JPH0364571B2 - - Google Patents
Info
- Publication number
- JPH0364571B2 JPH0364571B2 JP10441784A JP10441784A JPH0364571B2 JP H0364571 B2 JPH0364571 B2 JP H0364571B2 JP 10441784 A JP10441784 A JP 10441784A JP 10441784 A JP10441784 A JP 10441784A JP H0364571 B2 JPH0364571 B2 JP H0364571B2
- Authority
- JP
- Japan
- Prior art keywords
- strength
- iron ore
- roll
- powder
- experimental example
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 66
- 239000000843 powder Substances 0.000 claims description 35
- 229910052742 iron Inorganic materials 0.000 claims description 33
- 239000000203 mixture Substances 0.000 claims description 15
- 239000004215 Carbon black (E152) Substances 0.000 claims description 13
- 229930195733 hydrocarbon Natural products 0.000 claims description 13
- 150000002430 hydrocarbons Chemical class 0.000 claims description 13
- 238000000748 compression moulding Methods 0.000 claims description 9
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 239000010426 asphalt Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 5
- 239000003610 charcoal Substances 0.000 claims 1
- 238000000034 method Methods 0.000 description 16
- 239000002994 raw material Substances 0.000 description 14
- 238000000465 moulding Methods 0.000 description 11
- 239000011230 binding agent Substances 0.000 description 10
- 238000006722 reduction reaction Methods 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 239000004568 cement Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 239000008188 pellet Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 235000019738 Limestone Nutrition 0.000 description 3
- 239000000571 coke Substances 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 229910052595 hematite Inorganic materials 0.000 description 3
- 239000011019 hematite Substances 0.000 description 3
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 3
- 239000006028 limestone Substances 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 229910000805 Pig iron Inorganic materials 0.000 description 2
- 239000011398 Portland cement Substances 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 229910021397 glassy carbon Inorganic materials 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000011271 tar pitch Substances 0.000 description 2
- KZEVSDGEBAJOTK-UHFFFAOYSA-N 1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-2-[5-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]ethanone Chemical compound N1N=NC=2CN(CCC=21)C(CC=1OC(=NN=1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)=O KZEVSDGEBAJOTK-UHFFFAOYSA-N 0.000 description 1
- 239000004484 Briquette Substances 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Description
<技術分野>
本発明は鉄鉱石粉末又は酸化鉄粉末を高炉で製
銑する際高炉装入時の粉末の飛散を防止し且つ炉
内の通気性を保持して精錬反応を円滑に進行せし
めるための原料鉄鉱石粉末の予備処理に関する。
<従来技術>
近年は出銑比の増大あるいはコークス比の低減
等の要請から高炉に装入する鉄鉱石の粒度が更に
小さくなる傾向にある事、富鉱の涸渇化による低
品位鉱の利用の必要性から粉鉱石の取り扱い量が
増大している事、また製銑工場での粉塵公害防止
のためダストの回収が強化されている事、等のた
めに鉄鉱石粉末の使用量は益々増加する傾向にあ
る。これらの鉄鉱石粉末をそのまま高炉に装入す
ると、通気性の不良や不均一、ガス灰発生量の増
加、および荷下りの不良等を生じ、コークス比の
増大あるいは出銑比の低下等高炉の操業に著るし
