JPS6135133B2 - - Google Patents
Info
- Publication number
- JPS6135133B2 JPS6135133B2 JP56213519A JP21351981A JPS6135133B2 JP S6135133 B2 JPS6135133 B2 JP S6135133B2 JP 56213519 A JP56213519 A JP 56213519A JP 21351981 A JP21351981 A JP 21351981A JP S6135133 B2 JPS6135133 B2 JP S6135133B2
- Authority
- JP
- Japan
- Prior art keywords
- waste liquid
- ferrite
- ions
- steel pickling
- ferrous ions
- 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
- 239000002699 waste material Substances 0.000 claims description 66
- 239000007788 liquid Substances 0.000 claims description 61
- 229910000859 α-Fe Inorganic materials 0.000 claims description 32
- 238000005554 pickling Methods 0.000 claims description 25
- 229910000831 Steel Inorganic materials 0.000 claims description 23
- 239000010959 steel Substances 0.000 claims description 23
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 21
- 229910001448 ferrous ion Inorganic materials 0.000 claims description 21
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- 238000007254 oxidation reaction Methods 0.000 claims description 14
- 229910002651 NO3 Inorganic materials 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 230000005294 ferromagnetic effect Effects 0.000 claims description 7
- -1 iron ions Chemical class 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 230000003647 oxidation Effects 0.000 claims description 6
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 claims description 5
- 229910001447 ferric ion Inorganic materials 0.000 claims description 5
- 150000004679 hydroxides Chemical class 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 238000006386 neutralization reaction Methods 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 18
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- 239000000243 solution Substances 0.000 description 14
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 12
- 229910017604 nitric acid Inorganic materials 0.000 description 12
- 229910021645 metal ion Inorganic materials 0.000 description 10
- 238000004062 sedimentation Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 230000005291 magnetic effect Effects 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 4
- 239000010812 mixed waste Substances 0.000 description 4
- 238000010979 pH adjustment Methods 0.000 description 4
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000010802 sludge Substances 0.000 description 3
- 239000002351 wastewater Substances 0.000 description 3
- 102100021947 Survival motor neuron protein Human genes 0.000 description 2
