare a glycine buffer solution to 600 g.
Next, (2) 0.0817 g of calcium chloride dihydrate and 60 g of the glycine buffer solution prepared in (1) above were added pure water to 1000 g to prepare a dispersion. Moreover, 0.1% polymer aqueous solution was adjusted in conversion of solid content.
(3) In a general glass test tube of about 30 ml, put 0.3 g of “JIS powder 11 for JIS test” (trade name: Kanto loam powder, super fine powder, sold by Japan Powder Industry Technology Association) To this, 27 g of the dispersion liquid (2) and 3 g of 0.1% polymer aqueous solution as a granulating agent for iron making, adjusted as described above, were added. At this time, the calcium concentration in the test tube is 50 ppm in terms of calcium carbonate.
(4) After sealing the test tube with a general rubber test tube cap, shake vigorously for 20 seconds so that the clay is dispersed, and then turn upside down alternately 20 times to add the aqueous polymer solution. The clay was dispersed in the dispersion. After leaving this test tube in a place not exposed to direct sunlight for 20 hours, 5 ml of the supernatant of the dispersion in the test tube was collected with a whole pipette.
(5) This liquid (supernatant) was put into a 1 cm quartz cell, and the absorbance (ABS) at a wavelength of 380 nm was measured using a UV spectrometer, and this value was defined as clay dispersibility.
[0080]
(Acid value)
The acid value was determined by a colloid titration method. First, 0.1 g (in terms of solid content) of a measurement sample was weighed into a 50 ml sample tube, and weighed and diluted to 20 g with ion-exchanged water. When diluted, 0.1 g of a sample pretreated with sodium hydroxide so as to have a pH in the range of 6 to 9 was charged in terms of solid content.
Next, 0.5 g of this diluted solution was sampled, diluted with about 100 ml of ion-exchanged water, and adjusted to pH 11 with 0.1N sodium hydroxide aqueous solution.
Subsequently, 5 ml of an excessive amount of N / 200 methyl glycol chitosan solution was added to the above-mentioned diluted solution whose pH was adjusted, and the mixture was sufficiently stirred. Further, 6 drops of toluidine blue indicator was added and N / 400 polyvinyl potassium sulfate was stirred well. Colloid back titration was performed with a (PVSK) solution, and the point at which the color changed from blue to purple was defined as the end point. Moreover, the same operation was performed about 100 ml of ion-exchange water as a blank test, and the acid value was calculated | required with the following formula. In addition, solid content was computed from the preparation at the time of reaction.
[0081]
Acid value (mmol / g)
= (F × N × (ab)) / (sample amount (g) × solid content (%) / 100)
f: PVSK factor
N: Normality of PVSK (N / 400)
a: Titration of PVSK in blank test (ml)
b: PVSK titration of measurement sample (ml)
(Average particle size of pseudo particles, GI index)
The pseudo particles obtained by the granulation operation were dried at 80 ° C. for 1 hour and then classified using a sieve to obtain the particle size (pseudo particle size) and the average particle size. The GI index of the granulated pseudo particles is one of the evaluation methods disclosed in Steel Manufacturing Research No. 288 (1976), page 9, and indicates the ratio of fine particles adhering around the core particles. The GI index was measured according to the method described in Steel Manufacturing Research No. 288 (1976), page 9.
In each of the following Examples and Comparative Examples, the GI index of pseudo particles having a granulated particle size of 0.25 mm or less was determined.
[0082]
Moreover, the GI index (pseudo graining index) of pseudo particles of 0.25 mm or less was calculated by the following formula.
GI index = (ratio of raw material of 0.25 mm or less before granulation−ratio of raw material of 0.25 mm or less after granulation) / (ratio of raw material of 0.25 mm or less before granulation) × 100
[Example 1]
A 5 L separable flask equipped with a stirrer and a condenser (manufactured by SUS316) was charged with 805.5 parts of ion-exchanged water and 40.1 parts of 45% sodium hypophosphite monohydrate aqueous solution as a chain transfer agent, While stirring, the temperature was raised to the boiling point (100 ° C.) of the system.
