JP2005201479A - Method of treating slag containing chromium oxide - Google Patents

Method of treating slag containing chromium oxide Download PDF

Info

Publication number
JP2005201479A
JP2005201479A JP2004005730A JP2004005730A JP2005201479A JP 2005201479 A JP2005201479 A JP 2005201479A JP 2004005730 A JP2004005730 A JP 2004005730A JP 2004005730 A JP2004005730 A JP 2004005730A JP 2005201479 A JP2005201479 A JP 2005201479A
Authority
JP
Japan
Prior art keywords
chromium oxide
containing slag
chromium
water
warm water
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.)
Granted
Application number
JP2004005730A
Other languages
Japanese (ja)
Other versions
JP4540350B2 (en
Inventor
Eiji Ikezaki
英二 池崎
Toshitaka Yuki
敏隆 湯木
Masato Yanagi
正人 柳
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Navitas Co Ltd
Nippon Steel Corp
Original Assignee
Navitas Co Ltd
Nippon Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Navitas Co Ltd, Nippon Steel Corp filed Critical Navitas Co Ltd
Priority to JP2004005730A priority Critical patent/JP4540350B2/en
Publication of JP2005201479A publication Critical patent/JP2005201479A/en
Application granted granted Critical
Publication of JP4540350B2 publication Critical patent/JP4540350B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/30—Wastewater or sewage treatment systems using renewable energies
    • Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of treating slag containing a chromium oxide for easily treating hexavalent chromium in the slag containing the chromium oxide while preventing the generation of drain containing hydrogen sulfide or sulfur. <P>SOLUTION: The slag containing the chromium oxide is dipped in warm water, and hexavalent chromium in the slag containing the chromium oxide is eluted into the warm water and eliminated from the slag containing the chromium oxide. The temperature of the warm water is 30-100°C, and the slag containing the chromium oxide is dipped in a treatment vessel 15 at a ratio V/W of the volume V of warm water to the weight W of the slag containing the chromium oxide being 0.25 or more. A dipping time T is at least 30 minutes. Further, it is preferable that the layer of the slag containing the chromium oxide put in the treatment vessel 15 is rolled within the dipping time T at least the number of times N computed by N=INT[0.25T/(30V/W)]. INT shows arithmetic processing for obtaining an integer value by omitting fractions to a decimal point of 0.25T/(30V/W). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、クロム酸化物含有スラグの処理方法に係り、更に詳細には、含クロム鋼製造時の精錬工程で発生するクロム酸化物含有スラグ中の６価クロムの処理方法に関する。
ここで、クロム酸化物含有スラグとは、クロム酸化物の他に、カルシウムをＣａＯ換算で２０〜５０質量％、ＳｉＯ2 を１０〜４０質量％等を含むスラグを指す。 The present invention relates to a method for treating chromium oxide-containing slag, and more particularly to a method for treating hexavalent chromium in a chromium oxide-containing slag generated in a refining process during the production of chromium-containing steel.
Here, the chromium oxide-containing slag refers to a slag containing 20 to 50% by mass of calcium and 10 to 40% by mass of SiO 2 in terms of CaO in addition to the chromium oxide.

ステンレス鋼製造用の精錬炉、あるいはスクラップ市中屑を主原料とする鋼製造用の溶解炉（例えば、電気炉）から排出されるスラグ（鋼滓）中には、例えば、１〜７質量％のクロム酸化物が含有されている。このため、精錬炉あるいは溶解炉から排出されるスラグは、排滓容器に受けられ土間まで移送されて放流され、自然冷却された後に６価クロムの溶出値を求めていた。
ここで、６価クロムの溶出値が土壌環境基準（環境庁告示４６号法による溶出試験において０．０５ｍｇ／リットル以下）を満足しない場合は、このスラグを、例えば、道路用材（路盤材、アスファルト骨材等）等の資源として利用することができず、管理型埋め立て処分が実施されている。
しかし、管理型埋め立て処分地で管理できるスラグの容量には限界があり、また、循環型社会構築のためにも、多大な設備投資や処理コストをかける必要のない、簡便かつ確実なスラグの処理技術の確立が望まれていた。 In slag (steel) discharged from a refining furnace for producing stainless steel, or a melting furnace (for example, an electric furnace) for producing steel mainly containing scrap city scraps, for example, 1 to 7% by mass Of chromium oxide. For this reason, the slag discharged from the smelting furnace or melting furnace is received in the waste container, transferred to the soil, discharged, and naturally cooled, and then the elution value of hexavalent chromium was obtained.
Here, when the elution value of hexavalent chromium does not satisfy the soil environment standard (0.05 mg / liter or less in the elution test by the Environmental Agency Notification No. 46 method), this slag is used, for example, as road material (roadbed material, asphalt). It cannot be used as a resource such as aggregate, etc., and management-type landfill disposal is being implemented.
However, there is a limit to the capacity of slag that can be managed in a managed landfill site, and simple and reliable slag processing that does not require significant capital investment and processing costs to build a recycling-oriented society. The establishment of technology was desired.

そこで、６価クロムを無害化する方法として、特許文献１には、クロム含有物を反応容器に投入し、アルカリ硫化物又はアルカリ土類金属硫化物の水性エマルジョン中で、反応容器中にクロム含有物が１〜６０重量％、好ましくは３０〜３５重量％存在するようにして、約１００℃で撹拌しながら硫黄と１〜４時間反応させる湿式処理を行うことにより汚染を除去する方法が開示されている。
また、特許文献２には、６価クロム等の重金属を含有する製鋼ダストに、可溶性硫化物及び２価の鉄イオンを含む酸液と、必要に応じて水を加えて混練し、重金属の不溶物を形成させることにより水溶性有害物質の溶出を抑制する方法が開示されている。
更に、特許文献３には、ステンレス鋼の精錬の際に発生するステンレス鋼スラグ、重クロム酸ナトリウム等のクロム化合物の製造の際に発生するクロム鉱滓、廃棄物溶融スラグ等のクロム酸化物を含有する物質からの６価クロムの溶出を防止することが可能なクロム酸化物含有物質の処理方法が開示されている。 Therefore, as a method for detoxifying hexavalent chromium, Patent Document 1 discloses that a chromium-containing material is introduced into a reaction vessel, and the reaction vessel contains chromium in an aqueous emulsion of alkali sulfide or alkaline earth metal sulfide. Disclosed is a method for removing contamination by performing a wet treatment in which the product is present at 1 to 60 wt%, preferably 30 to 35 wt%, and reacted with sulfur for 1 to 4 hours with stirring at about 100 ° C. ing.
In Patent Document 2, steelmaking dust containing heavy metals such as hexavalent chromium is kneaded with an acid solution containing soluble sulfide and divalent iron ions, and water as necessary, and insoluble in heavy metals. A method for suppressing elution of water-soluble harmful substances by forming a product is disclosed.
Furthermore, Patent Document 3 contains chromium oxides such as stainless steel slag generated during the refining of stainless steel, chromium slag generated during the manufacture of chromium compounds such as sodium dichromate, and waste molten slag. A method for treating a chromium oxide-containing material capable of preventing elution of hexavalent chromium from the material to be released is disclosed.

特公昭５５−８４５４号公報Japanese Patent Publication No.55-8454 特開昭５６−２４０８４号公報JP-A-56-24084 特許第３２９９１７４号公報Japanese Patent No. 3299174

しかしながら、特許文献１に記載された方法では、約１００℃の硫黄を懸濁した高温水の下で６価クロムの還元反応を進行させるため、還元反応時に硫化水素の発生を伴い、作業環境が悪化するという問題があった。更に、発生した硫化水素により設備の腐食が生じるという難点があった。
特許文献２に記載された方法も、６価クロムを硫化水素で還元する原理に立脚したものであるため、特許文献１と同様の問題が生じる。また、可溶性硫化物等の還元物質を多量に含む排水が発生するため排水中のＣＯＤ値（化学的酸素要求量）が高くなり、ｐＨ調整に加えて次亜塩素酸等を用いてＣＯＤ値を水質汚濁防止法に定める基準値以下になるまで排水処理を行う必要が生じる。このため、新たな排水処理設備用の建設コストが発生すると共に、６価クロムの処理時に発生する排水の処理薬品の費用が別途必要になるという問題が生じる。
特許文献３に記載された方法では、酸化数が＋５価以下の硫黄をそれぞれ含有する未エージング高炉徐冷滓や溶銑予備処理スラグから得られる還元力を有する溶出水を６価クロムの還元に用いるため、溶出水は黄色を呈し、かつＣＯＤ値も高いため、６価クロムの還元処理後の溶出水を曝気槽に導入して空気に曝して透明化処理すると共に、ｐＨ調整に加えてＣＯＤ値を水質汚濁防止法に定める基準値以下になるまで処理を行う必要が生じる。こにため、処理薬品の費用がかさむという問題が生じる。 However, in the method described in Patent Document 1, since the reduction reaction of hexavalent chromium proceeds under high-temperature water in which sulfur at about 100 ° C. is suspended, the working environment is accompanied by the generation of hydrogen sulfide during the reduction reaction. There was a problem of getting worse. Furthermore, there was a problem that the equipment was corroded by the generated hydrogen sulfide.
Since the method described in Patent Document 2 is also based on the principle of reducing hexavalent chromium with hydrogen sulfide, the same problem as in Patent Document 1 occurs. In addition, since wastewater containing a large amount of reducing substances such as soluble sulfide is generated, the COD value (chemical oxygen demand) in the wastewater increases, and in addition to pH adjustment, the COD value is reduced using hypochlorous acid, etc. It will be necessary to carry out wastewater treatment until it falls below the standard value stipulated in the Water Pollution Control Law. For this reason, the construction cost for a new wastewater treatment facility is generated, and there is a problem that the cost of wastewater treatment chemicals generated during the treatment of hexavalent chromium is separately required.
In the method described in Patent Document 3, eluent water having reducing power obtained from unaging blast furnace chilled iron or hot metal pretreatment slag each containing sulfur having an oxidation number of +5 or less is used for reduction of hexavalent chromium. Therefore, since the elution water is yellow and has a high COD value, the elution water after the reduction treatment of hexavalent chromium is introduced into an aeration tank and exposed to air for a transparent treatment, and in addition to pH adjustment, the COD value Need to be treated until it falls below the standard value stipulated in the Water Pollution Control Law. For this reason, the problem that the expense of processing chemicals arises.

