JPS5910390A - Treatment of waste liquid containing copper having high concentration by iron powder - Google Patents

Abstract

PURPOSE:To treat efficiently waste liquid contg. copper having a high concn., by mixing acidic waste liquid and alkaline waste liquid to requlate pH to <=3.5, mixing specific acidic waste liquid, water and iron powder with the liquid mixture, and subjecting the mixture to oxidation and reduction. CONSTITUTION:Waste acidic etching liquid A contg. Cu and waste alkaline etching liquid B contg. Cu are mixed and stirred for 20hr in a mixing tank, and waste ferric chloride soln. and water are charged under stirring in a reaction vessel, whereby the waste liquid mixture is obtd. Iron powder is charged into the waste liquid mixture in the reaction vessel. The concn. of Cu therein determined by an analysis after stirring for 30min decreases to 200ppm and the concn. of Cu determined by the analysis again after charging of the iron of the amt. conforming to the amt. of copper and stirring for 30min is 4ppm. The pH in the stage of oxidation and reduction reaction is kept at 3.2. The liquid is then transferred through a relay tank into a flocculation tank, where an anionic flocculating agent is added to the liquid and the treated liquid is fed to a settling and concentrating device, so that the sludge thereof is treated in a concentrating tank.

Description

【発明の詳細な説明】 に関し、特には低廉なコストで実施でき，かつ銅成分の
回収が可能な処理方法に関するものである。　゛この種
の処理方法ではイオン交換樹脂により銅回収を行なう技
術が周知であるが，設備投資，運転費用共に高価で，多
量の廃液が発生する業者では製品単価にはね返る欠点が
ある。他に硫化法。DETAILED DESCRIPTION OF THE INVENTION In particular, the present invention relates to a treatment method that can be carried out at low cost and that can recover copper components. ``This type of treatment method uses ion-exchange resins to recover copper, but it is expensive in terms of equipment investment and operating costs, and it has the drawback of increasing the unit price of the product for companies that generate a large amount of waste liquid. Another method is sulfurization.

水酸化物沈澱法も行なわれてお９，前者は高価かつ維持
管理が難しい。一般に銅廃液中には多種多様の物質が含
まれているので，銅のみを取出してその後水処理を行な
うことは困難で，その場合には高次処理の必要が生ずる
。そのため、従来は最終的には稀釈して下水道，河川放
流を行なうか。Hydroxide precipitation methods have also been used,9 but the former is expensive and difficult to maintain. Generally, copper waste liquid contains a wide variety of substances, so it is difficult to extract only copper and then treat the water, and in that case, higher-level treatment becomes necessary. Therefore, in the past, the water was ultimately diluted before being discharged into sewers or rivers.

産業廃棄物として海洋投棄をするかの何れかの途しかと
られていない。従来方法は、複雑かつコストの高い一部
の方法を除外すれば、回収、無害化という技術的夢精を
満足し得なかったのである。The only option available is to dump it into the ocean as industrial waste. Conventional methods, with the exception of some complicated and costly methods, have not been able to satisfy the technical dream of recovery and detoxification.

