JP2022066111A - DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD - Google Patents
DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD Download PDFInfo
- Publication number
- JP2022066111A JP2022066111A JP2020175049A JP2020175049A JP2022066111A JP 2022066111 A JP2022066111 A JP 2022066111A JP 2020175049 A JP2020175049 A JP 2020175049A JP 2020175049 A JP2020175049 A JP 2020175049A JP 2022066111 A JP2022066111 A JP 2022066111A
- Authority
- JP
- Japan
- Prior art keywords
- hydrochloric acid
- ash
- chlorine
- washing
- solid
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000010612 desalination reaction Methods 0.000 title abstract description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 138
- 238000005406 washing Methods 0.000 claims abstract description 66
- 239000000460 chlorine Substances 0.000 claims abstract description 62
- 229910052801 chlorine Inorganic materials 0.000 claims abstract description 59
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims abstract description 58
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims abstract description 54
- 239000011575 calcium Substances 0.000 claims abstract description 54
- 239000007788 liquid Substances 0.000 claims abstract description 40
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 32
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 30
- 229910000019 calcium carbonate Inorganic materials 0.000 claims abstract description 27
- 239000002002 slurry Substances 0.000 claims abstract description 24
- 238000000926 separation method Methods 0.000 claims abstract description 21
- 239000007787 solid Substances 0.000 claims abstract description 17
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 claims abstract description 14
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 24
- 239000000706 filtrate Substances 0.000 claims description 21
- 239000003513 alkali Substances 0.000 claims description 18
- 239000001569 carbon dioxide Substances 0.000 claims description 12
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 12
- 238000011033 desalting Methods 0.000 claims description 12
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 9
- 238000003763 carbonization Methods 0.000 claims description 4
- 238000010828 elution Methods 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 abstract 1
- 239000002956 ash Substances 0.000 description 78
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 17
- 239000012535 impurity Substances 0.000 description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 238000004140 cleaning Methods 0.000 description 10
- 239000007789 gas Substances 0.000 description 10
- 239000004568 cement Substances 0.000 description 9
- 229910052710 silicon Inorganic materials 0.000 description 9
- 229910052782 aluminium Inorganic materials 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 8
- 239000002994 raw material Substances 0.000 description 7
- 239000010936 titanium Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- 239000002351 wastewater Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 229910052719 titanium Inorganic materials 0.000 description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 4
- 239000000428 dust Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002386 leaching Methods 0.000 description 4
- 238000003672 processing method Methods 0.000 description 4
- 238000004065 wastewater treatment Methods 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 239000002562 thickening agent Substances 0.000 description 3
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- 239000001099 ammonium carbonate Substances 0.000 description 2
- 150000001805 chlorine compounds Chemical class 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 150000001669 calcium Chemical class 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003818 cinder Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000003869 coulometry Methods 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 239000011736 potassium bicarbonate Substances 0.000 description 1
- 229910000028 potassium bicarbonate Inorganic materials 0.000 description 1
- 235000015497 potassium bicarbonate Nutrition 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 235000011181 potassium carbonates Nutrition 0.000 description 1
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 description 1
- 229940086066 potassium hydrogencarbonate Drugs 0.000 description 1
- VLYFRFHWUBBLRR-UHFFFAOYSA-L potassium;sodium;carbonate Chemical compound [Na+].[K+].[O-]C([O-])=O VLYFRFHWUBBLRR-UHFFFAOYSA-L 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Landscapes
- Processing Of Solid Wastes (AREA)
Abstract
Description
本発明は、塩素含有灰を脱塩洗浄してカルシウムを効果的に回収する方法に関する。 The present invention relates to a method for effectively recovering calcium by desalting and washing chlorine-containing ash.
一般廃棄物や産業廃棄物の焼却によって発生した焼却灰（主灰、飛灰、燃え殻、煤塵）や最終処分場に埋め立て処分された焼却灰、あるいはセメント工場から発生するクリンカダスト等をセメント原料等として再利用することが進められている。一方、これらの焼却灰等には十数％程度の塩素が含まれているので、これらの塩素を含む上記各種の焼却灰やクリンカダスト等（以下、これらを塩素含有灰と云う）を再資源化するには用途に応じた程度まで脱塩する必要がある。 Cement raw materials such as incineration ash (main ash, fly ash, cinders, soot and dust) generated by incineration of general waste and industrial waste, incineration ash landfilled at the final disposal site, and cleana dust generated from cement factories. It is being reused as a product. On the other hand, since these incinerator ash and the like contain about 10% of chlorine, the above-mentioned various incinerator ash and cleana dust containing these chlorine (hereinafter referred to as chlorine-containing ash) are recycled. It is necessary to desalt to the extent that it is suitable for the purpose.