本発明はかかる事情に鑑みてなされたもので、硫化水素の発生や硫黄含有排水の発生を防止し簡便な方法でクロム酸化物含有スラグ中の６価クロムを還元処理することが可能なクロム酸化物含有スラグの処理方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and is capable of preventing the generation of hydrogen sulfide and the generation of sulfur-containing wastewater, and capable of reducing hexavalent chromium in chromium oxide-containing slag by a simple method. It aims at providing the processing method of a thing containing slag.

前記目的に沿う請求項１記載のクロム酸化物含有スラグの処理方法は、クロム酸化物含有スラグを温水中に浸漬し、該クロム酸化物含有スラグ中に含まれる６価クロムを該温水中に溶出させて、該クロム酸化物含有スラグ中から６価クロムを除去する。
これによって、環境庁告示４６号法による溶出試験を実施した際のクロム酸化物含有スラグから溶出する６価クロムの溶出量を、土壌環境基準値（０．０５ｍｇ／リットル以下）を満たすようにすることができる。 The chromium oxide-containing slag treatment method according to claim 1, which meets the above object, comprises immersing the chromium oxide-containing slag in warm water and eluting hexavalent chromium contained in the chromium oxide-containing slag into the warm water. And hexavalent chromium is removed from the chromium oxide-containing slag.
As a result, the elution amount of hexavalent chromium eluted from the chromium oxide-containing slag when the elution test by the Environmental Agency Notification No. 46 method is carried out so as to satisfy the soil environmental standard value (0.05 mg / liter or less). be able to.

請求項２記載のクロム酸化物含有スラグの処理方法は、請求項１記載のクロム酸化物含有スラグの処理方法において、前記温水の温度は３０℃以上で１００℃未満であり、前記クロム酸化物含有スラグは処理槽内に該温水の体積Ｖと該クロム酸化物含有スラグの重量Ｗとの比Ｖ／Ｗが０．２５以上で浸漬され、浸漬時間Ｔは３０分以上である。 The chromium oxide-containing slag treatment method according to claim 2 is the chromium oxide-containing slag treatment method according to claim 1, wherein the temperature of the hot water is 30 ° C. or more and less than 100 ° C., and the chromium oxide-containing slag treatment method. The slag is immersed in the treatment tank at a ratio V / W of the volume V of the hot water and the weight W of the chromium oxide-containing slag being 0.25 or more, and the immersion time T is 30 minutes or more.

クロム酸化物含有スラグを温水中に浸漬した際の６価クロムの溶出は、温水の温度が高い程、浸漬時間が長い程、顕著となる。このため、環境庁告示４６号法による溶出試験で得られる６価クロムの溶出量が、土壌環境基準を満たすようにするには、クロム酸化物含有スラグの経済的な処理条件として、温水の温度を３０℃以上で１００℃未満にして、浸漬時間を３０分以上にする必要がある。
また、処理槽内のクロム酸化物含有スラグが温水中に浸漬されるには、クロム酸化物含有スラグ層の上面が概ね温水の水面と等しくなる温水量を下限として、それ以上の水量を保持しておく必要がある。そして、この下限温水量は、クロム酸化物含有スラグの粒度分布により多少左右されるが、実績上、温水の体積Ｖ（単位ｍ3 ）とクロム酸化物含有スラグの重量Ｗ（単位トン）との比Ｖ／Ｗ（水滓比という）が０．２５となるときの温水の体積となる。このため、水滓比を０．２５以上とした。
更に、クロム酸化物含有スラグに含まれるカルシウム化合物中の可溶性カルシウムも温水中に２価のカルシウムとして溶出していく。このため、温水中で６価クロムと２価カルシウムが反応して、例えばＣｒ2 （ＣａＯ4 ）等の不溶性塩を形成して沈澱する。これによって、温水中の６価クロムも除去できる。 The elution of hexavalent chromium when the chromium oxide-containing slag is immersed in warm water becomes more remarkable as the temperature of the warm water is higher and the immersion time is longer. For this reason, in order for the elution amount of hexavalent chromium obtained in the elution test by the Environmental Agency Notification No. 46 method to satisfy the soil environmental standards, the temperature of hot water is used as an economical treatment condition for chromium oxide-containing slag. Must be 30 ° C. or higher and lower than 100 ° C., and the immersion time must be 30 minutes or longer.
In addition, in order for the chromium oxide-containing slag in the treatment tank to be immersed in warm water, the upper limit of the amount of warm water at which the upper surface of the chromium oxide-containing slag layer is approximately equal to the surface of the warm water is kept as the lower limit, and the amount of water is maintained. It is necessary to keep. The lower limit hot water amount is somewhat affected by the particle size distribution of the chromium oxide-containing slag, but in actuality, the volume V of warm water (unit m 3 ) and the weight W (unit ton) of the chromium oxide-containing slag are This is the volume of hot water when the ratio V / W (referred to as the water tank ratio) is 0.25. For this reason, the water tank ratio was set to 0.25 or more.
Furthermore, the soluble calcium in the calcium compound contained in the chromium oxide-containing slag is also eluted as divalent calcium in the warm water. For this reason, hexavalent chromium reacts with divalent calcium in warm water to form an insoluble salt such as Cr 2 (CaO 4 ) and precipitate. Thereby, hexavalent chromium in warm water can also be removed.

請求項３記載のクロム酸化物含有スラグの処理方法は、請求項２記載のクロム酸化物含有スラグの処理方法において、前記処理槽内の前記クロム酸化物含有スラグの層を、前記浸漬時間Ｔの内で下式で算出される回数Ｎ以上転動させる。
Ｎ＝ＩＮＴ［０．２５Ｔ／（３０Ｖ／Ｗ）］
ここで、ＩＮＴ［ ］は、０．２５Ｔ／（３０Ｖ／Ｗ）の小数点以下を切り捨て整数値化する演算処理を示す。 The method for treating a chromium oxide-containing slag according to claim 3 is the method for treating a chromium oxide-containing slag according to claim 2, wherein the layer of the chromium oxide-containing slag in the treatment tank is immersed in the immersion time T. In this case, the roller is rolled more than N times calculated by the following formula.
N = INT [0.25 T / (30 V / W)]
Here, INT [] indicates a calculation process for rounding off the decimal point of 0.25 T / (30 V / W) to an integer value.

請求項４記載のクロム酸化物含有スラグの処理方法は、請求項１〜３記載のクロム酸化物含有スラグの処理方法において、前記温水中に浸漬する前記クロム酸化物含有スラグは、表面温度が２００℃以上で、内部に到るまで固化した状態である。 The processing method of the chromium oxide containing slag of Claim 4 is a processing method of the chromium oxide containing slag of Claims 1-3, The surface temperature of the said chromium oxide containing slag immersed in the said warm water is 200. It is in a solidified state at a temperature of ℃ or higher until reaching the inside.

水蒸気爆発は一般に高温溶融物と水の接触により発生するといわれている。そして、そのメカニズムは、高温溶融物が水と接触した際に水を内部に取り込み、取り込まれた水が高温溶融物内で蒸発して水蒸気になり、この水蒸気の圧力が急激に増大するためと考えられる。
従って、温水中に浸漬されるクロム酸化物含有スラグが内部に到るまで固化した状態とすれば、クロム酸化物含有スラグを水と接触させても、水をクロム酸化物含有スラグの内部に取り込むことができず、水蒸気爆発は生じない。なお、クロム酸化物含有スラグが内部に到るまで固化した状態となるには、クロム酸化物含有スラグの表面温度が１０００℃以下であればよい。
また、クロム酸化物含有スラグと水が接触した際に水は加熱されて、温水となる。このとき、温水中に浸漬するクロム酸化物含有スラグの温度が２００℃未満であると、冬場のように水の温度が低い場合には、水滓比が０．２５以上として、温水の温度を安定して３０℃以上に保持することが困難になる。このため、温水中に浸漬するクロム酸化物含有スラグの温度を２００℃以上にした。 It is said that a steam explosion is generally caused by contact between a high-temperature melt and water. And the mechanism is that when the high-temperature melt comes into contact with water, water is taken into the inside, and the taken-in water evaporates in the high-temperature melt to become water vapor, and the pressure of this water vapor increases rapidly. Conceivable.
Therefore, if the chromium oxide-containing slag immersed in warm water is solidified until it reaches the inside, even if the chromium oxide-containing slag is brought into contact with water, water is taken into the chromium oxide-containing slag. And no steam explosion occurs. In addition, the surface temperature of chromium oxide containing slag should just be 1000 degrees C or less in order to be in the state solidified until chromium oxide containing slag reached the inside.
Moreover, when a chromium oxide containing slag and water contact, water is heated and becomes warm water. At this time, if the temperature of the chromium oxide-containing slag immersed in the warm water is less than 200 ° C., the temperature of the warm water is set to 0.25 or more when the temperature of the water is low, such as in winter. It becomes difficult to stably maintain the temperature at 30 ° C. or higher. For this reason, the temperature of the chromium oxide containing slag immersed in warm water was 200 degreeC or more.

請求項５記載のクロム酸化物含有スラグの処理方法は、請求項１〜４記載のクロム酸化物含有スラグの処理方法において、前記温水から前記クロム酸化物含有スラグを回収し、水切りする際に発生する排水に還元剤を添加する。 The chromium oxide-containing slag treatment method according to claim 5 is generated when the chromium oxide-containing slag is recovered from the warm water and drained in the chromium oxide-containing slag treatment method according to claims 1 to 4. Add a reducing agent to the wastewater.