[0083]
Subsequently, in the separable flask, 226.1 parts of an 80% aqueous acrylic acid solution as a carboxyl group-containing monomer, 112.4 parts of an aqueous 15% sodium persulfate solution as a polymerization initiator, and 45% hypochlorous acid. 160.2 parts of an aqueous solution of sodium phosphate monohydrate was added dropwise. The 80% acrylic acid aqueous solution, 15% sodium persulfate aqueous solution, and 45% sodium hypophosphite monohydrate aqueous solution were each dropped from separate dropping ports. The 80% acrylic acid aqueous solution was dropped in 180 minutes. A 15% aqueous sodium persulfate solution was added dropwise over 185 minutes. A 45% aqueous sodium hypophosphite monohydrate solution was added dropwise over 180 minutes. During the dropping time, the reaction temperature maintained the boiling point of the system. After completion of the dropping, the mixture was kept at the same temperature for 5 minutes, and 1889.0 parts of a 48% aqueous sodium hydroxide solution as a neutralizing agent was dropped over 60 minutes to obtain a polymer aqueous solution. The number average molecular weight, polydispersity, acid value, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated. The number average molecular weight was 2100, polydispersity. Was 2.93, the acid value was 11.2 mmol / g, and the clay dispersibility was 1.16.
[0084]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, By making it 5250 parts, the granulation processing agent for iron manufacture concerning this invention (1) Got.
On the other hand, a sintering raw material (raw material for iron making) having the composition shown in Table 1 was prepared.
[0085]
[Table 1]

[0086]
70000 parts of the above sintered raw material is put into a drum mixer, and the rotational speed is 24 min.^-1For 1 minute. Then, 5250 parts of the granulating agent for iron making (1) prepared in advance according to the present invention was sprayed on the sintered raw material over about 1.5 minutes using a spray bottle while stirring at the same rotational speed. The ratio of the polymer compound to the sintering raw material, that is, the ratio of the polymer compound contained in the granulating agent for iron making (1) of the present invention was 0.03%. After spraying, the granulation operation was performed by further stirring for 3 minutes at the same rotational speed.
[0087]
The obtained pseudo particles were dried and classified using a sieve to obtain the GI index of the pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0088]
[Example 2]
In a 5 L separable flask (made of SUS316) equipped with a stirrer and a condenser, 805.5 parts of ion-exchanged water was charged, and the temperature was raised to the boiling point (100 ° C.) of the system with stirring.
[0089]
Subsequently, in the above separable flask, as the carboxyl group-containing monomer, 226.1 parts of an 80% aqueous acrylic acid solution, and 112.4 parts of a 15% aqueous sodium persulfate solution as a polymerization initiator and a chain transfer agent 88.5 parts of a 45% aqueous sodium hypophosphite monohydrate solution was added dropwise. The 80% acrylic acid aqueous solution, 15% sodium persulfate aqueous solution, and 45% sodium hypophosphite monohydrate aqueous solution were each dropped from separate dropping ports. The 80% acrylic acid aqueous solution was dropped in 180 minutes. A 15% aqueous sodium persulfate solution was added dropwise over 185 minutes. A 45% aqueous sodium hypophosphite monohydrate solution was added dropwise over 180 minutes. During the dropping time, the reaction temperature maintained the boiling point of the system. After completion of the dropping, the mixture was kept at the same temperature for 5 minutes, and 1889.0 parts of a 48% aqueous sodium hydroxide solution as a neutralizing agent was dropped over 60 minutes to obtain a polymer aqueous solution. The number average molecular weight, polydispersity, acid value, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated. The number average molecular weight was 2900, polydispersity. Was 4.21, the acid value was 11.1 mmol / g, and the clay dispersibility was 1.30.
[0090]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, and is made into 5250 parts, The granulation processing agent for iron manufacture concerning this invention (2) Got.
[0091]
Then, in Example 1, it replaced with the granulation processing agent for iron manufacture (1), and granulated by operation similar to Example 1 using this granulation processing agent for iron manufacture (2), and obtained pseudo particle After drying, the mixture was classified using a sieve to obtain the GI index of pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0092]
Example 3
A 5 L separable flask equipped with a stirrer and a condenser (manufactured by SUS316) was charged with 805.5 parts of ion-exchanged water and 40.1 parts of 45% sodium hypophosphite monohydrate aqueous solution as a chain transfer agent, While stirring, the temperature was raised to the boiling point (100 ° C.) of the system.