また、上記塩素含有灰にはカルシウム分が酸化物換算で概ね２０％～５０％程度と豊富に含まれおり、このカルシウム分を有効に回収できれば、塩素含有灰の再資源化を拡大することができる。例えば、塩素含有灰からカルシウム分を高純度に回収できれば、セメント原料以外にも様々な用途に再利用することが可能となる。一方、塩素含有灰には、塩素やカルシウムの他に、ケイ素(Ｓｉ)、鉄(Ｆｅ)、アルミニウム(Ａｌ)、チタン(Ｔｉ)などが含まれており、回収したカルシウム分にこれらの不純物が残留していると、セメント原料以外には利用し難くなり、再利用の用途が制限される場合がある。 In addition, the chlorine-containing ash contains abundant calcium content of about 20% to 50% in terms of oxide, and if this calcium content can be effectively recovered, the recycling of chlorine-containing ash can be expanded. can. For example, if calcium can be recovered from chlorine-containing ash with high purity, it can be reused for various purposes other than cement raw materials. On the other hand, chlorine-containing ash contains silicon (Si), iron (Fe), aluminum (Al), titanium (Ti), etc. in addition to chlorine and calcium, and these impurities are contained in the recovered calcium content. If it remains, it becomes difficult to use it for anything other than cement raw materials, and its reuse may be limited.
上記塩素含有灰の脱塩について、該塩素含有灰に含まれる塩素化合物の大部分は水溶性なので水洗浄して脱塩できるが、塩素化合物の一部は水に難溶性のフリーデル氏塩（3CaO・Al２O３・CaCl２・10H２O）等を形成しており、水洗浄だけでは十分に脱塩することができない。一方、フリーデル氏塩等に酸を加えてｐＨを低下させることで脱塩する方法が知られている。ただし、この方法ではｐＨの低下に伴い、塩素と一緒にカルシウムも溶出するので、酸洗浄だけではカルシウムを十分に回収することができない。 Regarding the desalting of the chlorine-containing ash, most of the chlorine compounds contained in the chlorine-containing ash are water-soluble and can be washed with water to desalt, but some of the chlorine compounds are sparingly soluble in water. It forms 3CaO, Al 2O 3 , CaCl 2 , 10H 2 O), etc., and cannot be sufficiently desalted only by washing with water. On the other hand, a method of desalting by adding an acid to Friedel's salt or the like to lower the pH is known. However, in this method, calcium is eluted together with chlorine as the pH decreases, so that calcium cannot be sufficiently recovered by pickling alone.
また、塩素含有灰に炭酸塩を含む水を加えて洗浄する方法（特開２００６－３２６４６２公報）、あるいは塩素含有灰の水スラリーに炭酸ガスを吹き込んで洗浄する方法が知られている（特許第３９２４８２２号公報）。炭酸塩や炭酸ガスを用いて洗浄すると、フリーデル氏塩は分解して脱塩されるので脱塩洗浄灰を得ることができるが、カルシウムの一部は水に難溶性の炭酸カルシウムになり、これが洗浄後の固液分離によって固形分として洗浄灰と共に回収されるため、カルシウムを分離して回収するのが難しくなる。 Further, a method of adding water containing a carbonate to chlorine-containing ash for cleaning (Japanese Patent Laid-Open No. 2006-326462) or a method of blowing carbonate gas into a water slurry of chlorine-containing ash for cleaning is known (Patent No. 1). 3924822 (Ab.). When washed with carbonate or carbon dioxide, Friedel's salt is decomposed and desalted, so that desalted washing ash can be obtained, but some of the calcium becomes poorly soluble calcium carbonate in water. Since this is recovered as solid content together with the washing ash by solid-liquid separation after washing, it becomes difficult to separate and recover calcium.
本発明は、上記問題を解決したものであり、塩素含有灰を十分に脱塩することができ、かつ脱塩によって塩素含有灰から溶出したカルシウムを洗浄灰から分離して有効に回収することができる処理方法を提供する。 The present invention solves the above-mentioned problems, and can sufficiently desalinate chlorine-containing ash, and can effectively recover calcium eluted from chlorine-containing ash by desalting from the washing ash. Provide a processing method that can be performed.
本発明の方法は、以下の構成によって上記問題を解決した処理方法であり、塩素含有灰を脱塩してカルシウムを効率よく回収する方法である。
〔１〕塩素含有灰を塩酸スラリーにし、ｐＨ２.５～６.０で塩酸洗浄して該塩素含有灰を脱塩すると共に該塩素含有灰に含まれるカルシウムを溶出させる塩酸洗浄工程と、該塩酸洗浄の後に該塩酸スラリーを固液分離して塩酸洗浄濾液と洗浄灰を回収する第一固液分離工程と、該塩酸洗浄濾液に炭酸源を導入し、ｐＨ７.０～１２.０に調整して該濾液に含まれるカルシウムを炭酸カルシウムにして固形化する炭酸化工程と、該炭酸カルシウムを含む固形分を回収する第二固液分離工程を有することを特徴とする塩素含有灰の脱塩とＣａ回収方法。
〔２〕上記炭酸化工程において、炭酸源としてアルカリ炭酸塩を用いて炭酸源と共にアルカリを導入し、あるいは炭酸源として二酸化炭素含有ガスを用いると共にアルカリを添加して、ｐＨ７.０～１２.０に調整して炭酸カルシウムを生成させる上記[１]に記載する塩素含有灰の脱塩とＣａ回収方法。
The method of the present invention is a treatment method that solves the above-mentioned problems by the following configuration, and is a method of desalting chlorine-containing ash to efficiently recover calcium.
