JPS59179727A - Preliminary reducing method of chromium ore - Google Patents

Abstract

PURPOSE:To perform titled preliminary reduction at a high rate with a small amt. of reducing gas by dividing a fluidized bed reaction furnace to a region for reducing preferentially iron oxide and a region for accelerating reduction of chromium oxide by means of an upright partition plate having plural through- holes and supplying mainly a reducing agent to the latter region. CONSTITUTION:A partition plate 13 provided with plural through-holes 12 is attached in a preliminary reduction furnace 1 to divide the inside of the furnace to a region 2a for reducing preferentially iron oxide on a raw material feed side and a region 2b for accelerating reduction of chromium oxide on the discharging side of the resultant product of preliminary reduction. The high temp. reducing gas for fluidization such as the waste gas generated in a melt reduction furnace is introduced into the furnace from the bottom thereof to fluidize the chromium powder ore accepted through a raw material supplying part 4 to shift the ore through the holes 12 into the region 2b. Then the iron oxide is preferentially reduced in the region 2a, then the hardly reducible chromium oxide is reduced to metallic chromium in the region 2b by the reducing agent such as gaseous saturated hydrocarbon introduced through the port 9. The metallic chromium is discharged through a discharging pipe 5.

Description

【発明の詳細な説明】 本発明は、クロム鉱石の予備還元法に関するものであり
、どくに流動層反応炉を１ｌＩ２止り、１の先還元領１
或と酸化りＩＩム還元促）仏領域どに分１−Ｊ　、　３
’３元剤どじでの炭化水素含有カスを］−どして醇化り
［１ム還元促進領域に供給しく多段流動１ｔｃｉ　ｊ、
潰似の効果を得るようにしたｈ法につぃＣ押環りる６の
Ｃある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for pre-reduction of chromium ore, in which a fluidized bed reactor is installed at the end of the reactor, and the pre-reduction area of 1 is reduced to 1.
1-J, 3
The hydrocarbon-containing sludge from the ternary agent is liquefied and liquefied by a multi-stage flow 1tci j,
There is a C of 6 in the h method that produces the effect of crushing.

従来技術の説明 近汗、酸化ａ、または酸化クロ１１等の各種金属酸化物
を含有する鉱す原料は、塊状鉱石が減少しく粉状もしく
は粒状の＃７Ａ石が多くなっ’ＣＪ３す、その傾向は今
後ますまづ顕著になるど予想される。Description of the Prior Art In ore raw materials containing various metal oxides such as peroxide, a oxide, or chromium oxide, there is a tendency that the amount of lumpy ore decreases and the amount of powdery or granular #7A stone increases. is expected to become even more prominent in the future.

こうした現状に鑑み、最近かがる粉、粒状鉱石を直接使
用しくＭ錬する幾つかの技術ｌバｇ’５　Ｈ’、、　−
１ぎた。例えば、流動層を用いて粉、粒状鉱石をＹ備還
元し、その後この予備還元鉱を電か、転炉その他の溶解
炉で′溶融還元りるｊ）法宿がイれＣ′ある。In view of this current situation, several technologies have recently been developed for directly using smelting powder and granular ores.
I got one. For example, powder or granular ore is reduced using a fluidized bed, and then the pre-reduced ore is smelted and reduced in an electric furnace, converter or other melting furnace.

また、ぞの他に６、アーク炉やブーノズマあるいは純酸
素を利用りる炉を用いＩＪ　Ｔ　ＩＲｆ＋　３’ｉ　ｉ
シ鉱石を粉粒状のまま溶融ｊｑ元する方式も１１？桑さ
れている。In addition, 6. IJ T IRf + 3'i i
11 Is there a method for melting ore in powder form? It is mulberry.

しかし、ト述した従来技術にあっ（ＬＬ、いＪれし技術
的Ｊ５よび経汎的に解決を要４る多くの課題が残されて
Ｊ′３つ、実用に供されていないものも多くある。However, there remain many problems with the prior art described above that require technical and general solutions, and many problems have not yet been put to practical use. be.