[0093]
Subsequently, in the separable flask, 226.1 parts of an 80% aqueous methacrylic acid solution as a carboxyl group-containing monomer, 112.4 parts of an aqueous 15% sodium persulfate solution as a polymerization initiator, and 45% hypochlorous acid. 160.2 parts of an aqueous solution of sodium phosphate monohydrate was added dropwise. The 80% aqueous methacrylic acid solution, the 15% aqueous sodium persulfate aqueous solution, and the 45% aqueous sodium hypophosphite monohydrate aqueous solution were each dropped from separate dropping ports. The 80% acrylic acid aqueous solution was dropped in 180 minutes. A 15% aqueous sodium persulfate solution was added dropwise over 185 minutes. A 45% aqueous sodium hypophosphite monohydrate solution was added dropwise over 180 minutes. During the dropping time, the reaction temperature maintained the boiling point of the system. After completion of dropping, the mixture was kept at the same temperature for 10 minutes, and then 1595.1 parts of a 48% sodium hydroxide aqueous solution as a neutralizing agent was dropped over 60 minutes to obtain a polymer aqueous solution. The number average molecular weight, polydispersity, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated. The number average molecular weight was 1900, and the polydispersity was 3. 31. The clay dispersibility was 1.11.
[0094]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, and is made into 5250 parts, The granulation processing agent for iron manufacture concerning this invention (3) Got.
[0095]
Then, in Example 1, it replaced with the granulation processing agent for iron making (1), granulated by operation similar to Example 1 using this granulation processing agent for iron making (3), and obtained pseudo particle After drying, the mixture was classified using a sieve to obtain the GI index of pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0096]
Example 4
A 1 L separable flask (made of SUS316) equipped with a stirrer and a condenser was charged with 355 parts of ion-exchanged water, 98 parts of maleic anhydride as a carboxyl group-containing monomer and 80 parts of sodium hydroxide as a neutralizing agent. The temperature was raised to the boiling point (100 ° C.) of the system with stirring.
[0097]
Subsequently, 180 parts of a 40% aqueous acrylic acid solution as a carboxyl group-containing monomer and 100 parts of a 10% aqueous sodium persulfate solution and 100 parts of a 14% aqueous hydrogen peroxide solution as a polymerization initiator are placed in the separable flask. Was dripped. The 40% acrylic acid aqueous solution, 10% sodium persulfate aqueous solution 100 parts, and 14% hydrogen peroxide aqueous solution were added dropwise from separate dropping ports over 4 hours. During the dropping time, the reaction temperature maintained the boiling point of the system. After completion of dropping, the mixture was kept at the same temperature for 60 minutes, and then 57 parts of a 49% aqueous sodium hydroxide solution as a neutralizing agent was dropped over 60 minutes to obtain a polymer aqueous solution. The number average molecular weight, polydispersity, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated. The number average molecular weight was 1200 and the polydispersity was 4. 94, and the clay dispersibility was 0.98.
[0098]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, By making it 5250 parts, the granulation processing agent for iron manufacture concerning this invention (4) Got.
[0099]
Then, in Example 1, it replaced with the granulation processing agent for iron making (1), granulated by operation similar to Example 1 using this granulation processing agent for iron making (4), and obtained pseudo particle After drying, the mixture was classified using a sieve to obtain the GI index of pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0100]
Example 5
A 1 L separable flask (made of SUS316) equipped with a stirrer and a condenser was charged with 1400 parts of ion-exchanged water and heated to the boiling point (100 ° C.) of the system with stirring.