処理槽内の温水の温度が低くなると（例えば、８０℃未満の場合）、温水中での６価クロムと２価カルシウムの反応が遅くなって、温水中の６価クロムが減少し難くなる。このため、温水からクロム酸化物含有スラグを回収し水切りする際に発生する排水中にも６価クロムが含まれている。
従って、この排水に還元剤を添加することにより、排水中の６価クロムを短時間で除去することができる。 When the temperature of the hot water in the treatment tank is lowered (for example, when it is less than 80 ° C.), the reaction between hexavalent chromium and divalent calcium in the warm water is delayed, and the hexavalent chromium in the warm water is difficult to decrease. For this reason, hexavalent chromium is also contained in the waste water generated when the chromium oxide-containing slag is recovered from the hot water and drained.
Therefore, by adding a reducing agent to the waste water, hexavalent chromium in the waste water can be removed in a short time.

請求項６記載のクロム酸化物含有スラグの処理方法は、請求項５のクロム酸化物含有スラグの処理方法において、前記還元剤は多硫化カルシウムであって、前記排水１００容量部に対して該多硫化カルシウムを多硫化カルシウムの飽和水溶液換算で０．０５容量部以上で１容量部以下の範囲で添加する。 The method for treating chromium oxide-containing slag according to claim 6 is the method for treating chromium oxide-containing slag according to claim 5, wherein the reducing agent is calcium polysulfide, and the amount of the reducing agent relative to 100 parts by volume of the waste water. Calcium sulfide is added in a range of 0.05 parts by volume or more and 1 part by volume or less in terms of a saturated aqueous solution of calcium polysulfide.

多硫化カルシウムを飽和水溶液換算で０．０５容量部未満添加した場合では、排水中の６価クロムの除去速度が遅く、排水中の６価クロム濃度が水質汚濁防止法に定められた排水基準値（０．５ｍｇ／リットル）以下まで低下するのに多くの時間を要する。
また、多硫化カルシウムを飽和水溶液換算で１容量部を超えて添加した場合では、排水中の６価クロムの除去速度は速くなるが、排水の着色が顕著になると共に、ＣＯＤ値も増大し、ＣＯＤ値を水質汚濁防止法に定める基準値以下にする処理が必要になる。このため、多硫化カルシウムの添加量を飽和水溶液換算で０．０５容量部以上で１容量部以下にした。 When calcium polysulfide is added in less than 0.05 parts by volume in terms of saturated aqueous solution, the removal rate of hexavalent chromium in wastewater is slow, and the concentration of hexavalent chromium in wastewater is the standard value for wastewater set forth in the Water Pollution Control Law. It takes a lot of time to drop below (0.5 mg / liter).
In addition, when calcium polysulfide is added in an amount exceeding 1 part by volume in terms of a saturated aqueous solution, the removal rate of hexavalent chromium in the wastewater is increased, but the coloration of the wastewater becomes remarkable and the COD value also increases. It is necessary to treat the COD value below the standard value stipulated in the Water Pollution Control Law. For this reason, the amount of calcium polysulfide added is 0.05 parts by volume or more and 1 part by volume or less in terms of saturated aqueous solution.

請求項１〜６記載のクロム酸化物含有スラグの処理方法においては、クロム酸化物含有スラグ中に含まれる６価クロムを温水中に溶出させてクロム酸化物含有スラグ中から６価クロムを除去するので、クロム酸化物含有スラグ中に含有される６価クロムを容易に、かつ安価に除去することが可能になる。 In the processing method of chromium oxide containing slag of Claims 1-6, the hexavalent chromium contained in chromium oxide containing slag is eluted in warm water, and hexavalent chromium is removed from chromium oxide containing slag. Therefore, hexavalent chromium contained in the chromium oxide-containing slag can be easily and inexpensively removed.

特に、請求項２記載のクロム酸化物含有スラグの処理方法においては、温水の温度は３０℃以上で１００℃未満であり、クロム酸化物含有スラグは処理槽内に温水の体積Ｖとクロム酸化物含有スラグの重量Ｗとの比Ｖ／Ｗが０．２５以上で浸漬され、浸漬時間Ｔは３０分以上であるので、環境庁告示４６号法による溶出試験で得られる６価クロムの溶出量を土壌環境基準を満たすようにすることができ、処理後のクロム酸化物含有スラグを、例えば路盤材、アスファルト骨材等の道路用材やコンクリート二次製品用資源として活用することが可能になる。なお、クロム酸化物含有スラグの処理中に、クロム酸化物含有スラグの水和膨張を促進することができるので、残存膨張の少ない高品位の道路用材やコンクリート二次製品用資源を提供することが可能になる。
また、クロム酸化物含有スラグから温水中に溶出した６価クロムと２価カルシウムは反応して、例えば、Ｃｒ2 （ＣａＯ4 ）等の不溶性塩を形成して沈澱するので、温水中の６価クロムを除去することができ、クロム酸化物含有スラグの処理後に排水される温水の処理を別途行う必要がなく、クロム酸化物含有スラグの処理を簡便、かつ安価に行うことが可能になる。
更に、クロム酸化物含有スラグは、硫黄や硫黄化合物を含有しない温水中に浸漬するので、処理中に腐食性を示す硫化水素の発生を防止することが可能になる。このため、良好な作業環境を維持することが可能になる。 In particular, in the method for treating a chromium oxide-containing slag according to claim 2, the temperature of the hot water is 30 ° C. or more and less than 100 ° C., and the chromium oxide-containing slag contains the volume V of the hot water and the chromium oxide in the treatment tank. Since the ratio V / W with the weight W of the contained slag is dipped at 0.25 or more and the dipping time T is 30 minutes or more, the elution amount of hexavalent chromium obtained by the elution test by the Environmental Agency Notification No. 46 method is Soil environmental standards can be satisfied, and the treated chromium oxide-containing slag can be utilized as road materials such as roadbed materials and asphalt aggregates, or resources for concrete secondary products. In addition, since the hydration expansion of the chromium oxide-containing slag can be promoted during the treatment of the chromium oxide-containing slag, it is possible to provide a high-grade road material and a resource for secondary concrete products with little residual expansion. It becomes possible.
Further, hexavalent chromium and divalent calcium eluted from the chromium oxide-containing slag into warm water react to form an insoluble salt such as Cr 2 (CaO 4 ), for example, and thus precipitate. Chromium can be removed, and it is not necessary to separately perform the treatment of warm water drained after the treatment of the chromium oxide-containing slag, and the treatment of the chromium oxide-containing slag can be performed easily and inexpensively.
Furthermore, since the chromium oxide-containing slag is immersed in warm water not containing sulfur or sulfur compounds, it is possible to prevent generation of hydrogen sulfide exhibiting corrosive properties during the treatment. For this reason, it becomes possible to maintain a favorable working environment.

請求項３記載のクロム酸化物含有スラグの処理方法においては、処理槽内のクロム酸化物含有スラグの層を転動するので、全てのクロム酸化物含有スラグを温水中に確実に浸漬させることができ、全てのクロム酸化物含有スラグのクロム酸化物から６価クロムを温水中に確実に溶出させることが可能になる。
また、クロム酸化物含有スラグの層を転動することにより、処理槽内の温水の温度分布、クロム酸化物含有スラグの層内の温度分布の均一化を図ることができ、６価クロムの溶出速度を高位に安定化させることが可能になる。 In the method for treating chromium oxide-containing slag according to claim 3, since the layer of chromium oxide-containing slag in the treatment tank rolls, all the chromium oxide-containing slag can be surely immersed in warm water. In addition, hexavalent chromium can be surely eluted from the chromium oxide of all chromium oxide-containing slag into the warm water.
Also, by rolling the chromium oxide-containing slag layer, the temperature distribution of hot water in the treatment tank and the temperature distribution in the chromium oxide-containing slag layer can be made uniform, and hexavalent chromium is eluted. The speed can be stabilized at a high level.

請求項４記載のクロム酸化物含有スラグの処理方法においては、温水中に浸漬するクロム酸化物含有スラグは、表面温度が２００℃以上で、内部に到るまで固化した状態であるので、クロム酸化物含有スラグを処理槽内に入れて水を直接放水しても、あるいは水を貯留している処理槽内にクロム酸化物含有スラグを直接入れても、水蒸気爆発を防止することができる。
更に、クロム酸化物含有スラグの表面温度が２００℃以上のため、クロム酸化物含有スラグに接触した水は加熱されて、容易に３０℃以上で１００℃未満の温水を得ることが可能になる。その結果、温水設備の製造コストや運転コストが不要になって、クロム酸化物含有スラグの処理を更に安価に行うことが可能になる。 In the processing method of the chromium oxide containing slag of Claim 4, since the chromium oxide containing slag immersed in warm water is the state solidified until it reached the inside with a surface temperature of 200 degreeC or more, chromium oxidation Even if the material-containing slag is put into the treatment tank and the water is discharged directly, or the chromium oxide-containing slag is directly put into the treatment tank storing the water, the steam explosion can be prevented.
Furthermore, since the surface temperature of chromium oxide containing slag is 200 degreeC or more, the water which contacted chromium oxide containing slag is heated, and it becomes possible to obtain warm water more than 30 degreeC and less than 100 degreeC easily. As a result, the manufacturing cost and operation cost of the hot water facility are no longer necessary, and the chromium oxide-containing slag can be processed at a lower cost.

請求項５記載のクロム酸化物含有スラグの処理方法においては、温水からクロム酸化物含有スラグを回収し水切りする際に発生する排水に還元剤を添加するので、排水中の６価クロムを素早く除去することができ、排水を短時間で処理して放水することが可能になる。
その結果、排水槽の回転率を上昇させることができ、排水槽の設置基数を減少させることが可能になる。 In the processing method of chromium oxide containing slag of Claim 5, since a reducing agent is added to the waste_water | drain generated when recovering and draining chromium oxide containing slag from warm water, hexavalent chromium in waste water is removed quickly It becomes possible to treat and discharge the wastewater in a short time.
As a result, the rotation rate of the drainage tank can be increased, and the number of installed drainage tanks can be reduced.