[1] A hydrochloric acid washing step in which a chlorine-containing ash is made into a hydrochloric acid slurry and washed with hydrochloric acid at pH 2.5 to 6.0 to desalinate the chlorine-containing ash and elute calcium contained in the chlorine-containing ash, and the hydrochloric acid. After washing, the hydrochloric acid slurry is solid-liquid separated to recover the hydrochloric acid washing filtrate and the washing ash, and a carbon dioxide source is introduced into the hydrochloric acid washing filtrate to adjust the pH to 7.0 to 12.0. Desalting of chlorine-containing ash, which comprises a carbonization step of converting calcium contained in the filtrate into calcium carbonate and solidifying it, and a second solid-liquid separation step of recovering the solid content containing the calcium carbonate. Ca recovery method.
[2] In the above carbonation step, an alkali carbonate is used as a carbonic acid source and an alkali is introduced together with the carbonic acid source, or a carbon dioxide-containing gas is used as a carbonic acid source and an alkali is added to pH 7.0 to 12.0. The method for desalting and Ca recovery of chlorine-containing ash according to the above [1], which is adjusted to produce calcium carbonate.
〔具体的な説明〕
本発明の処理方法は、塩素含有灰を塩酸スラリーにし、ｐＨ２.５～６.０で塩酸洗浄して該塩素含有灰を脱塩すると共に該塩素含有灰に含まれるカルシウムを溶出させる塩酸洗浄工程と、該塩酸洗浄の後に該塩酸スラリーを固液分離して塩酸洗浄濾液と洗浄灰を回収する第一固液分離工程と、該塩酸洗浄濾液に炭酸源を導入し、ｐＨ７.０～１２.０に調整して該濾液に含まれるカルシウムを炭酸カルシウムにして固形化する炭酸化工程と、該炭酸カルシウムを含む固形分を回収する第二固液分離工程を有することを特徴とする塩素含有灰の脱塩とＣａ回収方法である。
本発明の処理方法の概略を図１の工程図に示す。
[Specific explanation]
The treatment method of the present invention is a hydrochloric acid washing step in which chlorine-containing ash is made into a hydrochloric acid slurry and washed with hydrochloric acid at pH 2.5 to 6.0 to desalt the chlorine-containing ash and elute calcium contained in the chlorine-containing ash. After the hydrochloric acid washing, the hydrochloric acid slurry is solid-liquid separated to recover the hydrochloric acid washing filtrate and the washing ash, and a carbon dioxide source is introduced into the hydrochloric acid washing filtrate, and the pH is 7.0 to 12. Chlorine-containing ash characterized by having a carbonization step of adjusting to 0 and solidifying calcium contained in the filtrate to calcium carbonate, and a second solid-liquid separation step of recovering the solid content containing the calcium carbonate. It is a method of desalting and recovering Ca.
The outline of the processing method of the present invention is shown in the process diagram of FIG.
＜塩酸洗浄工程＞
本発明の処理方法は、塩素含有灰を塩酸スラリーにし、ｐＨ２.５～６.０の液性で塩酸洗浄し、該塩素含有灰を脱塩すると共に該塩素含有灰に含まれるカルシウムを溶出させる塩酸洗浄工程を有する。塩素含有灰に塩酸を直接加えて塩酸スラリーにしても良いし、塩素含有灰に洗浄水を加えてスラリー化した後に塩酸を加えて塩酸スラリーにしても良い。
<Hydrochloric acid cleaning process>
In the treatment method of the present invention, chlorine-containing ash is made into a hydrochloric acid slurry, washed with hydrochloric acid in a liquid state of pH 2.5 to 6.0, the chlorine-containing ash is desalted, and the calcium contained in the chlorine-containing ash is eluted. Has a hydrochloric acid cleaning step. Hydrochloric acid may be directly added to the chlorine-containing ash to form a hydrochloric acid slurry, or washing water may be added to the chlorine-containing ash to form a slurry, and then hydrochloric acid may be added to form a hydrochloric acid slurry.
塩素含有灰を塩酸スラリーにし、ｐＨ２.５～６.０の液性で撹拌して塩酸洗浄することによって、塩素含有灰に含まれるＳｉ、Ｆｅ、Ａｌ、Ｔｉの溶出を抑えつつ、ＣａとＣｌの大部分を塩素含有灰から溶出させることができる。ｐＨ２.５未満の強酸性下では、Ｓｉ、Ｆｅ、Ａｌが溶出しやすくなり、液分に含まれるＳｉやＦｅ、Ａｌの濃度が高くなるので好ましくない。一方、ｐＨが６.０を上回るとＣａの溶出量が少なくなり、また洗浄灰の残留塩素濃度が高くなり、脱塩効果が低下する。 Ca and Cl while suppressing the elution of Si, Fe, Al, and Ti contained in the chlorine-containing ash by converting the chlorine-containing ash into a hydrochloric acid slurry and stirring with a liquid of pH 2.5 to 6.0 and washing with hydrochloric acid. Most of it can be eluted from chlorine-containing ash. Under strong acidity of less than pH 2.5, Si, Fe, and Al are likely to elute, and the concentration of Si, Fe, and Al contained in the liquid is high, which is not preferable. On the other hand, when the pH exceeds 6.0, the amount of Ca eluted decreases, the residual chlorine concentration of the washing ash increases, and the desalting effect decreases.