い悪影響を及ぼすため鉄鉱石粉末は適当な方法で
塊成化して用いる必要がある。
鉄鉱石粉末又は酸化鉄粉末などの原料を塊成化
する方法として現在工業的に実施されているもの
には次の方法がある。
(1) 焼結法
約5mm以下の鉄鉱石粉末に適当な粒度のコー
クスと必要に応じて石灰石粉末とを混合し、格
子上で1200〜1400℃の温度下にて焼成し、鉄鉱
石の一部を溶融させて焼結させ、冷却後破砕し
て適当な粒とする方法。
(2) ペイツタイジング−焼成法
微粉砕した鉄鉱石粉末に適当量の水分および
必要に応じてベントナイト、石灰等を加え回転
ドラム、回転皿等を用いて造粒しその後ロータ
リーキルンで焼成し焼結させて充分な強度を得
る方法。
(3) ペレタイジング−冷間硬化法
俗にコールドボンド法と言われるもので微粉
砕した鉄鉱石粉末とポルトランドセメントある
いはポルトランドセメントクリンカー粉末の混
合物に適当量の水分を加えて、回転ドラムある
いは回転皿などを用いて造粒しその後養生して
充分な強度を得る方法。
以上の3法に大別されるが、(1)および(2)の方法
は何れも鉄鉱石粉末の粒状物あるいはペレツトに
強度を付与させるため、何等かの方法でこれらの
粒状物あるいはペレツトを焼成している。この焼
成には大規模な設備を必要とするばかりでなく、
焼成炉より発生するSOx、NOxあるいは粉塵等
が公害源になるという問題がある。このため非焼
成の塊成化方法として上記(3)の方法が開発されて
いるが、上記(3)の方法には次のような欠点があり
未だ充分ではない。
(イ) 強度発現までに長期間(通常7〜10日)を
要するために大規模な養生設備を必要とす
る。
(ロ) ペレツトは球状であるため安息角が小さ
く、高炉に投入した時炉の中央部に偏在する
ため高炉操業が著るしく不安定になる。これ
を避けるために使用量が非常に少量に限定さ
れる(通常10〜20重量%)。
(ハ) 充分な強度を達成させるにはセメントを多
量(通常7%以上)に添加する必要があるた
め、高炉の操業中にスラグ比が高くなるた
め、出銑比、コークス比および炉前作業性等
が悪くなる。
(ニ) ペレツトは球状且つトポ化学的に還元反応
が進行するため内部に未還元FeOが残留し易
い。
(ホ) セメントの水和水(結合水)の存在により
燃料比か高くなると共に炉頂で凝縮を生ずる
ことになり、操業上不都合である。
(ヘ) セメント水和物は加熱により結合が破壊さ
れ、このため500〜800℃での熱間強さが著し
く低下する。
<発明の目的>
本発明の予じめ焼結する事なしに成形後短時間
で強度を発現すると共に耐水性を有しそして高炉
中での被還元性に優れ、且つ鉄鉱石粉末が溶融温
度に達するまで自形を保持するに充分な強度を有
する非焼成塊成鉱を簡単な設備で製造する方法を
提供することを目的とする。
<発明の構成>
上記目的を達成するため、本発明の構成は、鉄
鉱石粉末に粘着性炭化水素混合物を添加混合した
後外混合物を圧縮成形し、硬化させることを特徴
とする。
本発明で使用する鉄鉱石粉末はヘマタイト系、
マグネタイト系およびリモナイト系いずれでも良
い。
本発明は上記鉄鉱石粉末に粘着性炭化水素混合
物を所定量添加する。ここで粘着性炭化水素混合
物とはアスフアルト、ピツチ又は溶剤抽出炭
(SRC)の一種又は二種以上からなるものを云
う。これらはいずれも粘着性を有し炭化水素を主
体とした混合物であり、常温下で固体ないし半固
体状をなし通常100℃以上の加熱下で溶融する。
更に中性又は還元雰囲気下で加熱すると揮発分が
蒸発し粘度は大きくなり遂にはガラス状炭素そし
て黒鉛になる。これら粘着性炭化水素混合物の添
加量は1重量%〜6重量%とするのがよい。1重
量%未満の場合は成形物の強度が小さく、又、6
重量%以上の場合には成形物表面に該粘着性炭化
水素が滲みだし相互に粘着したり、あるいは50℃
以上に加熱した際成形物が軟化するので好まし
い。
該粘着性炭化水素混合物を鉄鉱石粉末に添加す
るには溶融状の上記炭化水素混合物をスプレー等
で添加するのが好ましく、混合はパグミル等で行
なうとよい。鉄鉱石粉末へのバインダーの添加か
ら圧縮成形までの時間は出来るだけ短かくするの
が好ましい。この時間が長くなるとバインダーが
固化し成形性が低下するため好ましくない、この
ような場合は鉄鉱石粉末を加熱する必要がある。
鉄鉱石粉末に上記粘着性炭化水素混合物を添加
すると、該粘着性炭化水素混合がバインダーとし
て作用し、圧縮成形後常温まで冷却すると成形物
はバインダーの固化作用により強度を発現し高強
度を示す。この時回転皿型あるいは回転ドラム型
等の造粒機による造粒はバインダー量を多くせね
ば造粒出来ず、その結果50℃以上に加熱すると軟
化現象を示すため好ましくない。一方ロールによ
る圧縮成形によればバインダーの添加量を少なく
する事が出来るだけでなく成形体の強度が大きく
成形むらが小さい、大量処理が可能である等の理
由が好ましい。ロールで圧縮成形する時、ロール
上部に振動板を付属させたホツパーを設けホツパ
ー中の成形原料に振動を与えて成形するとロール
への原料の喰込みが良くなり又原料中の空気も脱
気されるので成形性が向上し、更に成形体の強度
も増加するので好ましい。この他原料に振動を与
えることによりホツパー中での原料の棚つり現象
も防止できる利点もある。
尚、ロール成形の際、鉄鉱石粉末は粒径が大き
過ぎると成形ロールへの喰込みが悪く成形性が低
下する。従つて粒子の最大径は成形ロール間隙よ
り小さくするのがよく、通常5mm以下が好まし
い。フレーク(成形物)の厚さは7mm以上15mm以
下が好ましく、ロール間隙を変化する事によりフ
レークの厚さをコントロールする事が出来る。得
られたフレークは必要に応じて解砕機で所要の粒
径(通常10〜50mm)まで解砕される。
次に、中性雰囲気又は還元雰囲気下て成形体を
加熱していくと約200℃程度からバインダー中の
揮発分が蒸発しバインダーの粘度が大きくなるた
め成形体の強度が増加する、約800℃になると揮
発分の蒸発はほぼ修了しガラス状の炭素が鉄鉱石
粒子を結合し成形体の強度は更に増加する。
炭素は中性又は還元性雰囲気下では非常に化学
的に不活性且つ熱間強度が大であるため、上記成
形時の加熱下においては成形体の熱間強度は低下
しない。一方製錬時には成形体中に残存した炭素
は最終的に鉄鉱石粉末と化学的に反応し鉄鉱石を
還元して消失する。
<発明の効果>
以上説明した本発明の製造方法は次の効果を有
する。
(1) 成形体の冷間強度はバインダーの固化により
達成されるため、成形直後に高強度を有する塊
成鉱を製造出来る。即ち、成形後の焼成設備お
よび養生設備を必要とせず成形後30分以内で冷
間落下強度が80%以上の強度を示すため直ちに
高炉に装入出来且つ熱間強度にも優れている。
このため良質な成形体を安価にかつ容易に大量
製造出来る。
(2) バインダーとしてセメントを使用しないた
め、スラグ比が高くならない塊成鉱を得ること
ができる。
(3) ロールによる圧縮成形法により製造される塊