請求項６記載のクロム酸化物含有スラグの処理方法においては、還元剤は多硫化カルシウムであって、排水１００容量部に対して多硫化カルシウムを多硫化カルシウムの飽和水溶液換算で０．０５容量部以上で１容量部以下の範囲で添加するので、硫化水素の発生、温水の着色、及びＣＯＤ値の増加を防止して、６価クロムを迅速に除去することが可能になる。
その結果、クロム酸化物含有スラグの処理後の排水の処理を別途行う必要がなく、クロム酸化物含有スラグの処理を簡便、かつ安価に行うことが可能になる。 In the processing method of chromium oxide containing slag of Claim 6, a reducing agent is calcium polysulfide, Comprising: 0.05 volume part of calcium polysulfide is converted into the saturated aqueous solution of calcium polysulfide with respect to 100 volume parts of waste_water | drain. Thus, since it is added in the range of 1 part by volume or less, generation of hydrogen sulfide, coloring of hot water, and increase in COD value can be prevented, and hexavalent chromium can be removed rapidly.
As a result, it is not necessary to separately process the wastewater after the treatment of the chromium oxide-containing slag, and the treatment of the chromium oxide-containing slag can be performed easily and inexpensively.

続いて、添付した図面を参照しつつ、本発明を具体化した実施の形態につき説明し、本発明の理解に供する。
ここで、図１は本発明の一実施の形態に係るクロム酸化物含有スラグの処理方法を適用したクロム酸化物含有スラグの処理設備のブロック図である。
図１に示すように、本発明の一実施の形態に係るクロム酸化物含有スラグの処理方法を適用したクロム酸化物含有スラグの処理設備１０は、運搬車両１１に載置された排滓容器１２内に収容されている溶融状態のクロム酸化物含有スラグが放流されるクロム酸化物含有スラグ放流場１３と、放流されたクロム酸化物含有スラグの表面温度を測定する表面温度測定器１４を有している。
ここで、クロム酸化物含有スラグ放流場１３は、放流されたクロム酸化物含有スラグが広がって固化するのに必要な広さを有する、例えば、土間で構成することができる。また、表面温度測定器１４としては、遠隔から表面温度が測定できる、例えば、放射温度計を使用することができる。 Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a block diagram of a processing facility for chromium oxide-containing slag to which the processing method for chromium oxide-containing slag according to one embodiment of the present invention is applied.
As shown in FIG. 1, a chromium oxide-containing slag treatment facility 10 to which a chromium oxide-containing slag treatment method according to an embodiment of the present invention is applied is a waste container 12 mounted on a transport vehicle 11. A chromium oxide-containing slag discharge field 13 in which the molten chromium oxide-containing slag contained therein is discharged, and a surface temperature measuring device 14 for measuring the surface temperature of the discharged chromium oxide-containing slag. ing.
Here, the chrome oxide-containing slag discharge field 13 can be configured, for example, between soils having an area necessary for the discharged chromium oxide-containing slag to spread and solidify. Moreover, as the surface temperature measuring device 14, for example, a radiation thermometer that can measure the surface temperature from a remote location can be used.

また、クロム酸化物含有スラグの処理設備１０は、クロム酸化物含有スラグ放流場１３に放流されて内部に到るまで固化した状態のクロム酸化物含有スラグが投入される処理槽１５と、処理槽１５に固化したクロム酸化物含有スラグを投入する投入装置１６と、処理槽１６内に水を供給する水供給装置１７と、処理槽１５内に形成されたクロム酸化物含有スラグの投入層を転動する転動装置１８を有している。
ここで、処理槽１５としては、例えば、鉄製の上部が開口したタンクを使用することができ、投入装置１６には、例えば、バックフォー、ホイールローダー等の重機を、転動装置１８には、例えば、バックフォー等の重機を使用することができる。また、水供給装置１７は、例えば、水を貯留するタンクと、タンク内の水を処理槽１５に送るポンプを備えた給水配管を用いて構成することができる。 Also, the chromium oxide-containing slag treatment facility 10 includes a treatment tank 15 into which the chromium oxide-containing slag in a state of being discharged into the chromium oxide-containing slag discharge field 13 and solidified until reaching the inside, and a treatment tank 15, a charging device 16 for feeding the solidified chromium oxide-containing slag, a water supply device 17 for supplying water into the treatment tank 16, and a loading layer for the chromium oxide-containing slag formed in the treatment tank 15. It has a rolling device 18 that moves.
Here, as the processing tank 15, for example, a tank with an open top made of iron can be used. For the charging device 16, for example, a heavy machine such as a back fore, a wheel loader, etc., and for the rolling device 18, For example, a heavy machine such as a back for can be used. Moreover, the water supply apparatus 17 can be comprised using the water supply piping provided with the tank which stores water and the pump which sends the water in a tank to the process tank 15, for example.

更に、クロム酸化物含有スラグの処理設備１０は、処理槽１５から処理済のクロム酸化物含有スラグを回収し水切りを行う回収装置１９と、処理済のクロム酸化物含有スラグを収容する処理済スラグ貯留場２０と、水切りにより発生した排水を貯留する排水槽２１と、排水槽２１の排水中の６価クロムを除去する還元材の一例である多硫化カルシウムの飽和水溶液を供給する多硫化カルシウム飽和水溶液供給装置２２を有している。
ここで、回収装置１９には、例えば、バックフォー等の重機を使用することができ、排水槽２１には、例えば、鉄製の上部が開口したタンクを使用することができる。また、処理済スラグ貯留場２０は、回収された放処理済のクロム酸化物含有スラグを広げて天日乾燥するのに必要な広さを有する、例えば、土間で構成することができる。更に、多硫化カルシウム飽和水溶液供給装置２２は、例えば、多硫化カルシウムの飽和水溶液を貯留する撹拌機構を備えたタンクと、タンク内の多硫化カルシウムの飽和水溶液を排水槽２１に送るポンプを備えた供給配管を用いて構成することができる。 Further, the chromium oxide-containing slag processing facility 10 includes a recovery device 19 that recovers and drains the processed chromium oxide-containing slag from the processing tank 15, and a processed slag that contains the processed chromium oxide-containing slag. Calcium sulfide saturated to supply a reservoir 20, a drainage tank 21 that stores drainage generated by draining, and a saturated aqueous solution of calcium polysulfide that is an example of a reducing material that removes hexavalent chromium in the drainage of the drainage tank 21 An aqueous solution supply device 22 is provided.
Here, for example, a heavy machine such as a back-for can be used for the recovery device 19, and for example, a tank with an open upper portion made of iron can be used for the drainage tank 21. Further, the treated slag reservoir 20 can be configured with, for example, soil, having a size necessary for spreading the recovered released chrome oxide-containing slag and drying it in the sun. Further, the saturated calcium polysulfide aqueous solution supply device 22 includes, for example, a tank having a stirring mechanism for storing a saturated aqueous solution of calcium polysulfide and a pump that sends the saturated aqueous solution of calcium polysulfide in the tank to the drain tank 21. It can comprise using supply piping.

次に、本発明の一実施の形態に係るクロム酸化物含有スラグの処理方法について説明する。
例えば、ステンレス鋼製造用の精錬炉から排出された溶融状態のクロム酸化物含有スラグを運搬車両１１に載置された排滓容器１２で受けて、クロム酸化物含有スラグ放流場１３まで運搬する。そして、排滓容器１２を転動させて、収容しているクロム酸化物含有スラグをクロム酸化物含有スラグ放流場１３に放流する。
放流されたクロム酸化物含有スラグは、クロム酸化物含有スラグ放流場１３上で、例えば、１００〜３００ｍｍの厚みを有して拡がり、徐々に冷却される。このとき、放流されたクロム酸化物含有スラグの表面温度を表面温度測定器１４で測定する。 Next, the processing method of the chromium oxide containing slag which concerns on one embodiment of this invention is demonstrated.
For example, a molten chromium oxide-containing slag discharged from a smelting furnace for producing stainless steel is received by a waste container 12 placed on a transport vehicle 11 and transported to a chromium oxide-containing slag discharge field 13. And the waste container 12 is rolled, and the chromium oxide containing slag accommodated is discharged to the chromium oxide containing slag discharge field 13.
The released chrome oxide-containing slag spreads on the chromium oxide-containing slag discharge field 13 with a thickness of, for example, 100 to 300 mm, and is gradually cooled. At this time, the surface temperature of the released chromium oxide-containing slag is measured by the surface temperature measuring device 14.

放流されたクロム酸化物含有スラグが、その内部に到るまで固化した時点で（例えば、表面温度測定器１４で測定したクロム酸化物含有スラグの表面温度が１０００℃以下になった時点で）、クロム酸化物含有スラグ放流場１３に拡がっているクロム酸化物含有スラグを、例えば、バックフォー等の投入装置１６を用いて処理槽１５に投入する。
ここで、処理槽１５に投入するクロム酸化物含有スラグの粒度は、例えば、２５ｍｍ以下にすることが好ましい。粒径を２５ｍｍ以下にすることで、クロム酸化物含有スラグの内部からの６価クロムの溶出を確実に行わせることができる。 When the released chromium oxide-containing slag solidifies until reaching the inside thereof (for example, when the surface temperature of the chromium oxide-containing slag measured by the surface temperature measuring device 14 becomes 1000 ° C. or less), The chromium oxide-containing slag spreading in the chromium oxide-containing slag discharge field 13 is charged into the processing tank 15 using a charging device 16 such as a back-for example.
Here, it is preferable that the particle size of the chromium oxide containing slag thrown into the treatment tank 15 is, for example, 25 mm or less. By making the particle size 25 mm or less, hexavalent chromium can be reliably eluted from the inside of the chromium oxide-containing slag.

