JP7273305B2 - Method for producing sintered ore - Google Patents
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Description
本発明は、焼結鉱の製造方法、特に、被還元性を向上させる焼結鉱の製造方法に関する。 TECHNICAL FIELD The present invention relates to a method for producing sintered ore, particularly to a method for producing sintered ore with improved reducibility.
現在、高炉製銑の主原料は、焼結鉱である。この焼結鉱は、例えば一段装入一段点火焼結法では、次のように製造される。まず、原料となる鉄鉱石（粉）、製鋼ダスト等の含鉄雑原料、橄欖岩等のＭｇＯ含有副原料、石灰石等のＣａＯ含有副原料、返鉱、および燃焼熱によって焼結鉱を焼結（凝結）させる燃料となる炭材（凝結材ともいう）を所定の割合で混合し、混合物（配合原料）を造粒する。次に、造粒した配合原料を、ホッパなどにより、下方吸引式のドワイトロイド（ＤＬ）式焼結機のパレット上に装入して、原料充填層を形成する。形成した原料充填層の上部から、原料充填層の表面層中の炭材に点火する。そして、パレットを連続的に移動させながらパレットの下方から空気を吸引する。原料充填層中の炭材に酸素を供給し、層厚方向の上部から下部に向けて燃焼させることにより、順次、炭材の燃焼熱により原料充填層を焼結させる。得られた焼結ケーキは、所定の粒度に粉砕され、篩分け等により整粒されて高炉の原料である焼結鉱となる。 Currently, the main raw material for blast furnace ironmaking is sintered ore. This sintered ore is produced in the following manner, for example, by the one-step charging and one-step ignition sintering method. First, iron ore (powder) as a raw material, iron-containing miscellaneous raw materials such as steelmaking dust, MgO-containing auxiliary raw materials such as peridotite, CaO-containing auxiliary raw materials such as limestone, return ore, and sintered ore are sintered by combustion heat ( A carbonaceous material (also referred to as a coagulant) that serves as a fuel to be coagulated is mixed in a predetermined ratio, and the mixture (blended raw material) is granulated. Next, the granulated blended raw material is charged onto a pallet of a downward suction type Dwight Lloyd (DL) sintering machine using a hopper or the like to form a raw material packed layer. The carbon material in the surface layer of the raw material packed bed is ignited from above the formed raw material packed bed. Then, air is sucked from below the pallet while continuously moving the pallet. Oxygen is supplied to the carbonaceous material in the raw material packed bed, and the raw material packed bed is sintered by the combustion heat of the carbonaceous material sequentially by burning from the top to the bottom in the layer thickness direction. The obtained sintered cake is pulverized to a predetermined particle size and sized by sieving or the like to become a sintered ore which is a raw material for a blast furnace.
（焼結鉱に求められる品質）
高炉による銑鉄製造の主原料である焼結鉱の品質を管理することは、高炉操業にとって重要なことである。焼結鉱の品質としては、焼結鉱の冷間強度、被還元性、還元粉化性がある。
品質の指標として、焼結鉱の冷間強度は、一般に、ＳＩ（シャッターインデックス）、又は、ＴＩ（タンブラーインデックス）が用いられる。また、焼結鉱の被還元性は、ＪＩＳ－ＲＩが用いられ、還元粉化性は、還元粉化率（ＲＤＩ）が用いられる。
(Quality required for sintered ore)
It is important for blast furnace operation to control the quality of sintered ore, which is the main raw material for pig iron production by blast furnaces. The quality of the sintered ore includes cold strength, reducibility, and reduction pulverizability of the sintered ore.
As an index of quality, SI (shutter index) or TI (tumbler index) is generally used for the cold strength of sintered ore. JIS-RI is used for the reducibility of the sintered ore, and the reduction disintegration ratio (RDI) is used for the reduction disintegration property.
焼結鉱の冷間強度（ＳＩ又はＴＩ）は、焼結機から焼結鉱を高炉に輸送する過程、又は高炉内に装入する際の耐粉化性を示す指標であり、冷間強度（ＳＩ又はＴＩ）の高い焼結鉱が望まれる。
焼結鉱の還元粉化率（ＲＤＩ）は、高炉に装入された焼結鉱の、シャフト上部の５００℃程度の還元雰囲気での粉化されやすさを示す指標であり、還元粉化率（ＲＤＩ）の低い焼結鉱が望まれる。
焼結鉱のＪＩＳ－ＲＩは、高炉内のシャフト部における焼結鉱の還元されやすさを示す指標であり、ＪＩＳ－ＲＩの高い焼結鉱が望まれる。
The cold strength (SI or TI) of the sintered ore is an index showing the resistance to pulverization during the process of transporting the sintered ore from the sintering machine to the blast furnace or when charging it into the blast furnace. Sintered ore with high (SI or TI) is desired.
The reduction ratio of sintered ore (RDI) is an index that indicates the ease with which the sintered ore charged into the blast furnace is pulverized in a reducing atmosphere of about 500 ° C at the upper part of the shaft. A sintered ore with a low (RDI) is desired.
The JIS-RI of sintered ore is an index indicating the easiness of reduction of sintered ore in the shaft portion in the blast furnace, and sintered ore with a high JIS-RI is desired.
焼結鉱の冷間強度（ＳＩ又はＴＩ）と還元粉化率（ＲＤＩ）は、共に、高炉内での焼結鉱の耐粉化性を管理する指標であり、高炉内のガスの通気性を確保し、高炉の生産性を確保するための重要な焼結鉱品質である。
一方、焼結鉱の被還元率性は、高炉の銑鉄製造量に対する還元材比（コークス比＋微粉炭比）を低減するための重要な焼結鉱品質である。
焼結鉱の冷間強度（ＳＩ又はＴＩ）、被還元性、還元粉化率（ＲＤＩ）は、焼結用の原料の組成や配合割合だけでなく、焼結鉱製造工程における温度や圧力などの様々な条件の影響を相関的に受けるため、それぞれを個別に管理することは難しい。
Both the cold strength (SI or TI) and reduction disintegration rate (RDI) of sintered ore are indices for controlling the resistance to disintegration of sintered ore in the blast furnace, and the gas permeability in the blast furnace It is an important sinter quality to ensure the productivity of the blast furnace.
On the other hand, the reducibility of sintered ore is an important sintered ore quality for reducing the reducing agent ratio (coke ratio + pulverized coal ratio) to the amount of pig iron produced in the blast furnace.
The cold strength (SI or TI), reducibility, and reduction ratio (RDI) of sintered ore depend not only on the composition and blending ratio of raw materials for sintering, but also on the temperature and pressure in the sintered ore manufacturing process. It is difficult to manage each of them individually because they are affected by various conditions of
焼結鉱は、高炉の通気性の確保のために、冷間強度（ＳＩ）が高いことが望まれる一方で、高炉の還元材比（コークス比＋微粉炭比）を低減するために、被還元性も、高いことが望まれる。 Sintered ore is desired to have a high cold strength (SI) in order to ensure the permeability of the blast furnace. High reducibility is also desired.
焼結鉱の被還元性の指標として用いられているＪＩＳ－ＲＩは、９００℃における定温還元率であって、これまでその改善のための研究がなされている。基礎的知見として、ＪＩＳ－ＲＩは、焼結鉱の気孔率およびカルシウムフェライト量に、主に支配されることが知られている。焼成前の焼結用の配合原料の化学成分で言えば、塩基度（ＣａＯ／ＳｉＯ２比）が高い方が好ましいとされる。ＣａＯ濃度が高いと、焼結鉱中に晶出するカルシウムフェライトの生成量が増え、焼結鉱中に晶出する還元性の低いケイ酸塩鉱物の生成量が抑えられるからである。
また、原料充填層層厚方向の焼結鉱のＪＩＳ－ＲＩ分布に関しては、下層ほど燃焼温度が高くなり焼結が進行して気孔率が減少するので、下層ほどＪＩＳ－ＲＩが低下することも知られている。
JIS-RI, which is used as an index of the reducibility of sintered ore, is a constant temperature reduction rate at 900° C., and research has been conducted to improve it. As a basic knowledge, it is known that JIS-RI is mainly governed by the porosity of sintered ore and the amount of calcium ferrite. In terms of the chemical composition of the compounded raw material for sintering before firing, the higher the basicity (CaO/SiO 2 ratio), the better. This is because when the CaO concentration is high, the amount of calcium ferrite crystallized in the sintered ore increases, and the amount of low-reducing silicate minerals crystallized in the sintered ore is suppressed.
In addition, regarding the JIS-RI distribution of the sintered ore in the thickness direction of the raw material packed layer, the lower the layer, the higher the combustion temperature and the sintering progresses and the porosity decreases, so the lower the layer, the JIS-RI may decrease. Are known.
（層高方向の偏析制御技術）
層高方向の成分偏析を好適化する粒度偏析制御技術としては、以下の開示がある。
特許文献１には、焼結ケーキ層高方向における成分系の分布について、粒度偏析を保ちつつ特に冷間強度に影響を及ぼすＭｇＯの偏差を縮小し、冷間強度の目標値に対する偏差、又はケーキ内の冷間強度偏差を縮小する発明の記載がある。
特許文献２には、焼結層高方向における歩留分布について、最も劣位となる表層を改善する発明の記載がある。
特許文献３には、焼結生産性改善並びに余剰下層熱源原単位を削減する発明の記載がある。
特許文献４には、焼結鉱強度を改善し、最適なカーボン濃度を制御出来る発明の記載がある。
特許文献５、６には、石灰石の粒度偏析によって焼結生産性を改善する発明の記載がある。
(Segregation control technology in layer height direction)
The grain size segregation control technology for optimizing the segregation of ingredients in the bed height direction is disclosed below.
