JP3620965B2 - Phosphorus immobilization method - Google Patents
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Description
【０００１】
【発明に属する技術分野】
本発明は、下水汚泥、産業廃棄物等の溶融対象物中に含まれるリンをスラグ中に固定するリン固定化方法に関する。
【０００２】
【従来の技術】
下水汚泥や産業廃棄物等の減容化、無害化、資源化を図る処理方法の一つに、これらを溶融してスラグ化させる溶融処理がある。溶融処理においては、溶融対象物をそのまま溶融させると溶融温度が高くなり、溶融対象物中の汚染物質の固定化率が低くなる恐れがあるため、溶融対象物の成分を予め調整することによって溶融温度を下げるようにしており、通常は、ＣａＯ／ＳｉＯ２［ｗ／ｗ］で表される塩基度が１．０前後になるように、溶融対象物に消石灰Ｃａ（ＯＨ）２や砕石（ＳｉＯ２）を添加している。
【０００３】
【発明が解決しようとする課題】
しかしながら、上記した塩基度を指標とした方法以外の成分調整方法は一般化されておらず、溶融対象物中の個々の成分の挙動制御を目的とした成分調整方法は行われていないのが現状であり、そのために溶融時に問題となる成分の一つにリンがある。リンはたとえば下水汚泥中に固形物あたり２〜３％含まれており、溶融時に一部が気体となって揮散し、排ガス中に移行して、溶融炉の後段に設けられた熱交換機や排煙処理設備で凝縮して析出し、設備の腐食やダストの肥大堅固化を招き、機器破損等の不具合を引き起こすことがある。また、リンを含んだ排ガスを湿式洗浄し、洗浄排水を返流水として水処理系に戻した場合の悪影響も懸念される。
【０００４】
本発明は上記問題を解決するもので、溶融時にリンを揮散させることなくスラグ中に固定できるリン固定化方法を提供することを目的とするものである。
【０００５】
【課題を解決するための手段】
上記問題を解決するために、本発明のリン固定化方法は、溶融対象物中に含まれたリンをスラグ中に固定するリン固定化方法であって、溶融対象物に対して、溶融処理温度で酸性酸化物を生成する酸性酸化物生成元素ＰとＳｉの濃度と、前記酸性酸化物に対応する塩基性酸化物を生成する塩基性酸化物生成元素ＣａとＦｅとＡｌの濃度とのモル比で定義された酸塩基比（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）が予め設定した下限値以上になるように、前記塩基性酸化物生成元素ＣａとＦｅとＡｌの何れかの化合物の１種または複数種からなる成分調整剤を添加し、成分調整した溶融対象物を溶融炉に導入して溶融スラグ化させるようにしたものである。
【０００６】
以下、上記したリン固定化方法について説明する。
下水汚泥溶融プロセスでは、汚泥中の無機分を約１３００〜１４００℃で加熱溶融するという点で乾式リン製造法と共通しており、汚泥溶融時には、乾式リン製造時と同様に以下の化学反応が起こっていると考えられる。
【０００７】
【化１】
（１）式の反応は、以下の（２）式に示す酸塩基反応と（３）式に示す酸化還元反応との連続反応と解釈できる。反応の結果、リンはＰ４ ↑ の形態で気体として揮散し、後工程で冷却されて単体リンＰとして析出する。
【０００９】
【化２】
【化３】
上記化学反応において、下水汚泥の主成分であって水処理あるいは汚泥処理方式により含有量が変化するＣａ、Ｆｅ、Ａｌ、Ｐ、Ｓｉの５つの元素成分に注目すると、ＳｉＯ２ やＰ２ Ｏ５ はＯ２−を受容する酸として作用し（酸性酸化物）、ＣａＯはＯ２−を供与する塩基として作用し（塩基性酸化物）、ＦｅやＡｌのリン酸塩もＣａ３（ＰＯ４）２と同様の挙動を示すと考えられる。
【００１２】
このため、（２）式から説明されるように、Ｃａ、Ｆｅ、Ａｌの含量が増えると、Ｐ２ Ｏ５ はそれらの金属と塩を生成し、スラグ中に固定化される。一方、ＳｉＯ２ はＰ２ Ｏ５ と競合する形になり、Ｓｉの含量が増加すると、Ｐ２ Ｏ５ が遊離し、リンの揮散を促す。ＦｅはＦｅ２ Ｐとなってリンを固定化する可能性もあり、事実、スラグ中にはリン含有率の高い鉄化合物が認められる。汚泥中の炭素成分や生成した一酸化炭素の一部は、（２）式に示されるように還元剤として作用し、リンの揮散を招く。