- 229910052793 cadmium Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 101000617738 Homo sapiens Survival motor neuron protein Proteins 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910000639 Spring steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001447 alkali salts Chemical class 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000007885 magnetic separation Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/0018—Mixed oxides or hydroxides
- C01G49/0036—Mixed oxides or hydroxides containing one alkaline earth metal, magnesium or lead
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/0018—Mixed oxides or hydroxides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/0018—Mixed oxides or hydroxides
- C01G49/0063—Mixed oxides or hydroxides containing zinc
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/0018—Mixed oxides or hydroxides
- C01G49/0072—Mixed oxides or hydroxides containing manganese
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Soft Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Hard Magnetic Materials (AREA)
Description
本発明は鉄鋼酸洗廃液からフエライトを製造す
る方法、更に詳しくは硫酸廃液や塩酸廃液等の鉄
鋼酸洗廃液中に高濃度に含まれる第１鉄イオンを
アルカリ剤で水酸化物とし、更に硝酸根により酸
化して、この際該廃液中に含まれる種々の有害金
属イオンを抱合わせるように取込みつつ、強磁性
のフエライトを製造する方法に関する。
一般式MO・Fe2O3（但しＭはFe，Cu，Zn，
Pb，Cd，Mn，Ni，Cr等の金属イオン）で表示
されるフエライトは、Ｍが第１鉄イオンである場
合のマグネタイト（Fe3O4）を代表例として、磁
性材原料や顔料等に利用することができる。そし
てこの種のフエライトは、第１鉄イオンを含む液
をアルカリ剤で水酸化物とした後に酸化してフエ
ライト化する方法（例えば特公昭42−20381号）
によつて製造される。
一方、ボイラや各種プラントの酸洗廃液のよう
に、ppm乃至mg％単位で鉄イオンを含み、加え
て各種の有害金属イオンを含有するものがある。
かかる酸洗廃液はそのままでは放出することがで
きず、極く一般には凝集沈澱法で処理される。と
ころが、凝集沈澱法による沈澱汚泥は沈澱の際に
占める容積が大きく、したがつて処理装置が膨大
となり、沈澱汚泥の再処理も困難で、またこの沈
澱汚泥自体有効利用されることは少なく、埋立等
で最終処分すれば二次公害を引き起こすことにも
なる。そこで第１鉄イオンを添加し、各種有害金
属イオンを抱合わせるように取込みつつ鉄イオン
がフエライト化されることを利用して、有害な金
属イオンを回収して該廃液を無害化処理する方法
（例えば特開昭49−83257号や特開昭54−21051
号）がある。しかし、これらの従来法は、いずれ
も第１鉄イオン等をアルカリ剤で水酸化物とした
後にこれを酸化するに際し空気やその他の酸化性
ガスを用いる方法であるため、酸化反応が著るし
く遅速で滞留時間を長くしなければならない。し
たがつて非効率的で且つ前記した凝集沈澱法と同
様に処理装置が膨大となることを避けられない欠
点がある。
かかる従来法に対し、前記酸化に際し亜硝酸塩
を用いる方法（特公昭55−28205号）が提供され
ている。この従来法は、亜硝酸塩を用いることに
よつて前記酸化反応をある程度促進し且つ沈澱容
積も小さいという利点を有して、ppm乃至mg％
単位で第１鉄イオンを含む廃液、例えばボイラや
各種プラントの酸洗廃液、に対しては相応に効果
的であるが、高濃度に第１鉄イオンを含む廃液、
例えば数％以上の単位で第１鉄イオンを含み且つ
各種の有害金属イオンも多量に含有する鉄鋼酸洗
廃液、に対しては前記酸化反応がなお遅速であ
り、また比較的高いPH域で処理するため処理後の
廃液のPHを再調整しなければならず面倒であると
いう欠点がある。
本発明は、叙上の従来欠点を解消する改良され
たフエライトの製造方法を提供するもので、特に
高濃度の第１鉄イオン及び各種有害金属イオンを
含む鉄鋼酸洗廃液を対象として、一方で該廃液を
無害化処理しつつ、強磁性のフエライトを効率的
且つ経済的に製造する方法を提供するものであ
る。
すなわち本発明は、鉄鋼酸洗廃液中の第１鉄イ
オン等をアルカリ剤で水酸化物とし、更に酸化し
てフエライト化する方法であつて、
(1) 前記酸化を硝酸根により行うこと
(2) 硝酸根源として鉄鋼酸洗廃液を利用し、鉄鋼
酸洗廃液を適宜組合せることにより該廃液中に
含まれる第２鉄イオンが全鉄イオンの略2/3に
なるように、該廃液中に含まれる第１鉄イオン
を第２鉄イオンに酸化するに充分な量の硝酸根
が共存されるようにすること
(3) 該廃液をアルカリ剤でPH７〜９に調整し、更
に要すればこの際の中和熱による液温の上昇を
加水することにより抑制して、硝酸根による酸
化を強磁性のフエライトを得るに好適の条件下
で制御すること
以上の各要素を備えて構成されている。
本発明の対象となる鉄鋼酸洗廃液は、鉄鋼製品
を処理乃至製造する際の各種工程から排出される
硫酸廃液や塩酸廃液等、これらの混合廃液も含む
全ての酸洗廃液である。該廃液中には一般に数％
以上の単位で高濃度に第１鉄イオンが含まれ、ま
た場合によつて異なるがCu，Zn，Pb，Cd，
Mn，Ni，Cr等の金属イオンも数ppm〜数千ppm
の単位で多量に含まれている。