In Patent Document 1, regarding the distribution of the component system in the height direction of the sintered cake layer, the deviation of MgO, which particularly affects the cold strength, is reduced while maintaining the grain size segregation, and the deviation from the target value of the cold strength, or the cake There is a description of an invention that reduces the internal cold strength deviation.
Patent Document 2 describes an invention for improving the surface layer, which is the most inferior in the yield distribution in the high direction of the sintered layer.
Patent Literature 3 describes an invention that improves sintering productivity and reduces the unit consumption of the surplus lower layer heat source.
Patent Document 4 describes an invention capable of improving the strength of sintered ore and controlling the optimum carbon concentration.
Patent Literatures 5 and 6 describe inventions for improving sintering productivity by grain size segregation of limestone.
（低アルミナ濃度微粉原料の事前造粒技術）
低アルミナ濃度微粉原料を予め造粒する技術には、次の開示がある。
特許文献７には、配合原料、特にペレットフィード等の微粉原料についてパンペレタイザーを用いて粗大造粒物製造の製造を実現する発明の記載がある。
(Pre-granulation technology for low alumina concentration fine raw material)
Techniques for pregranulating low alumina concentration fine raw materials include the following disclosures.
Patent Document 7 describes an invention that realizes production of coarse granules by using a pan pelletizer for blended raw materials, particularly fine raw materials such as pellet feed.
（還元特性値を測定する方法）
鉄系原料の還元特性値（被還元性）を測定する代表的な方法として、ＪＩＳ－ＲＩ（ＪＩＳ Ｍ８７１３）が知られている。この方法は、製鉄業界で広く知られた方法であり、鉄系原料を９００℃の温度下で一定時間（３時間）ＣＯ還元を行うことで鉄系原料の被還元性を測定する。
(Method for measuring reduction characteristic value)
JIS-RI (JIS M8713) is known as a representative method for measuring the reduction characteristic value (reducibility) of iron-based raw materials. This method is widely known in the steelmaking industry, and measures the reducibility of the iron-based raw material by subjecting the iron-based raw material to CO reduction at a temperature of 900° C. for a certain period of time (3 hours).
特許文献８及び特許文献９には、鉄系原料の融液生成を伴う挙動を再現して高温還元率等を測定する方法が開示されている。特許文献９に開示された測定方法は、大型の高温荷重軟化試験装置を用いて高炉の還元条件を模擬する測定方法であり、ＪＩＳ－ＲＩ法では測定できない溶融から滴下までの焼結鉱の挙動を追跡できる試験法であって、高温性状試験とも称される。この測定方法では、竪型炉で使用する塊状の鉄鉱石類をるつぼに装入し、該るつぼを電気炉内に配設し、電気炉の下方より還元ガスを導入して鉄鉱石類の加熱還元を行う。具体的には、特許文献９では、電気炉を上下２段に配設し、両電気炉間の継目をフランジで結合し、下段電気炉の下方より還元ガスを導入し、該下段電気炉を空塔のまま昇温するとともに、上段電気炉に鉄鉱石類を装入したるつぼを配設する。そして、上段電気炉の温度とるつぼ内鉄鉱石類の温度とを同時に測定し、該温度の差をあらかじめ設定した一定の値となるように上段電気炉の電力を調整する。 Patent Literatures 8 and 9 disclose a method of measuring the high-temperature reduction rate and the like by reproducing the behavior associated with the melt generation of the iron-based raw material. The measurement method disclosed in Patent Document 9 is a measurement method that simulates the reduction conditions of a blast furnace using a large high-temperature load softening test device, and the behavior of sintered ore from melting to dropping that cannot be measured by the JIS-RI method. It is a test method that can track the , and is also called a high temperature property test. In this measurement method, a lump of iron ore used in a vertical furnace is charged into a crucible, the crucible is placed in an electric furnace, and a reducing gas is introduced from the bottom of the electric furnace to heat the iron ore. make a reduction. Specifically, in Patent Document 9, electric furnaces are arranged in two stages, upper and lower, joints between the two electric furnaces are joined by flanges, reducing gas is introduced from below the lower electric furnace, and the lower electric furnace is The temperature is raised in an empty tower, and a crucible charged with iron ores is placed in the upper electric furnace. Then, the temperature of the upper electric furnace and the temperature of the iron ore in the crucible are measured simultaneously, and the electric power of the upper electric furnace is adjusted so that the temperature difference becomes a predetermined constant value.
（問題点）
特許文献１～６に記載の層高方向の偏析制御技術に関する発明は、焼結歩留や焼結生産性の向上を目指すものであって、被還元性への対応や被還元性劣位部（焼結ケーキ下部）を考慮したものではない。
特許文献７に記載の低アルミナ濃度微粉原料の事前造粒技術は、原料の微粉化に伴う焼結の生産性低下を改善することを目的とするものであり、焼結鉱の被還元性の改善に対応出来るものではない。
(problem)
Inventions related to segregation control technology in the layer height direction described in Patent Documents 1 to 6 aim to improve sintering yield and sintering productivity, and are intended to deal with reducibility and poor reducibility parts ( sintered cake bottom) is not considered.
The pre-granulation technology for the low alumina concentration fine powder raw material described in Patent Document 7 is intended to improve the decrease in sintering productivity due to the pulverization of the raw material, and the reducibility of the sintered ore It is not something that can be improved.
（技術課題）
本発明の目的は、層高方向（以下、層厚方向ともいう）の成分偏析を好適化することによって、最近ＪＩＳ－ＲＩより高炉操業への対応が高いとされている高温還元率の改善を可能とする焼結鉱の製造方法を提供することである。
(Technical problems)
The object of the present invention is to improve the high-temperature reduction rate, which is recently considered to be highly compatible with blast furnace operation according to JIS-RI, by optimizing the segregation of ingredients in the layer height direction (hereinafter also referred to as the layer thickness direction). It is to provide a method for producing sintered ore that makes it possible.
本発明は以下を構成要件とする。
（１）焼結用の配合原料を、原料装入装置を介して下方吸引焼結機に供給し、原料充填層を形成して焼成する焼結鉱の製造方法において、
前記原料装入装置は、層厚方向の粒度偏析を形成する篩機能を有する篩部材を備えた粒度偏析形成装入装置であり、
前記配合原料中の石灰石は、粒度区分３ｍｍを超え５ｍｍ以下の石灰石の割合が、全石灰石に対し１０質量％以上３０質量％以下であり、
前記配合原料は、前記配合原料として使用される全鉄鉱石の平均アルミナ（Ａｌ2Ｏ3）濃度よりも低い低アルミナ鉄鉱石を造粒した造粒物である低アルミナ造粒物を、前記配合原料に対して６質量％以上２５質量％以下含み、
前記配合原料は、前記原料装入装置により、前記原料充填層の下層に向けて粒度が大きくなるように、前記下方吸引焼結機のパレット上に装入される、
ことを特徴とする焼結鉱の製造方法。
ここで、配合原料とは、焼結機に装入される全原料（鉄鉱石、雑原料、副原料からなる新原料と、返鉱と、粉コークスなどの炭材）をいう。
（２）（１）に記載の焼結鉱の製造方法において、
前記低アルミナ造粒物の原料として、前記低アルミナ鉄鉱石を、前記低アルミナ造粒物の９０質量％以上使用し、
前記低アルミナ造粒物の原料として、前記配合原料として使用される全鉄鉱石の平均アルミナ濃度よりもアルミナ濃度の高い鉄鉱石は使用しない、ことを特徴とする焼結鉱の製造方法。
（３）（１）又は（２）に記載の焼結鉱の製造方法において、
前記低アルミナ鉄鉱石は、アルミナ濃度が０．８質量％以下である、ことを特徴とする焼結鉱の製造方法。
（４）（１）ないし（３）のいずれか１つに記載の焼結鉱の製造方法において、
前記低アルミナ鉄鉱石は微粉鉱石である、ことを特徴とする焼結鉱の製造方法。
（５）（１）ないし（４）のいずれか１つに記載の焼結鉱の製造方法において、
前記配合原料は、粒度区分３ｍｍを超え５ｍｍ以下の橄欖岩の割合が全橄欖岩に対し２０質量％以上４０質量％以下である、ことを特徴とする焼結鉱の製造方法。
The present invention has the following configuration requirements.
(1) In a method for producing a sintered ore, a mixed raw material for sintering is supplied to a downward suction sintering machine through a raw material charging device, and a raw material packed layer is formed and sintered,
The raw material charging device is a particle size segregation forming charging device equipped with a sieve member having a sieve function to form particle size segregation in the layer thickness direction,
Limestone in the blended raw material has a ratio of limestone with a particle size division of more than 3 mm and 5 mm or less, with respect to the total limestone, is 10% by mass or more and 30% by mass or less,
The blended raw material is a low-alumina granule, which is a granule obtained by granulating low-alumina iron ore having an average alumina (Al 2 O 3 ) concentration lower than the average alumina (Al 2 O 3 ) concentration of all the iron ores used as the blended raw material. Contains 6% by mass or more and 25% by mass or less with respect to the raw material,
The blended raw material is charged onto the pallet of the downward suction sintering machine by the raw material charging device so that the particle size increases toward the lower layer of the raw material packed layer.