【００１３】
これらのことは、本発明者らが行った試験において、１）炭素添加率を上げるにしたがってスラグへのリン固定化率が低下したこと、２）リン固定化率はリンの形態には依存せず、金属成分の割合、すなわち塩基度および（Ｃａ＋Ｆｅ＋Ａｌ）の割合と正の相関が認められたことでも裏付けられた。リン固定化率は、（スラグ中リン濃度×スラグ重量）／（溶融対象物中リン濃度×溶融対象物重量）として算出した。
【００１４】
このような知見に基づいて、溶融処理温度で酸性酸化物を生成する元素ＰとＳｉとを酸性酸化物生成元素とし、酸性酸化物に対応する塩基性酸化物を生成する元素ＣａとＦｅとＡｌとを塩基性酸化物生成元素とし、酸性酸化物生成元素と塩基性酸化物生成元素との濃度の比（ｍｏｌ／ｍｏｌ）を酸塩基比とした。
【００１５】
酸塩基比には、たとえば（Ｃａ＋Ｆｅ＋Ａｌ）／（Ｐ＋Ｓｉ）で示されるもの、（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）で示されるものがある。
（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）で示される酸塩基比では、各元素に付した係数は次のようにして決定した。まず、各元素の酸化物の酸素イオン解離エネルギーＵ（ＭＯ→Ｍ２＋＋Ｏ２−＋Ｕ）から、次のような塩基性の強さ（相対値）を算出した：ＣａＯ／１３９、ＭｇＯ／１５５、ＦｅＯ／１５７、Ｆｅ２ Ｏ３ ／４５６、Ａｌ２ Ｏ３ ／４５６、ＳｉＯ２ ／７７７、Ｐ２ Ｏ５ ／１２１４であり、この値が小さいほど塩基性が強い（化学便覧、日本金属学会誌）。次に、塩基性酸化物ＣａＯ、Ａｌ２ Ｏ３ については算出値の逆数を用い、ＦｅＯとＦｅ２ Ｏ３ については算出値の逆数の平均を用い、酸性酸化物ＳｉＯ２ 、Ｐ２ Ｏ５ については算出値を用いて、簡単な比に直し、各元素の係数とした。したがって、この酸塩基比は概ね、元素毎の塩基性・酸性の強さのばらつきに拘わりなく、各元素の原子数を代入するだけで、全体としての塩基性・酸性の強さを表わせるようにしたものと言える。
【００１６】
下水汚泥の酸塩基比とスラグへのリン固定化率の関係を調べてみても、溶融時のリン挙動は、溶融対象物の酸塩基比と正の相関があり、このことから、酸塩基比を指標として溶融対象物の成分調整を行うことで、溶融時のリン揮散を抑制可能であることが明らかである。
【００１７】
特に、（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）で示される酸塩基比を使用した時には、溶融時のリン挙動は、溶融対象物の酸塩基比０．７付近を境に大きく異なり、酸塩基比０．７以上ではほとんどのリンがスラグ中に固定されたことから、下限値を０．７以上に設定するのが適当である。溶融時のリン揮散は、溶融対象物中の炭素含量など、溶融時の酸化還元雰囲気にも依存するので、酸化還元雰囲気に対応して適切な下限値を設定する。
【００１８】
成分調整剤として用いる化合物は、酸化物、水酸化物、塩化物等、化合物形態を問わず、また粉末、スラリー等、添加形態も問わない。
成分調整剤の少なくとも一部は、溶融スラグ化に先立って行う前工程の処理操作のための薬剤として添加するのが好ましく、それにより、溶融スラグ化工程の導入部で成分調整剤として添加する化合物量を低減できる。溶融対象物が下水汚泥であれば、その汚泥脱水工程、汚泥消化工程、濃縮工程、あるいは汚泥を発生する水処理工程などでの添加が可能であり、各処理工程、あるいは処理系に支障を来さなければ、添加時期は問わない。
【００１９】
【実施の形態】
下水汚泥の溶融処理を模倣して以下のようにしてスラグを生成させ、スラグへのリン固定化率を調べた。
【００２０】
下記の表１に示した組成を有する高分子系流動床焼却灰（下水汚泥焼却灰）に、汚泥中の有機分を想定して炭素粉末を２０重量％添加して、原灰とした。
この原灰に金属試薬Ｃａ（ＯＨ）２、Ｆｅ２Ｏ３、あるいはＡｌ２ Ｏ３ を等モル量添加したものをそれぞれ、試料とした。
【００２１】
【表１】