本発明は叙上に鑑みなされたもので、その目的は銅の回
収が可能でしかも稀釈、反応性制御等を廃液で行なうこ
とにより、廉価かつ安全な海洋投棄等の処分を可能にす
ることにある。前記目的を達する本発明の要旨は、酸性
系銅廃液とアルカリ系銅廃液とを混合槽内で攪拌・混合
することによりｐＨ３，！；以下に調整し、該混合廃液
を反応槽に送給後特定酸性鋼廃液と水と鉄粉を混合して
酸化・還元反応を行なわせｐＨ２〜３Ｊに調整するか、
又は各廃酸においてもｐ’Ｈを２〜３．５とし、その後
被処理液に凝集剤を投入した後沈降濃縮装置へ送給し、
沈澱スラッジと上澄液に分離するときもに１、洗清スラ
ッジは濃縮槽において濃縮し、その上澄液を前記混合槽
等へ還元するよう圧したことを特徴とする鉄粉による高
濃聞銅廃液の処理方法である。回収目的に対応できるよ
うな銅を高濃度に含む廃液は、電子、印刷或いはメッキ
業等の諸分野において多く排出され、そこでは例えば食
刻に使用（７た銅エツチング液やメッキ浴の各廃液など
が銅を多く含有している。エツチング液は酸性系鋼、ア
ルカリ性系鋼或いは特定酸性系銅廃液（塩化第２鉄液系
銅）などに分けられる。そしてこれらの廃液は、当然、
異なるイオン化傾向を有すると考えられるが、本発明者
はこのイオン化傾向の差に着目して銅廃酸を処理する方
法について研究を進めた結果、次のような知見を得た。The present invention has been made in view of the above, and its purpose is to enable the recovery of copper, and to perform dilution, reactivity control, etc. using waste liquid, thereby making it possible to dispose of copper cheaply and safely, such as by dumping it into the ocean. be. The gist of the present invention that achieves the above object is to stir and mix an acidic copper waste liquid and an alkaline copper waste liquid in a mixing tank to achieve a pH of 3! ; After adjusting the mixed waste liquid to the reaction tank, mix the specified acidic steel waste liquid with water and iron powder to perform an oxidation/reduction reaction and adjust the pH to 2 to 3 J;
Alternatively, the pH of each waste acid is adjusted to 2 to 3.5, and then a flocculant is added to the liquid to be treated, and then sent to a sedimentation concentration device.
When separating the precipitated sludge and supernatant liquid, 1. The washed sludge is concentrated in a concentration tank, and the supernatant liquid is pressurized to be returned to the mixing tank or the like. This is a method for processing copper waste liquid. Waste liquids containing high concentrations of copper that can be used for recovery purposes are often discharged in various fields such as the electronics, printing, and plating industries. Etching solutions are divided into acidic steel, alkaline steel, specified acidic copper waste liquid (ferric chloride liquid copper), etc.These waste liquids are, of course,
Although they are thought to have different ionization tendencies, the inventors of the present invention focused on the difference in ionization tendency and conducted research on a method for treating copper waste acid, and as a result, the following findings were obtained.

即ち、イオン化傾向の小さい金属イオンを含有する溶液
に、ぞれよりイオン化傾向の大きい金属を接触させると
。That is, when a metal with a larger ionization tendency is brought into contact with a solution containing metal ions with a smaller ionization tendency.

イオン化傾向の小さい金属イオンは還元され金属として
析出するから、これを利用した銅廃液の処理により銅を
析出させることができる訳である。Since metal ions with a small ionization tendency are reduced and precipitated as metal, copper can be precipitated by treating copper waste liquid using these ions.

そこで利用し得る金属のうち、銅を析出させることが可
能なイオン化傾向を有し、かつ廉価に入手できるものと
して鉄粉の使用に想到した。鉄と銅の標準酸化電位は夫
々−０，４ｔ１１０（ｖ）ト＋θ、３３７（Ｖ）である
から、銅溶液に金属鉄粉を加えると銅を析出させること
ができる。鉄粉としては、市販鉄粉のほか、鉄鋼業婢よ
り排出されるものが使用でき。Among the available metals, we decided to use iron powder because it has an ionization tendency that allows copper to be deposited and is available at a low cost. Since the standard oxidation potentials of iron and copper are −0, 4t110(v), +θ, and 337(V), respectively, copper can be precipitated by adding metallic iron powder to a copper solution. As the iron powder, in addition to commercially available iron powder, those discharged from the steel industry can be used.

資源活用の面からまたコスト低減の面から有効である。This is effective in terms of resource utilization and cost reduction.

次に本発明においては、銅廃液混合槽でのｐ）ｌを３．
ｊ以下に調整することが要件とされているが。Next, in the present invention, p)l in the copper waste liquid mixing tank is set to 3.
However, it is required to adjust it to below j.

その主要な理由は特定酸性系銅廃液（塩化第二鉄系銅廃
液）の性状がほぼ一定であるため銅廃液混合槽でのｐｔ
ｌを調整することによりこの後の工程が標準化する、反
応槽でのｐＨを−〜３．５に調整する要件は銅廃液の混
合液に鉄粉を反応させると銅の析出がＦｅ”からＦｅ２
＋に還元の時点から開始しｐＨが９以上に力ると銅廃液
中に含まれている酸化物及び攪拌の影響により酸化反応
力が促進され、Ｆｅ（ＯＨ）ａ　が生成することになり
これによりスラノッ、ジボリｚ−ムが高くなるためその
後の分離工程が困難となるから、又ｐＨ−以下では銅が
再溶解する為これらを防止するために設定したものであ
る。The main reason for this is that the properties of specific acidic copper waste liquid (ferric chloride copper waste liquid) are almost constant;
The requirement to adjust the pH in the reaction tank to -~3.5 is to standardize the subsequent steps by adjusting
When the pH is increased to 9 or higher starting from the point of reduction to +, the oxidation reaction is accelerated by the oxides contained in the copper waste solution and the influence of stirring, and Fe(OH)a is produced. This setting was made in order to prevent copper from re-dissolving at pH below -, which would make the subsequent separation process difficult since the slurry and dibolium would become high.