[0101]
Subsequently, 578.5 parts of an 80% aqueous solution of acrylic acid as a carboxyl group-containing compound and 62.5 parts of a 15% aqueous solution of ammonium persulfate as a polymerization initiator were put into the separable flask from separate dripping ports for 2 hours. And dripped. During the dropping time, the reaction temperature maintained the boiling point of the system. After completion of dropping, the mixture was kept at the same temperature for 120 minutes, and then 353 parts of a 48% aqueous sodium hydroxide solution as a neutralizing agent was dropped over 60 minutes to obtain a polymer aqueous solution. The number average molecular weight, polydispersity, acid value, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated, and the number average molecular weight was 4900, polydispersity. Was 9.84, the acid value was 10.7 mmol / g, and the clay dispersibility was 0.65.
[0102]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, By making it 5250 parts, the granulation processing agent for iron manufacture concerning this invention (5) Got.
[0103]
Then, in Example 1, it replaced with the granulation processing agent for iron manufacture (1), granulated by operation similar to Example 1 using this granulation processing agent for iron manufacture (5), and obtained pseudo particle After drying, the mixture was classified using a sieve to obtain the GI index of pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0104]
Example 6
A 5 L separable flask (manufactured by SUS316) equipped with a stirrer and a condenser was charged with 300 parts of ion-exchanged water and heated to the boiling point with stirring.
[0105]
There, 720 parts of 80% acrylic acid aqueous solution as a carboxyl group-containing compound, 106.7 parts of 15% sodium persulfate aqueous solution and 182.9 parts of sodium bisulfite aqueous solution as a polymerization initiator, 126.5 parts of ion-exchanged water, In addition, 600 parts of a 48% sodium hydroxide aqueous solution as a neutralizing agent was added dropwise from a separate dropping port over 120 minutes. The reaction temperature maintained the boiling point during the dropping time. After completion of dropping, the mixture was kept at the boiling point for 30 minutes. The number average molecular weight, polydispersity, acid value, and clay dispersibility of the polymer (polymer compound) in the aqueous polymer solution thus obtained were measured and calculated. The number average molecular weight was 5200 and the polydispersity. Was 11.8, the acid value was 8.7, and the clay dispersibility was 0.51.
[0106]
Moreover, the obtained polymer aqueous solution is extract | collected so that it may become 21 parts in conversion of solid content, This is diluted with ion-exchange water, By making it 5250 parts, the granulation processing agent for iron manufacture concerning this invention (6) Got.
[0107]
Then, in Example 1, it replaced with the granulation processing agent for iron making (1), granulated by the same operation as Example 1 using this granulation processing agent for iron making (6), and obtained pseudo particle After drying, the mixture was classified using a sieve to obtain the GI index of pseudo particles having a granulated particle size of 0.25 mm or less. The results are shown in Table 2 together with the physical properties of the polymer compound used.
[0108]
[Comparative Example 1]
A comparative steelmaking structure in which sodium polyacrylate having a number average molecular weight of 21000 and a polydispersity of 7.57 was collected to 21 parts in terms of solid content and diluted with ion-exchanged water to 5250 parts. Granulation is carried out in the same manner as in Example 5 except that the grain treatment agent (I) is used instead of the granulation treatment agent for iron making in Example 5 (5), and the obtained pseudo particles are dried and sieved. The GI index of the pseudo particles having a particle diameter after granulation of 0.25 mm or less was determined by classifying the particles. The GI index was 87.2. The sodium polyacrylate had a clay dispersibility of 0.32 and an acid value of 10.8 mmol / g. The results are shown in Table 2 together with the physical properties of the sodium polyacrylate.
[0109]
[Comparative Example 2]
A sodium salt of acrylic acid-maleic acid copolymer (acrylic acid: maleic acid composition ratio 50:50) was sampled to 21 parts in terms of solid content and diluted with ion-exchanged water to 5250 parts. The simulated product obtained was granulated in the same manner as in Example 5 except that the adjusted comparative granulating agent for iron making (II) was used instead of the granulating agent for iron making in Example 5 (5). The particles were dried and classified using a sieve to obtain the GI index of pseudo particles having a particle size after granulation of 0.25 mm or less. The GI index was 88.1. As the sodium salt of the acrylic acid-maleic acid copolymer, one having a number average molecular weight of 7400, a polydispersity of 13.5, and a clay dispersibility of 0.29 was used.