内容量２８０ｍＬのアルミナ製るつぼに、原灰および各試料を別途に１００ｇ程度精秤して入れ、小型電気炉にて１４００℃で４時間溶融した。
得られた各スラグの重量とを測定するとともに、溶融前および溶融後の原灰および各試料のリン濃度を、微粉砕し酸分解したものについてモリブデン青（アスコルビン酸）吸光光度法を行うことにより測定した。また、原灰および各試料について、スラグへのリン固定化率、すなわち（溶融後リン濃度×溶融後重量）／（溶融前リン濃度×溶融前重量）を算出した。
【００２３】
原灰および各試料の塩基度、（Ｃａ＋Ｆｅ＋Ａｌ）／（Ｐ＋Ｓｉ）で示される酸塩基比、およびリン固定化率は表２および図１に示した通りであり、この酸塩基比０．７５の原灰ではリン固定化率は４４％であったが、Ｃａ（ＯＨ）２、Ｆｅ２Ｏ３、あるいはＡｌ２Ｏ３を添加することで、酸塩基比をそれぞれ１．１４に成分調整した各試料では、原灰に比べてリン固定化率が大幅に向上し、いずれも８０％以上となり、（Ｃａ＋Ｆｅ＋Ａｌ）／（Ｐ＋Ｓｉ）（ｍｏｌ／ｍｏｌ）で示される酸塩基比とリン固定化率には正の相関が見られた。
【００２４】
同一の原灰および各試料についての（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）で示される酸塩基比およびリン固定化率は表２および図２に示した通りであり、この酸塩基比０．６２の原灰ではリン固定化率は４４％であったが、Ｃａ（ＯＨ）２、Ｆｅ２Ｏ３、あるいはＡｌ２Ｏ３を添加することで、酸塩基比をそれぞれ１．０９、０．９３、０．７７に成分調整した各試料では、原灰に比べてリン固定化率が大幅に向上し、（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）（ｍｏｌ／ｍｏｌ）で示される酸塩基比０．７以上でリン固定化率が大幅に向上する結果となった。
【００２５】
【表２】
これらの結果から、溶融対象物の酸塩基比を調整することによって、溶融時のリン挙動を制御できることがわかる。つまり、溶融時のリン揮散を抑制するには、酸塩基比が適当な値になるように、Ｃａ、Ｆｅ、Ａｌのいずれかを含んだ化合物を添加するのが効果的である。
【００２７】
このようにしてリン揮散を抑制できる結果、排ガスへのリン移行を抑制することができ、リンに起因する熱交換機や排煙処理設備での問題を解消し、溶融施設全体の安定運転を図ることができる。
【００２８】
なお、上述したように、汚泥中に含まれる炭素成分や生成した一酸化炭素が還元剤として作用し、リンの揮散を招く原因となるので、これらの還元物質の完全燃焼を促進するように空気量を調節することも、リンの挙動の制御の重要な要素となり得る。
【００２９】
実際の下水汚泥の溶融処理にあたって成分調整を行うには、溶融炉へ導入する脱水ケーキや乾燥ケーキに消石灰を添加してもよいが、溶融処理の上流に位置する処理過程、たとえば汚泥脱水工程で鉄やアルミニウム系の脱水助剤を添加したり、汚泥を発生する水処理工程で凝集剤として鉄塩やアルミニウム塩を添加するなど、その処理工程で必要な薬剤としてカルシウムや鉄やアルミニウム系の化合物を選択するのが効率的である。
【００３０】
本発明のリン固定化方法は、上記したような下水汚泥焼却灰、下水汚泥の他、産業廃棄物など、リンを含んだその他の溶融対象物にも好適に実施できる。
【００３１】
【発明の効果】
以上のように、本発明によれば、酸塩基比が所定値以上になるように溶融対象物の成分調整を行うことにより、リンを揮散させることなくスラグ中に固定することができ、リン揮散による熱交換機や排煙処理施設の不具合を防止し、溶融施設全体の安定運転を図ることができる。
【図面の簡単な説明】
【図１】本発明にしたがって成分調整した下水汚泥の（Ｃａ＋Ｆｅ＋Ａｌ）／（Ｐ＋Ｓｉ）で示される酸塩基比とスラグへのリン固定化率との関係を示したグラフである。
【図２】本発明にしたがって成分調整した下水汚泥の（３Ｃａ＋２Ｆｅ＋Ａｌ）／（３Ｐ＋２Ｓｉ）で示される酸塩基比とスラグへのリン固定化率との関係を示したグラフである。[0001]
[Technical field belonging to the invention]
