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METHOD FOR SEPARATING HEAVY METAL meetings

Foreign code F190009782
File No. S2017-0782-C0
Posted date May 7, 2019
Country WIPO
International application number 2018JP021139
International publication number WO 2018225638
Date of international filing Jun 1, 2018
Date of international publication Dec 13, 2018
Priority data
  • P2017-112428 (Jun 7, 2017) JP
Title METHOD FOR SEPARATING HEAVY METAL meetings
Abstract This method for separating a heavy metal is characterized by comprising: a first dissolution step wherein an acidic liquid and an object to be treated containing phosphorus and a heavy metal are mixed with each other, so that the phosphorus and the heavy metal contained in the object to be treated are dissolved into the liquid; a first solid-liquid separation step wherein a first liquid, in which the phosphorus and the heavy metal are dissolved, is separated from the solid component; a first precipitation step wherein the first liquid is mixed with a precipitation agent, while increasing the pH thereof, so that a first solid that contains the phosphorus and the heavy metal is precipitated; a second solid-liquid separation step wherein the first solid is separated from the liquid component; a second dissolution step wherein the phosphorus contained in the first solid is dissolved into an alkaline liquid; and a third solid-liquid separation step wherein a second liquid, in which the phosphorus is dissolved, is separated from the solid component that contains the heavy metal. Consequently, the present invention is able to provide a method for separating a heavy metal, which is capable of efficiently separating a heavy metal at low cost from an object to be treated containing phosphorus and the heavy metal.
Outline of related art and contending technology BACKGROUND ART
Sludge ash, in general, highly useful as a resource-rich and contains phosphorus, phosphorus is separated and collected, there is an attempt to effectively utilize (for example, see Patent Document 1).
In this way, the sludge ash, in general, highly useful as a natural resource includes a lot of phosphorus but, on the other hand, a relatively high content of heavy metals is also included. Contains heavy metal and phosphorus, phosphorus is effectively utilized, it is necessary to remove a heavy metal in advance.
However, in the conventional method, phosphorus of low recovery rate, in addition, the content of heavy metals in order to sufficiently low, it takes a long time processing, further, a problem that an enormous cost is incurred. Therefore, as a useful component in spite of phosphorus, as the landfill disposal and industrial waste, from the viewpoint of effective use of resources and environmental protection has become a major problem.
Scope of claims (In Japanese)[請求項1]
 リンおよび重金属を含む被処理物と酸性の液体とを混合し、前記被処理物中に含まれるリンおよび重金属を溶解させる第1の溶解工程と、
 リンおよび重金属が溶解した第1の液体を固体成分と分離する第1の固液分離工程と、
 前記第1の液体を析出剤と混合するとともにpHを上昇させ、リンおよび重金属を含む第1の固体を析出させる第1の析出工程と、
 前記第1の固体を液体成分と分離する第2の固液分離工程と、
 前記第1の固体中に含まれるリンをアルカリ性の液体で溶解させる第2の溶解工程と、
 リンが溶解した第2の液体を、重金属を含む固体成分と分離する第3の固液分離工程とを有することを特徴とする重金属の分離方法。

[請求項2]
 前記第3の固液分離工程の後に、前記第2の液体を析出剤と混合するとともにpHを低下させ、リンを含む第2の固体を析出させる第2の析出工程をさらに有する請求項1に記載の重金属の分離方法。

[請求項3]
 前記第2の析出工程の終了時における液相のpHが2.0以上12.0以下である請求項2に記載の重金属の分離方法。

[請求項4]
 前記第2の析出工程で、pHが-1.0以上2以下の酸性液体を用いる請求項2または3に記載の重金属の分離方法。

[請求項5]
 前記第2の析出工程で、CaCl 2、Ca(OH) 2およびCaCO 3よりなる群から選択される1種または2種以上を用いる請求項2ないし4のいずれか1項に記載の重金属の分離方法。

[請求項6]
 前記第1の溶解工程で、前記酸性の液体としてpHが-1.0以上1.5以下の強酸を用いる請求項1ないし5のいずれか1項に記載の重金属の分離方法。

[請求項7]
 前記第1の析出工程の終了時における液相のpHが1.0以上12以下である請求項1ないし6のいずれか1項に記載の重金属の分離方法。

[請求項8]
 前記第1の析出工程で、pHが10以上のアルカリ性液体を用いる請求項1ないし7のいずれか1項に記載の重金属の分離方法。

[請求項9]
 前記第1の析出工程で、CaCl 2、Ca(OH) 2、CaCO 3および、Al、Mg、Fe成分を持つ塩化物よりなる群から選択される1種または2種以上を用いる請求項1ないし8のいずれか1項に記載の重金属の分離方法。

[請求項10]
 前記第2の溶解工程で、NaOHを含む液体を用いる請求項1ないし9のいずれか1項に記載の重金属の分離方法。

  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • NIIGATA UNIVERSITY
  • Inventor
  • KIM, Hee Joon
IPC(International Patent Classification)
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