塩酸に代えて硝酸を用いると、排水に窒素分が混入するため排水処理に大きな負荷がかかるので好ましくない。また、塩酸に代えて硫酸を用いると、難溶性の硫酸カルシウムが生成するため、相対的に液中のＣａ量が減少し、次工程の炭酸化工程において液中のカルシウム分を炭酸カルシウムの形態で固形化して回収するのに適さない。なお、特開２０１５－２１８３６９号公報（特許文献３）には、セメント製造の排ガスから回収したダストを硫酸浸出した後にアルカリ浸出して金、銀を回収する方法が開示されているが、この方法では硫酸カルシウムが生成し、固形分に残留するＳｉやＦｅ等の不純物との分離が面倒になり、効率よくカルシウムを回収することができない。硫酸浸出後にアルカリ浸出を行うことは本発明の方法と全く異質の処理方法である。 It is not preferable to use nitric acid instead of hydrochloric acid because nitrogen is mixed in the wastewater and a large load is applied to the wastewater treatment. In addition, when sulfuric acid is used instead of hydrochloric acid, sparingly soluble calcium sulfate is produced, so that the amount of Ca in the liquid is relatively reduced, and the calcium content in the liquid is converted into the form of calcium carbonate in the next step of carbonization. Not suitable for solidification and recovery. Japanese Unexamined Patent Publication No. 2015-218369 (Patent Document 3) discloses a method of recovering gold and silver by leaching dust recovered from exhaust gas of cement manufacturing with sulfuric acid and then leaching with alkali. In this case, calcium sulfate is generated, and separation from impurities such as Si and Fe remaining in the solid content becomes troublesome, and calcium cannot be efficiently recovered. Performing alkali leaching after sulfuric acid leaching is a treatment method completely different from the method of the present invention.
上記塩酸スラリーの液固比は２～２０（液体：固体＝２：１～２０：１）が好ましく、３～１０（液体：固体＝３：１～１０：１）がより好ましい。液固比がこれより小さいとスラリー濃度が高くなり、配管やポンプ等の摩耗が激しくなる。一方、液固比がこれより大きいと、塩酸量が多くなり薬剤コストが嵩むとともに排水処理の負荷が増す。 The liquid-solidity ratio of the hydrochloric acid slurry is preferably 2 to 20 (liquid: solid = 2: 1 to 20: 1), more preferably 3 to 10 (liquid: solid = 3: 1 to 10: 1). If the liquid-solidity ratio is smaller than this, the slurry concentration becomes high, and the wear of pipes, pumps, etc. becomes severe. On the other hand, if the liquid-solidification ratio is larger than this, the amount of hydrochloric acid increases, the cost of chemicals increases, and the load of wastewater treatment increases.
塩酸洗浄の前に、塩素含有灰を粉砕することによって効率よく脱塩洗浄することができる。粉砕装置としては、例えば、振動ミル、ハンマーミルなどがある。粉砕と塩酸洗浄を同時に行っても良い。 Before washing with hydrochloric acid, the chlorine-containing ash can be efficiently desalted and washed by pulverizing the ash. Examples of the crushing device include a vibration mill and a hammer mill. Grinding and washing with hydrochloric acid may be performed at the same time.
＜第一固液分離工程＞
塩酸洗浄したスラリーを固液分離して、溶出した塩素とカルシウムを含む塩酸洗浄濾液を回収する。分離した固形分の洗浄灰には原灰（塩素含有灰）に含まれる不純物のＳｉ、Ｆｅ、Ａｌ、Ｔｉの大部分が溶出せずに残留するので、これらの不純物が少ない塩酸洗浄濾液を回収することができる。固形分の脱水ケーキ（脱塩洗浄灰）は回収してセメント原料等に利用することができる。
<First solid-liquid separation process>
The hydrochloric acid-washed slurry is separated into solid and liquid, and the hydrochloric acid-washed filtrate containing eluted chlorine and calcium is recovered. Most of the impurities Si, Fe, Al, and Ti contained in the raw ash (chlorine-containing ash) remain in the separated solid cleaning ash without elution, so the hydrochloric acid cleaning filtrate with less impurities is recovered. can do. The solid dehydrated cake (demineralized and washed ash) can be recovered and used as a raw material for cement.
＜炭酸化工程＞
本発明の処理方法は、上記塩酸洗浄濾液に炭酸源を導入し、ｐＨ７.０～１２.０に調整して該濾液に含まれるカルシウムを炭酸カルシウムにして固形化する炭酸化工程を有する。炭酸源としてアルカリ炭酸塩を用いて炭酸源と共にアルカリを導入してもよく、あるいは炭酸源として二酸化炭素含有ガスを用いると共にアルカリを添加して、ｐＨ７.０～１２.０に調整してもよい。
<Carbonation process>
The treatment method of the present invention includes a carbonation step in which a carbonic acid source is introduced into the hydrochloric acid washing filtrate, the pH is adjusted to 7.0 to 12.0, and the calcium contained in the filtrate is converted into calcium carbonate and solidified. Alkaline carbonate may be used as a carbonic acid source and an alkali may be introduced together with the carbonic acid source, or a carbon dioxide-containing gas may be used as a carbonic acid source and an alkali may be added to adjust the pH to 7.0 to 12.0. ..