A method for producing sintered ore, characterized by:
Here, the raw materials to be mixed refer to all the raw materials charged into the sintering machine (new raw materials including iron ore, miscellaneous raw materials, and auxiliary raw materials, return ores, and carbonaceous materials such as coke fines).
(2) In the method for producing sintered ore described in (1),
90% by mass or more of the low-alumina granules is used as a raw material for the low-alumina granules,
A method for producing sintered ore, wherein iron ore having a higher alumina concentration than the average alumina concentration of all iron ore used as the mixed raw material is not used as the raw material of the low alumina granules.
(3) In the method for producing sintered ore according to (1) or (2),
A method for producing sintered ore, wherein the low-alumina iron ore has an alumina concentration of 0.8% by mass or less.
(4) In the method for producing sintered ore according to any one of (1) to (3),
A method for producing sintered ore, wherein the low-alumina iron ore is a fine ore.
(5) In the method for producing sintered ore according to any one of (1) to (4),
A method for producing a sintered ore, wherein the blended raw material has a ratio of peridotite having a particle size classification of more than 3 mm and not more than 5 mm in an amount of 20% by mass or more and 40% by mass or less with respect to the total peridotite.
粗粒化した石灰石と低アルミナ造粒物との両方を同時に偏析装入して粒度の粗いものを下層側に誘導することで、歩留を低下させることなく、焼結鉱の還元率（ＲＩ）を向上することができる。 By segregating and charging both the coarse-grained limestone and the low-alumina granules at the same time and guiding the coarse-grained ones to the lower layer side, the reduction rate of the sintered ore (RI ) can be improved.
本発明者は、焼結鉱の高温還還元率がより良好となる、原料充填層層厚方向における配合原料の化学成分偏析について検討した。そして、下層におけるＣａＯ濃度の上昇とＡｌ2Ｏ3濃度の低減を同時に行なうことで、下層のＲＩが各段に向上することを発見した。本発明は、ＣａＯを主成分とする石灰石を粗粒化するとともに、低アルミナ（Ａｌ2Ｏ3）鉄鉱石を予め造粒して粗粒化したものを配合原料とし、粒度偏析を形成する篩機能を有する篩部材を備えた粒度偏析形成装入装置を用いて装入することで、ＣａＯ濃度とＡｌ2Ｏ3濃度の両方の原料充填層層厚方向偏析を同時に強めることを骨子とする。 The present inventors have studied the chemical component segregation of the mixed raw material in the layer thickness direction of the raw material packed bed, which makes the high-temperature reduction rate of the sintered ore better. Then, they discovered that the RI of the lower layer is significantly improved by increasing the CaO concentration and decreasing the Al 2 O 3 concentration in the lower layer at the same time. In the present invention, limestone containing CaO as a main component is coarsened, and low-alumina (Al 2 O 3 ) iron ore is previously granulated and coarsened, and this is used as a blending raw material, and a sieve that forms grain size segregation. The gist of this is that the thickness direction segregation of both the CaO concentration and the Al 2 O 3 concentration in the raw material packed bed is enhanced at the same time by charging using a particle size segregation forming charging device equipped with a sieve member having a function.
本発明によれば、上層においては、ＣａＯ濃度の低下とＡｌ2Ｏ3濃度の上昇を招くものの、本来、下層に比べて燃焼温度が低く層厚方向の荷重が小さいため、気孔率を高く維持できるので、高温還元率への悪影響は少ない。一方、下層では、ＣａＯ濃度の上昇とＡｌ2Ｏ3濃度の低減の相乗効果により、高温還元率向上効果が得られる。これらにより、上層と下層とを合わせた平均の高温還元率（焼結鉱全体の高温還元率）を大きく改善することができる。 According to the present invention, in the upper layer, although the CaO concentration decreases and the Al 2 O 3 concentration increases, the combustion temperature is originally lower than that in the lower layer and the load in the layer thickness direction is small, so the porosity is maintained high. Therefore, there is little adverse effect on the high temperature reduction rate. On the other hand, in the lower layer, the synergistic effect of increasing the CaO concentration and decreasing the Al 2 O 3 concentration provides an effect of improving the high-temperature reduction rate. As a result, the average high-temperature reduction rate (high-temperature reduction rate of the entire sintered ore) combining the upper layer and the lower layer can be significantly improved.
＜定義＞
（焼結鉱のＪＩＳ還元率：ＲＩ（ＪＩＳ Ｍ８７１３））
焼結鉱のＪＩＳ還元率（ＲＩ）は、焼結鉱を９００℃の温度下で一定時間（３時間）ＣＯ還元を行って、下式（１）に従って計算される。
還元率(質量％)
＝（除去された酸素(質量％)）／(初期被還元酸素(質量％)）＊１００ ・・・（１）
除去された酸素は、反応（還元）過程の排ガス分析から得る場合、反応後の試料を回収して、反応前後の試料の化学分析によって得る場合と、反応前後の試料の重量変化から得る場合があり、測定する方法に応じて、任意に算出方法を選択しても良い。除去された酸素は、試料の総質量に対する割合（質量％）として示される。
初期被還元酸素は、反応前の試料の化学分析から得られる。具体的には、以下の式（２）により得られる。
初期被還元酸素(質量％)＝（Ｔ．Ｆｅ－Ｍ．Ｆｅ－ＦｅＯ＊（５５．８５）／
（５５．８５＋１６））＊１６＊１．５／５５．８５＋１６／
（５５．８５＋１６）＊ＦｅＯ ・・・（２）
ここで、Ｔ．Ｆｅは、試料に含まれる全鉄の割合（質量％）であり、Ｍ．Ｆｅは試料に含まれる金属鉄の割合（質量％）であり、ＦｅＯは、試料に含まれるＦｅＯの割合（質量％）である。初期被還元酸素は、反応（還元）前に鉄と結合していた酸素の試料の総質量に対する割合（質量％）として示される。
（高温還元率：Ｒ1100℃、Ｒ1200℃）
高炉のガス利用率、高炉の還元材比は、融着帯上面での焼結鉱の還元率（以下、高温還元率）で決まる（山岡ら／ＮＫＫ（株）、日本鉄鋼協会討論会１９８１、６２２．３４１．１－１８５：６２２．７８５「焼結鉱に要求される性状とその製造技術」）ので、原料の被還元性の評価指標として、通例のＪＩＳ－ＲＩより、高温還元率の方が好ましいとされる。高温還元率は、実際の高炉内で原料が受ける条件を精緻に模擬できる荷重軟化試験装置（細谷ら／新日本製鐵（株）、鉄と鋼，Ｖｏｌ．８３（１９９７）Ｎｏ．２、ｐ．９７－１０２「焼結鉱の軟化溶融性状評価法の開発」）を用いて測定される。
（高温還元率の測定方法）
高温還元率の測定方法については、特許文献９にその一例が開示されている。まず、測定対象の原料をるつぼに装入する。ついで、該るつぼを電気炉内に配設し、電気炉の下方より還元ガスを導入して鉄鉱石類の加熱還元を行う。電気炉は上下２段から構成され、両電気炉間の継目をフランジで結合し、下段電気炉の下方より還元ガスを導入し、該下段電気炉を空塔のまま昇温するとともに、上段電気炉に鉄鉱石類を装入したるつぼを配設する。そして、上段電気炉の温度とるつぼ内鉄鉱石類の温度とを同時に測定し、該温度の差をあらかじめ設定した一定の値となるように上段電気炉の電力を調整する。試料の還元は、実際の高炉内で原料が受ける昇温速度、還元ガス組成、荷重を模擬した条件で行われる。そして、所定の温度（通常１１００℃または１２００℃、実施例では１２００℃）に到達した時点での還元率（Ｒ1100℃またはＲ1200℃）を測定する。
<Definition>
(JIS reduction rate of sintered ore: RI (JIS M8713))
The JIS reduction rate (RI) of sintered ore is calculated according to the following formula (1) by CO reduction of sintered ore at a temperature of 900° C. for a certain period of time (3 hours).
Reduction rate (mass%)
= (Removed oxygen (mass%))/(Initially reducible oxygen (mass%)) * 100 (1)
The removed oxygen can be obtained from exhaust gas analysis during the reaction (reduction) process, by collecting a post-reaction sample and chemically analyzing the sample before and after the reaction, or from the change in weight of the sample before and after the reaction. Yes, the calculation method may be arbitrarily selected according to the method of measurement. The oxygen removed is reported as a percentage (wt%) of the total weight of the sample.
Initial reducible oxygen is obtained from chemical analysis of the sample prior to reaction. Specifically, it is obtained by the following formula (2).