そこで最近は最も進歩的なものとして、電力によらない
で酸化物を還元する方法が、例えばフェロクロムその他
のフェロアロイ製造技術どして具体化されている。例え
ば、本発明者らの提案にかかる流動層予備還元炉と竪型
溶融還元炉との結合にかかる装置を用い、粉粒状鉱石か
ら直接フェロアロイを製造する方法等がそれである。こ
の本発明者らの提案にかかる技術は、金属酸化物含有鉱
石の予備還元に必要な還元剤ｄ−３よび熱の供給源とし
て、前工程の溶融還元炉の高温排ガスを利用して流動層
形成により予備還元する方法であり、粉、粒状鉱石を塊
成化することなく直接使用できる点で前述の方法に比べ
ると低コストで溶融金属の製造が可能である。Recently, the most advanced method for reducing oxides without using electric power has been realized, for example, in the production of ferrochrome and other ferroalloys. For example, there is a method of directly producing ferroalloy from powdery ore using an apparatus proposed by the present inventors that combines a fluidized bed pre-reduction furnace and a vertical smelting reduction furnace. The technology proposed by the present inventors utilizes high-temperature exhaust gas from the melting reduction furnace in the previous process as a source of reducing agent d-3 and heat necessary for preliminary reduction of metal oxide-containing ores. This is a method of pre-reducing by forming, and it is possible to produce molten metal at a lower cost than the above-mentioned methods in that it can directly use powdered or granular ore without agglomerating it.

ただ、かような改良された予備還元方法にあっても、例
えばクロム鉱石のようなＨａ元性鉱石を予ｆｆｆｆｔ還
元する場合、溶融還元炉からの高温の排カスを還元ガス
として使用すると、鉱石中に含まれる酸化鉄に比し、酸
化り［］ムの方が還元されにくいので、クロム鉱石全体
としての予備還元率が上がらないという問題点が残され
でいた。However, even with such an improved pre-reduction method, when pre-fffft reducing Ha-based ore such as chromium ore, if the high temperature exhaust gas from the smelting reduction furnace is used as the reducing gas, the ore Since chromium oxide is more difficult to reduce than the iron oxide contained therein, the problem remains that the preliminary reduction rate of the chromium ore as a whole cannot be increased.

さらに本発明者らは、クロム鉱６の予備還元方法どじで
重油やイ」炭などを使って予備還元Ｊる方法について特
開昭５７−０３２３５１号としＣ提案し／ｊが、この方
法の場合反応炉内温度を１１００・〜１３００℃に保持
した高温での１７元が必要であった。Furthermore, the present inventors have proposed a method for preliminary reduction of chrome ore using heavy oil, charcoal, etc. in JP-A No. 57-032351. 17 yuan was required at a high temperature where the temperature inside the reactor was maintained at 1100-1300°C.

このような事情からクロム鉱石をもつと低温で還元する
技術についＣ検問したところ、ｊ茗元剤どしＣメタン竹
の飽和炭化水素系のカスがｈ効であることが判った。Under these circumstances, we investigated the technology for reducing chromium ore at low temperatures, and found that the saturated hydrocarbon residue of methane bamboo is effective.

一般に、メタンの還元力は、ｌ−１２，ＧＯよりも優れ
ている。ジなわら、反応炉内温度１１００℃においＣ１
Ｈ２，ＣＯを用いてクロム鉱石を還元する場合、り［１
ム鉱石中のＦｅＯやＦｅ２Ｏ２の還元はＪ：＜進むが、
Ｃｒ２Ｏ３の還元は著しく悪い。Generally, the reducing power of methane is superior to that of 1-12,GO. However, at a temperature inside the reactor of 1100°C, C1
When reducing chromium ore using H2, CO, ri[1
The reduction of FeO and Fe2O2 in Mu ore proceeds as J:<, but
The reduction of Cr2O3 is extremely poor.

これに対し、メタンを用いると、Ｆｅｄ。On the other hand, when using methane, Fed.

Ｃ；ｒ２０３の両方の還元ともによく進むのである。Both reductions of C; r203 proceeded well.

ここで問題となるのは、このメタンを還元カスとして使
用すると価格が高いのが欠点である。The problem here is that using this methane as the reduction residue is expensive.

発明の目的と要旨の説明 本発明は、少量のメタン使用で上記の問題点を回避する
ことに併け、高還元率を達成することを目的とし、Ｃｒ
　９４　？’ｉ中のＦｅＯヤＦｅ　２０３どＣｒ２Ｏ３
の還元性のちがいに着目して、難還元性のＣｒ２Ｏ３の
還元についＣは主として特定の領域でメタン等の炭化水
素含有ガスによって行い、易還元性のＦｅＯやＦｅ　２
０３の運）［はＣ０９Ｈ２によってする２段階の予備還
元を行うようにづることＣ１従来技術の問題点を解決し
たのである。Description of the purpose and gist of the invention The present invention aims to avoid the above problems by using a small amount of methane, and also to achieve a high reduction rate.
94? 'FeOya Fe 203 in i Cr2O3
Focusing on the difference in the reducibility of
Luck of 03)[ solved the problems of the C1 prior art by performing a two-step preliminary reduction using C09H2.