アルカリ炭酸塩として、炭酸アンモニウム、炭酸カリウム、炭酸カリウムナトリウム、炭酸ナトリウム、炭酸水素アンモニウム、炭酸水素カリウム、炭酸水素ナトリウムを用いることができる。炭酸ナトリウムが反応当量およびコストの点から好ましい。アルカリ炭酸塩の添加によって、該濾液のｐＨが７.０～１２.０になった場合は、アルカリを添加する必要はない。 As the alkaline carbonate, ammonium carbonate, potassium carbonate, sodium potassium carbonate, sodium carbonate, ammonium hydrogencarbonate, potassium hydrogencarbonate, and sodium hydrogencarbonate can be used. Sodium carbonate is preferred in terms of reaction equivalents and cost. If the pH of the filtrate becomes 7.0 to 12.0 due to the addition of alkaline carbonate, it is not necessary to add alkali.
炭酸源として用いる二酸化炭素含有ガスは燃焼排ガスなど利用することができる。二酸化炭素の導入によってｐＨは徐々に低下する。ｐＨが７.０～１２.０の範囲になるようにアルカリを添加する。アルカリとして、水酸化ナトリウム、水酸化カリウムなどの一般的なアルカリ金属の水酸化物を用いることができる。このアルカリは溶液でも粉末ないし粒状でもよい。 The carbon dioxide-containing gas used as a carbonic acid source can be used as combustion exhaust gas or the like. The pH gradually decreases with the introduction of carbon dioxide. Alkali is added so that the pH is in the range of 7.0 to 12.0. As the alkali, a hydroxide of a general alkali metal such as sodium hydroxide and potassium hydroxide can be used. The alkali may be a solution, powder or granular.
液性をｐＨ７.０～１２.０に調整することによって、液中のカルシウムは炭酸カルシウムを生成して固形化する。ｐＨが７.０未満では、大部分が溶存したままで、炭酸カルシウムを殆ど形成しない。ｐＨが１２.０を超えるとアルカリの使用量が増大し、本工程の処理の効率が低下する。 By adjusting the liquid property to pH 7.0 to 12.0, the calcium in the liquid produces calcium carbonate and solidifies. When the pH is less than 7.0, most of it remains dissolved and almost no calcium carbonate is formed. When the pH exceeds 12.0, the amount of alkali used increases and the processing efficiency of this step decreases.
＜第二固液分離工程＞
上記炭酸化処理の後に固液分離して固形分を回収する。この固形分には生成した炭酸カルシウムが含まれている。塩素含有灰（原灰）を塩酸洗浄してカルシウムを溶出させ、その塩酸洗浄濾液に炭酸源を導入し上記ｐＨ域で液中のカルシウムを炭酸カルシウムにして固定化することによって、原灰に含まれるカルシウムの６０質量％以上を炭酸カルシウムとして回収することができる。また、原灰に含まれるＳｉ、Ｆｅ、Ａｌ、Ｔｉなどの不純物は上記塩酸洗浄で溶出せずに洗浄灰に残るので、これらの不純物の少ない炭酸カルシウムを回収することができる。
<Second solid-liquid separation step>
After the carbonation treatment, solid-liquid separation is performed to recover the solid content. This solid content contains the calcium carbonate produced. Calcium-containing ash (raw ash) is washed with hydrochloric acid to elute calcium, and a carbon dioxide source is introduced into the hydrochloric acid washing filtrate to convert calcium in the liquid to calcium carbonate and immobilize it in the above pH range. 60% by mass or more of the calcium carbonate can be recovered as calcium carbonate. Further, since impurities such as Si, Fe, Al, and Ti contained in the raw ash remain in the washing ash without being eluted by the above-mentioned hydrochloric acid washing, calcium carbonate having few these impurities can be recovered.
第一固液分離工程および第二固液分離工程の固液分離装置として、フィルタープレス、真空ベルトフィルター、遠心脱水機などを用いることができる。フィルタープレスが使用しやすい。例えば、フィルタープレスで固液分離して得た脱水ケーキ（第一固液分離の洗浄灰または第二固液分離の炭酸カルシウムを、さらに洗浄水で貫通洗浄することによって、脱塩効果をさらに高めることができる。また、フィルタープレスによって得られる上記脱水ケーキの含水率は２５～４０％程度と低く、余剰な水分が付着していないため、重量が軽減されてハンドリング性も向上する。 A filter press, a vacuum belt filter, a centrifugal dehydrator, or the like can be used as the solid-liquid separation device in the first solid-liquid separation step and the second solid-liquid separation step. Easy to use filter press. For example, the dehydrated cake obtained by solid-liquid separation with a filter press (washing ash of the first solid-liquid separation or calcium carbonate of the second solid-liquid separation is further washed through with washing water to further enhance the desalting effect. Further, the water content of the dehydrated cake obtained by the filter press is as low as about 25 to 40%, and since excess water is not attached, the weight is reduced and the handling property is improved.