成鉱はフレーク状であるため従来の非焼成ペレ
ツトよりも安息角が大きく且つ被還元性状に優
れている。
(4) 成形体中に残存する炭素は鉄鉱石を還元する
ため高炉操業でコークス比を小さくする等の利
点がある。
<実験例>
次に本発明の実験例を以下に示す。
実験例 1
1mm以下に粉砕したブラジルリオドセ産鉄鉱石
(ヘマタイト系)粉末を150℃に加熱した後、150
℃で溶融したストレートアスフアルトを1.0重量
%〜8.0重量%添加し、パグミルで混合した後、
一対の加圧成形用ロールでフレーク状に圧縮成形
した。成形物を室温まで放冷した後JISM8711に
準じて冷間落下強度を測定し第1図の結果を得
た。
尚、ロールの成形条件は以下の通りである。
ロール径:450mm
ロール巾:300mm
成形圧:800〜1000Kg/cm2
ロール回転数:2rpm
フレーク厚さ:10mm
第1図から明らかなように鉄鉱石粉末へのセメ
ントの添加量は2重量%〜6重量%が好ましいこ
とが解る。2重量%以下のときは強度が小さく、
又6重量%以上のときは強度向上の効果が小さい
ばかりか余分のアスフアルトが成形体の表面に滲
み出し、固壊化し易くなる現象がみられる。
実験例 2
実験例1で使用したリオドセ産鉄鉱石粉末に
150℃で溶融したストレートアスフアルトを4重
量%添加し、パグミルで混合した後実験例1で使
用したと同じロール機を使用し、ロール間隙を変
更して種々の厚さのフレークを成形した。フレー
クを常温まで放冷した後JIS M8711に準じて冷間
落下強度を、JIS M8713に準じて最終還元率を測
定し第2図の結果を得た。
第2図から明らかなように成形されるフレーク
の厚さは6mm以上15mm以下が好ましい事が解る。
即ち6mm以下の時は落下強度が小さく、又15mm以
上の時はフレークの被還元性が不良となるため好
ましくない。
実験例 3
140〜150℃に加熱した3mm以下のオーストラリ
アハスマレー産鉄鉱石(ヘマタイト系)粉末に
180〜210℃で加熱溶融したタールピツチを4重量
%添加しパグミルで混合した後実験例1で使用し
た加圧成形用ロール機のロール上部に振動板を設
けたホツパーを用い、成形原料に振動を与えて空
気を脱気しながらロールで圧縮成形した。
成形条件は次の通りである。
ロール間隙:6mm、成形圧900Kg/cm2フレーク
を室温まで冷却した後、収率および冷間落下強度
を測定し表−1の結果を得た。比較のため同一原
料をブリケツトマシンで成形した成形物について
も測定した。
<Technical field> The present invention is aimed at preventing scattering of the powder when charging iron ore powder or iron oxide powder in a blast furnace, and maintaining air permeability in the furnace to allow the refining reaction to proceed smoothly. Regarding the preliminary treatment of raw material iron ore powder. <Prior art> In recent years, the grain size of iron ore charged into blast furnaces has tended to become smaller due to demands such as increasing the pig iron production ratio or reducing the coke ratio. The amount of iron ore powder used will continue to increase due to the increasing amount of iron ore handled due to necessity, and the strengthening of dust collection to prevent dust pollution at pig iron factories. There is a tendency. If these iron ore powders are charged into a blast furnace as they are, they will cause poor and uneven ventilation, an increase in the amount of gas ash generated, and poor unloading. Iron ore powder must be agglomerated using an appropriate method because it has a significant negative impact on operations. The following methods are currently used industrially to agglomerate raw materials such as iron ore powder or iron oxide powder. (1) Sintering method Iron ore powder of approximately 5 mm or less is mixed with coke of an appropriate particle size and limestone powder as needed, and fired on a grid at a temperature of 1,200 to 1,400 degrees Celsius. A method in which the parts are melted and sintered, and after cooling, they are crushed into suitable particles. (2) Peitzizing - Calcination method An appropriate amount of water and, if necessary, bentonite, lime, etc. are added to finely ground iron ore powder, and it is granulated using a rotating drum or rotating plate, and then fired and sintered in a rotary kiln. How to obtain sufficient strength by (3) Pelletizing - Cold hardening method A suitable amount of water is added to a mixture of