また、処理槽１５内には、予め水供給装置１７を用いて水を供給しておくことが好ましい。処理槽１５内に投入されるクロム酸化物含有スラグの温度は１０００℃以下のため、クロム酸化物含有スラグの投入により処理槽１５に貯留されている水の温度は上昇する。このため、例えば、水蒸気を水中に吹き込む手段を講じずに、処理槽１５内の水を、３０℃以上１００℃未満の温水に保持することができる。
なお、クロム酸化物含有スラグの表面温度は２００℃以上とする。これによって、特に冬場でも、処理槽１５内に３０℃以上の温水を安定して保持することが可能になる。
また、処理槽１５内に供給する水の体積は、投入するクロム酸化物含有スラグの重量から、クロム酸化物含有スラグ１トン当たり０．２５ｍ3 以上、すなわち、水滓比が０．２５以上になるようにする。これによって、クロム酸化物含有スラグの投入が終了したときに、クロム酸化物含有スラグの層（以下、投入層ともいう）の最上面の位置を処理槽１５内の水面以下にすることができる。 Moreover, it is preferable to supply water into the treatment tank 15 in advance using the water supply device 17. Since the temperature of the chromium oxide containing slag thrown in in the processing tank 15 is 1000 degrees C or less, the temperature of the water currently stored by the processing tank 15 rises by injection | throwing-in of chromium oxide containing slag. For this reason, for example, the water in the treatment tank 15 can be held in warm water of 30 ° C. or more and less than 100 ° C. without taking means for blowing water vapor into the water.
In addition, the surface temperature of chromium oxide containing slag shall be 200 degreeC or more. This makes it possible to stably hold hot water of 30 ° C. or higher in the treatment tank 15 even in winter.
Further, the volume of water supplied into the treatment tank 15 is 0.25 m 3 or more per ton of chromium oxide-containing slag, that is, the water tank ratio is 0.25 or more, based on the weight of the chromium oxide-containing slag to be charged. To be. Thereby, when the addition of the chromium oxide-containing slag is completed, the position of the uppermost surface of the layer of chromium oxide-containing slag (hereinafter also referred to as the input layer) can be made below the water level in the treatment tank 15.

処理槽１５内で３０℃以上の温水中にクロム酸化物含有スラグを浸漬していると、クロム酸化物含有スラグ中の６価クロムは徐々に温水中に溶出していき、これによって、クロム酸化物含有スラグ中の６価クロムは徐々に減少していく。そして、３０℃以上の温水中に、水滓比が０．２５以上で３０分以上浸漬することにより、クロム酸化物含有スラグ中の６価クロムの大半を温水中に溶出させることができ、浸漬処理後のクロム酸化物含有スラグからの６価クロムの溶出値を土壌環境基準値以下にすることができる。
更に、温水中には、クロム酸化物含有スラグ中の可溶性カルシウムが２価カルシウムとして溶出していくので、温水中で６価クロムと２価カルシウムが反応して、例えばＣｒ2 （ＣａＯ4 ）等の不溶性塩を形成して沈澱する。このため、温水中の６価クロムも除去できる。 When chromium oxide-containing slag is immersed in warm water of 30 ° C. or higher in the treatment tank 15, hexavalent chromium in the chromium oxide-containing slag gradually elutes into the warm water, and thereby oxidizes chromium. Hexavalent chromium in the material-containing slag gradually decreases. And most of the hexavalent chromium in the chromium oxide-containing slag can be eluted in warm water by immersing in warm water of 30 ° C. or higher at a water tank ratio of 0.25 or more for 30 minutes or more. The elution value of hexavalent chromium from the chromium oxide containing slag after a process can be made into the soil environmental standard value or less.
Furthermore, since the soluble calcium in the chromium oxide-containing slag elutes as divalent calcium in the warm water, the hexavalent chromium reacts with the divalent calcium in the warm water, for example, Cr 2 (CaO 4 ) or the like. To form an insoluble salt. For this reason, hexavalent chromium in warm water can also be removed.

そして、処理槽１５内でクロム酸化物含有スラグを３０℃以上の温水中に浸漬しているときに、処理槽１５内のクロム酸化物含有スラグの投入層を、例えば、バックフォー等の転動装置１８を用いて転動する。
これによって、処理槽１５内の投入層に凹凸が生じて温水表面から投入層の上部が一部露出すること、処理槽１５内の温水及び投入層の温度分布、クロム酸化物含有スラグの粒度分布等に基づく６価クロムの温水中への溶出量のバラツキを抑えることができる。
ここで、転動回数を多くする程、６価クロムの温水中への溶出量のバラツキを減少させることができるが、３０℃以上の温水中に水滓比（温水の体積Ｖ／クロム酸化物含有スラグの重量Ｗ）で、浸漬時間Ｔの処理を行う場合、転動回数Ｎは（１）式で算出される回数以上行えば、浸漬処理後のクロム酸化物含有スラグからの６価クロムの溶出値を土壌環境基準値以下にすることができる。
Ｎ＝ＩＮＴ［０．２５Ｔ／（３０Ｖ／Ｗ）］ ・・・・・（１）
ここで、ＩＮＴ［ ］は、０．２５Ｔ／（３０Ｖ／Ｗ）の小数点以下を切り捨て整数値化する演算処理を示す。 Then, when the chromium oxide-containing slag is immersed in warm water of 30 ° C. or higher in the treatment tank 15, the input layer of the chromium oxide-containing slag in the treatment tank 15 is made, for example, as a rolling back Roll using device 18.
As a result, irregularities are generated in the charging layer in the processing tank 15 and the upper part of the charging layer is partially exposed from the hot water surface, the temperature distribution of the hot water and the charging layer in the processing tank 15, and the particle size distribution of the chromium oxide-containing slag. The variation in the elution amount of hexavalent chromium into warm water based on the above can be suppressed.
Here, as the number of rolling is increased, the variation in the elution amount of hexavalent chromium into warm water can be reduced. When the treatment of the immersion time T is performed with the weight W of the contained slag, if the rolling number N is equal to or greater than the number calculated by the formula (1), the hexavalent chromium from the chromium oxide-containing slag after the immersion treatment The elution value can be made lower than the soil environment standard value.
N = INT [0.25 T / (30 V / W)] (1)
Here, INT [] indicates a calculation process for rounding off the decimal point of 0.25 T / (30 V / W) to an integer value.

３０℃以上の温水中に、水滓比が０．２５以上で３０分以上浸漬すると、クロム酸化物含有スラグ中の６価クロム量は溶出値が土壌環境基準値以下になっているので、クロム酸化物含有スラグを処理槽１５から、例えば、バックフォー等の回収装置１９を用いて回収する。そして、回収したクロム酸化物含有スラグは水切りを行って、処理済スラグ貯留場２０に移送する。また、水切りの際に発生する排水は排水槽２１に貯留する。
ここで、処理槽１５内の温水の温度が低い場合（例えば、８０℃未満の場合）、クロム酸化物含有スラグからは６価クロムの溶出値が土壌環境基準値以下の値となるまで６価クロムが温水中に溶出するが、温水中での６価クロムと２価カルシウムの反応が遅くなって、温水中の６価クロムが減少し難くなる。このため、排水槽２１中に貯留される排水中には６価クロムが残存している。 When immersed in warm water of 30 ° C or higher at a water tank ratio of 0.25 or more for 30 minutes or more, the amount of hexavalent chromium in the chromium oxide-containing slag is less than the soil environment standard value. The oxide-containing slag is recovered from the treatment tank 15 by using a recovery device 19 such as a back-for example. The recovered chromium oxide-containing slag is drained and transferred to the treated slag reservoir 20. Further, drainage generated at the time of draining is stored in the drainage tank 21.
Here, when the temperature of the hot water in the treatment tank 15 is low (for example, less than 80 ° C.), the hexavalent chromium is eluted from the chromium oxide-containing slag until the elution value of hexavalent chromium becomes a value equal to or lower than the soil environment standard value. Chromium elutes in the warm water, but the reaction between hexavalent chromium and divalent calcium in the warm water slows down, making it difficult for hexavalent chromium in the warm water to decrease. For this reason, hexavalent chromium remains in the wastewater stored in the drainage tank 21.

そこで、排水中から６価クロムを除去するために、多硫化カルシウムを、排水槽２１内の排水１００容量部に対して多硫化カルシウム飽和水溶液換算で０．０５容量部以上で１容量部以下の範囲で添加する。
これによって、排水中の６価クロムを短時間（例えば、５分間程度）で排水中の６価クロム濃度を水質汚濁防止法に定められた排水基準値（０．５ｍｇ／リットル）以下まで低下させることができる。
なお、多硫化カルシウムの添加量を多硫化カルシウム飽和水溶液換算で１容量部以下としているので、排水の着色を防止して、ＣＯＤ値を水質汚濁防止法に定める基準値以下に維持することができる。 Therefore, in order to remove hexavalent chromium from the wastewater, the calcium polysulfide is 0.05 to 1 part by volume in terms of a saturated aqueous solution of calcium polysulfide with respect to 100 parts by volume of the wastewater in the drainage tank 21. Add in range.
As a result, the hexavalent chromium in the wastewater is reduced to a drainage standard value (0.5 mg / liter) or less defined in the Water Pollution Control Law in a short time (for example, about 5 minutes). be able to.
In addition, since the addition amount of calcium polysulfide is set to 1 part by volume or less in terms of a saturated aqueous solution of calcium polysulfide, coloring of waste water can be prevented and the COD value can be maintained below the standard value defined in the Water Pollution Control Law. .