Initial reducible oxygen (mass%) = (T.Fe-M.Fe-FeO * (55.85) /
(55.85+16))*16*1.5/55.85+16/
(55.85+16) * FeO (2)
Here, T. Fe is the ratio (mass%) of the total iron contained in the sample, and M. Fe is the proportion (% by mass) of metallic iron contained in the sample, and FeO is the proportion (% by mass) of FeO contained in the sample. The initial reducible oxygen is given as the percentage (mass %) of the total mass of the sample of oxygen that was bound to the iron prior to the reaction (reduction).
(High temperature reduction rate: R1100°C, R1200°C)
The gas utilization rate of the blast furnace and the reducing agent ratio of the blast furnace are determined by the reduction rate of the sintered ore on the upper surface of the cohesive zone (hereinafter referred to as the high-temperature reduction rate) (Yamaoka et al. / NKK Corporation, The Japan Iron and Steel Institute Discussion 1981, 622.341.1-185: 622.785 "Properties required for sintered ore and its manufacturing technology"), as an evaluation index for the reducibility of raw materials, the high-temperature reduction rate is higher than the usual JIS-RI. is preferred. The high-temperature reduction rate was determined using a load softening tester (Hosoya et al./Nippon Steel Co., Ltd., Tetsu to Hagane, Vol. 83 (1997) No. 2, p. .97-102 "Development of method for evaluating softening and melting properties of sintered ore").
(Method for measuring high-temperature reduction rate)
An example of a method for measuring the high-temperature reduction rate is disclosed in Patent Document 9. First, the material to be measured is charged into the crucible. Next, the crucible is placed in an electric furnace, and a reducing gas is introduced from below the electric furnace to heat and reduce the iron ores. The electric furnace consists of two stages, upper and lower. The joints between the two electric furnaces are connected by a flange, and reducing gas is introduced from below the lower electric furnace to raise the temperature of the lower electric furnace while the upper electric furnace is empty. A crucible charged with iron ores is placed in the furnace. Then, the temperature of the upper electric furnace and the temperature of the iron ore in the crucible are measured simultaneously, and the electric power of the upper electric furnace is adjusted so that the temperature difference becomes a predetermined constant value. The reduction of the sample is performed under conditions simulating the temperature rise rate, reducing gas composition, and load that the raw material receives in an actual blast furnace. Then, the reduction rate (R1100° C. or R1200° C.) is measured when a predetermined temperature (usually 1100° C. or 1200° C., 1200° C. in the examples) is reached.
＜第１の実施形態＞
以下、本発明の第１の実施形態に係る焼結鉱の製造方法について説明する。
本発明においては、原料装入装置として粒度偏析形成装入装置を用い、一段装入法により下方吸引式焼結機に装入して、一段点火焼結法により焼結鉱を製造する。なお、一段装入一段点火焼結法については上述したので、説明を省略する。
<First embodiment>
Hereinafter, a method for producing sintered ore according to the first embodiment of the present invention will be described.
In the present invention, a grain size segregation forming charging device is used as a raw material charging device, and raw materials are charged into a downward suction sintering machine by a single-stage charging method to produce sintered ore by a single-stage ignition sintering method. Since the one-step charging and one-step ignition sintering method has been described above, the explanation is omitted.
（原料装入装置）
本実施形態においては、従来の単純な板状のスローピングシュートに比較して、下層に向けて粒度が大きくなる層厚方向粒度偏析を強化する篩機能を持った篩部材を有する原料装入装置（粒度偏析形成装入装置）を用いる。篩部材は、例えば、スリットバー式の偏析強化型シュートや、整流分散式の確率分級篩等である。スリットバー式は、パレット進行方向と反対方向に下方に傾斜して装備され、パレット幅方向に平行なワイヤ（又はロッド）が、パレットの上部から下部に向かうにつれてその間隔が広くなるように設けられているものである（鉄と鋼, ８7(2001), S846）。整流分散式は、多数のバーを原料流れに沿って並べ、かつ上流から下流にむけて隣接のバー同士を互いに下流に向かうほど段差が大きくなるように設置して構成される（鉄と鋼, 77(1991), p.63-70）。
(Raw material charging device)
In this embodiment, compared to a conventional simple plate-shaped sloping chute, a raw material charging device ( A particle size segregation forming charging device) is used. The sieve member is, for example, a slit-bar type segregation-enhancing chute, a rectifying-dispersion type stochastic classifying sieve, or the like. The slit bar type is installed inclined downward in the direction opposite to the direction of pallet movement, and the wires (or rods) parallel to the pallet width direction are provided so that the distance between them increases from the top to the bottom of the pallet. (Tetsu to Hagane, 87 (2001), S846). The rectifying and dispersing type is constructed by arranging a large number of bars along the raw material flow, and installing adjacent bars from upstream to downstream so that the difference in level increases toward the downstream (iron and steel, 77 (1991), p.63-70).
（石灰石の粒度調整）
配合原料のうち、石灰石は、粒度区分３ｍｍを超え５ｍｍ以下の石灰石の割合が、全石灰石に対し１０質量％以上３０質量％以下となるように、好ましくは１５質量％以上２５質量％以下となるように、粒度調整したものを使用する。ここで、石灰石の粒度区分は、篩分け法による篩の目開き寸法で定義されるものである。
石灰石の粒度調整は、石灰石破砕処理工程における最終篩の目開きを通常採用されている３ｍｍから５ｍｍ程度に拡大変更することにより行う。粒度区分３ｍｍを超え５ｍｍ以下の石灰石の割合を、石灰石の全質量に対し、１０質量％以上３０質量％以下と規定した。粒度区分３ｍｍを超え５ｍｍ以下の石灰石の割合が１０質量％未満では、石灰石を粗粒化する効果が小さく、３０質量％を超えると石灰石の下層偏析が過大となり、むしろ歩留の低下を招くためである。
なお、この粒度調整の場合、実用上３質量％程度の＋５ｍｍ（５ｍｍ篩上）の粒度の石灰石を含むが、それは本発明の効果を著しく損なうものではない。
(Particle size adjustment of limestone)
Of the raw materials to be blended, the proportion of limestone with a particle size division of more than 3 mm and 5 mm or less is 10% by mass or more and 30% by mass or less, preferably 15% by mass or more and 25% by mass or less. Use the granularity adjusted as follows. Here, the particle size classification of limestone is defined by the mesh size of a sieve according to a sieving method.
The particle size adjustment of the limestone is performed by enlarging and changing the final sieve opening in the limestone crushing treatment process from the normally employed 3 mm to about 5 mm. The proportion of limestone with a grain size division of more than 3 mm and 5 mm or less was defined as 10% by mass or more and 30% by mass or less with respect to the total mass of limestone. If the proportion of limestone with a particle size division of more than 5 mm and less than 10% by mass is less than 10% by mass, the effect of coarsening the limestone is small, and if it exceeds 30% by mass, the lower layer segregation of limestone becomes excessive, resulting in a decrease in yield. is.
In addition, in the case of this particle size adjustment, practically about 3% by mass of limestone with a particle size of +5 mm (on a 5 mm sieve) is included, but this does not significantly impair the effects of the present invention.
（低Ａｌ2Ｏ3造粒物の事前造粒）
配合原料の鉄鉱石のうち、低アルミナ鉄鉱石は、他の原料と混合する前に事前造粒する。本発明において、低アルミナ鉄鉱石とは、それを除いて配合原料として使用される全鉄鉱石の平均アルミナ濃度よりもアルミナ濃度が１．０質量％以上低いものをいい、好ましくは、アルミナ濃度が０．８質量％以下の鉄鉱石をいう。
表１に、代表的な鉄鉱石の平均粒径（直径）とアルミナ濃度（質量％）を示す。平均粒径は、篩分け法による篩の目開き寸法による粒度区分の中央値を、粒度区分毎の質量分率で荷重して算出した平均値である。ここで、ＰＦＦＴはペレットフィードと呼ばれる微粉鉱石であり、アルミナ濃度が０．５２質量％と少ない。ペレットフィードは、本発明の低アルミナ（Ａｌ2Ｏ3）造粒物を製造するための原料対象となる鉱石の一例である。ペレットフィードは表１に示すように平均粒径の小さい微粉鉱石であるため粉砕する必要がなく、また、凝集し易く造粒しやすい。なお、低アルミナ鉄鉱石が塊状である場合には、造粒前に粉砕する必要がある。
(Pre-granulation of low Al 2 O 3 granules)
Among the iron ores of the blending raw materials, the low-alumina iron ores are pre-granulated before being mixed with other raw materials. In the present invention, the low-alumina iron ore refers to an iron ore having an alumina concentration lower than the average alumina concentration of all the iron ores other than the iron ore used as a blending raw material by 1.0% by mass or more. Preferably, the alumina concentration is Refers to iron ore of 0.8% by mass or less.
Table 1 shows the average particle size (diameter) and alumina concentration (% by mass) of typical iron ores. The average particle size is the average value calculated by weighting the median value of the particle size division according to the mesh size of the sieve by the sieving method with the mass fraction for each particle size division. Here, PFFT is a fine ore called pellet feed, and has a low alumina concentration of 0.52% by mass. Pellet feed is an example of ore that is a raw material target for producing the low alumina (Al 2 O 3 ) granules of the present invention. As shown in Table 1, the pellet feed is a fine ore with a small average particle size, so it does not need to be pulverized, and is easily agglomerated and easily granulated. If the low-alumina iron ore is lumpy, it must be pulverized before granulation.