[0110]
[Comparative Example 3]
Other than using 1400 parts of quicklime and 5250 parts of water together and using this as a comparative granulating agent for iron making (III) instead of 5250 parts of the granulating agent for iron making in Example 5 (5) Granulation was performed in the same manner as in Example 5, and the obtained pseudo particles were dried and classified using a sieve to measure the GI index of the pseudo particles having a granulated particle size of 0.25 mm or less. The GI index was 76.2.
[0111]
[Comparative Example 4]
A sodium salt of acrylic acid-maleic acid copolymer (acrylic acid: maleic acid composition ratio 70:30) was sampled to be 21 parts in terms of solid content and diluted with ion-exchanged water to 5250 parts. The simulated product obtained was granulated in the same manner as in Example 5 except that the adjusted comparative granulating agent for iron making (IV) was used instead of the granulating agent for iron making in Example 5 (5). The particles were dried and classified using a sieve to obtain the GI index of pseudo particles having a particle size after granulation of 0.25 mm or less. The GI index was 88.4. As the sodium salt of the acrylic acid-maleic acid copolymer, one having a number average molecular weight of 3000, a polydispersity of 16.5, and a clay dispersibility of 0.44 was used.
[0112]
[Table 2]

[0113]
As is clear from the results shown in Table 2, the GI index, that is, the granulation property of iron ore can be greatly increased by using a small amount of the granulating agent for iron making containing the polymer compound according to the present invention. I understand.
[0114]
Also, from this result, by using a small amount of the granulating agent for iron making containing the polymer compound according to the present invention, the production rate, product yield, sintered ore strength of the sintering machine formed by sintering pseudo particles. It is inferred that this can be improved. Sintered ore with weak sinter strength is likely to generate fine powder, so that the amount of returned ore is increased, the product yield is lowered, and the production efficiency is lowered.
[0115]
【The invention's effect】
  The granulating agent for iron making according to the present invention is as described above.A processing agent used for granulating a raw material for iron making containing fine iron ore, containing a carboxyl group and / or a salt thereof, having a number average molecular weight of 500 or more and 20000 or less, and The polydispersity represented by weight average molecular weight / number average molecular weight is in the range of 1.2 to 12.0.It is the structure containing a high molecular compound.
[0116]
  Moreover, the granulating agent for iron manufacture concerning this inventionsoAs above,The polymer compound is a water-soluble polymer having a clay dispersibility of 0.5 or more.High molecular compoundIt is preferable that
[0117]
Each of the polymer compounds according to the present invention, when granulating (pseudo granulation or pelletization) a raw material for iron making (sintering raw material or pellet raw material) containing fine iron ore, The effect of adhering to the surroundings is excellent, the production efficiency of the sintering machine can be improved, and therefore the effect of providing a granulating agent for iron making can be provided at low cost.
[0118]
As described above, the granulation treatment method according to the present invention has a configuration in which the iron granulation treatment agent according to the present invention is added to the iron production raw material.
[0119]
This provides a granulation treatment method suitable for granulating (pseudo granulation or pelletizing) a raw material for iron making (sintering raw material or pellet raw material) containing fine iron ore to obtain sintered ore. There is an effect that can be.

Claims (4)

A processing agent used for granulating a raw material for iron making containing fine iron ore,
  11. It contains a carboxyl group and / or a salt thereof, has a number average molecular weight in the range of 500 or more and 20000 or less, and a polydispersity expressed by weight average molecular weight / number average molecular weight is 1.2 or more. A granulating agent for iron making, comprising a polymer compound in a range of 0 or less. The granulation treatment agent for iron making according to claim 1, wherein the polymer compound is a water-soluble polymer compound having a clay dispersibility of 0.5 or more.   The polymer compound was neutralized with at least one selected from the group consisting of sodium, potassium, calcium, and ammonia, with a part or all of the carboxyl groups contained in (a) polyacrylic acid and (b) polyacrylic acid. The granulating agent for iron making according to claim 1 or 2, which is at least one compound selected from the group consisting of polyacrylates. In the method of granulating the raw material for iron making containing fine iron ore,
The granulation processing method characterized by adding the granulation processing agent for iron manufacture of any one of Claims 1-3 to the said raw material for iron manufacture.