finely pulverized iron ore powder and Portland cement or Portland cement clinker powder using what is commonly called the cold bond method. A method of obtaining sufficient strength by granulating and then curing. These methods can be roughly divided into the three methods mentioned above, but methods (1) and (2) both involve adding strength to the iron ore powder granules or pellets by using some method. It is being fired. This firing not only requires large-scale equipment, but also
There is a problem that SOx, NOx, dust, etc. generated from the kiln become a source of pollution. For this reason, the method (3) above has been developed as a non-fired agglomeration method, but the method (3) has the following drawbacks and is still not sufficient. (b) It takes a long time (usually 7 to 10 days) to develop strength, so large-scale curing equipment is required. (b) Since pellets are spherical, their angle of repose is small, and when they are introduced into a blast furnace, they are unevenly distributed in the center of the furnace, making blast furnace operation extremely unstable. To avoid this, the amount used is limited to very small amounts (usually 10-20% by weight). (c) In order to achieve sufficient strength, it is necessary to add a large amount of cement (usually 7% or more), which increases the slag ratio during blast furnace operation. Sexuality becomes worse. (d) Since the pellets are spherical and the reduction reaction proceeds topochemically, unreduced FeO tends to remain inside the pellets. (e) Due to the presence of hydration water (bound water) in cement, the fuel ratio increases and condensation occurs at the top of the furnace, which is inconvenient for operation. (F) The bonds of cement hydrate are destroyed by heating, and therefore the hot strength at 500 to 800°C is significantly reduced. <Objective of the invention> The present invention develops strength in a short time after forming without sintering in advance, has water resistance, has excellent reducibility in a blast furnace, and has iron ore powder at a melting temperature. It is an object of the present invention to provide a method for producing uncalcined agglomerated ore having sufficient strength to maintain its shape until it reaches . <Configuration of the Invention> In order to achieve the above object, the configuration of the present invention is characterized in that a sticky hydrocarbon mixture is added and mixed with iron ore powder, and then the mixture is compression molded and hardened. The iron ore powder used in the present invention is hematite-based,
Either magnetite type or limonite type may be used. In the present invention, a predetermined amount of a sticky hydrocarbon mixture is added to the iron ore powder. Here, the viscous hydrocarbon mixture refers to one consisting of one or more of asphalt, pitch, or solvent extracted carbon (SRC). All of these are sticky and hydrocarbon-based mixtures that are solid or semi-solid at room temperature and usually melt when heated to 100°C or higher.