上記固液分離によって生じた排水は、排水処理して放流するが、塩素濃度の低い排水は塩酸洗浄工程に循環して洗浄水として利用してもよい。 The wastewater generated by the solid-liquid separation is treated as wastewater and discharged, but the wastewater having a low chlorine concentration may be circulated in the hydrochloric acid washing step and used as washing water.
〔処理設備〕
本発明の方法を実施する処理設備の一例を図２に示す。図示する処理設備では、塩素含有灰と洗浄水を受け入れる振動ミル１が設けられている。該振動ミル１において塩素含有灰が適度に粉砕される。該振動ミル１から排出された塩素含有灰スラリーは撹拌洗浄槽２に送られる。該撹拌洗浄槽２には塩酸が供給され、ｐＨ２.５～６.０に調整されて塩酸洗浄が行われる（塩酸洗浄工程）。塩酸洗浄後のスラリーはフィルタープレス３に送られる。フィルタープレス３には洗浄水が供給され、脱水処理される（第一固液分離工程）。この脱水洗浄灰は系外に送られる。一方、回収された脱水分（塩酸洗浄濾液）は反応槽４に送られる。さらに該反応槽４に炭酸ガスとアルカリが導入されてｐＨ７.０～１２.０のアルカリ域に調整された後にシックナー５に送られ、炭酸カルシウムの生成が促される（炭酸化工程）。シックナー５の上澄液は排水され、一方、該シックナー５から抜き出されたスラリーはフィルタープレス６に送られる。フィルタープレス６には洗浄水が供給され、脱水処理され（第二固液分離工程）、脱水ケーキ（炭酸カルシウム）が回収される。この炭酸カルシウムは各種の用途に再利用することができる。排水は排水処理設備７に送られて排水処理される。
[Processing equipment]
FIG. 2 shows an example of a processing facility that implements the method of the present invention. In the illustrated processing equipment, a vibration mill 1 for receiving chlorine-containing ash and washing water is provided. Chlorine-containing ash is appropriately pulverized in the vibration mill 1. The chlorine-containing ash slurry discharged from the vibration mill 1 is sent to the stirring and washing tank 2. Hydrochloric acid is supplied to the stirring and washing tank 2, and the pH is adjusted to 2.5 to 6.0 to perform hydrochloric acid washing (hydrochloric acid washing step). The slurry after washing with hydrochloric acid is sent to the
本発明の処理方法によれば、塩素含有灰（原灰）の塩酸洗浄によって十分に脱塩された洗浄灰を回収することができる。この脱塩洗浄灰はセメント原料に再利用することができる。また、塩酸洗浄は原灰に含まれる不純物のＳｉ、Ｆｅ、Ａｌ、Ｔｉが溶出し難い液性下（ｐＨ２.５～６.０）で行うので、これらの不純物が少ない塩酸洗浄濾液を得ることができ、この濾液から炭酸カルシウムを回収することができる。この炭酸カルシウムは不純物が少ないので多くの用途に再利用することができる。具体的には、例えば、セメント原料の他に、排水や排ガスの処理薬剤、建材などに利用することができる。このように、本発明の処理方法では十分に脱塩された洗浄灰と不純物の少ない炭酸カルシウムを分離して回収することができるので、塩素含有灰の処理回収物を、セメント原料に限らず、幅広い用途を広げることができる。 According to the treatment method of the present invention, the washed ash sufficiently desalted by washing the chlorine-containing ash (raw ash) with hydrochloric acid can be recovered. This desalted and washed ash can be reused as a raw material for cement. Further, since the hydrochloric acid cleaning is carried out under a liquid condition (pH 2.5 to 6.0) in which the impurities Si, Fe, Al and Ti contained in the raw ash are difficult to elute, a hydrochloric acid cleaning filtrate having less of these impurities can be obtained. And calcium carbonate can be recovered from this filtrate. Since this calcium carbonate has few impurities, it can be reused for many purposes. Specifically, for example, it can be used as a wastewater or exhaust gas treatment agent, a building material, or the like, in addition to a cement raw material. As described above, in the treatment method of the present invention, sufficiently desalted cleaning ash and calcium carbonate having few impurities can be separated and recovered. Therefore, the treated recovery product of chlorine-containing ash is not limited to the cement raw material. It can be used in a wide range of applications.
本発明の処理方法は、アルカリ添加の炭酸化であるので、アルカリの使用量を減らすことができ、また炭酸源として工場排ガスを利用することができるので、処理コストを大幅に低減することができる。 Since the treatment method of the present invention is carbonation with addition of alkali, the amount of alkali used can be reduced, and since factory exhaust gas can be used as a carbonic acid source, the treatment cost can be significantly reduced. ..
以下、本発明の実施例を比較例と共に示す。回収した洗浄灰のＣｌ濃度は洗浄灰を酸溶解後に溶解液中のＣｌ濃度を電量滴定装置で測定して分析した。回収した洗浄灰のＣａ濃度、Ｓｉ濃度、Ｆｅ濃度、Ａｌ濃度およびＴｉ濃度は蛍光Ｘ線分析(ＸＲＦ)にて測定した。この結果を表１に示す。また、回収した洗浄灰のＸＲＤパターンを図３に示す。 Hereinafter, examples of the present invention will be shown together with comparative examples. The Cl concentration of the recovered washing ash was analyzed by measuring the Cl concentration in the solution after acid-dissolving the washing ash with a coulometric titrator. The Ca concentration, Si concentration, Fe concentration, Al concentration and Ti concentration of the recovered washing ash were measured by fluorescent X-ray analysis (XRF). The results are shown in Table 1. The XRD pattern of the recovered wash ash is shown in FIG.