また酸化・還元反応時のｐＨを３．ｊ以下に調整したの
は、鉄粉として前記の如く市販のものや工場排出物を利
用する場合、純度により過剰に混合させたり、酸化鉄の
多い鉄粉を使用したりすると、ｐＨの上昇を招きその結
果スラッジボリュームが増加し、以後の分離が困難にな
ってしまうからである。ｐ）ｌが、２〜３Ｊ内からはず
れた場合（特に各廃液（単独及び二種の混合廃液）を処
理する場合）は、硫酸（ｐＨ＞３Ｊにはずれた場合に使
用、　Ｏｕが再溶解しにくい。）又はアンモニア（ｐＨ
＞ｊにはずれた場合に使用、沈降性には影響はない）を
使用し調整する。Also, the pH during oxidation/reduction reaction was set to 3. The reason for adjusting the pH below J is that when using commercially available iron powder or factory waste as mentioned above, if you mix excessively depending on the purity or use iron powder with a high amount of iron oxide, the pH may increase. This is because the sludge volume increases as a result, making subsequent separation difficult. p) If l deviates from within 2 to 3 J (especially when treating each waste liquid (single or mixed waste liquid)), use sulfuric acid (use it if the pH exceeds 3 J to prevent Ou from redissolving. ) or ammonia (pH
Use this when the value exceeds j (it does not affect sedimentation) and adjust.

次に１本発明の鉄粉による高濃度銅廃液の処理方法を具
体的に説明する。Next, a method for treating high concentration copper waste liquid using iron powder according to the present invention will be specifically explained.

〔実施工程の説明〕図面は本発明の処理方法の工程順を
示したフローシートの一例であり、１は銅廃液混合槽、
２は反応槽、３は中継槽、４は凝集槽、５は沈降濃縮装
置、６は沈澱スラッジの濃縮槽、又は中和槽そして８は
デカンタ−を夫々示す。[Description of the implementation process] The drawing is an example of a flow sheet showing the process order of the treatment method of the present invention, 1 is a copper waste liquid mixing tank,
2 is a reaction tank, 3 is a relay tank, 4 is a coagulation tank, 5 is a sedimentation concentration device, 6 is a concentration tank or neutralization tank for settled sludge, and 8 is a decanter.

図中０は攪拌操作、矢印は各段階で加えられる添加剤を
示す。In the figure, 0 indicates the stirring operation, and arrows indicate the additives added at each stage.

〔実施例〕 別表／に記載の組成を有する酸性系鋼エツチング廃液Ａ
及びアルカリ性銅エツチング廃液Ｂを別紙工程図に従っ
て処理した。まず混合槽中にて両〔単位ｐｐｍ） 廃液＾−ＢｌｔｔＩＪ　（Ｏｕ濃度３Ｓ、θθθｐｐｍ
）を−〇時間混合・攪拌し１反応槽で該混合廃液に塩（
７） 化第２鉄廃液０をｌｙ　ｍ’　（Ｏｕ濃度／θ、θθθ
ｐｐｍ）と、水６−を投入し７時間攪拌しｐＨ／・−の
混合廃液を得た。水を投入したのは反応性を制御しかつ
沈降速度を向上させるためである。該反応槽段階でのＯ
ｕ濃度は／７．θθθｐｐｍであった。[Example] Acidic steel etching waste liquid A having the composition listed in the attached table/
and alkaline copper etching waste solution B were treated according to the attached process diagram. First, in a mixing tank, both [unit: ppm] waste liquid ^-BlttIJ (Ou concentration 3S, θθθppm
) was mixed and stirred for -〇 hours, and salt (
7) ly m' (Ou concentration/θ, θθθ
ppm) and 6- of water were added and stirred for 7 hours to obtain a mixed waste liquid with pH/.--. Water was added to control the reactivity and improve the sedimentation rate. O at the reactor stage
The u concentration is /7. θθθppm.