発明の構成、作用の説明 従来、還元剤の供給については、予め流動化還元カス中
に混合しておく方法や多段流動層を使って同じガス成分
を通す思想もあるが、ガスが有効に利用されないとか流
動層が複雑になるなどの欠点が見られた。Description of structure and operation of the invention Conventionally, there have been ideas for supplying the reducing agent by mixing it in the fluidized reduction scum in advance or by using a multi-stage fluidized bed to pass the same gas components, but it has not been possible to effectively utilize the gas. However, there were some disadvantages such as the fluidized bed becoming complicated.

これに対しＣ１本発明のように、クロム鉱石について、
ＣＨ４を主成分どする還元剤を反応の後半に使うことで
、著しい還元率の向上が得られることが判った。On the other hand, as in the C1 invention, regarding chromium ore,
It has been found that the reduction rate can be significantly improved by using a reducing agent containing CH4 as the main component in the latter half of the reaction.

リーなわら、表−１の還元ガス成分のものを使い、クロ
ム鉱石２眩を、内径８０關の流動層反応炉に入れて１１
００℃で還元しｌ〔。Using the reducing gas components listed in Table 1, two pieces of chromium ore were placed in a fluidized bed reactor with an inner diameter of 80mm and heated to 11.
Reduced at 00°C.

表−１ガス組成 な（１３、還元率は、化学分析によつＵ　１％だＴ、Ｆ
ｅ％、Ｓｏ、ｃ、Ｆｅ％、Ｔ、Ｃｒ％、ｓｏｂ。Table 1: Gas composition (13) The reduction rate is U 1% according to chemical analysis.
e%, So, c, Fe%, T, Cr%, sob.

Ｃｒ％を用いて、（１）〜（３）式で定義した。Defined by formulas (1) to (3) using Cr%.

鉄還元ＩＲＦｅ　　＝　（ｓｏｆ、　　トｃ　、／王、
Ｆｅ）Ｘ　　１００（％）　　・・・　（１）Ｏｒ還元
率ＲＯｒ＝＜ｓｏρ、Ｃｒ　／”Ｔ、ＣＩ’　）ｘｌｏ
ｏ（％）　　・・・　（２） その結果、表−２に示すように、Ｃｒ１４を同じ流量流
しても、後半のみに流した実施例Ｂの方が還元率が高く
、Ｃｒ２０ａの還元により有効であることが判る。Iron-reduced IRFe = (sof, toc, / king,
Fe)
o (%) ... (2) As a result, as shown in Table 2, even if Cr14 was flowed at the same flow rate, Example B, in which it was flowed only in the latter half, had a higher reduction rate and was more effective in reducing Cr20a. It turns out that.

表−２ 第１図は、本発明の実施に用いる流動層形式による扮、
粒状鉱石の予備還元炉の例を承り。この−７；備還元か
１はだＣ型で、その胴部（炉側壁）の一方に粉、粒状ク
ロム鉱石の原料供給口４を具えＣ８３す、ここには鉱石
ホッパー７からの鉱石炉内に供給づるための供給装置６
が設置しＣある。また、鉱石を滞留させるために炉内（
流！ＩＩ層２域）に設置したガス分散板（火格子）３Ｆ
に当る炉下部には、高温の流動化還元ガス導入口ε３が
開口させである。この流動化ｉ１元ガスとしＣは、加熱
炉、還元ガス発生炉あるいは溶融還元炉から発生した高
温の排ガスを使い、還元剤ならびに流動化ガスどする。Table 2 FIG.
We received an example of a preliminary reduction furnace for granular ore. This -7; Beikanka 1 is C-shaped, and one side of its body (furnace side wall) is equipped with a raw material supply port 4 for powder and granular chromium ore. Supply device 6 for supplying
There is a C installed. In addition, the inside of the furnace (
Flow! Gas distribution plate (grate) installed in II layer 2 area) 3F
A high temperature fluidized reducing gas inlet ε3 is opened at the lower part of the furnace. The source gas C for fluidization I1 uses high-temperature exhaust gas generated from a heating furnace, a reducing gas generating furnace, or a melting reduction furnace, and is used as a reducing agent and a fluidizing gas.