Further heating in a neutral or reducing atmosphere evaporates the volatile components and increases the viscosity, eventually turning into glassy carbon and graphite. The amount of these sticky hydrocarbon mixtures added is preferably 1% to 6% by weight. If it is less than 1% by weight, the strength of the molded product will be low;
If the amount exceeds 50°C, the adhesive hydrocarbon may ooze out onto the surface of the molded product and cause them to stick to each other.
This is preferable because the molded product softens when heated to a higher temperature. In order to add the sticky hydrocarbon mixture to the iron ore powder, it is preferable to add the molten hydrocarbon mixture by spraying or the like, and mixing is preferably carried out using a pug mill or the like. It is preferred that the time from addition of the binder to the iron ore powder to compression molding be as short as possible. If this time is too long, the binder will solidify and the moldability will deteriorate, which is not preferable. In such a case, it is necessary to heat the iron ore powder. When the above sticky hydrocarbon mixture is added to iron ore powder, the sticky hydrocarbon mixture acts as a binder, and when cooled to room temperature after compression molding, the molded product develops strength due to the solidification effect of the binder and exhibits high strength. At this time, granulation using a rotating plate type or rotating drum type granulator is not preferred because granulation cannot be achieved unless the amount of binder is increased, and as a result, a softening phenomenon occurs when heated to 50° C. or higher. On the other hand, compression molding using rolls is preferred because not only can the amount of binder added be reduced, but also the strength of the molded product is high, molding unevenness is small, and large-scale processing is possible. When performing compression molding with a roll, a hopper with a vibration plate attached to the top of the roll gives vibration to the molding material in the hopper, which improves the biting of the raw material into the roll and also deaerates the air in the raw material. This is preferable because it improves moldability and also increases the strength of the molded product. Another advantage is that by applying vibration to the raw material, the phenomenon of hanging of the raw material in the hopper can be prevented. In addition, during roll forming, if the particle size of the iron ore powder is too large, it will be difficult to bite into the forming roll, resulting in a decrease in formability. Therefore, the maximum diameter of the particles is preferably smaller than the gap between the forming rolls, and is usually preferably 5 mm or less. The thickness of the flakes (molded product) is preferably 7 mm or more and 15 mm or less, and the thickness of the flakes can be controlled by changing the roll gap. The obtained flakes are crushed to the required particle size (usually 10 to 50 mm) using a crusher as necessary. Next, when the molded body is heated in a neutral or reducing atmosphere, the volatile content in the binder evaporates from about 200°C and the viscosity of the binder increases, so the strength of the molded body increases, and the strength of the molded body increases until it reaches about 800°C. At this point, the evaporation of volatile matter is almost completed and the glassy carbon binds the iron ore particles, further increasing the strength of the compact. Since carbon is very chemically inert and has high hot strength in a neutral or reducing atmosphere, the hot strength of the molded article does not decrease under heating during the above-mentioned molding. On the other hand, during smelting, the carbon remaining in the compact ultimately chemically reacts with the iron ore powder to reduce the iron ore and disappear. <Effects of the Invention> The manufacturing method of the present invention described above has the following effects. (1) Since the cold strength of the compact is achieved by solidifying the binder, agglomerates with high strength can be produced immediately after compaction. That is, it does not require post-forming firing equipment or curing equipment and exhibits a cold drop strength of 80% or more within 30 minutes after molding, so it can be immediately charged into a blast furnace and has excellent hot strength.