The present invention relates to a phosphorus immobilization method for fixing phosphorus contained in a molten object such as sewage sludge and industrial waste in slag.
[0002]
[Prior art]
One of the processing methods for reducing the volume, detoxifying, and recycling resources of sewage sludge and industrial waste is a melting process that melts them into slag. In the melting process, if the object to be melted is melted as it is, the melting temperature becomes high, and there is a risk that the fixation rate of the contaminants in the object to be melted may be lowered. The temperature is lowered, and normally the slaked lime Ca (OH) 2 or crushed stone (SiO 2 ) is added to the melting target so that the basicity represented by CaO / SiO 2 [w / w] is around 1.0. 2 ) is added.
[0003]
[Problems to be solved by the invention]
However, the component adjustment methods other than the method using the basicity as an index have not been generalized, and the component adjustment method for the purpose of controlling the behavior of individual components in the object to be melted has not been performed. Therefore, phosphorus is one of the components that cause problems when melted. Phosphorus, for example, is contained in sewage sludge in an amount of 2 to 3% per solid matter, and part of it is volatilized and vaporized when melted, and then transferred to exhaust gas, and a heat exchanger or exhaust provided at the subsequent stage of the melting furnace. It may be condensed and deposited in the smoke treatment facility, leading to corrosion of the facility and thickening and solidification of dust, leading to problems such as equipment damage. In addition, there is a concern about an adverse effect when the exhaust gas containing phosphorus is wet-cleaned and the cleaning wastewater is returned to the water treatment system as return water.