また本発明で用いられる硝酸根源は、鉄鋼酸洗
廃液である硝酸廃液や弗硝酸廃液等である。これ
らの硝酸根源は、同当量比較で亜硝酸塩に比べ第
１鉄イオンに対する酸化力が強く、前記のような
鉄鋼酸洗廃液のように高濃度の第１鉄イオン等を
含むものを対象とし、第１鉄イオンを酸化してフ
エライト化する場合、該酸化反応を著るしく促進
することができ、しかも酸化によつて生じるフエ
ライトの沈澱物はこれを沈澱分離する場合にその
占める容積も小さい。そして特に、硝酸根源とし
て前記のような鉄鋼酸洗廃液を用いれば、該廃液
自体もともと無害化処理されなければならないも
のであるから、廃液の処理とフエライトの製造と
を同時に充足することとなつて正に効率的且つ経
済的である。但しこの場合は、鉄鋼酸洗廃液中に
最も高濃度で含まれるのが第１鉄イオンであり、
これをフエライト化するのであるから、Fe3O4す
なわちFeO・Fe2O3というマグネタイトの化学的
組成上、廃液中に含まれる第２鉄イオンが全鉄イ
オンの略2/3になるように、廃液中に含まれる第
１鉄イオンを第２鉄イオンに酸化するに充分な量
の硝酸根が共存されるように鉄鋼酸洗廃液を適宜
組合せることが肝要である。
更に本発明で用いられるアルカリ剤は、水酸化
ナトリウムや水酸化カルシウム等、極く一般的な
ものでよい。これらのアルカリ剤により鉄鋼酸洗
廃液中の第１鉄イオン等を水酸化物とする。とこ
ろで、かかる水酸化物を前記のような硝酸根で酸
化してフエライト化する場合、該酸化反応は硝酸
根の量が多いほど、また液温が高いほど、更に廃
液のPHが高いほど促進される。しかし本発明者等
の試験研究によれば、鉄鋼酸洗廃液中に前記のご
とく充分な量の硝酸根があり且つ液温が通常得ら
れるような略50℃以下の条件下では、該廃液中の
金属イオン濃度及び特に酸化反応時のPHが得られ
るフエライトの磁化率に強く影響を及ぼし、高濃
度に第１鉄イオンを含む一般的な鉄鋼酸洗廃液を
対象とする場合にPH９以上のアルカリ性下では得
られるフエライトの磁化率が急に低くなることが
見出された。そしてまた一方では、酸化により生
成するフエライトを分離した後の廃液をそのPHが
排水基準（5.8〜8.6）に適合してそのまま放出し
得るようにするためには、酸化反応時のPHを７〜
９の範囲にすることが必要であつた。したがつ
て、前記廃液のアルカリ剤によるPHを７〜９に調
整して硝酸根により酸化すれば、磁化率の高いフ
エライトを得ること及び処理後のPH再調整という
面倒を避けることの双方を充足することができる
のである。
第１図は本発明の一実施手順を例示する工程図
である。この場合、塩酸廃液を対象とし、硝酸根
源として硝酸廃液を用い、更にアルカリ剤として
水酸化ナトリウム水溶液を用いている。これらの
三者を混合調整して、充分な量の硝酸根が共存す
る条件下で廃液のPHと要すれば図中破線矢印で示
すように加水して液温とを制御し、廃液中の第１
鉄イオン等を水酸化物としつつ酸化する。この際
の所要時間は余裕をみても１時間あれば充分であ
る。この段階で強磁性のフエライトが生成されて
いるが、かかる生成の際に一般式MO・Fe2O3で
表示されるＭの部分に鉄イオンその他の前記した
ような有害金属イオンが抱合わされるように取込
まれるため、引き続く沈降分離での上部における
処理後の廃液中にこれらの有害金属イオンはいず
れも排水基準に適合する数ppm〜痕跡〜0ppmと
なつている。そして、前記PHの調整が７〜９であ
る場合にはPHに関する排水基準上の問題もないた
め、処理後の廃液はそのまま放出できる。一方、
沈降分離したフエライトのアルカリ塩の含有率を
低下させるために水洗し、再びこれを沈降分離す
る。要すればこの際の一部を前記混合調整の段階
に返送して結晶核に利用しつつ、以下常用手段で
脱水、乾燥、粉砕等をして製品フエライトを得
る。もつとも、沈降分離に代えて、本発明で得ら
れるフエライトの強磁性を利用し、磁力分離する
こともでき、かかる場合は沈澱槽を設けるまでも
なく、連続的分離が可能である。
第２図は次の第１表の条件下で前記第１図の工
程図にしたがつて行つた本発明の複数の実施例に
つき調整PH値と得られるフエライトの磁化率との
関係を代表で例示するグラフである。ここに使用
した塩酸廃液、硝酸廃液及びPH調整用の水酸化ナ
トリウム水溶液はそれぞれ以下の）〜）に示
す内容組成を有するものである。また第１図に示
す混合・調整がフエライトの生成反応に関与する
ところであるが、第１表に示す所要時間（分）及
び液温（℃）は上記混合・調整における条件であ
つて、この段階での第２図に示す個々のPH調整は
PH調節計で自動制御した。このPH調整において、
水酸化ナトリウムの添加量は、PH７の調整で測定
したところ、化学当量からの計算値とほぼ一致し
ていた。そして、第２図のPH７〜９の調整範囲に
おいて、フエライト（MO・Fe2O3）の収量は、第
１表に示す曲線番号１，２の場合に89Kg／混合廃
液１m3、曲線番号３の場合に71Kg／混合廃液１m3
であつた。
塩酸廃液；
20％（Ｗ／Ｖ）の塩酸水溶液に界面活性剤を
0.1％（Ｗ／Ｖ）加えた溶液を用いて、機械構
造用炭素鋼（SC材）と構造用合金鋼（SMN，
SMNC，SCR，SN材の４種）を酸洗したも
の。合計５種の鋼材を別々の個所でほぼ同時に
酸洗したので、塩酸廃液はそれらの合硫廃液で
ある。この塩酸廃液は、PH１以下、HCl180
ｇ／（酸洗中にHClが消費されている）、
Fe120ｇ／、Mn0.24ｇ／、Ni0.12ｇ／、
Cr0.36ｇ／を含有していた。
硝酸廃液；
20％（Ｗ／Ｖ）の硝酸水溶液を用いて、ばね
鋼（SUP材）と軸受鋼（SUJ，SCM材の２
種）を酸洗したもの。合計３種の鋼材を別々の
個所でほぼ同時に酸洗したので、硝酸廃液はそ
れらの合流廃液である。この硝酸廃液は、PH１
以下、HNO3100ｇ／（酸洗中にHNO3が消費
されている）、Fe30ｇ／、Mn0.3ｇ／、
Ni0.03ｇ／、Cr0.6ｇ／を含有していた。
PH調整用の水酸化ナトリウム水溶液；
25％（Ｗ／Ｖ）の水酸化ナトリウム水溶液
