JP5466749B2 - Vanadium oxide production wastewater treatment method - Google Patents
Vanadium oxide production wastewater treatment method Download PDFInfo
- Publication number
- JP5466749B2 JP5466749B2 JP2012242387A JP2012242387A JP5466749B2 JP 5466749 B2 JP5466749 B2 JP 5466749B2 JP 2012242387 A JP2012242387 A JP 2012242387A JP 2012242387 A JP2012242387 A JP 2012242387A JP 5466749 B2 JP5466749 B2 JP 5466749B2
- Authority
- JP
- Japan
- Prior art keywords
- ammonium
- temperature
- solution
- wastewater
- salt
- 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.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 title claims description 6
- 229910001935 vanadium oxide Inorganic materials 0.000 title claims description 6
- 238000004065 wastewater treatment Methods 0.000 title claims description 4
- 239000002351 wastewater Substances 0.000 claims description 78
- 238000000034 method Methods 0.000 claims description 69
- 239000007788 liquid Substances 0.000 claims description 46
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 43
- 239000013078 crystal Substances 0.000 claims description 41
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 40
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 40
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 40
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 38
- 238000002425 crystallisation Methods 0.000 claims description 33
- 230000008025 crystallization Effects 0.000 claims description 33
- 159000000000 sodium salts Chemical class 0.000 claims description 26
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 24
- 235000011152 sodium sulphate Nutrition 0.000 claims description 24
- 235000019270 ammonium chloride Nutrition 0.000 claims description 19
- 150000003839 salts Chemical class 0.000 claims description 19
- 239000002002 slurry Substances 0.000 claims description 19
- 150000003863 ammonium salts Chemical class 0.000 claims description 18
- 239000011734 sodium Substances 0.000 claims description 14
- 238000000926 separation method Methods 0.000 claims description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 7
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 5
- 238000003672 processing method Methods 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 239000000243 solution Substances 0.000 description 33
- 235000002639 sodium chloride Nutrition 0.000 description 26
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 21
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 18
- 238000001704 evaporation Methods 0.000 description 18
- 239000011651 chromium Substances 0.000 description 16
- 230000008020 evaporation Effects 0.000 description 16
- 229910052720 vanadium Inorganic materials 0.000 description 15
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 12
- 229910021529 ammonia Inorganic materials 0.000 description 11
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 229910052804 chromium Inorganic materials 0.000 description 9
- 239000002893 slag Substances 0.000 description 9
- 239000011780 sodium chloride Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- 238000011084 recovery Methods 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 238000000967 suction filtration Methods 0.000 description 8
- 230000002378 acidificating effect Effects 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 4
- -1 ammonium ions Chemical class 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- LSGOVYNHVSXFFJ-UHFFFAOYSA-N vanadate(3-) Chemical compound [O-][V]([O-])([O-])=O LSGOVYNHVSXFFJ-UHFFFAOYSA-N 0.000 description 4
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 3
- CMZUMMUJMWNLFH-UHFFFAOYSA-N sodium metavanadate Chemical compound [Na+].[O-][V](=O)=O CMZUMMUJMWNLFH-UHFFFAOYSA-N 0.000 description 3
- 229910000166 zirconium phosphate Inorganic materials 0.000 description 3
- PQUCIEFHOVEZAU-UHFFFAOYSA-N Diammonium sulfite Chemical compound [NH4+].[NH4+].[O-]S([O-])=O PQUCIEFHOVEZAU-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 229910004283 SiO 4 Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 1
- 239000003830 anthracite Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229940043430 calcium compound Drugs 0.000 description 1
- 150000001674 calcium compounds Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
- 230000004087 circulation Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 229940077449 dichromate ion Drugs 0.000 description 1
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 235000010265 sodium sulphite Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- WQEVDHBJGNOKKO-UHFFFAOYSA-K vanadic acid Chemical compound O[V](O)(O)=O WQEVDHBJGNOKKO-UHFFFAOYSA-K 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Description
本発明は廃水の処理方法に関し、特に酸化バナジウムの生産工程で発生した廃水の処理方法に関する。 The present invention relates to a method for treating wastewater, and more particularly to a method for treating wastewater generated in a production process of vanadium oxide.
現在、世界上で酸化バナジウムの生産工程は主に二つがあり、原料は含バナジウム鉱物から得られたバナジウム鉱滓、含バナジウム無煙炭、廃触媒、石油燃焼残渣等を含む。一つの工程は、原料をカルシウム化合物と共に焙焼し、酸を用いて可溶性バナジウム酸塩を浸出させ、浸出液から加水分解を通じてバナジウム酸塩を析出させる工程である（石灰法と略称する）。もう一つの工程は、原料をナトリウム塩と共に焙焼し、可溶性バナジン酸ナトリウムを浸出させ、アンモニウム塩を投入した酸性の浸出液からバナジン酸アンモニウムを析出させる工程であり（ナトリウム塩法と略称する）、当該工程で生産したバナジウム製品は品質が高く、生産が安定している。 Currently, there are mainly two production processes of vanadium oxide in the world, and raw materials include vanadium slag obtained from vanadium-containing minerals, vanadium-containing anthracite, waste catalyst, petroleum combustion residue, and the like. One step is a step in which the raw material is roasted together with a calcium compound, soluble vanadate is leached using an acid, and vanadate is precipitated from the leachate through hydrolysis (abbreviated as lime method). Another step is a step of roasting the raw material with sodium salt, leaching soluble sodium vanadate, and precipitating ammonium vanadate from an acidic leachate charged with ammonium salt (abbreviated as sodium salt method), The vanadium product produced in this process has high quality and stable production.