微粉状の低アルミナ鉄鉱石は、予め、造粒剤（例えば、消石灰または生石灰など）が加えられ、パンペレタイザーや高速撹拌ミキサー等を用いて造粒されて、低アルミナ造粒物とされる。低アルミナ造粒物の原料としては、低アルミナ鉄鉱石を、低アルミナ造粒物の９０質量％以上使用することが好ましい。また、低アルミナ造粒物の原料としては、配合原料として使用される全鉄鉱石の平均アルミナ濃度よりもアルミナ濃度の高い鉄鉱石は使用しないことが望ましい。 A granulating agent (for example, slaked lime or quicklime) is added to the fine powdery low-alumina iron ore in advance, and the mixture is granulated using a pan pelletizer, a high-speed stirring mixer, or the like to obtain a low-alumina granule. As a raw material for the low-alumina granules, it is preferable to use low-alumina iron ore in an amount of 90% by mass or more of the low-alumina granules. Moreover, as a raw material for the low alumina granules, it is desirable not to use iron ore having an alumina concentration higher than the average alumina concentration of all the iron ore used as the blended raw material.
低アルミナ造粒物は、その他の原料を別途造粒した疑似粒子と混合されて、上述した粒度偏析形成装入装置を介して下方吸引焼結機に供給される。低アルミナ造粒物の粒度は、その他の原料を造粒した擬似粒子の平均粒度（通常２ｍｍ以上３ｍｍ以下の範囲）に対し同等又は大きいことが好ましい。粒度が大きいことにより低アルミナ造粒物は下層に偏析しやすくなる。また、粒度が同等であっても、低アルミナ造粒物は鉄分が相対的に高く比重が大きいため、下層に偏析し易くなる。一方、低アルミナ造粒物が５ｍｍを超えて過大なものは焼成が不十分となる。したがって、低アルミナ造粒物は、３ｍｍを超え５ｍｍ以下の粒度の収率が多くなるように調整する。例えば、粒度区分３ｍｍを超え５ｍｍ以下の低アルミナ造粒物の割合が、低アルミナ造粒物全体に対し、７０質量％以上となるように造粒する。
本発明では、低アルミナ造粒物を、配合原料に対して、６質量％以上２５質量％以下の割合、好ましくは１０質量％以上２０質量％以下の割合で使用する。低アルミナ造粒物の割合が６質量％未満では十分な効果が得られず、２５質量％を超えると上層のアルミナ濃度上昇の影響が大きくなり、むしろ歩留の低下を招く。
The low-alumina granules are mixed with quasi-particles obtained by granulating other raw materials separately, and supplied to the downward suction sintering machine through the above-described particle size segregation forming charging device. The particle size of the low-alumina granules is preferably equal to or larger than the average particle size of pseudo-particles obtained by granulating other raw materials (usually in the range of 2 mm or more and 3 mm or less). Due to the large grain size, the low alumina granules tend to segregate in the lower layer. In addition, even if the particle size is the same, the low alumina granules have a relatively high iron content and a large specific gravity, so they tend to segregate in the lower layer. On the other hand, when the low-alumina granules exceed 5 mm and are excessively large, the sintering becomes insufficient. Therefore, the low alumina granules are adjusted to increase the yield of particle sizes greater than 3 mm and less than or equal to 5 mm. For example, granulation is performed so that the proportion of low alumina granules having a particle size division of more than 3 mm and 5 mm or less is 70% by mass or more with respect to the entire low alumina granules.
In the present invention, the low-alumina granules are used at a ratio of 6% by mass or more and 25% by mass or less, preferably 10% by mass or more and 20% by mass or less, based on the raw materials to be mixed. If the proportion of the low-alumina granules is less than 6% by mass, a sufficient effect cannot be obtained, and if it exceeds 25% by mass, the influence of an increase in the alumina concentration in the upper layer becomes greater, resulting in a decrease in yield.
（作用・効果）
以上、説明したように、本実施形態によれば、石灰石を粗粒化することによって、転動分級作用により装入時に斜面をよく転がり、石灰石が比較的下層に集中して装入される。さらに、粒度偏析形成装入装置を用いることにより、偏析形成を強化することができる。これに伴って、下層部のＣａＯ濃度が増加し、下層部の被還元性（ＪＩＳ－ＲＩや高温還元率）を改善することができる。
また、直径３ｍｍ以上の低アルミナ造粒物は、その他の原料を造粒した擬似粒子より粒度が大きくかつ球形に近くなるので、転動分級作用により装入時に斜面をよく転がり、さらに、粒度偏析形成装入装置を用いることにより、低アルミナ造粒物の多くが下層に集中して装入される。これに伴って、下層部のアルミナ濃度を低減でき、下層部の高温還元率を改善することができる。これは、焼結鉱の高温還元性が、Ａｌ2Ｏ3に代表される還元前の焼結鉱中の脈石量の悪影響を大きく受けるためである。
(action/effect)
As described above, according to the present embodiment, by making the limestone coarser, the limestone rolls well on the slope during charging due to the rolling classifying action, and the limestone is charged relatively concentrated in the lower layer. In addition, segregation formation can be enhanced by using a grain size segregation charging device. As a result, the CaO concentration in the lower layer increases, and the reducibility (JIS-RI or high-temperature reduction rate) of the lower layer can be improved.
In addition, since the low-alumina granules with a diameter of 3 mm or more have a larger particle size and a spherical shape than the pseudo-particles obtained by granulating other raw materials, they roll well on the slope during charging due to the rolling classification action, and furthermore, the particle size segregates. By using a forming charge device, most of the low alumina granules are concentrated and charged in the lower layer. Accordingly, the concentration of alumina in the lower layer can be reduced, and the high-temperature reduction rate of the lower layer can be improved. This is because the high-temperature reducibility of the sintered ore is greatly affected by the amount of gangue in the sintered ore before reduction, represented by Al 2 O 3 .
一方、上層部では、これらの偏析の変化は焼結鉱の高温還元率には悪影響に働く。しかし、上層部はもともと低温で焼成されるため、十分な気孔を含む焼結鉱となるので、上述したＣａＯ、Ａｌ2Ｏ3の成分偏析の悪影響は顕在化しない。
以上から、上層から下層にわたる全層平均の焼結鉱の高温還元率は改善する。
On the other hand, in the upper layer, these segregation changes adversely affect the high-temperature reduction rate of the sinter. However, since the upper layer is originally sintered at a low temperature, the sintered ore contains sufficient pores, so that the above-described adverse effects of the segregation of components of CaO and Al 2 O 3 do not become apparent.
As described above, the average high-temperature reduction rate of sintered ore from the upper layer to the lower layer is improved.
＜第２の実施形態＞
以下、本発明の第２の実施形態に係る焼結鉱の製造方法について説明する。第２の実施形態においては、第１の実施形態での石灰石および低アルミナ造粒物の粒度偏析に加え、ＭｇＯ成分を含有する副原料も粗粒化して粒度偏析を形成させる。
<Second embodiment>
Hereinafter, a method for producing sintered ore according to the second embodiment of the present invention will be described. In the second embodiment, in addition to the grain size segregation of limestone and low alumina granules in the first embodiment, the auxiliary material containing the MgO component is also coarsened to form grain size segregation.
（含ＭｇＯ副原料）
焼結鉱製造には、ＭｇＯ成分の調整を目的として、焼結用の原料の一部にＭｇＯ成分を含有する副原料（含ＭｇＯ副原料）が用いられる。含ＭｇＯ副原料には、蛇紋岩、橄欖岩、ニッケルスラグ、およびドロマイトがある。前３者は、ＭｇＯとＳｉＯ２を主成分とし、これらの含有量は概ね等しい。そこで、以下では橄欖岩を用いた例で説明するが、蛇紋岩、ニッケルスラグも同様に適用できる。ただし、ドロマイトは、ＭｇＯとＣａＯを主成分とする副原料であるので、本発明の対象外である。
(Contains MgO auxiliary raw material)
In the production of sintered ore, an auxiliary raw material (MgO-containing auxiliary raw material) containing an MgO component is used as part of the raw material for sintering for the purpose of adjusting the MgO component. MgO-containing auxiliary materials include serpentinite, peridotite, nickel slag, and dolomite. The former three are mainly composed of MgO and SiO2, and their contents are approximately equal. Therefore, an example using peridotite will be described below, but serpentinite and nickel slag are also applicable. However, since dolomite is an auxiliary raw material containing MgO and CaO as main components, it is outside the scope of the present invention.
（橄欖岩の粒度調整）
橄欖岩の粒度調整は、橄欖岩破砕処理工程における最終篩の目開きを通常採用されている３ｍｍから５ｍｍ程度に拡大変更することにより行う。粒度区分３ｍｍを超え５ｍｍ以下の橄欖岩の割合を、橄欖岩全質量に対し２０質量％以上４０質量％以下と規定した。粒度区分３ｍｍを超え５ｍｍ以下の橄欖岩の割合が、２０％未満では、橄欖岩を粗粒化する効果が小さく、４０％質量を超えると橄欖岩の下層偏析が過大となり、上層の高温性状の大幅な低下を招くためである。
この粒度調整の場合、実用上３％質量程度の＋５ｍｍ（５ｍｍ篩上）を含むが、それは本発明の効果を著しく損なうものではない。
(Particle size adjustment of peridotite)
The grain size of the peridotite is adjusted by increasing the final mesh size of the sieve in the peridotite crushing treatment process from the normally employed 3 mm to about 5 mm. The proportion of peridotite having a grain size classification of more than 3 mm and 5 mm or less is defined as 20% by mass or more and 40% by mass or less with respect to the total mass of peridotite. If the proportion of peridotite with a grain size classification of more than 3 mm and 5 mm or less is less than 20%, the effect of coarsening the peridotite is small. This is because it causes a significant decrease.