次に、本発明の作用効果を確認するために行った実施例について説明する。
ここで、図２はクロム酸化物含有スラグを３０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフ、図３はクロム酸化物含有スラグを４０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフ、図４はクロム酸化物含有スラグを６０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフ、図５はクロム酸化物含有スラグを８０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフ、図６は６価クロムが存在する温水中に多硫化カルシウム飽和水溶液を添加した際の、添加量と温水中の６価クロム濃度の関係を示すグラフである。 Next, examples carried out for confirming the effects of the present invention will be described.
Here, FIG. 2 is a graph showing the relationship between the immersion time when the chromium oxide-containing slag is immersed in 30 ° C. warm water and the concentration of hexavalent chromium eluted in the warm water, and FIG. FIG. 4 is a graph showing the relationship between the immersion time when immersed in warm water at 0 ° C. and the concentration of hexavalent chromium eluted in the warm water, and FIG. 4 shows the immersion time and warm water when the chromium oxide-containing slag is immersed in warm water at 60 ° C. FIG. 5 is a graph showing the relationship between the immersion time when chrome slag containing chromium oxide is immersed in 80 ° C. warm water and the concentration of hexavalent chromium eluted in warm water. FIG. 6 is a graph showing the relationship between the amount added and the concentration of hexavalent chromium in warm water when a saturated aqueous solution of calcium polysulfide is added to warm water containing hexavalent chromium.

〔実施例１〕
クロム酸化物含有スラグを３０〜８０℃の温水中に、水滓比０．２５〜１、浸漬時間３０〜１２０分の条件で浸漬処理した。浸漬処理後、クロム酸化物含有スラグを回収して、このクロム酸化物含有スラグからの６価クロム溶出値を環境庁告示４６号法により求めた。その結果を表１に示す。
ここで、６価クロム溶出値の測定方法として、ＩＣＰ発光分光分析法（以下、ＩＣＰ法という）を採用した。なお、６価クロムの溶出値の測定方法としては、ジフェニールカルバチド法（以下、ＤＣ法という）もあるが、ＪＩＳハンドブック（２００２年版）Ｋ０１２０、５７０ページの備考１３に、ＤＣ法適用時の注意事項として、「試料が着色していたり、酸性にしたとき、クロム（ＩＶ）を還元する物質が共存するときは、定量は困難である」と記載されているため、採用しなかった。 [Example 1]
The chromium oxide-containing slag was immersed in hot water at 30 to 80 ° C. under conditions of a water tank ratio of 0.25 to 1 and an immersion time of 30 to 120 minutes. After the immersion treatment, the chromium oxide-containing slag was recovered, and the hexavalent chromium elution value from the chromium oxide-containing slag was determined by the Environmental Agency Notification No. 46 method. The results are shown in Table 1.
Here, ICP emission spectroscopic analysis (hereinafter referred to as ICP method) was employed as a method for measuring the hexavalent chromium elution value. In addition, as a method for measuring the elution value of hexavalent chromium, there is a diphenylcarbide method (hereinafter referred to as DC method), but JIS Handbook (2002 edition) K0120, page 570, remarks 13, page 570 As a precaution, it was described that “When a sample is colored or acidified, and a substance that reduces chromium (IV) coexists, quantification is difficult”, and therefore, it was not adopted.

Figure 2005201479
Figure 2005201479

表１に示すように、温水の温度が３０℃以上、水滓比が０．２５以上、浸漬時間が３０分以上の条件を満足すれば、クロム酸化物含有スラグから大半の６価クロムを温水中に溶出させることができ、浸漬処理後のクロム酸化物含有スラグからの６価クロムの溶出値を土壌環境基準値（０．０５ｍｇ／リットル）以下にできることが確認できた。 As shown in Table 1, most of the hexavalent chromium is heated from the chromium oxide-containing slag as long as the temperature of the hot water satisfies the conditions of 30 ° C. or higher, the water ratio is 0.25 or higher, and the immersion time is 30 minutes or longer. It was confirmed that the elution value of hexavalent chromium from the chromium oxide-containing slag after the immersion treatment could be reduced to a soil environment standard value (0.05 mg / liter) or less.

一方、クロム酸化物含有スラグを浸漬している各温度の温水の上澄み水を３０分間隔でサンプリングして、上澄み水中の６価クロム濃度の時間変化を求めた。その結果を図２〜図５に示す。ここで、図２〜図５において、上澄み水中の６価クロム濃度が０の場合は、上澄み水中の６価クロム濃度の分析結果が検出限界濃度（０．０２ｍｇ／リットル）以下であることを示す。
図２〜図５に示すように、クロム酸化物含有スラグを浸漬する温水の温度が高い程、浸漬時間が長い程、温水中の６価クロム濃度は増加し、クロム酸化物含有スラグからの６価クロムの溶出が進行することが判る。 On the other hand, the supernatant water of warm water at each temperature in which the chromium oxide-containing slag was immersed was sampled at intervals of 30 minutes, and the time change of the hexavalent chromium concentration in the supernatant water was determined. The results are shown in FIGS. Here, in FIG. 2 to FIG. 5, when the hexavalent chromium concentration in the supernatant water is 0, it indicates that the analysis result of the hexavalent chromium concentration in the supernatant water is below the detection limit concentration (0.02 mg / liter). .
As shown in FIGS. 2 to 5, the higher the temperature of the hot water in which the chromium oxide-containing slag is immersed, the longer the immersion time, the higher the hexavalent chromium concentration in the hot water. It can be seen that elution of valent chromium proceeds.

また、上澄み水中の６価クロム濃度は、浸漬時間の経過に伴って最大値を示した後に、徐々に減少することが判った。そして、温水中の沈澱物をＸ線回折により調査したところ、Ｃｒ2 （ＣａＯ4 ）等のクロムの不溶塩が生成していることが確認された。
特に、図５に示すように、温水温度が８０℃の場合は、上澄み水中の６価クロム濃度の減少が顕著になって、約２時間経過後には上澄み水中の６価クロム濃度は水質汚濁法に定められた排水基準（０．５ｍｇ／リットル）以下になることが確認された。なお、３０〜６０℃の温水に浸漬した場合でも、１０日間放置すると、上澄み水中の６価クロム濃度はいずれも水質汚濁法に定められた排水基準以下になることが確認された。
従って、クロム酸化物含有スラグを浸漬処理した後の温水は、温水温度により異なるが、１０日間放置すれば処理槽１５から排出することができる。 Moreover, it turned out that the hexavalent chromium density | concentration in supernatant water reduces gradually, after showing the maximum value with progress of immersion time. And when the precipitate in warm water was investigated by X-ray diffraction, it was confirmed that insoluble salts of chromium such as Cr 2 (CaO 4 ) are formed.
In particular, as shown in FIG. 5, when the hot water temperature is 80 ° C., the decrease in the hexavalent chromium concentration in the supernatant water becomes significant, and after about 2 hours, the hexavalent chromium concentration in the supernatant water becomes the water pollution method. It was confirmed that it would be less than the drainage standard (0.5 mg / liter) defined in. In addition, even when it was immersed in 30-60 degreeC warm water, when it was left to stand for 10 days, it was confirmed that all the hexavalent chromium density | concentrations in supernatant water will be below the waste-water standard stipulated by the water pollution method.
Therefore, the hot water after the immersion treatment of the chromium oxide-containing slag varies depending on the hot water temperature, but can be discharged from the treatment tank 15 if left for 10 days.

〔実施例２〕
水滓比（Ｖ／Ｗ）が０．２５〜０．５になるように温度が３００〜５００℃のクロム酸化物含有スラグ約２トンを処理槽内に投入し、浸漬時間Ｔが１５〜１２０分の条件で浸漬しながら、Ｎ＝ＩＮＴ［０．２５Ｔ／（３０Ｖ／Ｗ）］で求められる回数Ｎ以上転動を行った。
また、比較例として、水滓比（Ｖ／Ｗ）が０．２になるように温度が３００〜５００℃のクロム酸化物含有スラグ約２トンを処理槽内に投入し、浸漬時間Ｔが１５〜１２０分の条件で浸漬しながら、Ｎ＝ＩＮＴ［０．２５Ｔ／（３０Ｖ／Ｗ）］で求められる回数Ｎだけ転動を行う処理と、水滓比（Ｖ／Ｗ）が０．２〜０．５になるように温度が３００〜５００℃のクロム酸化物含有スラグ約２トンを処理槽内に投入し、浸漬時間１５〜１２０分の条件で静置する浸漬処理を行った。
なお、実施例２、比較例共に、処理槽内の温水は、常温の水に３００〜５００℃のクロム酸化物含有スラグを投入することにより加熱した。
そして、浸漬処理後、クロム酸化物含有スラグの投入層の任意位置５０〜６０箇所からクロム酸化物含有スラグをサンプリングし、各サンプル毎に６価クロム溶出値を環境庁告示４６号法により求め、６価クロム溶出値が０．０５ｍｇ／リットルを超えたサンプル数の出現率を算出した。その結果を表２に示す。 [Example 2]
About 2 tons of chromium oxide-containing slag having a temperature of 300 to 500 ° C. is introduced into the treatment tank so that the water tank ratio (V / W) is 0.25 to 0.5, and the immersion time T is 15 to 120. Rolling was performed N times or more as required by N = INT [0.25 T / (30 V / W)] while dipping under the condition of minutes.
Further, as a comparative example, about 2 tons of chromium oxide-containing slag having a temperature of 300 to 500 ° C. is introduced into the treatment tank so that the water tank ratio (V / W) is 0.2, and the immersion time T is 15 A process of rolling N times INT = 0.25 [T / (30V / W)] while being immersed under a condition of 120 minutes, and a water tank ratio (V / W) of 0.2 to About 2 tons of chromium oxide-containing slag having a temperature of 300 to 500 ° C. was introduced into the treatment tank so as to be 0.5, and immersion treatment was performed by allowing to stand for 15 to 120 minutes.
In both the example 2 and the comparative example, the hot water in the treatment tank was heated by introducing 300 to 500 ° C. chromium oxide-containing slag into normal temperature water.
And after immersion treatment, sample the chromium oxide-containing slag from 50 to 60 arbitrary positions of the input layer of the chromium oxide-containing slag, obtain the hexavalent chromium elution value for each sample by the Environmental Agency Notification No. 46 method, The appearance rate of the number of samples in which the hexavalent chromium elution value exceeded 0.05 mg / liter was calculated. The results are shown in Table 2.