Therefore, high-quality molded bodies can be manufactured in large quantities easily and inexpensively. (2) Since cement is not used as a binder, it is possible to obtain agglomerated ore without a high slag ratio. (3) Since the agglomerate produced by the compression molding method using rolls is in the form of flakes, it has a larger angle of repose and better reducibility than conventional uncalcined pellets. (4) Since the carbon remaining in the compact reduces iron ore, it has the advantage of reducing the coke ratio during blast furnace operation. <Experimental Example> Next, an experimental example of the present invention will be shown below. Experimental example 1 Iron ore (hematite type) powder from Rio Doce, Brazil, crushed to 1 mm or less, was heated to 150℃,
After adding 1.0% to 8.0% by weight of straight asphalt melted at °C and mixing in a pug mill,
It was compression molded into flakes using a pair of pressure molding rolls. After the molded product was allowed to cool to room temperature, the cold drop strength was measured according to JISM8711, and the results shown in FIG. 1 were obtained. The conditions for forming the roll are as follows. Roll diameter: 450mm Roll width: 300mm Molding pressure: 800-1000Kg/cm 2- roll rotation speed: 2rpm Flake thickness: 10mm As is clear from Figure 1, the amount of cement added to iron ore powder is 2% to 6% by weight. It turns out that weight % is preferred. When it is less than 2% by weight, the strength is low;
Moreover, when the amount is 6% by weight or more, not only the effect of improving strength is small, but also excess asphalt oozes out onto the surface of the molded product, making it more likely to solidify. Experimental Example 2 The iron ore powder from Rio Doce used in Experimental Example 1
4% by weight of straight asphalt melted at 150°C was added and mixed in a pug mill. Using the same roll machine as used in Experimental Example 1, flakes of various thicknesses were formed by changing the roll gap. After the flakes were allowed to cool to room temperature, the cold drop strength was measured according to JIS M8711, and the final reduction rate was measured according to JIS M8713, and the results shown in Figure 2 were obtained. As is clear from FIG. 2, it is preferable that the thickness of the molded flakes is 6 mm or more and 15 mm or less.
That is, when it is less than 6 mm, the drop strength is low, and when it is more than 15 mm, the reducibility of the flakes becomes poor, which is not preferable. Experimental example 3 Australian Hasmalay iron ore (hematite type) powder of 3 mm or less heated to 140-150℃
After adding 4% by weight of tar pitch heated and melted at 180 to 210°C and mixing in a pug mill, vibration was applied to the forming raw material using a hopper equipped with a vibrating plate on the top of the roll of the pressure forming roll machine used in Experimental Example 1. Compression molding was performed using a roll while degassing the air. The molding conditions were as follows. Roll gap: 6 mm, molding pressure: 900 Kg/cm 2 After cooling the flakes to room temperature, the yield and cold drop strength were measured, and the results shown in Table 1 were obtained. For comparison, measurements were also taken on molded products made from the same raw materials using a briquetting machine.