〔実施例１〕
焼却飛灰（Ｃｌ濃度、Ｃａ濃度等を表１に示す）を１０５℃で乾燥した後に篩分けし、１mm以下の灰１０ｇに６.０mol/Lの塩酸と水（合計１００mL）を加えてスラリーにし、表１に示すｐＨに調整して振とうし、塩酸洗浄を行った（塩酸洗浄工程）。この塩酸洗浄後にスラリーを濾過し、塩酸洗浄濾液を回収すると共に、固形分（塩酸洗浄灰）を純水２００mLで洗浄して洗浄灰を回収し、これを１０５℃で乾燥して乾燥洗浄灰を得た。乾燥洗浄灰のＣａ濃度等を測定することで、乾燥洗浄灰と塩酸洗浄濾液への各成分の移行率を算出した。その結果を表２に示す。
[Example 1]
Incinerated flying ash (Cl concentration, Ca concentration, etc. are shown in Table 1) is dried at 105 ° C., sieved, and 6.0 mol / L hydrochloric acid and water (100 mL in total) are added to 10 g of ash of 1 mm or less to form a slurry. The pH was adjusted to the pH shown in Table 1, shaken, and washed with hydrochloric acid (hydrochloric acid washing step). After this washing with hydrochloric acid, the slurry is filtered to recover the hydrochloric acid washing filtrate, and the solid content (hydrous washing ash) is washed with 200 mL of pure water to recover the washing ash, which is dried at 105 ° C. to obtain dry washing ash. Obtained. By measuring the Ca concentration of the dry wash ash and the like, the transfer rate of each component to the dry wash ash and the hydrochloric acid wash filtrate was calculated. The results are shown in Table 2.
表２示すように、塩酸洗浄時のｐＨ２.６～５.１の試料No.３～６は、Ｃａの溶出量が多く、洗浄灰の残留Ｃａ量が少ない。また、塩素の溶出量が多く、洗浄灰の残留塩素が少なく脱塩効果が高い。一方、塩酸洗浄時のｐＨ８.２、ｐＨ６.５の試料No.１、２は、Ｃａの溶出量が少ないため洗浄灰の残留Ｃａ量が多い。さらに洗浄灰の残留塩素も多く、脱塩効果が低い。塩酸洗浄時のｐＨ２.２の試料No.７は、Ｃａと塩素の溶出量は多いが、Ｓｉ、Ｆｅ、Ａｌも少量溶出し、後段の工程でこれら不純物との分離が不十分になる。 As shown in Table 2, the samples Nos. 3 to 6 having a pH of 2.6 to 5.1 during washing with hydrochloric acid have a large amount of Ca elution and a small amount of residual Ca in the washing ash. In addition, the amount of chlorine eluted is large, the residual chlorine in the washing ash is small, and the desalination effect is high. On the other hand, the samples No. 1 and 2 having pH 8.2 and pH 6.5 at the time of washing with hydrochloric acid have a large amount of residual Ca in the washing ash because the amount of Ca eluted is small. Furthermore, there is a large amount of residual chlorine in the washing ash, and the desalination effect is low. In the sample No. 7 having a pH of 2.2 during washing with hydrochloric acid, the amount of Ca and chlorine eluted is large, but Si, Fe, and Al are also eluted in a small amount, and the separation from these impurities becomes insufficient in the subsequent step.
〔実施例２〕
実施例１の試料No.４で回収した塩酸洗浄濾液１００mLに、１.０mol/Lの水酸化ナトリウム溶液を添加して表３に示すｐＨに調整すると共に、炭酸ガス（ＣＯ２濃度９９.５ｖｏｌ.％以上）を０.１L/minの流量で１時間導入して、液中のＣａを固形化した（炭酸化工程）。このアルカリスラリーを濾過して脱塩ケーキ（炭酸Ｃａ）を回収した。この脱塩ケーキに純水１００mLを加えて洗浄し、脱水して洗浄ケーキを回収した。この洗浄ケーキを真空乾燥して乾燥ケーキを得た。この乾燥ケーキの塩素濃度、Ｃａ濃度を測定した。この結果を表３に示す。また、回収した乾燥ケーキのＸＲＤパターンを図３に示す。
[Example 2]
To 100 mL of the hydrochloric acid washing filtrate recovered in Sample No. 4 of Example 1, a 1.0 mol / L sodium hydroxide solution was added to adjust the pH to the pH shown in Table 3, and carbon dioxide gas (CO 2 concentration 99.5 vol) was added. .% Or more) was introduced at a flow rate of 0.1 L / min for 1 hour to solidify Ca in the liquid (carbonation step). The alkaline slurry was filtered to recover the desalted cake (Ca carbonate). 100 mL of pure water was added to this desalted cake for washing, dehydration was performed, and the washed cake was recovered. This washed cake was vacuum dried to obtain a dried cake. The chlorine concentration and Ca concentration of this dried cake were measured. The results are shown in Table 3. The XRD pattern of the recovered dried cake is shown in FIG.
