飛灰の処理方法及び無害化飛灰を含有する固形化物

Method for treating flying ash and solidified material containing non-polluted flying ash

Abstract

PROBLEM TO BE SOLVED: To provide a method advantageous for non-polluting hazardous flying ash and to obtain a solidified material which contains the non-polluted flying ash and has excellent handing quality. SOLUTION: This method for treating the flying ash containing dioxins and heavy metals consists of (i) a non-polluting treatment stage for bringing the flying ash into contact with an aqueous acidic solution held at a temperature lower than 100°C and a pH in a range of 2 to 6 to extract heavy metal components in the flying ash into this aqueous solution and to crack the dioxins in the flying ash thereby making the dioxins non-polluting, (ii) a neutralizing treatment stage of adding an alkali to the non-polluting flying ash obtain by the non-polluting treatment stage and adjusting its pH to a range of 7.5 to 19 and (iii) a solidifying stage for adding a solidifying agent to the neutralized slurry liquid obtained in the neutralizing treatment stage to solidify the liquid. This solidified material has a structure to immobilize the non- polluting flying ash into the solidified material in the solidifying agent and the flying ash content in the solidified material is in a range of 7 to 40%, the metal-component content in the solidified material is in a range of 0.002 to 4% and the uniaxial compression strength of the solidified material is ≥3 kgf/cm2. COPYRIGHT: (C)2001,JPO
(57)【要約】 【課題】 有害性飛灰を無害化するための有利な方法を 提供するとともに、無害化飛灰を含有する取り扱い性に すぐれた固形化物を提供する。 【解決手段】 ダイオキシン類及び重金属を含む飛灰の 処理方法であって、(i)該飛灰を100℃より低い温 度、pH2〜6の範囲に保持された酸性水溶液と接触さ せて、該飛灰中の重金属成分を該水溶液中に抽出させる とともに、該飛灰中のダイオキシン類を分解無害化させ る無害化処理工程と、(ii)該無害化処理工程で得られ た無害化飛灰にアルカリを添加して、そのpHを7.5 〜10の範囲に調節する中和処理工程と、(iii)該中和 処理工程で得られた中和スラリー液に、固化剤を添加し て固形化させる固形化工程からなることを特徴とする飛 灰の処理方法。無害化飛灰を固化剤の固形化物中に固定 化させた構造を有する固形化物であって、該固形化物中 の飛灰含有量が7〜40%の範囲にあり、該固形化物中 の金属分含有量が0.002〜4%の範囲にあり、かつ 該固形化物の一軸圧縮強度が3kgf/cm 2 以上であ ることを特徴とする無害化飛灰を含有する固形化物。

Claims

Description

Topics

Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)

    Title

Cited By (0)

    Publication numberPublication dateAssigneeTitle