In the case of this particle size adjustment, +5 mm (on a 5 mm sieve) of about 3% mass is practically included, but it does not significantly impair the effects of the present invention.
（作用・効果）
以上、説明したように、本実施形態によれば、上述した第１の実施形態による効果に加え、以下に示す効果も得られる。第２の実施形態によれば、橄欖岩を粗粒化することによって、石灰石同様に転動分級作用により装入時に斜面をよく転がり、橄欖岩が比較的下層部に集中して装入される。これに伴って、下層部のＭｇＯ濃度が増加する。下層部のＭｇＯの増加によって、下層部の高温還元率をより改善することができる。
(action/effect)
As described above, according to the present embodiment, in addition to the effects of the first embodiment, the following effects can be obtained. According to the second embodiment, by coarsening the peridotite, it rolls well on the slope during charging due to the rolling classification action similar to limestone, and the peridotite is charged relatively concentrated in the lower layer. . Along with this, the MgO concentration in the lower layer increases. An increase in MgO in the lower layer can further improve the high-temperature reduction rate of the lower layer.
一方、上層部では、これらの偏析の変化は焼結鉱の高温還元率、例えば、焼結鉱１２００℃まで到達した時点の還元率Ｒ1200℃には悪影響に働く。しかし、上層部はもともと低温で焼成されるため、十分な気孔を含む焼結鉱となるので、ＣａＯ、Ａｌ2Ｏ3、ＭｇＯの成分偏析の悪影響は顕在化しない。
以上から、上層から下層にわたる全層平均の焼結鉱の高温還元率も改善する。
On the other hand, in the upper layer, these segregation changes adversely affect the high-temperature reduction rate of the sintered ore, for example, the reduction rate R1200°C when the sintered ore reaches 1200°C. However, since the upper layer is originally sintered at a low temperature, the sintered ore contains sufficient pores, and the adverse effects of the segregation of components of CaO, Al 2 O 3 and MgO do not become obvious.
As described above, the average high-temperature reduction rate of the sintered ore from the upper layer to the lower layer is also improved.
以下、本発明の実施例について説明する。実施例においては、実際の下方吸引焼結機での焼成を模した焼成鍋を用いた試験を行ったので、その結果を説明する。なお、本発明は、この実施例に限定されるものではない。また、以下の説明において、数値範囲を示す「Ａ～Ｂ」の記載は、下端点であるＡは含まず、上端点であるＢを含む数値範囲である「Ａを超えＢ以下」を表すものとする。 Examples of the present invention will be described below. In the examples, tests were conducted using a sintering pan simulating sintering in an actual downward suction sintering machine, and the results will be described. However, the present invention is not limited to this embodiment. Also, in the following description, the description of "A to B" indicating a numerical range indicates "above A and below B", which is a numerical range that does not include A, which is the lower end point, but includes B, which is the upper end point. and
（試験水準）
試験水準を表２に示す。石灰石の粗粒化の有無および低アルミナ造粒物の有無の組み合わせの４水準（参考例、比較例１、比較例２、および実施例１）に、実施例１の試験条件に橄欖岩の粗粒化したもの（実施例２）を追加して、５水準とした。
(test level)
Test levels are shown in Table 2. Four levels of combinations of presence or absence of limestone coarsening and presence or absence of low alumina granules (Reference Example, Comparative Example 1, Comparative Example 2, and Example 1) were applied under the test conditions of Example 1. A granulated product (Example 2) was added to make 5 levels.
（原料調製方法）
石灰石の粒度調整：表３に示すように、粒度分布の異なる石灰石を２種類用意した。表３の上段は、通常粒度分布を有する石灰石の粒度分布を示す。また、表３の下段は、予め粒度区分ごとに篩い分けられた石灰石を、表３に示す比率で再配合して、所望の粒度分布に調整したものである。粗粒化した石灰石の３～５ｍｍの粒度区分の比率は２２．５質量％であった。
(Raw material preparation method)
Particle size adjustment of limestone: As shown in Table 3, two types of limestone with different particle size distributions were prepared. The upper part of Table 3 shows the particle size distribution of limestone having a normal particle size distribution. In addition, in the lower part of Table 3, the limestone previously sieved for each particle size classification was reblended at the ratio shown in Table 3 to adjust the desired particle size distribution. The proportion of the 3-5 mm grain size fraction of the coarse-grained limestone was 22.5% by weight.
橄欖岩の粒度調整：表４に示すように、粒度分布の異なる橄欖岩を２種類用意した。表４の上段は、通常粒度分布を有する橄欖岩の粒度分布を示す。また、表４の下段は、予め粒度区分ごとに篩い分けられた橄欖岩を、表４に示す比率で再配合して、所望の粒度分布に調整したものである。粗粒化した橄欖岩の３～５ｍｍの粒度区分の比率は２９．２質量％であった。 Grain size adjustment of peridotite: As shown in Table 4, two types of peridotite having different particle size distributions were prepared. The upper part of Table 4 shows the grain size distribution of peridotite with a normal grain size distribution. Further, in the lower part of Table 4, the peridotite preliminarily sieved for each particle size classification was reblended at the ratio shown in Table 4 to adjust the desired particle size distribution. The proportion of the 3-5 mm grain size division of the coarse-grained peridotite was 29.2% by mass.
低アルミナ（Ａｌ2Ｏ3）造粒物の製造：表５に示すように、低アルミナ造粒物の原料として、ＰＦＦＴ（Ａｌ2Ｏ3濃度：０．５２質量％）と造粒材としての消石灰を使用した。ＰＦＦＴおよび消石灰を、ＰＦＦＴおよび消石灰に対し水分１０質量％の割合で高速撹拌ミキサーを用いて造粒した。低アルミナ造粒物の粒度区分の比率は、１ｍｍ以下が１５質量％、１～３ｍｍが３２質量％、３～５ｍｍが３８質量％、５ｍｍ以上が１５質量％であった。 Production of low-alumina (Al 2 O 3 ) granules: As shown in Table 5, PFFT (Al 2 O 3 concentration: 0.52% by mass) and granules as raw materials for low-alumina granules Slaked lime was used. PFFT and slaked lime were granulated using a high-speed stirring mixer at a ratio of 10% by weight of water to PFFT and slaked lime. The particle size division ratio of the low alumina granules was 15% by mass for 1 mm or less, 32% by mass for 1 to 3 mm, 38% by mass for 3 to 5 mm, and 15% by mass for 5 mm or more.
原料配合：配合原料の原料配合の割合を表５に示す。表５に示すように、返鉱およびコークスを除いた原料（低アルミナ造粒物、鉄鉱石、橄欖岩、石灰石、および生石灰）を１００質量％として、返鉱とコークスの配合割合を、それぞれ外数で、１５．０質量％、４．５質量％とした。上述の低アルミナ造粒物に用いたＰＦＦＴ以外に、原料として使用した鉄鉱石（６２．５質量％）のアルミナ（Ａｌ2Ｏ3）濃度は、１．７７質量％であり、配合原料として使用した全鉄鉱石の平均アルミナ濃度は、１．４７質量％であった。 Raw material blending: Table 5 shows the ratio of the raw material blending of the blended raw materials. As shown in Table 5, the raw materials (low alumina granules, iron ore, peridotite, limestone, and quicklime) excluding return ore and coke are taken as 100% by mass, and the blending ratio of return ore and coke is The numbers were 15.0% by mass and 4.5% by mass. In addition to the PFFT used for the low alumina granules described above, the iron ore (62.5% by mass) used as a raw material had an alumina (Al 2 O 3 ) concentration of 1.77% by mass, and was used as a blending raw material. The average alumina concentration of the total iron ore obtained was 1.47% by mass.
実験は以下の方法で行った。実験に使用した。主要な実験装置は表６に示す通りである。 Experiments were conducted in the following manner. Used for experiments. The main experimental equipment is shown in Table 6.
（実験方法）
配合原料の造粒：低アルミナ造粒物（以下、ＰＦＦＴ造粒物ともいう）以外の原料を、ドラムミキサーで、ＰＦＦＴ造粒物以外の原料に対して７．５質量％の水分を加えて、５分間造粒した。そのあと、ドラムミキサーの中に、さらに、ＰＦＦＴ造粒物を加えて１分混合し、配合原料造粒物とした。配合原料造粒物に対するＰＦＦＴ造粒物の比率は、返鉱およびコークスを除いた原料（低アルミナ造粒物、鉄鉱石、橄欖岩、石灰石、および生石灰）を１００質量％として、２１質量％（＝ＰＦＦＴ＋消石灰）とした。
(experimental method)
Granulation of blended raw materials: Raw materials other than low alumina granules (hereinafter also referred to as PFFT granules) were mixed with a drum mixer by adding 7.5% by mass of water to the raw materials other than PFFT granules. , granulated for 5 minutes. After that, the PFFT granules were added to the drum mixer and mixed for 1 minute to obtain the blended raw material granules. The ratio of PFFT granules to blended raw material granules is 21 mass% ( = PFFT + slaked lime).