【表】
表−1の結果から本発明のロール成形は従来の
ブリケツトマシン成形よりも製品収率および成形
物の強さの点で優れている事が判る。
又本発明のロール成形において、ロール上部の
原料ホツパー原料に振動を与えて原料中の空気を
分離した後ロール成形すると、ロールへの原料の
喰い込みが向上しその結果製品収率および成形物
強度が向上する事が明らかである。
実験例 4
実験例3で原料に振動を与えてロールで成形し
たフレークを室温まで冷却した後N2ガス雰囲気
の電気炉で所定温度で所定時間加熱し炉内で放冷
した後JIS M8711に従つて冷間落下強度を測定し
第3図の結果を得た。尚フレークの1水準当り加
熱量は25Kg、加熱温度は300〜900℃、加熱時間は
5時間であつた。
第3図の結果から本発明の成形物は加熱により
強度が低下しない事が判る。
実験例 5
150〜170℃で加熱した1mm以下のオーストラリ
アローブリバー産鉄鉱石粉末に150〜170℃で加熱
溶融したアスフアルトを5重量%添加しパグミル
で混合した後実験例1で使用したロール成形機で
原料に振動を与えながら成形圧600Kg/cm2で圧縮
成形した。フレークを冷却後JISに準じて冷間落
下強度、最終還元率およびふくれ指数を測定し次
の結果を得た。尚フレークの厚さは8mmであつ
た。
冷間落下強度 91%
最終還元率 97%
ふくれ指数 3.5%
上記結果から明らかなように本発明の塊成鉱は
冷間強度、最終還元率とも大きく、高炉装入用原
料として優れている事が判る。
実験例 6
140〜150℃に加熱した1mm以下のカナダタツス
産鉄鉱石粉末に88μ全通の石灰石粉末を2重量%
添加混合した後180〜210℃で加熱溶融したタール
ピツチを3重量%添加しパグミルで混合した後、
実験例1で使用した伸銅板付きロール成形機で成
形圧900Kg/cm2で圧縮成形した。フレークを室温
まで冷却した後JISに従つて冷間落下強度、最終
還元率およびふくれ指数を測定し次の結果を得
た。
冷間落下強度88%
最終還元率97%
ふくれ指数 3.7%
本実験例から明らかなように本発明の製造法で
は石灰石粉末を混合して成形しても何等差しつか
えなくむしろより良好な非焼成塊成鉱が製造出来
る。
実験例 7
実験例1で使用したブラジルリオドセ産鉄鉱石
粉末に1mm以下のコークス粉末を7重量%混合し
180〜200℃に加熱した後、290〜310℃で加熱溶融
したSRC(灰分0.6重量%、揮発力49.7重量%)を
6重量%添加しパグミルで混合した後実験例1で
使用した振動板付きロール成形機で成形圧500
Kg/cm2で圧縮成形した。フレークを室温まで冷却
した後JISに従つて冷間落下強度、最終還元率お
よびふくれ指数を測定し次の結果を得た。
冷間落下強度 92%
最終還元率 98%
ふくれ指数 3.8%
本実験例から明らかなように本発明の製造法で
はコークス粉末を混合して成形しても差し支えな
くむしろ良好な非焼成塊成鉱が製造出来る。[Table] From the results in Table 1, it can be seen that the roll forming of the present invention is superior to the conventional briquette machine forming in terms of product yield and strength of the molded product. In addition, in the roll forming of the present invention, when the raw material hopper above the roll is vibrated to separate the air in the raw material and then roll formed, the biting of the raw material into the roll is improved, resulting in improved product yield and molded product strength. It is clear that the results are improved. Experimental Example 4 In Experimental Example 3, the raw material was vibrated and the flakes formed with a roll were cooled to room temperature, heated in an electric furnace with N2 gas atmosphere at a specified temperature for a specified period of time, allowed to cool in the furnace, and then processed according to JIS M8711. The cold drop strength was measured and the results shown in Figure 3 were obtained. The amount of heating per level of flakes was 25 kg, the heating temperature was 300 to 900°C, and the heating time was 5 hours. From the results shown in FIG. 3, it can be seen that the strength of the molded product of the present invention does not decrease due to heating. Experimental Example 5 5% by weight of asphalt heated and melted at 150-170°C was added to Australian Robe River iron ore powder of 1 mm or less heated at 150-170°C, mixed in a pug mill, and then mixed in the roll forming machine used in Experimental Example 1. Compression molding was performed at a molding pressure of 600 kg/cm 2 while applying vibration to the raw material. After cooling the flakes, the cold drop strength, final reduction rate, and blistering index were measured according to JIS, and the following results were obtained. The thickness of the flakes was 8 mm. Cold drop strength 91% Final reduction rate 97% Blistering index 3.5% As is clear from the above results, the agglomerate of the present invention has high cold strength and final reduction rate, and is excellent as a raw material for blast furnace charging. I understand. Experimental example 6 2% by weight of 88μ limestone powder was added to Canadian Tatsusu iron ore powder of 1 mm or less heated to 140-150℃.
After addition and mixing, 3% by weight of tar pitch heated and melted at 180-210°C was added and mixed in a pug mill.
Compression molding was performed at a molding pressure of 900 kg/cm 2 using the roll molding machine equipped with a rolled copper plate used in Experimental Example 1. After cooling the flakes to room temperature, the cold drop strength, final reduction rate, and blistering index were measured according to JIS, and the following results were obtained. Cold drop strength: 88% Final reduction rate: 97% Blistering index: 3.7% As is clear from this experimental example, in the manufacturing method of the present invention, there is no problem even if limestone powder is mixed and molded. Ore can be produced. Experimental Example 7 7% by weight of coke powder of 1 mm or less was mixed with the iron ore powder from Rio Doce, Brazil used in Experimental Example 1.