[0004]
This invention solves the said problem, and it aims at providing the phosphorus fixation method which can be fixed in slag without volatilizing phosphorus at the time of fusion | melting.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, the phosphorus immobilization method of the present invention is a phosphorus immobilization method for fixing phosphorus contained in a molten object in a slag, and is a melting treatment temperature for the molten object. The molar ratio of the concentration of the acidic oxide-generating element P and Si that generates an acidic oxide with the concentration of the basic oxide-generating element Ca, Fe, and Al that generates a basic oxide corresponding to the acidic oxide From one or more of the basic oxide-forming elements Ca, Fe, and Al so that the acid-base ratio (3Ca + 2Fe + Al) / (3P + 2Si) defined in (1) is equal to or greater than a preset lower limit value The component adjustment agent to be added is added, and the component-adjusted melting object is introduced into a melting furnace to form molten slag.
[0006]
Hereinafter, the phosphorus immobilization method described above will be described.
The sewage sludge melting process is the same as the dry phosphorus production method in that the inorganic content in the sludge is heated and melted at about 1300 to 1400 ° C. When the sludge is melted, the following chemical reaction is performed as in dry phosphorus production. It seems that it is happening.
[0007]
[Chemical 1]
The reaction of the formula (1) can be interpreted as a continuous reaction of the acid-base reaction represented by the following formula (2) and the oxidation-reduction reaction represented by the formula (3). As a result of the reaction, phosphorus is volatilized as a gas in the form of P 4 ↑, cooled in a subsequent step, and precipitated as simple phosphorus P.
[0009]
[Chemical formula 2]
[Chemical 3]
In the above chemical reaction, when attention is paid to five elemental components of Ca, Fe, Al, P, and Si, which are main components of sewage sludge and change in content depending on the water treatment or sludge treatment method, SiO 2 and P 2 O 5 Acts as an acid that accepts O 2− (acidic oxide), CaO acts as a base that donates O 2− (basic oxide), and Fe and Al phosphates are also Ca 3 (PO 4 ). It is thought that the same behavior as 2 is shown.
[0012]
For this reason, as explained from the formula (2), when the content of Ca, Fe, and Al increases, P 2 O 5 generates salts with those metals and is immobilized in the slag. On the other hand, SiO 2 becomes a form competing with P 2 O 5, and when the Si content increases, P 2 O 5 is liberated and promotes the volatilization of phosphorus. Fe may become Fe 2 P to immobilize phosphorus, and in fact, iron compounds having a high phosphorus content are observed in the slag. The carbon component in the sludge and a part of the generated carbon monoxide act as a reducing agent as shown in the formula (2), leading to volatilization of phosphorus.
[0013]
In these tests conducted by the present inventors, 1) the phosphorus immobilization rate to slag decreased as the carbon addition rate increased, and 2) the phosphorus immobilization rate depended on the form of phosphorus. It was also confirmed that a positive correlation was observed with the ratio of the metal component, that is, the basicity and the ratio of (Ca + Fe + Al). The phosphorus immobilization ratio was calculated as (phosphorus concentration in slag × slag weight) / (phosphorus concentration in molten object × weight of molten object).
[0014]
Based on such knowledge, elements P and Si that generate acidic oxides at the melting temperature are used as acidic oxide generating elements, and elements Ca, Fe, and Al that generate basic oxides corresponding to acidic oxides. Was the basic oxide generating element, and the ratio of the concentration of the acidic oxide generating element to the basic oxide generating element (mol / mol) was the acid-base ratio.
[0015]
Examples of the acid-base ratio include those represented by (Ca + Fe + Al) / (P + Si) and those represented by (3Ca + 2Fe + Al) / (3P + 2Si).
In the acid-base ratio represented by (3Ca + 2Fe + Al) / (3P + 2Si), the coefficient assigned to each element was determined as follows. First, the following basic strengths (relative values) were calculated from the oxygen ion dissociation energy U (MO → M 2+ + O 2 + U) of the oxide of each element: CaO / 139, MgO / 155, FeO / 157, a Fe 2 O 3/456, Al 2 O 3/456,
[0016]
Examining the relationship between the acid-base ratio of sewage sludge and the phosphorus immobilization rate in the slag, the phosphorus behavior during melting has a positive correlation with the acid-base ratio of the object to be melted. It is clear that phosphorus volatilization at the time of melting can be suppressed by adjusting the components of the object to be melted using as an index.