The present invention relates to a method for producing ferrite from steel pickling waste liquid, and more specifically, ferrous ions contained in high concentrations in steel pickling waste liquid such as sulfuric acid waste liquid and hydrochloric acid waste liquid are converted into hydroxide using an alkaline agent, and then nitric acid The present invention relates to a method for producing ferromagnetic ferrite by oxidizing it with roots and incorporating various harmful metal ions contained in the waste liquid. General formula: MO・Fe 2 O 3 (where M is Fe, Cu, Zn,
Ferrite, represented by metal ions such as Pb, Cd, Mn, Ni, Cr, etc., is used as a raw material for magnetic materials and pigments, with magnetite (Fe 3 O 4 ), where M is a ferrous ion, as a representative example. can be used. This type of ferrite is produced by a method in which a liquid containing ferrous ions is converted into hydroxide using an alkaline agent and then oxidized to form ferrite (for example, Japanese Patent Publication No. 42-20381).
Manufactured by. On the other hand, some waste liquids, such as pickling waste from boilers and various plants, contain iron ions in ppm to mg% units, as well as various harmful metal ions.
Such pickling waste liquid cannot be discharged as it is, and is most commonly treated by a coagulation-sedimentation method. However, precipitated sludge produced by the coagulation-sedimentation method occupies a large volume during sedimentation, which requires a huge amount of processing equipment, making it difficult to reprocess the precipitated sludge, and the precipitated sludge itself is rarely used effectively and is often discarded in landfills. If the waste is disposed of in a final manner, it may cause secondary pollution. Therefore, a method of adding ferrous ions and taking in various harmful metal ions in a conjugate manner and making use of the fact that the iron ions are converted into ferrite to recover harmful metal ions and detoxify the waste liquid ( For example, JP-A-49-83257 and JP-A-54-21051.
No.). However, all of these conventional methods use air or other oxidizing gases to oxidize ferrous ions, etc., after converting them into hydroxides with an alkaline agent, resulting in a significant oxidation reaction. The residence time must be increased at a slow speed. Therefore, it is inefficient and, like the above-mentioned coagulation-sedimentation method, has the disadvantage that the processing equipment becomes enormous. In contrast to such conventional methods, a method (Japanese Patent Publication No. 55-28205) has been proposed in which nitrite is used during the oxidation. This conventional method has the advantage that the oxidation reaction is promoted to some extent by using nitrite and the precipitation volume is small, and the precipitation range is from ppm to mg%.