Figure 2005201479
Figure 2005201479

表２の比較例に示すように、水滓比が０．２５以上で、浸漬時間Ｔが３０分以上の条件で浸漬した場合、６価クロム溶出値が０．０５ｍｇ／リットルを超えたサンプル数の出現率を０％にするには、水滓比が０．３では浸漬時間が１２０分、水滓比が０．３５では浸漬時間が９０分、水滓比が０．５では浸漬時間が６０分とする必要が判明した。
一方、実施例２に示すように、水滓比が０．２５以上で、浸漬時間Ｔが３０分以上の条件で浸漬した場合、Ｎ回以上転動を行うことで、６価クロム溶出値が０．０５ｍｇ／リットルを超えたサンプル数の出現率は、浸漬時間が３０分の場合で０．１％又は０．２％であるのを除いて、出現率を０％にすることができた。従って、処理槽内でクロム酸化物含有スラグの投入層を転動して撹拌することで、投入層全体からの６価クロム溶出を均一化できることが確認できた。
なお、水滓比が０．２の場合、静置では浸漬時間Ｔが１２０分でも６価クロム溶出値が０．０５ｍｇ／リットルを超えたサンプル数の出現率が０．４％となったが、浸漬時間を６０分、転動回数を２回とすれば、出現率を０％にすることができた。 As shown in the comparative example in Table 2, when the elutriation ratio was 0.25 or more and the immersion time T was immersed for 30 minutes or more, the number of samples in which the hexavalent chromium elution value exceeded 0.05 mg / liter In order to make the appearance rate of 0%, the immersion time is 120 minutes when the water tank ratio is 0.3, the immersion time is 90 minutes when the water tank ratio is 0.35, and the immersion time is when the water tank ratio is 0.5. It turned out to be 60 minutes.
On the other hand, as shown in Example 2, when immersion is performed under conditions where the water tank ratio is 0.25 or more and the immersion time T is 30 minutes or more, the hexavalent chromium elution value is obtained by rolling N times or more. The appearance rate of the number of samples exceeding 0.05 mg / liter was able to be 0%, except that the immersion time was 0.1% or 0.2% when the immersion time was 30 minutes. . Therefore, it was confirmed that the elution of hexavalent chromium from the entire charged layer can be made uniform by rolling and stirring the charged layer of the chromium oxide-containing slag in the treatment tank.
In addition, when the elutriation ratio was 0.2, the appearance rate of the number of samples in which the elution value of hexavalent chromium exceeded 0.05 mg / liter was 0.4% even when the soaking time T was 120 minutes. When the immersion time was 60 minutes and the number of rolling was 2, the appearance rate could be reduced to 0%.

〔実施例３〕
６価クロム濃度が１、２、及び３ｍｇ／リットルの温水（温度が３０〜５０℃）１００容量部に対して多硫化カルシウムを多硫化カルシウムの飽和水溶液換算で０．０５〜１容量部添加し、５分経過後の温水中の６価クロム濃度を測定した。その結果を、図６に示す。ここで、図６において、６価クロム濃度が０の場合は、６価クロム濃度の分析結果が検出限界濃度（０．０２ｍｇ／リットル）未満であることを示す。
図６に示すように、多硫化カルシウムを添加することで、温水中の６価クロム濃度を減少できることが確認できた。
従って、処理槽内からクロム酸化物含有スラグを回収し水切りする際に発生する排水を排水槽に貯留し、貯留している排水１００容量部に対して多硫化カルシウムを多硫化カルシウム飽和水溶液換算で０．０５〜１容量部添加して、例えば、５分保持すれば、排水中の６価クロム濃度を水質汚濁防止法に定められた排水基準値（０．５ｍｇ／リットル）以下できる。 Example 3
Calcium polysulfide is added in an amount of 0.05 to 1 part by volume in terms of a saturated aqueous solution of calcium polysulfide to 100 parts by volume of warm water (temperature is 30 to 50 ° C.) with hexavalent chromium concentrations of 1, 2 and 3 mg / liter. The hexavalent chromium concentration in warm water after 5 minutes was measured. The result is shown in FIG. Here, in FIG. 6, when the hexavalent chromium concentration is 0, it indicates that the analysis result of the hexavalent chromium concentration is less than the detection limit concentration (0.02 mg / liter).
As shown in FIG. 6, it was confirmed that the hexavalent chromium concentration in the warm water can be reduced by adding calcium polysulfide.
Therefore, the wastewater generated when the chromium oxide-containing slag is collected and drained from the treatment tank is stored in the drainage tank, and the calcium polysulfide is converted into a saturated aqueous solution of calcium polysulfide with respect to the 100 parts by volume of the stored wastewater. If 0.05 to 1 part by volume is added and held for 5 minutes, for example, the hexavalent chromium concentration in the wastewater can be reduced below the wastewater standard value (0.5 mg / liter) defined in the Water Pollution Control Law.

以上、本発明の実施の形態を説明したが、本発明は、この実施の形態に限定されるものではなく、発明の要旨を変更しない範囲での変更は可能であり、前記したそれぞれの実施の形態や変形例の一部又は全部を組み合わせて本発明のクロム酸化物含有スラグの処理方法を構成する場合も本発明の権利範囲に含まれる。
例えば、処理槽内に固化したクロム酸化物含有スラグを入れる際、例えば、網目間隔が２５ｍｍの篩を通過したクロム酸化物含有スラグだけを処理槽内に入れるようにしてもよい。これによって、クロム酸化物含有スラグの粒度分布の変動を抑えることができ、クロム酸化物含有スラグの層内での６価クロムの溶出量を均一化して、より安定した処理を行うことができる。 As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. The case where the processing method for a chromium oxide-containing slag according to the present invention is configured by combining some or all of the forms and modifications is also included in the scope of the present invention.
For example, when the solidified chromium oxide-containing slag is placed in the treatment tank, for example, only the chromium oxide-containing slag that has passed through a sieve having a mesh interval of 25 mm may be placed in the treatment tank. As a result, fluctuations in the particle size distribution of the chromium oxide-containing slag can be suppressed, and the amount of hexavalent chromium eluted in the layer of the chromium oxide-containing slag can be made uniform, so that more stable treatment can be performed.

本発明の一実施の形態に係るクロム酸化物含有スラグの処理方法を適用したクロム酸化物含有スラグの処理設備のブロック図である。It is a block diagram of the processing equipment of chromium oxide content slag to which the processing method of chromium oxide content slag concerning one embodiment of the present invention is applied. クロム酸化物含有スラグを３０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフである。It is a graph which shows the relationship between the immersion time at the time of immersing chromium oxide containing slag in 30 degreeC warm water, and the hexavalent chromium concentration eluted in warm water. クロム酸化物含有スラグを４０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフである。It is a graph which shows the relationship between the immersion time at the time of immersing chromium oxide containing slag in 40 degreeC warm water, and the hexavalent chromium concentration eluted in warm water. クロム酸化物含有スラグを６０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフである。It is a graph which shows the relationship between the immersion time at the time of immersing chromium oxide containing slag in 60 degreeC warm water, and the hexavalent chromium concentration eluted in warm water. クロム酸化物含有スラグを８０℃の温水中に浸漬した際の浸漬時間と温水中に溶出した６価クロム濃度の関係を示すグラフである。It is a graph which shows the relationship between the immersion time at the time of immersing chromium oxide containing slag in 80 degreeC warm water, and the hexavalent chromium concentration eluted in warm water. ６価クロム濃度が１、２、及び３ｍｇ／リットルの各温水中に多硫化カルシウム飽和水溶液を添加した際の、添加量と温水中の６価クロム濃度の関係を示すグラフである。It is a graph which shows the relationship between the addition amount and the hexavalent chromium density | concentration in warm water at the time of adding calcium polysulfide saturated aqueous solution to each warm water whose hexavalent chromium density | concentration is 1, 2, and 3 mg / liter.

符号の説明Explanation of symbols

１０：クロム酸化物含有スラグの処理設備、１１：運搬車両、１２：排滓容器、１３：クロム酸化物含有スラグ放流場、１４：表面温度測定器、１５：処理槽、１６：投入装置、１７：水供給装置、１８：転動装置、１９：回収装置、２０：処理済スラグ貯留場、２１：排水槽、２２：多硫化カルシウム飽和水溶液供給装置 10: Treatment equipment for chromium oxide-containing slag, 11: Transportation vehicle, 12: Waste container, 13: Chromium oxide-containing slag discharge field, 14: Surface temperature measuring device, 15: Treatment tank, 16: Input device, 17 : Water supply device, 18: Rolling device, 19: Recovery device, 20: Treated slag reservoir, 21: Drain tank, 22: Saturated calcium polysulfide aqueous solution supply device

Claims (6)