かかる流動化還元ガスを炉内に導入Ｊることにより、ガ
ス分散板３上の粉、粒状クロム鉱石を流動化させ流＃層
２を形成させることにより流動還元が−できる。なお、
分散板３下の一方に片寄って配置した図示の９としＣ示
づ開口は還元剤としてメタンなどの炭化水素含有ノｊス
を供給するための主としＣクロムの還元に供りる還元剤
供給口である。また図示の１０は排ガスの排出口で、こ
こを通じＣ排出される流動層２からの排出ガス中には、
タストを多量に含有するのでサイクロンを通じて除ゆす
る。一方、予備還元生成物は、ＪＪｉ出管出土５排出し
Ｃ１次工程の溶ｈ１：還元炉などへ移送覆る。By introducing such a fluidized reducing gas into the furnace, the powder and granular chromium ore on the gas distribution plate 3 are fluidized to form a flow layer 2, thereby achieving fluidized reduction. In addition,
Openings shown in the figure, 9 and C, which are arranged offset to one side under the dispersion plate 3, are mainly for supplying a gas containing hydrocarbons such as methane as a reducing agent, and are mainly for supplying a reducing agent for reducing chromium. It is the mouth. In addition, numeral 10 in the figure is an exhaust gas exhaust port, and the exhaust gas from the fluidized bed 2 that is discharged through this port includes:
Since it contains a large amount of tast, it is removed through a cyclone. On the other hand, the preliminary reduction product is discharged from the JJi outlet pipe 5 and transferred to a reduction furnace or the like in the C primary process.

本発明は上述の予備還元炉に対し、その内部に複数個の
通孔１２を設けた仕切板１３を取付け、該炉内を層別供
給側の酸化鉄優先還元領域２ａど予備還元生成物排出側
の酸化クロム還元促進領域２１）とに区分し、原料供給
４より受は入れたクロム粉鉱石が流動化しながら前記通
孔１２を介して反対の排出側酸化クロム還元領域２１）
にシフ１〜されるように構成する。The present invention installs a partition plate 13 with a plurality of through holes 12 in the pre-reduction furnace described above, and discharges pre-reduction products such as the iron oxide preferential reduction area 2a on the stratified supply side in the furnace. The chromium oxide reduction promotion area 21) is divided into a side chromium oxide reduction promotion area 21), and the chromium powder ore received from the raw material supply 4 is fluidized while passing through the through hole 12 to the opposite discharge side chromium oxide reduction area 21).
It is configured so that shifts 1 to 1 are performed.

そして、炉底部からは溶融還元炉（図示せず）発生排ガ
スを好適例とするＣｏ、Ｎ２　、Ｈ２含有の高温の流動
化還元ガスを導入し、炉内流動化域２のクロム鉱石を流
動化させ、まず酸化鉄優先還元額ｂ＝５２ａにａ３い（
酸化鉄を優先的に還元し、次いで主として酸化鉄のみが
１７元された状態の鉱石が通孔１２を経て排出側に移動
するので、ここにメタン、プロパン等の飽和炭化水素系
のガス（Ｃｍ［・１ｎ）（あるいはエチレン等の不飽和
炭化水素系のものでもよい）を好適例と覆る還元剤を供
給口９を通して導入することにより、該排出側の酸化ク
ロム還元促進領域２ｂにおいて、勤３平元性のクロム酸
化物を金属クロムに還元する。Then, a high-temperature fluidizing reducing gas containing Co, N2, and H2, preferably the exhaust gas generated from a smelting reduction furnace (not shown), is introduced from the bottom of the furnace to fluidize the chromium ore in the fluidizing zone 2 in the furnace. First, the iron oxide preferential reduction amount b = 52a and a3 (
Iron oxide is preferentially reduced, and then the ore in which only iron oxide has been reduced to 17 elements moves to the discharge side through the through hole 12, where saturated hydrocarbon gas (Cm) such as methane and propane is [・1n) (or it may be an unsaturated hydrocarbon such as ethylene) is introduced through the supply port 9 to reduce the concentration of chromium oxide in the chromium oxide reduction promoting region 2b on the discharge side. Reduces normal chromium oxide to metallic chromium.

発明の実施例と効果の説明 第１図に示す予備還元炉を用い、その炉内に、クロム鉱
石：フィリピン産クロム鉱石 組成：　Ｃｒ　２０３　　　　４９，２％Ｆｅ　Ｏ２３
，８％ 粒径：２８〜４８メツシユ　　　７．９％４８〜１００
メツシユ　８６．７％ １００メツシユ以下　５．４％ なるクロム鉱石を装入する一方、ＣＯ：３６％。Embodiments of the invention and description of effects A pre-reduction furnace shown in FIG.
, 8% Particle size: 28-48 mesh 7.9% 48-100
Mesh 86.7% 100 mesh or less 5.4% Chromium ore is charged, while CO: 36%.