Although it is reasonably effective against waste liquids containing ferrous ions in units, such as pickling waste liquids from boilers and various plants, it is effective against waste liquids containing ferrous ions in high concentrations,
For example, the oxidation reaction is still slow for steel pickling waste liquid that contains ferrous ions in units of several percent or more and also contains large amounts of various harmful metal ions, and is treated in a relatively high pH range. Therefore, the PH of the waste liquid after treatment must be readjusted, which is troublesome. The present invention provides an improved method for producing ferrite that eliminates the above-mentioned conventional drawbacks. The present invention provides a method for efficiently and economically producing ferromagnetic ferrite while detoxifying the waste liquid. That is, the present invention is a method for converting ferrous ions and the like in steel pickling waste liquid into hydroxides with an alkaline agent and further oxidizing them to ferrite, comprising: (1) carrying out the oxidation with nitrate radicals; ) By using the steel pickling waste liquid as the source of nitric acid and appropriately combining the steel pickling waste liquid, the ferric ions contained in the waste liquid are approximately 2/3 of the total iron ions. (3) Adjust the pH of the waste liquid to 7 to 9 with an alkaline agent, and if necessary, By adding water, the increase in liquid temperature due to neutralization heat is suppressed, and oxidation by nitrate radicals is controlled under conditions suitable for obtaining ferromagnetic ferrite. . The steel pickling waste liquid that is the object of the present invention includes all pickling waste liquids, such as sulfuric acid waste liquid and hydrochloric acid waste liquid discharged from various processes when treating or manufacturing steel products, and mixed waste liquids thereof. The waste liquid generally contains several percent
The above units contain high concentrations of ferrous ions, and depending on the case, Cu, Zn, Pb, Cd,
Metal ions such as Mn, Ni, Cr, etc. also range from several ppm to several thousand ppm.
It is contained in large amounts in units of . Further, the nitric acid source used in the present invention is a nitric acid waste solution, a fluoronitric acid waste solution, etc., which is a steel pickling waste solution. These nitrate sources have a stronger oxidizing power for ferrous ions than nitrite when compared with the same equivalent, and are targeted at those containing high concentrations of ferrous ions, such as the steel pickling waste liquid mentioned above, When ferrous ions are oxidized to form ferrite, the oxidation reaction can be significantly accelerated, and the ferrite precipitate produced by the oxidation occupies a small volume when separated by precipitation. In particular, if the above-mentioned steel pickling waste liquid is used as a source of nitric acid, since the waste liquid itself must be treated to make it harmless, processing of the waste liquid and production of ferrite can be accomplished at the same time. It is truly efficient and economical. However, in this case, the highest concentration of ferrous ions in the steel pickling waste liquid is ferrous ions.
Since this is converted into ferrite, due to the chemical composition of magnetite, which is Fe 3 O 4 (FeO・Fe 2 O 3 ), the ferric ions contained in the waste liquid should be approximately 2/3 of the total iron ions. It is important to appropriately combine the steel pickling waste solution so that a sufficient amount of nitrate radicals to oxidize the ferrous ions contained in the waste solution into ferric ions coexists. Furthermore, the alkaline agents used in the present invention may be extremely common ones such as sodium hydroxide and calcium hydroxide. These alkaline agents convert ferrous ions and the like in the steel pickling waste into hydroxides. By the way, when such hydroxide is oxidized with the above-mentioned nitrate radicals to form ferrite, the oxidation reaction is accelerated as the amount of nitrate radicals is large, the liquid temperature is high, and the pH of the waste liquid is high. Ru. However, according to the test and research conducted by the present inventors, when there is a sufficient amount of nitrate radicals in the steel pickling waste liquid as mentioned above and the liquid temperature is approximately 50°C or lower, which is normally obtained, The metal ion concentration and especially the pH during the oxidation reaction strongly affect the magnetic susceptibility of the obtained ferrite, and when using a general steel pickling waste solution containing a high concentration of ferrous ions, an alkaline pH of 9 or higher is required. It was found that the magnetic susceptibility of the obtained ferrite suddenly decreases at lower temperatures. On the other hand, in order to ensure that the pH of the waste liquid after separating the ferrite produced by oxidation complies with the wastewater standards (5.8 to 8.6) and can be discharged as is, the pH during the oxidation reaction must be adjusted to 7 to 8.6.