反応槽では、鉄粉／、　３　！；　ＯＫｌを混合廃液に
投入し、３０分攪拌後分析したところＯｕ濃度は２θθ
ｐｐｍまで低下しており、更に銅量（濃度）に見合つ友
鉄粉ＳＫ２を投入し３０分攪拌して再び分析したところ
銅濃度はグｐｐｍであった。この例の場合鉄粉を投入し
たこの酸化・還元反応時ｐ）ｌ値は３．−と条件を満し
ていたので、ｐＨ調整をするとと々〈中継槽を経て凝集
槽へ移し、アニオン系凝集剤（θ、／Ｓ）を／θｐｐｍ
添加した。In the reaction tank, iron powder/, 3! When OKl was added to the mixed waste liquid and analyzed after stirring for 30 minutes, the O concentration was found to be 2θθ
The copper concentration had decreased to ppm, and when Tomatetsu powder SK2 corresponding to the amount (concentration) of copper was added and the mixture was stirred for 30 minutes and analyzed again, the copper concentration was found to be 1 ppm. In this example, the p)l value during this oxidation/reduction reaction with iron powder added was 3. -, so after adjusting the pH, it was transferred to a flocculating tank via a relay tank, and the anionic flocculant (θ, /S) was added at /θppm.
Added.

上記処理液を沈降濃縮装置に送給し、それのス（８） ラックを濃縮槽へまた越流液を中和槽へ夫々送給して処
理した。濃縮槽での濃縮率は６時間後シＳ（体積率）で
ある。この上部液及びデカンタ−の脱水Ｐ液は１反応槽
並びに中継槽へ還流しクローズドシステムをとっている
。デカンタ−スラッジ及び炉液の性質等は別表コに記載
の通りである。The treated solution was sent to a sedimentation and concentration device, and its sluck (8) rack was sent to a concentration tank and the overflow liquid was sent to a neutralization tank for treatment. The concentration rate in the concentration tank is S (volume rate) after 6 hours. This upper liquid and the dehydrated P liquid in the decanter are returned to one reaction tank and a relay tank to form a closed system. The properties of the decanter sludge and furnace liquid are as listed in Appendix C.

前表より明らかな如く１本発明の方法によれば銅を効率
良く回収することができ、しかもそのスラッジの含水率
は３−へチ　と少なく取扱い上好適である。他方、前記
越流液でのＯｕ濃度は６．７９９ｍ５中和槽でｐＨ６程
度甘で中和すれば、最終処分例えば海洋投棄を問題な〈
実施することができる。As is clear from the table above, according to the method of the present invention, copper can be efficiently recovered, and the water content of the sludge is as low as 3-h, making it suitable for handling. On the other hand, if the O concentration in the overflow liquid is neutralized to a pH of about 6 in a 6.799 m5 neutralization tank, the final disposal, for example, ocean dumping, will not be a problem.
It can be implemented.

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

図面は本発明に係る鉄粉による高濃度廃液の処理方法の
／実施例を示すフローシートである。 （１１） ミ 最終処分The drawing is a flow sheet showing an embodiment of the method for treating high concentration waste liquid using iron powder according to the present invention. (11) Final disposition

Claims (1)

【特許請求の範囲】[Claims] 酸性系鋼廃液とアルカリ系銅廃液とを混合槽内で攪拌・
混合することによｔ）　ｐＨ３，３以下に調整し、該混
合液を反応槽に送給後特定酸性系鋼廃液と水と鉄粉を混
合して酸化・還元反応を行なわせｐＨｆｆ−，２〜３．
５とするか又は各廃液においてもｐＨを２〜３．５とし
、その後被処理液に凝集剤を投入した後沈降濃縮装置へ
送給し、沈澱スラッジと上置液に分離するとともに、沈
澱スラッジは濃縮槽において濃縮し、その上澄液を前記
混合槽等へ還流するようにしたことを特徴とする鉄粉に
よる高濃度銅廃液の処理方法。Acidic steel waste liquid and alkaline copper waste liquid are stirred in a mixing tank.
By mixing t) Adjust the pH to 3.3 or less, send the mixed solution to the reaction tank, and then mix the specified acidic steel waste liquid, water, and iron powder to perform an oxidation/reduction reaction to pHff-, 2. ~3.
5 or adjust the pH of each waste liquid to 2 to 3.5, and then add a flocculant to the liquid to be treated, and then feed it to a sedimentation and concentration device to separate it into settled sludge and supernatant liquid. A method for treating high-concentration copper waste liquid using iron powder, characterized in that it is concentrated in a concentration tank and the supernatant liquid is returned to the mixing tank or the like.