原料装入：上述の粒度偏析形成装入装置を用いて配合原料造粒物の装入を模すために、本試験での焼結鍋への装入は、新たに製造した偏析給鉱型大型鍋焼結シミュレーターを用いた。この偏析給鉱型大型鍋焼結シミュレーターは、焼結鍋に偏析を付与しつつ配合原料を投入する焼結実験用の偏析装置であり、その詳細は、鉄と鋼「偏析給鉱型大型焼結シミュレーターの開発」石山ら、早期公開TETSU-2017-007に記載されているので、ここでの説明は省略する。
長辺６５０ｍｍ×短辺３５０ｍｍの箱型試験鍋（焼結鍋）内に、まず、床敷鉱５．０ｋｇをロストル上に敷設した。次に、上述の配合原料造粒物を、偏析給鉱型大型鍋焼結シミュレーターを用いて装入した。このとき、床敷鉱の厚みは２０ｍｍであったので、原料層厚みは５００ｍｍとなった。
Raw material charging: In order to simulate the charging of blended raw material granules using the above-described particle size segregation forming charging device, the charging into the sintering pot in this test was a newly manufactured segregation feed mold. A large pot sintering simulator was used. This segregation ore feed type large pot sintering simulator is a segregation device for sintering experiments in which the raw materials are added while imparting segregation to the sintering pot. Development of Simulator”, Ishiyama et al.
In a box-shaped test pot (sintering pot) having a long side of 650 mm and a short side of 350 mm, 5.0 kg of bedding ore was first laid on the roster. Next, the above-described mixed raw material granules were charged using a segregation feed type large pot sintering simulator. At this time, since the thickness of the bedding ore was 20 mm, the raw material layer thickness was 500 mm.
焼結処理：装入した配合原料造粒物の表面に、ＬＰＧバーナーを用いて６０秒間着火後に、圧力マイナス１５ｋＰａで空気を吸引し、焼成を実施した。 Sintering treatment: After igniting for 60 seconds using an LPG burner on the surface of the loaded granulated raw material, sintering was performed by sucking air at a pressure of minus 15 kPa.
（測定）
焼成完了後、焼結ケーキの下面から層厚方向上方に向かっての位置（ケーキ高さ）が５０ｍｍ、１９０ｍｍ、３００ｍｍ、４５０ｍｍの４箇所において、コアボーリングマシンを用いて抜き取った焼結ケーキから分割し、それらを落下強度試験機によって落下破砕した焼結鉱粒子の中から１５ｍｍを超え２０ｍｍ以下の焼結鉱を試料として採取した。採取した試料について、Ｘ線蛍光分析により、ＣａＯ，Ａｌ２Ｏ３，ＭｇＯについて成分分析を行った。また、被還元性指標であるＲＩ（JIS_M8713(2009)「鉄鉱石－被還元性試験方法」に規定された試験による）、およびＲ1200℃（上述した特許文献９に開示された測定方法による）を評価した。
(measurement)
After the completion of baking, the sintered cake extracted using a core boring machine is divided at four positions (cake heights) of 50 mm, 190 mm, 300 mm, and 450 mm in the upper layer thickness direction from the lower surface of the sintered cake. Then, sintered ore having a size of more than 15 mm and 20 mm or less was collected as a sample from the sintered ore particles that were crushed by a drop strength tester. The components of CaO, Al 2 O 3 and MgO of the collected sample were analyzed by X-ray fluorescence analysis. In addition, the reducibility index RI (according to the test specified in JIS_M8713 (2009) "Iron ore-reducibility test method") and R1200 ° C (according to the measurement method disclosed in the above-mentioned Patent Document 9). evaluated.
（試験結果）
表７、表８に、上記測定の結果を示す。表７は、焼成した原料層全体（床敷層を除く）の生産率、ＪＩＳ－ＲＩ、およびＲ1200℃の数値を示すものであり、基準とする参考例の値からの増加分を、増分として示している。表８は、焼結用配合原料の充填層（焼結ケーキ）について、ＣａＯ、Ａｌ2Ｏ3およびＭｇＯの濃度分布と、ＪＩＳ－ＲＩおよびＲ1200℃の分布を示す。ここに、空欄は測定していない。
(Test results)
Tables 7 and 8 show the results of the above measurements. Table 7 shows the production rate, JIS-RI, and R1200°C values for the entire baked raw material layer (excluding the bedding layer). showing. Table 8 shows the concentration distributions of CaO, Al 2 O 3 and MgO, and the JIS-RI and R1200°C distributions of the packed bed (sintered cake) of the compounded raw material for sintering. Here, blanks are not measured.
表７に示すように、焼結実験から生産率、焼結鉱の被還元性について、以下の結果が得られた。
（実施例１）
焼結生産率は、石灰石の粗粒化（比較例１）、低アルミナ造粒物の使用（比較例２）ともに基準（参考例）に対して向上した。さらに、両条件を同時に行う本願発明（実施例１）では、各条件の向上効果の和に相当する向上効果が確認された。
焼結鉱の被還元性（ＪＩＳ－ＲＩおよびＲ1200℃）については、石灰石の粗粒化（比較例１）、低アルミナ造粒物の使用（比較例２）ともに基準（参考例）に対して向上した。さらに、両条件を同時に行う本願発明（実施例１）では、それぞれの向上効果の和以上の向上効果が確認された。すなわち、被還元性では、石灰石の粗粒化と低アルミナ造粒物の使用とが相乗効果を有することが分かった。
As shown in Table 7, the following results were obtained from the sintering experiment with respect to the production rate and the reducibility of the sintered ore.
(Example 1)
The sintering productivity improved relative to the standard (reference example) in both the coarsening of limestone (comparative example 1) and the use of low alumina granules (comparative example 2). Furthermore, in the present invention (Example 1) in which both conditions are performed at the same time, an improvement effect corresponding to the sum of the improvement effects of each condition was confirmed.
Regarding the reducibility of sintered ore (JIS-RI and R1200°C), both the coarsening of limestone (Comparative Example 1) and the use of low-alumina granules (Comparative Example 2) are compared to the standard (Reference Example). Improved. Furthermore, in the present invention (Example 1) in which both conditions are performed at the same time, an improvement effect equal to or greater than the sum of the respective improvement effects was confirmed. In other words, it was found that coarsening of limestone and use of low-alumina granules have a synergistic effect in terms of reducibility.
（実施例２）
焼結生産率は、橄欖岩の粗粒化（実施例２）で基準（参考例）、比較例１～２、および実施例１に対して向上した。また焼結鉱のＪＩＳ－ＲIは、橄欖岩の粗粒化（実施例２）で実施例１に対して変わらなかったものの、Ｒ1200℃については、橄欖岩の粗粒化（実施例２）で基準（参考例）および実施例１に対して向上した。すなわち、橄欖岩の粗粒化によって、ＪＩＳ－ＲＩを維持しながら更に高温還元率が向上することが分かった。
(Example 2)
The sintering productivity improved with peridotite coarsening (Example 2) relative to the reference (reference example), Comparative Examples 1-2, and Example 1. In addition, the JIS-RI of the sintered ore did not change from Example 1 due to coarsening of peridotite (Example 2), but for R1200 ° C, coarsening of peridotite (Example 2) Compared to the reference (reference example) and Example 1, it is improved. That is, it was found that the high-temperature reduction rate is further improved while maintaining the JIS-RI by coarsening the peridotite.
（考察：各成分の層厚方向分布と被還元性との関連）
図１～図５は、表８に示す値に基づいた、各試験水準における層厚方向の成分濃度分布や被還元性を示すグラフである。
図１および図２は、焼結用配合原料の充填層（焼結ケーキ）における、ＣａＯおよびＡｌ2Ｏ3の濃度分布を示す。粗粒化した石灰石を使用したケース（比較例１および実施例１）では粗粒石灰石の下層への偏析が助長されることによって下層のＣａＯ濃度が増大すること、低アルミナ造粒物を使用したケース（比較例２および実施例１）では低アルミナ造粒物の下層への偏析が助長されることによって下層のアルミナ濃度が低下することが確認できた。
(Consideration: relationship between layer thickness direction distribution of each component and reducibility)
1 to 5 are graphs showing the component concentration distribution in the layer thickness direction and the reducibility at each test level based on the values shown in Table 8. FIG.
FIGS. 1 and 2 show the concentration distributions of CaO and Al 2 O 3 in the packed bed (sintered cake) of the compounded raw material for sintering. In the case of using coarse-grained limestone (Comparative Example 1 and Example 1), the segregation of coarse-grained limestone to the lower layer was promoted, which increased the CaO concentration in the lower layer, and low alumina granules were used. In the cases (Comparative Example 2 and Example 1), it was confirmed that the segregation of the low-alumina granules to the lower layer was promoted, thereby lowering the alumina concentration in the lower layer.