It was necessary to set it in the range of 9. Therefore, by adjusting the pH of the waste liquid to 7 to 9 with an alkaline agent and oxidizing it with nitrate radicals, it is possible to obtain ferrite with high magnetic susceptibility and avoid the trouble of readjusting the pH after treatment. It is possible. FIG. 1 is a process diagram illustrating one implementation procedure of the present invention. In this case, the target is hydrochloric acid waste liquid, and the nitric acid waste liquid is used as the nitric acid source, and furthermore, a sodium hydroxide aqueous solution is used as the alkaline agent. By mixing and adjusting these three components, under conditions where a sufficient amount of nitrate radicals coexist, the pH of the waste liquid and, if necessary, the temperature of the liquid by adding water as shown by the dashed arrow in the figure, are controlled. 1st
Oxidizes iron ions, etc. while converting them to hydroxide. In this case, one hour is enough time even if you consider the allowance. At this stage, ferromagnetic ferrite is generated, and during this generation, iron ions and other harmful metal ions such as those mentioned above are conjugated to the M part represented by the general formula MO・Fe 2 O 3 . As a result, the amount of these harmful metal ions in the waste liquid after treatment in the upper part of the subsequent sedimentation separation ranges from several ppm to traces to 0 ppm, which meets wastewater standards. When the PH is adjusted to 7 to 9, there are no problems regarding PH in terms of wastewater standards, and the treated waste liquid can be discharged as is. on the other hand,
The ferrite separated by precipitation is washed with water to reduce the alkali salt content, and then separated by precipitation again. If necessary, a part of the mixture is returned to the mixing and adjustment stage to be used as crystal nuclei, and then dehydrated, dried, pulverized, etc. by conventional means to obtain the product ferrite. However, instead of sedimentation separation, it is also possible to perform magnetic separation by utilizing the ferromagnetism of the ferrite obtained in the present invention, and in such a case, continuous separation is possible without providing a sedimentation tank. Figure 2 is a representative representation of the relationship between the adjusted PH value and the magnetic susceptibility of the obtained ferrite for several embodiments of the present invention carried out according to the process chart of Figure 1 under the conditions of Table 1 below. This is an illustrative graph. The hydrochloric acid waste solution, nitric acid waste solution, and aqueous sodium hydroxide solution for pH adjustment used here each have the content compositions shown in () to () below. In addition, the mixing and adjustment shown in Figure 1 are involved in the ferrite production reaction, and the required time (minutes) and liquid temperature (°C) shown in Table 1 are the conditions for the above mixing and adjustment. The individual PH adjustments shown in Figure 2 are
Automatically controlled with a PH controller. In this PH adjustment,
When the amount of sodium hydroxide added was measured by adjusting the pH to 7, it almost matched the value calculated from the chemical equivalent. In the adjustment range of PH 7 to 9 in Figure 2, the yield of ferrite (MO/Fe 2 O 3 ) is 89 kg/m 3 of mixed waste liquid in the case of curve numbers 1 and 2 shown in Table 1, and 1 m 3 of mixed waste liquid in the case of curve number 3. 71Kg/ 1m3 of mixed waste liquid
It was hot. Hydrochloric acid waste solution: Add surfactant to 20% (W/V) hydrochloric acid aqueous solution.
Using a solution containing 0.1% (W/V), mechanical structural carbon steel (SC material) and structural alloy steel (SMN,
Acid-washed SMNC, SCR, and SN materials. Since a total of five types of steel materials were pickled at different locations almost simultaneously, the hydrochloric acid waste solution is a combined sulfur waste solution. This hydrochloric acid waste liquid has a pH of 1 or less and a HCl of 180
g/(HCl consumed during pickling),
Fe120g/, Mn0.24g/, Ni0.12g/,
It contained 0.36g/Cr. Nitric acid waste solution: Using a 20% (W/V) nitric acid aqueous solution, two types of spring steel (SUP material) and bearing steel (SUJ, SCM material)
Seeds) are pickled. Since a total of three types of steel materials were pickled at different locations almost simultaneously, the nitric acid waste liquid is a combined waste liquid of these. This nitric acid waste liquid has a pH of 1
Below, HNO 3 100g/(HNO 3 is consumed during pickling), Fe30g/, Mn0.3g/,
It contained 0.03 g of Ni and 0.6 g of Cr. Sodium hydroxide aqueous solution for pH adjustment; 25% (W/V) sodium hydroxide aqueous solution
【表】
第２図の結果からも、特に調整PH値との関係
で、強磁性のフエライトの得られることが明らか
である。
以上説明した通りであるから、本発明には、好
適に制御され得る条件下において廃液自体が活用
可能な硝酸根により酸化反応を促進することを要
旨として、小型の装置で極めて経済的に成し得る
という利点を備え、鉄鋼酸洗廃液を一方では無害
化処理しつつ他方では該廃液から用途の広い強磁
性のフエライトを効率的に得ることのできる効果
がある。[Table] From the results shown in Figure 2, it is clear that ferromagnetic ferrite can be obtained, especially in relation to the adjusted PH value. As explained above, the purpose of the present invention is to promote the oxidation reaction using nitrate radicals that can be utilized in the waste liquid itself under conditions that can be suitably controlled, and can be accomplished extremely economically with a small device. On the one hand, it is possible to detoxify the steel pickling waste liquid, and on the other hand, it is possible to efficiently obtain ferromagnetic ferrite, which has a wide range of uses, from the waste liquid.