Ｈ２：２％、Ｎ２：６２％の成分の高温流動化還元ガス
を、導入口８を通して供給し、また供給口９からはメタ
ンを含有するコークス炉発生ガスを前記酸化クロム還元
促進領域２ｈ中へ供給し、所定の時間予備還元をした。A high-temperature fluidized reducing gas containing 2% H2 and 62% N2 is supplied through an inlet 8, and a coke oven gas containing methane is introduced into the chromium oxide reduction promotion region 2h from a supply inlet 9. It was supplied and pre-reduced for a predetermined period of time.

その結果を表−３に示すが、メタン含有ガスを炉内に一
様に流した従来例に較べると、本発明法の還元寧がよい
ことが明らかである。The results are shown in Table 3, and it is clear that the reduction efficiency of the method of the present invention is better than that of the conventional example in which methane-containing gas was uniformly flowed into the furnace.

表−３ 、従来法゛　本発明法 □ １還元率　（Ｒ，）　　　４・８％　　　　：６３　％
第］区分二酸化鉄優先還元領域 第２区分二酸化クロム還元促進領域 なお、前記仕切板は、第２図に示す炉内を２分するもの
の他、第３図に示すように、炉内を３分割以上するもの
でもよく、より一層のクロム還元率の向−［が期待でき
る。Table 3, Conventional method ゛ Present invention method □ 1 Reduction rate (R,) 4.8%: 63%
2nd section Chromium dioxide reduction promotion zone 2nd section Iron dioxide preferential reduction zone 2nd section Chromium dioxide reduction promotion zone In addition to dividing the inside of the furnace into two as shown in FIG. 2, the partition plate divides the inside of the furnace into three as shown in FIG. Any of the above may be used, and a further improvement in the chromium reduction rate can be expected.

以上説明したように本発明によれば、少ないｊＶ元剤使
用量で高い予備還元率を達成することがで凸゛、Ｎ　’
ｒＷ元のり【」ム鉱石を経済的に予備還元づることかで
きる。As explained above, according to the present invention, it is possible to achieve a high preliminary reduction rate with a small amount of JV base material used.
The original glue ore can be pre-reduced economically.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は、本発明法の実施に用いる予備還元炉の一例を
示す路線図、 第２図、第３図はいずれも本発明Ｃ゛用いる予備還元炉
の異なる実施態様の水平断面図である。 ２ａ・・・酸化鉄優先還元領域 ２ｂ・・・酸化りし］ム還元促進領域 ４・・・原料供給］］５・・・予備還元生成物排出口９
・・・還元剤供給【」１２・・・通孔１３・・・仕切板 Ｏ ２ ２FIG. 1 is a route diagram showing an example of a pre-reduction furnace used in carrying out the method of the present invention, and FIGS. 2 and 3 are horizontal sectional views of different embodiments of the pre-reduction furnace used in the present invention C. . 2a... Iron oxide preferential reduction region 2b... Oxidized iron] Mu reduction promotion region 4... Raw material supply]] 5... Preliminary reduction product discharge port 9
... Reducing agent supply ['' 12 ... Through hole 13 ... Partition plate O 2 2

Claims (1)

【特許請求の範囲】 １、炉底部より高温の流動化還元ガスならびに還元剤を
導入し、流動層反応炉内の流動化域に臨む一方に設けた
原料供給口からクロム粉鉱石を供給し、その他方の側に
設【プた排出口より予備還元生成物を取出すようにした
クロム鉱石の予備還元法にｄ３いて、 上記流動層反応炉内に復数の通孔をもつ仕切板を設ｉプ
、原料供給側の酸化鉄優先還元領域と予備還元生成物排
出側の酸化クロム還元促進領域とに区分し、供給側に受
は入れたクロム粉鉱石を通孔を介して排出側に移動させ
る間の流動化反応に当り、上記還元剤については主とし
′Ｃ酸化クロム還元促進領域に導入することによって予
備還元反応を行わせることを特徴とづ−るクロム鉱石の
予備還元法。[Claims] 1. Introducing high-temperature fluidizing reducing gas and reducing agent from the bottom of the reactor, and supplying chromium powder ore from a raw material supply port provided on one side facing the fluidizing zone in the fluidized bed reactor, In the chromium ore pre-reduction method in which the pre-reduced products are taken out from the discharge port installed on the other side, a partition plate with a number of through holes is installed in the fluidized bed reactor. It is divided into an iron oxide preferential reduction area on the raw material supply side and a chromium oxide reduction promotion area on the preliminary reduction product discharge side, and the chromium powder ore placed in the supply side is transferred to the discharge side through the through hole. A method for preliminary reduction of chromium ore, characterized in that, during the fluidization reaction, the above-mentioned reducing agent is mainly introduced into a C chromium oxide reduction promotion region to carry out a preliminary reduction reaction.