[0017]
In particular, when the acid-base ratio represented by (3Ca + 2Fe + Al) / (3P + 2Si) is used, the phosphorus behavior at the time of melting differs greatly around the vicinity of the acid-base ratio 0.7 of the object to be melted, and the acid-base ratio 0.7 In the above, since most phosphorus is fixed in the slag, it is appropriate to set the lower limit value to 0.7 or more. Since phosphorus volatilization at the time of melting also depends on the redox atmosphere at the time of melting, such as the carbon content in the object to be melted, an appropriate lower limit is set corresponding to the redox atmosphere.
[0018]
The compound used as a component modifier may be in any compound form such as oxide, hydroxide, chloride, etc., and may be added in any form such as powder or slurry.
It is preferable to add at least a part of the component modifier as a chemical agent for the pre-treatment process performed prior to the melting slag formation, whereby the compound added as a component modifier at the introduction of the molten slag transformation step The amount can be reduced. If the object to be melted is sewage sludge, it can be added in the sludge dewatering process, sludge digestion process, concentration process, water treatment process that generates sludge, etc., which hinders each treatment process or treatment system. Otherwise, the addition time does not matter.
[0019]
Embodiment
Slag was generated as follows by imitating the melting treatment of sewage sludge, and the phosphorus immobilization rate on the slag was examined.
[0020]
20% by weight of carbon powder was added to a polymer fluidized bed incineration ash (sewage sludge incineration ash) having the composition shown in Table 1 below assuming an organic content in the sludge to obtain a raw ash.
Samples obtained by adding equimolar amounts of the metal reagent Ca (OH) 2 , Fe 2 O 3 , or Al 2 O 3 to the raw ash were used as samples.
[0021]
[Table 1]
About 100 g of raw ash and each sample were separately weighed separately into an alumina crucible having an internal volume of 280 mL, and melted at 1400 ° C. for 4 hours in a small electric furnace.
By measuring the weight of each slag obtained and performing molybdenum blue (ascorbic acid) absorptiometry on the raw ash before and after melting and the phosphorus concentration of each sample finely ground and acid-decomposed. It was measured. For the raw ash and each sample, the phosphorus immobilization ratio in the slag, that is, (phosphorus concentration after melting × weight after melting) / (phosphorus concentration before melting × weight before melting) was calculated.
[0023]
The basicity of the raw ash and each sample, the acid-base ratio represented by (Ca + Fe + Al) / (P + Si), and the phosphorus immobilization ratio are as shown in Table 2 and FIG. In ash, the phosphorus immobilization rate was 44%, but each sample was adjusted to have an acid-base ratio of 1.14 by adding Ca (OH) 2 , Fe 2 O 3 , or Al 2 O 3. In this case, the phosphorus immobilization rate is significantly improved compared to the raw ash, and both are 80% or more, and the acid-base ratio and the phosphorus immobilization rate indicated by (Ca + Fe + Al) / (P + Si) (mol / mol) are positive. The correlation was seen.
[0024]
The acid-base ratio and phosphorus immobilization ratio indicated by (3Ca + 2Fe + Al) / (3P + 2Si) for the same raw ash and each sample are as shown in Table 2 and FIG. Then, the phosphorous immobilization ratio was 44%, but by adding Ca (OH) 2 , Fe 2 O 3 , or Al 2 O 3 , the acid-base ratios were 1.09, 0.93, and 0.8, respectively. In each sample adjusted to 77, the phosphorous immobilization rate was significantly improved compared to the raw ash, and the phosphorous immobilization was performed at an acid-base ratio of 0.7 or more represented by (3Ca + 2Fe + Al) / (3P + 2Si) (mol / mol). The result was a significant improvement.