図３は、層厚方向のＪＩＳ－ＲＩの分布を示す。上層では、条件によらずＪＩＳ－ＲＩの変化は大きくないのに対して、下層では、石灰石の粗粒化（比較例１）、低アルミナ造粒物の使用（比較例２）、および両条件の同時実施（実施例１）の順に、しだいに大きな改善幅で向上し、層厚方向においてＪＩＳ－ＲＩ値が均一化されることが分かった。これより、ＪＩＳ－ＲＩにおける本発明の相乗効果は、以下のように発現されると考えられる。すなわち、元来より熱量が過剰でＪＩＳ－ＲＩの低い下層において、ＣａＯとＡｌ2Ｏ3の一方で効果を十分享受出来なかったところに対し、同時に存在する条件を得たことで焼結塊成化に必要なカルシウムフェライト融液の生成が確保され、加えて高被還元率鉱物カルシウムフェライトの生成領域も増大し、単独の効果の合算値よりも向上したと考えられる。 FIG. 3 shows the JIS-RI distribution in the layer thickness direction. In the upper layer, the change in JIS-RI is not large regardless of the conditions, while in the lower layer, coarsening of limestone (Comparative Example 1), use of low alumina granules (Comparative Example 2), and both conditions Simultaneous implementation (Example 1) gradually improved with a large improvement width, and it was found that the JIS-RI value was made uniform in the layer thickness direction. From this, it is considered that the synergistic effect of the present invention in JIS-RI is expressed as follows. That is, in the lower layer where the heat quantity is excessive and the JIS-RI is low from the beginning, the effect of only CaO and Al 2 O 3 could not be sufficiently enjoyed, but by obtaining the conditions that exist at the same time, sintering agglomeration It is considered that the formation of the calcium ferrite melt necessary for the reduction is ensured, and in addition, the formation region of the highly reducible mineral calcium ferrite is also increased, and the total value of the individual effects is considered to be improved.
図４は、層厚方向の高温還元率Ｒ1200℃の分布を示す。また、図５は、焼結用配合原料の充填層（焼結ケーキ）における、ＭｇＯの濃度分布を示す。図５に示すように、橄欖岩の粗粒化により、ＭｇＯの濃度偏析が形成され、下層においてＭｇＯ濃度が上昇している。また、Ｒ1200℃については、図４に示すように、上層では、条件によらず値が変化していないのに対して、下層では、橄欖岩の粗粒化（実施例２）も粗粒化して同時に比較的下層に誘導することで、より向上していることが分かった。これより、Ｒ1200℃における本発明の効果は、以下のように発現されると考えられる。すなわち、元来より熱量が過剰で被還元率の低い下層において、ＣａＯの濃度上昇とＡｌ2Ｏ3の濃度低下の双方で効果を十分享受出来たところに加え、図５に示す通り下層にＭｇＯが同時に多く存在する条件を得たことで、高温での軟化溶融を抑制出来る特性が確保され、高温における被還元性が更に向上したと考えられる。 FIG. 4 shows the distribution of the high-temperature reduction rate R1200°C in the layer thickness direction. Moreover, FIG. 5 shows the concentration distribution of MgO in the packed layer (sintered cake) of the mixed raw material for sintering. As shown in FIG. 5, the coarsening of peridotite forms MgO concentration segregation, and the MgO concentration increases in the lower layer. As for R1200°C, as shown in Fig. 4, in the upper layer, the value does not change regardless of the conditions, while in the lower layer, the coarsening of peridotite (Example 2) also becomes coarser. It was found that by simultaneously guiding to a relatively lower layer at the same time, the improvement was further improved. From this, it is considered that the effects of the present invention at R1200°C are exhibited as follows. That is, in the lower layer, which originally has an excessive amount of heat and a low reducibility rate, the effects of both the increase in the concentration of CaO and the decrease in the concentration of Al 2 O 3 were sufficiently obtained. It is considered that the property of suppressing softening and melting at high temperature is secured by obtaining the condition in which many are present at the same time, and the reducibility at high temperature is further improved.
Claims (5)
前記原料装入装置は、層厚方向の粒度偏析を形成する篩機能を有する篩部材を備えた粒度偏析形成装入装置であり、
前記配合原料中の石灰石は、粒度区分３ｍｍを超え５ｍｍ以下の石灰石の割合が、全石灰石に対し１０質量％以上３０質量％以下であり、
前記配合原料は、低アルミナ鉄鉱石を除いて前記配合原料として使用される全鉄鉱石の平均アルミナ濃度よりもアルミナ濃度が１．０質量％以上低い低アルミナ鉄鉱石を予め造粒した造粒物である低アルミナ造粒物を、前記配合原料に対して６質量％以上２５質量％以下含み、
前記配合原料は、前記原料装入装置により、前記原料充填層の下層に向けて粒度が大きくなるように、前記パレット上に装入される、ことを特徴とする焼結鉱の製造方法。 In a method for producing sintered ore, in which mixed raw materials for sintering are supplied to a lower suction sintering machine through a raw material charging device, and a raw material packed layer is formed on a pallet of the lower suction sintering machine and sintered. ,
The raw material charging device is a particle size segregation forming charging device equipped with a sieve member having a sieve function to form particle size segregation in the layer thickness direction,
Limestone in the blended raw material has a ratio of limestone with a particle size division of more than 3 mm and 5 mm or less, with respect to the total limestone, is 10% by mass or more and 30% by mass or less,
The blended raw material is a granule obtained by pre-granulating low alumina iron ore having an alumina concentration lower than the average alumina concentration of all the iron ores used as the blended raw material by 1.0% by mass or more, excluding the low alumina iron ore. contains 6% by mass or more and 25% by mass or less of the low alumina granules with respect to the blended raw material,
A method for producing sintered ore, wherein the mixed raw material is charged onto the pallet by the raw material charging device so that the grain size increases toward the lower layer of the raw material packed bed.
前記低アルミナ造粒物の原料として、前記低アルミナ鉄鉱石を、前記低アルミナ造粒物の９０質量％以上使用し、
前記低アルミナ造粒物の原料として、前記配合原料として使用される全鉄鉱石の平均アルミナ濃度よりもアルミナ濃度の高い鉄鉱石は使用しない、ことを特徴とする焼結鉱の製造方法。 In the method for producing sintered ore according to claim 1,
90% by mass or more of the low-alumina granules is used as a raw material for the low-alumina granules,
A method for producing sintered ore, wherein iron ore having a higher alumina concentration than the average alumina concentration of all iron ore used as the mixed raw material is not used as the raw material of the low alumina granules.
前記低アルミナ鉄鉱石は、アルミナ濃度が０．８質量％以下である、ことを特徴とする焼結鉱の製造方法。 In the method for producing sintered ore according to claim 1 or claim 2,
A method for producing sintered ore, wherein the low-alumina iron ore has an alumina concentration of 0.8% by mass or less.
前記低アルミナ鉄鉱石はペレットフィードである、ことを特徴とする焼結鉱の製造方法。 In the method for producing sintered ore according to any one of claims 1 to 3,
A method for producing sintered ore, wherein the low-alumina iron ore is pellet feed .
前記配合原料は、粒度区分３ｍｍを超え５ｍｍ以下の橄欖岩の割合が全橄欖岩に対し２０質量％以上４０質量％以下である、ことを特徴とする焼結鉱の製造方法。 In the method for producing sintered ore according to any one of claims 1 to 4,
A method for producing a sintered ore, wherein the blended raw material has a ratio of peridotite having a particle size classification of more than 3 mm and not more than 5 mm in an amount of 20% by mass or more and 40% by mass or less with respect to the total peridotite.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000336434A (en) | 1999-05-26 | 2000-12-05 | Nkk Corp | Production of sintered ore |
| JP2002266037A (en) | 2001-03-09 | 2002-09-18 | Nkk Corp | Method for manufacturing sintered ore |
| JP2012031450A (en) | 2010-07-29 | 2012-02-16 | Jfe Steel Corp | METHOD FOR MANUFACTURING SINTERED ORE INCLUDING MgO LUMP |
| JP2013253281A (en) | 2012-06-06 | 2013-12-19 | Nippon Steel & Sumitomo Metal Corp | Method for producing sintered ore |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63282216A (en) * | 1987-05-12 | 1988-11-18 | Nkk Corp | Manufacture of sintered ore excellent in reducibility |
| JP2606881B2 (en) * | 1987-10-17 | 1997-05-07 | 新日本製鐵株式会社 | Sintering raw material charging method |
| JPH01172529A (en) * | 1987-12-28 | 1989-07-07 | Kawasaki Steel Corp | Production of sintered ore |
| JP2714276B2 (en) * | 1991-06-25 | 1998-02-16 | 日本鋼管株式会社 | Raw material supply device for sintering machine |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2000336434A (en) | 1999-05-26 | 2000-12-05 | Nkk Corp | Production of sintered ore |
| JP2002266037A (en) | 2001-03-09 | 2002-09-18 | Nkk Corp | Method for manufacturing sintered ore |
| JP2012031450A (en) | 2010-07-29 | 2012-02-16 | Jfe Steel Corp | METHOD FOR MANUFACTURING SINTERED ORE INCLUDING MgO LUMP |
| JP2013253281A (en) | 2012-06-06 | 2013-12-19 | Nippon Steel & Sumitomo Metal Corp | Method for producing sintered ore |
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