表３に示すように、炭酸化工程のｐＨ７.０～１２.０の試料No.２０～No.２４は、乾燥ケーキのＣａ濃度が高く、Ｃａ回収率は６０％以上である。一方、炭酸化工程のｐＨ６.０、ｐＨ６.５の試料No.２５、２６は、乾燥ケーキのＣａ回収率は３７～４９％と低い。また、図３に示すように、回収した試料No.２０～No.２４の乾燥ケーキは大部分が炭酸カルシウムである。 As shown in Table 3, the samples No. 20 to No. 24 having a pH of 7.0 to 12.0 in the carbonation step have a high Ca concentration in the dried cake, and the Ca recovery rate is 60% or more. On the other hand, in the samples No. 25 and 26 of pH 6.0 and pH 6.5 in the carbonation step, the Ca recovery rate of the dried cake is as low as 37 to 49%. Further, as shown in FIG. 3, most of the recovered dried cakes of Samples No. 20 to No. 24 are calcium carbonate.
Claims (2)
After the hydrochloric acid washing step of converting the chlorine-containing ash into a hydrochloric acid slurry and washing with hydrochloric acid at pH 2.5 to 6.0 to desalt the chlorine-containing ash and elution the calcium contained in the chlorine-containing ash, and after the hydrochloric acid washing. The first solid-liquid separation step of separating the hydrochloric acid slurry into solid and liquid to recover the hydrochloric acid washing filtrate and the washing ash, and introducing a carbon dioxide source into the hydrochloric acid washing filtrate to adjust the pH to 7.0 to 12.0 and adjusting the filtrate. A method for desalting chlorine-containing ash and recovering Ca, which comprises a carbonization step of converting calcium contained in calcium into calcium carbonate and solidifying it, and a second solid-liquid separation step of recovering the solid content containing the calcium carbonate. ..
In the above carbonation step, an alkali carbonate is used as a carbonic acid source and an alkali is introduced together with the carbonic acid source, or a carbon dioxide-containing gas is used as a carbonic acid source and an alkali is added to adjust the pH to 7.0 to 12.0. The method for desalting chlorine-containing ash and recovering Ca according to claim 1, wherein carbonic acid is produced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020175049A JP2022066111A (en) | 2020-10-17 | 2020-10-17 | DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020175049A JP2022066111A (en) | 2020-10-17 | 2020-10-17 | DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2022066111A true JP2022066111A (en) | 2022-04-28 |
Family
ID=81387565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2020175049A Pending JP2022066111A (en) | 2020-10-17 | 2020-10-17 | DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2022066111A (en) |
-
2020
- 2020-10-17 JP JP2020175049A patent/JP2022066111A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6252653B1 (en) | Method and system for treating chlorine-containing ash | |
| CN101309761A (en) | Method of and apparatus for treating chlorine-containing waste | |
| CN109534466B (en) | Method for preparing water purifying agent containing polymerized aluminum chloride from aluminum ash | |
| JP2006272168A (en) | Chlorine and heavy metal containing waste treatment method | |
| CN110304646A (en) | A method of fluorine, chlorine, nitrogen component coproduction aluminium oxide concentrate are efficiently separated from aluminium ash | |
| JP4174708B2 (en) | Method for recovering and purifying calcium fluoride from a by-product mixed salt containing fluorine | |
| JP5359197B2 (en) | Waste chromium removal method and chromium removal apparatus | |
| CA2400854C (en) | Method for utilising steelworks dust | |
| JP2022066111A (en) | DESALINATION OF CHLORINE-CONTAINING ASH AND Ca RECOVERING METHOD | |
| JP4253203B2 (en) | How to remove fluorine from gypsum | |
| CN218798139U (en) | Waste incineration fly ash and waste sulfuric acid co-processing and utilizing equipment | |
| JP4536257B2 (en) | Method for producing sodium chloride aqueous solution | |
| JP2003292350A (en) | Method for treating cement kiln extracted gas | |
| JP2022057081A (en) | Method for desalinating chlorine-containing ash and recovering calcium | |
| JP2003334510A (en) | Chlorine removing treatment method for molten fly ash | |
| KR950013314B1 (en) | Retreatment method for sludge containing fluorine | |
| JP3717869B2 (en) | Waste stabilization treatment method and waste stabilization treatment product | |
| JP2022057080A (en) | Method for recovering desalinated washed ash of chlorine-containing ash | |
| JP4525014B2 (en) | By-product salt purification method, by-product salt and snow melting agent | |
| JP2000167529A (en) | Separation of water soluble component from exhaust gas dust or incineration ash | |
| JP2023056767A (en) | METHOD FOR DESALTING CHLORINE-CONTAINING ASH AND RECOVERING Ca | |
| JPH01284381A (en) | Treatment of fly ash | |
| JP2005230655A (en) | Dust treatment method | |
| JP2008169424A (en) | Method for treating substance containing heavy metals including zinc | |
| JP4118495B2 (en) | How to reuse mud |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20230629 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20240415 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20240430 |