[0025]
[Table 2]
From these results, it can be seen that the phosphorus behavior during melting can be controlled by adjusting the acid-base ratio of the object to be melted. That is, in order to suppress phosphorus volatilization at the time of melting, it is effective to add a compound containing any of Ca, Fe, and Al so that the acid-base ratio becomes an appropriate value.
[0027]
As a result of suppressing phosphorus volatilization in this way, it is possible to suppress phosphorus transfer to exhaust gas, eliminate problems with heat exchangers and flue gas treatment equipment caused by phosphorus, and achieve stable operation of the entire melting facility Can do.
[0028]
As described above, since the carbon component contained in the sludge and the generated carbon monoxide act as a reducing agent and cause the volatilization of phosphorus, air is used to promote complete combustion of these reducing substances. Adjusting the amount can also be an important factor in controlling the behavior of phosphorus.
[0029]
In order to adjust the components in the actual sewage sludge melting process, slaked lime may be added to the dewatered cake or dried cake introduced into the melting furnace, but in the process located upstream of the melting process, for example, the sludge dewatering process. Calcium, iron or aluminum compounds as chemicals required in the treatment process, such as adding iron or aluminum dehydration aids or adding iron salts or aluminum salts as flocculants in the water treatment process that generates sludge It is efficient to select
[0030]
The phosphorus immobilization method of the present invention can be suitably carried out on other melting objects containing phosphorus, such as industrial waste, in addition to the sewage sludge incineration ash and sewage sludge as described above.
[0031]
【The invention's effect】
As described above, according to the present invention, by adjusting the components of the object to be melted so that the acid-base ratio is a predetermined value or more, it can be fixed in the slag without volatilizing phosphorus, This prevents problems with heat exchangers and flue gas treatment facilities, and ensures stable operation of the entire melting facility.
[Brief description of the drawings]
FIG. 1 is a graph showing a relationship between an acid-base ratio indicated by (Ca + Fe + Al) / (P + Si) of sewage sludge whose components are adjusted according to the present invention and a phosphorus immobilization ratio to slag.
FIG. 2 is a graph showing the relationship between the acid-base ratio indicated by (3Ca + 2Fe + Al) / (3P + 2Si) of sewage sludge whose components are adjusted according to the present invention and the phosphorus immobilization rate to slag.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| JP15181598A JP3620965B2 (en) | 1998-06-02 | 1998-06-02 | Phosphorus immobilization method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15181598A JP3620965B2 (en) | 1998-06-02 | 1998-06-02 | Phosphorus immobilization method |
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| JPH11342378A JPH11342378A (en) | 1999-12-14 |
| JP3620965B2 true JP3620965B2 (en) | 2005-02-16 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2016070569A (en) * | 2014-09-29 | 2016-05-09 | Ｄｏｗａエコシステム株式会社 | Incineration treatment method for solid industrial waste |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4514529B2 (en) * | 2004-06-30 | 2010-07-28 | 株式会社クボタ | Sewage sludge melting treatment method |
| JP6434725B2 (en) * | 2013-07-09 | 2018-12-05 | 株式会社クボタ | Method for melting phosphorus-containing material and method for operating melting furnace |
| JP5881260B2 (en) * | 2014-05-12 | 2016-03-09 | 株式会社日水コン | Incinerator blockage risk evaluation method and incinerator blockage prevention method |
| JP5976152B2 (en) * | 2015-03-04 | 2016-08-23 | 月島テクノメンテサービス株式会社 | Sewage sludge incineration treatment method and sewage treatment equipment |
| JP5974335B2 (en) * | 2015-12-16 | 2016-08-23 | 株式会社日水コン | Incinerator blockage prevention method |
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1998
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2016070569A (en) * | 2014-09-29 | 2016-05-09 | Ｄｏｗａエコシステム株式会社 | Incineration treatment method for solid industrial waste |
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