After heating to 180-200℃, 6% by weight of SRC (ash content 0.6% by weight, volatility 49.7% by weight) heated and melted at 290-310℃ was added and mixed in a pug mill. Molding pressure 500 with roll forming machine
Compression molded at kg/ cm2 . After cooling the flakes to room temperature, the cold drop strength, final reduction rate, and blistering index were measured according to JIS, and the following results were obtained. Cold drop strength: 92% Final reduction rate: 98% Blistering index: 3.8% As is clear from this experimental example, in the production method of the present invention, there is no problem even if coke powder is mixed and molded, but rather good unburned agglomerate ore is produced. Can be manufactured.
第1図ないし第3図は本発明の製造方法による
成形体の性状を示すグラフであり、第1図はセメ
ント添加量と冷間落下強度との関係を示すグラ
フ、第2図はフレーク厚さと冷間落下強度、最終
還元率との関係を示すグラフ、第3図は冷間落下
強度と加熱温度との関係を示すグラフである。
Figures 1 to 3 are graphs showing the properties of molded products produced by the manufacturing method of the present invention. Figure 1 is a graph showing the relationship between cement addition amount and cold drop strength, and Figure 2 is a graph showing the relationship between flake thickness and cold drop strength. A graph showing the relationship between cold drop strength and final reduction rate, and FIG. 3 is a graph showing the relationship between cold drop strength and heating temperature.
Claims (1)
合した後、該混合物を圧縮成形し、硬化させるこ
とを特徴とする非焼成塊成鉱の製造方法。 2 上記粘着性炭化水素混合物としてアスフアル
ト、ピツチ又は溶剤抽出炭の一種あるいは二種以
上を用いることを特徴とする特許請求の範囲第1
項記載の非焼成塊成鉱の製造方法。 3 上記粘着性炭化水素混合物の添加量が1重量
%〜6重量%であることを特徴とする特許請求の
範囲第1項記載の非焼成塊成鉱の製造方法。[Scope of Claims] 1. A method for producing non-calcined agglomerate ore, which comprises adding and mixing a sticky hydrocarbon mixture to iron ore powder, and then compression molding and hardening the mixture. 2. Claim 1, characterized in that one or more of asphalt, pitch, or solvent-extracted charcoal is used as the sticky hydrocarbon mixture.
A method for producing uncalcined agglomerated ore as described in Section 1. 3. The method for producing uncalcined agglomerate ore according to claim 1, wherein the amount of the sticky hydrocarbon mixture added is 1% to 6% by weight.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10441784A JPS60248831A (en) | 1984-05-25 | 1984-05-25 | Manufacture of uncalcined lump ore |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10441784A JPS60248831A (en) | 1984-05-25 | 1984-05-25 | Manufacture of uncalcined lump ore |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60248831A JPS60248831A (en) | 1985-12-09 |
JPH0364571B2 true JPH0364571B2 (en) | 1991-10-07 |
Family
ID=14380114
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10441784A Granted JPS60248831A (en) | 1984-05-25 | 1984-05-25 | Manufacture of uncalcined lump ore |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60248831A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100386560C (en) * | 2006-06-30 | 2008-05-07 | 刘柱艳 | Equipment for wrapping fuel agent in liquid state on mixing material for sinter machine, and fuel agent in liquid state used by the equipment |
TWI558657B (en) * | 2011-09-08 | 2016-11-21 | 淡水河谷公司 | Application of carbon nanotubes on agglomerates of fine ore to increase the mechanical strength |
JP6330536B2 (en) * | 2014-07-14 | 2018-05-30 | 新日鐵住金株式会社 | Pretreatment method of sintering raw materials |
JP7188033B2 (en) * | 2018-11-30 | 2022-12-13 | 日本製鉄株式会社 | Method for producing coal-bearing agglomerate ore |
-
1984
- 1984-05-25 JP JP10441784A patent/JPS60248831A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS60248831A (en) | 1985-12-09 |
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