クロム酸化物含有スラグを温水中に浸漬し、該クロム酸化物含有スラグ中に含まれる６価クロムを該温水中に溶出させて、該クロム酸化物含有スラグ中から６価クロムを除去することを特徴とするクロム酸化物含有スラグの処理方法。 Immersing the chromium oxide-containing slag in warm water, and eluting hexavalent chromium contained in the chromium oxide-containing slag into the warm water to remove hexavalent chromium from the chromium oxide-containing slag. A method for treating chromium oxide-containing slag, which is characterized. 請求項１記載のクロム酸化物含有スラグの処理方法において、前記温水の温度は３０℃以上で１００℃未満であり、前記クロム酸化物含有スラグは処理槽内に該温水の体積Ｖと該クロム酸化物含有スラグの重量Ｗとの比Ｖ／Ｗが０．２５以上で浸漬され、浸漬時間Ｔは３０分以上であることを特徴とするクロム酸化物含有スラグの処理方法。 2. The method for treating a chromium oxide-containing slag according to claim 1, wherein the temperature of the hot water is 30 ° C. or more and less than 100 ° C., and the chromium oxide-containing slag is contained in the treatment tank with the volume V of the hot water and the chromium oxidation. A method for treating chromium oxide-containing slag, wherein the ratio V / W to the weight W of the object-containing slag is immersed at 0.25 or more, and the immersion time T is 30 minutes or more. 請求項２記載のクロム酸化物含有スラグの処理方法において、前記処理槽内の前記クロム酸化物含有スラグの層を、前記浸漬時間Ｔの内で下式で算出される回数Ｎ以上転動させることを特徴とするクロム酸化物含有スラグの処理方法。
Ｎ＝ＩＮＴ［０．２５Ｔ／（３０Ｖ／Ｗ）］
ここで、ＩＮＴ［ ］は、０．２５Ｔ／（３０Ｖ／Ｗ）の小数点以下を切り捨て整数値化する演算処理を示す。 In the processing method of the chromium oxide containing slag of Claim 2, rolling the layer of the said chromium oxide containing slag in the said processing tank N times or more calculated by the following Formula within the said immersion time T. The processing method of chromium oxide containing slag characterized by these.
N = INT [0.25 T / (30 V / W)]
Here, INT [] indicates a calculation process for rounding off the decimal point of 0.25 T / (30 V / W) to an integer value. 請求項１〜３のいずれか１項に記載のクロム酸化物含有スラグの処理方法において、前記温水中に浸漬する前記クロム酸化物含有スラグは、表面温度が２００℃以上で、内部に到るまで固化した状態であることを特徴とするクロム酸化物含有スラグの処理方法。 In the processing method of the chromium oxide containing slag of any one of Claims 1-3, the surface temperature of the said chromium oxide containing slag immersed in the said warm water is 200 degreeC or more until it reaches an inside. A method for treating chromium oxide-containing slag, characterized by being in a solidified state. 請求項１〜４のいずれか１項に記載のクロム酸化物含有スラグの処理方法において、前記温水から前記クロム酸化物含有スラグを回収し、水切りする際に発生する排水に還元剤を添加することを特徴とするクロム酸化物含有スラグの処理方法。 In the processing method of the chromium oxide containing slag of any one of Claims 1-4, collect | recovering the said chromium oxide containing slag from the said warm water, and adding a reducing agent to the waste_water | drain generated when draining. The processing method of chromium oxide containing slag characterized by these. 請求項５記載のクロム酸化物含有スラグの処理方法において、前記還元剤は多硫化カルシウムであって、前記排水１００容量部に対して該多硫化カルシウムを多硫化カルシウムの飽和水溶液換算で０．０５容量部以上で１容量部以下の範囲で添加することを特徴とするクロム酸化物含有スラグの処理方法。 6. The method for treating a chromium oxide-containing slag according to claim 5, wherein the reducing agent is calcium polysulfide, and the calcium polysulfide is converted to 0.05 in terms of a saturated aqueous solution of calcium polysulfide with respect to 100 parts by volume of the waste water. A method for treating chromium oxide-containing slag, comprising adding in the range of not less than 1 part by volume and not more than 1 part by volume.
JP2004005730A 2004-01-13 2004-01-13 Method for treating chromium oxide-containing slag Expired - Fee Related JP4540350B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004005730A JP4540350B2 (en) 2004-01-13 2004-01-13 Method for treating chromium oxide-containing slag

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004005730A JP4540350B2 (en) 2004-01-13 2004-01-13 Method for treating chromium oxide-containing slag

Publications (2)

Publication Number Publication Date
JP2005201479A true JP2005201479A (en) 2005-07-28
JP4540350B2 JP4540350B2 (en) 2010-09-08

Family

ID=34819953

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004005730A Expired - Fee Related JP4540350B2 (en) 2004-01-13 2004-01-13 Method for treating chromium oxide-containing slag

Country Status (1)

Country Link
JP (1) JP4540350B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007298320A (en) * 2006-04-28 2007-11-15 Fujitsu Ltd Detector and detection method
WO2013182897A1 (en) 2012-06-08 2013-12-12 Toyota Jidosha Kabushiki Kaisha Heat treatment method, heat-treating furnace, and heat treatment system
JP2014226580A (en) * 2013-05-20 2014-12-08 株式会社ワールド・リンク Heavy metal-contaminated water treatment method, heavy metal-contaminated solid-shaped object treatment method and composition for removal treatment of heavy metal

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51113357A (en) * 1975-03-31 1976-10-06 Kiyomitsu Yahikosawa Chrome-containing service and waste water treating method
JPH03249984A (en) * 1990-02-28 1991-11-07 Shinagawa Refract Co Ltd Method for regenerating used cr6+-containing basic brick
JPH08229305A (en) * 1995-03-01 1996-09-10 Hitachi Zosen Corp Device for eluting harmful matter in inorganic-fiber insulating material
JPH10219330A (en) * 1997-02-04 1998-08-18 Kawasaki Steel Corp Refining method into stainless steel
JPH10324547A (en) * 1997-03-27 1998-12-08 Kawasaki Steel Corp Treatment of chromium oxide-containing material
JPH1161118A (en) * 1997-08-15 1999-03-05 Nippon Chem Ind Co Ltd Preventive agent against soil acidification by acid rain
JPH11100242A (en) * 1997-09-30 1999-04-13 Kawasaki Steel Corp Treatment of chromium oxide-containing material
JP2000093923A (en) * 1998-09-25 2000-04-04 Kawasaki Steel Corp Method for treating substance containing chromium oxide
JP2002059141A (en) * 2000-08-23 2002-02-26 Sumitomo Metal Ind Ltd Stabilizing technique for chromium-containing industrial waste
JP2003334568A (en) * 2002-05-16 2003-11-25 Taiheiyo Cement Corp Method for treating drain containing heavy metal

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51113357A (en) * 1975-03-31 1976-10-06 Kiyomitsu Yahikosawa Chrome-containing service and waste water treating method
JPH03249984A (en) * 1990-02-28 1991-11-07 Shinagawa Refract Co Ltd Method for regenerating used cr6+-containing basic brick
JPH08229305A (en) * 1995-03-01 1996-09-10 Hitachi Zosen Corp Device for eluting harmful matter in inorganic-fiber insulating material
JPH10219330A (en) * 1997-02-04 1998-08-18 Kawasaki Steel Corp Refining method into stainless steel
JPH10324547A (en) * 1997-03-27 1998-12-08 Kawasaki Steel Corp Treatment of chromium oxide-containing material
JPH1161118A (en) * 1997-08-15 1999-03-05 Nippon Chem Ind Co Ltd Preventive agent against soil acidification by acid rain
JPH11100242A (en) * 1997-09-30 1999-04-13 Kawasaki Steel Corp Treatment of chromium oxide-containing material
JP2000093923A (en) * 1998-09-25 2000-04-04 Kawasaki Steel Corp Method for treating substance containing chromium oxide
JP2002059141A (en) * 2000-08-23 2002-02-26 Sumitomo Metal Ind Ltd Stabilizing technique for chromium-containing industrial waste
JP2003334568A (en) * 2002-05-16 2003-11-25 Taiheiyo Cement Corp Method for treating drain containing heavy metal

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007298320A (en) * 2006-04-28 2007-11-15 Fujitsu Ltd Detector and detection method
WO2013182897A1 (en) 2012-06-08 2013-12-12 Toyota Jidosha Kabushiki Kaisha Heat treatment method, heat-treating furnace, and heat treatment system
US9498807B2 (en) 2012-06-08 2016-11-22 Toyota Jidosha Kabushiki Kaisha Heat treatment method, heat-treating furnace, and heat treatment system
JP2014226580A (en) * 2013-05-20 2014-12-08 株式会社ワールド・リンク Heavy metal-contaminated water treatment method, heavy metal-contaminated solid-shaped object treatment method and composition for removal treatment of heavy metal

Also Published As

Publication number Publication date
JP4540350B2 (en) 2010-09-08

Similar Documents

Publication Publication Date Title
Ottosen et al. Extracting phosphorous from incinerated sewage sludge ash rich in iron or aluminum
Li et al. Co-treatment of gypsum sludge and Pb/Zn smelting slag for the solidification of sludge containing arsenic and heavy metals
Erdem et al. Hexavalent chromium removal by ferrochromium slag
Hendrych et al. Stabilisation/solidification of landfill leachate concentrate and its residue obtained by partial evaporation
Liao et al. Removal of toxic arsenic (As (Ⅲ)) from industrial wastewater by ultrasonic enhanced zero-valent lead combined with CuSO4
CN105873644B (en) Metal treatment method
CN101708499B (en) Method for jointly stabilizing fly ash and arsenic-containing waste
Erdem et al. Cr (VI) reduction in aqueous solutions by siderite
Li et al. Leaching kinetics of acid-soluble Cr (VI) from chromite ore processing residue with hydrofluoric acid
CN108002499A (en) One kind removes heavy metal treatment agent and preparation method thereof in iron removaling system heavy-metal contaminated soil ring waste
EP0869193B1 (en) Method for processing chromium oxide-containing substances in large quantities
JP4540350B2 (en) Method for treating chromium oxide-containing slag
JP3299174B2 (en) Method for treating chromium oxide-containing material
JP4692064B2 (en) Reduction treatment agent and reduction treatment method
JP3171912B2 (en) Detoxification method for waste liquid containing hexavalent chromium
JP5363975B2 (en) Methods related to steel production
JP2002248444A (en) Method for treating waste containing chromium oxide
JP5470699B2 (en) Detoxification method for heavy metal-containing basic waste
Petersen Assessment and modelling of chromium release in minerals processing waste deposits
JP2002192125A (en) Reduction treatment method for chromium oxide- containing substance
Liang et al. Research on Wet Acid-Free Treatment Technology for SPL
JP4717018B2 (en) Soil purification agent and method for producing soil purification agent
JP6686982B2 (en) Method for reducing chromium oxide-containing substance and method for manufacturing civil engineering material
Hassan Remediation of chromium-contaminated soil using blast furnace slag
JP5337956B2 (en) Method for treating chromium oxide-containing material

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20061030

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080722

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080819

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20081010

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100126

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20100324

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20100608

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20100622

R151 Written notification of patent or utility model registration

Ref document number: 4540350

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130702

Year of fee payment: 3

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130702

Year of fee payment: 3

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313117

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

LAPS Cancellation because of no payment of annual fees