第１図は本発明の一実施手順を示す工程図、第
２図は本発明の複数の実施例につき調整PH値と得
られるフエライトの磁化率との関係を示すグラフ
である。
FIG. 1 is a process diagram showing one implementation procedure of the present invention, and FIG. 2 is a graph showing the relationship between the adjusted PH value and the magnetic susceptibility of the obtained ferrite in a plurality of embodiments of the present invention.
Claims (1)
剤で水酸化物とし、更に酸化してフエライト化す
る方法であつて、鉄鋼酸洗廃液を適宜組合せるこ
とにより該廃液中に含まれる第２鉄イオンが全鉄
イオンの略2/3になるように、該廃液中に含まれ
る第１鉄イオンを第２鉄イオンに酸化するに充分
な量の硝酸根が共存されるようにし、これをアル
カリ剤でPH７〜９に調整して、要すればこの際の
中和熱による液温の上昇を加水することにより抑
制し、硝酸根による酸化を強磁性のフエライトを
得るに好適の条件下で制御することを特徴とする
鉄鋼酸洗廃液からフエライトを製造する方法。1 A method in which ferrous ions, etc. in steel pickling waste liquid are converted into hydroxides with an alkaline agent, and further oxidized to form ferrite, in which iron and steel pickling waste liquids are appropriately combined to reduce the ferrous ions contained in the waste liquid. A sufficient amount of nitrate radicals is coexisting to oxidize the ferrous ions contained in the waste liquid to ferric ions so that ferric ions account for approximately 2/3 of the total iron ions, and this Adjust the pH to 7 to 9 with an alkaline agent, and if necessary, suppress the rise in liquid temperature due to the heat of neutralization by adding water, under conditions suitable for oxidation by nitrate radicals to obtain ferromagnetic ferrite. 1. A method for producing ferrite from steel pickling waste, characterized by controlling the process by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56213519A JPS58110434A (en) | 1981-12-23 | 1981-12-23 | Manufacture of ferrite from waste liquor produced by pickling steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56213519A JPS58110434A (en) | 1981-12-23 | 1981-12-23 | Manufacture of ferrite from waste liquor produced by pickling steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58110434A JPS58110434A (en) | 1983-07-01 |
| JPS6135133B2 true JPS6135133B2 (en) | 1986-08-11 |
Family
ID=16640525
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56213519A Granted JPS58110434A (en) | 1981-12-23 | 1981-12-23 | Manufacture of ferrite from waste liquor produced by pickling steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58110434A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63225535A (en) * | 1987-03-13 | 1988-09-20 | Ube Ind Ltd | Method for producing iron nitrate and barium ferrite powder |
| KR100368272B1 (en) * | 1997-12-16 | 2003-03-15 | 주식회사 포스코 | Method for fabricating raw materials of nickel-copper-zinc ferrite utilizing spent resources |
| KR100368273B1 (en) * | 1997-12-17 | 2003-04-11 | 주식회사 포스코 | Method for fabricating nickel-copper-zinc ferrite material using waste liquid and iron oxide |
| KR100401988B1 (en) * | 1998-12-19 | 2003-12-18 | 주식회사 포스코 | A METHOD OF MANUFACTURING Ni-Zn FERRITE RAW MATERIAL BY USING Zn-Ni SPENT ELECTROLYTE AND A METHOD OF ANUFACTURING Ni-Zn FERRITE USING THE SAME |
| CN109437316A (en) * | 2018-12-06 | 2019-03-08 | 钦州学院 | A kind of preparation method of nanometer level superfine iron zinc composite oxide material |
-
1981
- 1981-12-23 JP JP56213519A patent/JPS58110434A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58110434A (en) | 1983-07-01 |
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