ナトリウム塩法で発生した廃水は、アンモニア性窒素の含有量、Ｖ(V)の含有量、又はＶ(V)及びＣｒ(VI)の含有量が高い酸性無機廃水であり、同時に高い濃度の硫酸塩及び塩化物、並びに少量の異物を含む。当該廃水を排出基準に満たすように経済的に処理することは、今までの廃水処理分野おける世界的な問題の一つである。現在、当該廃水を処理するため、様々な方法が提案されている。 Wastewater generated by the sodium salt method is acidic inorganic wastewater with a high content of ammonia nitrogen, V (V) , or V (V) and Cr (VI) , and at the same time a high concentration of sulfuric acid. Contains salt and chloride, and a small amount of foreign matter. It is one of the global problems in the wastewater treatment field so far to treat the wastewater economically so as to meet the emission standards. Currently, various methods have been proposed for treating the wastewater.
一つの方法は、廃水からバナジウム及びクロムを除去し、続いて苛性化（ｐＨが１１〜１２）して脱アンモニア処理を行い、脱アンモニア処理を行った後に、硫酸でｐＨ値を７〜８に調整し、その後、多重効用蒸発して濃縮且つ結晶させ、無水硫酸ナトリウムと塩化ナトリウムとの混合塩を得ることができ、一方、脱アンモニア過程の含アンモニアオフガスは硫酸に吸収されて、硫酸アンモニウム溶液又は結晶体を製造し、硫酸アンモニウム結晶体はバナジウム酸塩を析出するエージェント（薬剤）として再利用し、凝縮水は生産水として再利用する。当該方法は、処理が徹底的であるが、プロセスフローが長く、投資が多く、エネルギー消費が高いため、多くの企業は高い投資及び運転コストを負担することが難しいので、常にバナジウム及びクロムを除去した後、希釈して排出する。 One method is to remove vanadium and chromium from wastewater, then causticize (pH is 11 to 12), deamminate treatment, and after deammonia treatment, the pH value is adjusted to 7 to 8 with sulfuric acid. And then concentrated and crystallized by multi-effect evaporation to obtain a mixed salt of anhydrous sodium sulfate and sodium chloride, while the ammonia-containing off-gas in the deammonification process is absorbed into the sulfuric acid, and the ammonium sulfate solution or A crystal is produced, the ammonium sulfate crystal is reused as an agent (drug) for depositing vanadate, and the condensed water is reused as production water. Although the method is thorough in processing, the long process flow, high investment, and high energy consumption make it difficult for many companies to bear high investment and operating costs, so always remove vanadium and chromium. Then dilute and discharge.
もう一つの方法は、特許文献１に開示されるように、廃水からバナジウム及びクロムを除去した後、８０℃以上に加熱して多重効用蒸発し、蒸発濃縮されたスラリーを５０℃〜７０℃の温度で結晶化させ、硫酸ナトリウムと硫酸アンモニウムとの混合結晶体及び凝縮水のみを回収する。当該方法は工程が比較的に簡単であるが、廃水中のナトリウム塩及びアンモニウム塩を効果的に回収且つ利用することができない。アンモニウム塩は、異物の形態で硫酸ナトリウム結晶体及び凝縮水中に入れるため、硫酸ナトリウム製品のアンモニウム塩含有量が高くなり（６％〜２０％）、有効的利用することができない。蒸発濃縮過程で溶液のｐＨ値を８．０〜８．５に制御したので、凝縮水のアンモニア性窒素含有量が高く（アンモニア４００ｍｇ／Ｌ〜１，２００ｍｇ／Ｌ）、再利用過程中にアンモニアの排出で環境を汚染する。 In another method, as disclosed in Patent Document 1, after removing vanadium and chromium from wastewater, the mixture is heated to 80 ° C. or more to effect multi-effect evaporation, and the evaporated and concentrated slurry is heated to 50 ° C. to 70 ° C. Crystallize at temperature and collect only mixed crystals of sodium sulfate and ammonium sulfate and condensed water. Although the process is relatively simple, it cannot effectively recover and utilize sodium and ammonium salts in wastewater. Since the ammonium salt is put in the sodium sulfate crystal and condensed water in the form of foreign matter, the ammonium salt content of the sodium sulfate product becomes high (6% to 20%) and cannot be effectively used. Since the pH value of the solution was controlled to 8.0 to 8.5 during the evaporation and concentration process, the ammonia nitrogen content of the condensed water was high (ammonia 400 mg / L to 1,200 mg / L), and ammonia was used during the recycling process. Pollutes the environment.
また一つの方法は、特許文献２及び特許文献３に開示されるように、廃水を蒸発濃縮して得られた結晶物を焙焼し、焙焼を通じて結晶物中の硫酸アンモニウムをＮＨ3、Ｎ2及びＳＯ2に分解し、ＮＨ3、Ｎ2及びＳＯ2をガスの形態で排出して無水硫酸ナトリウムを得る。焙焼ガスに対して脱硫処理を通じて亜硫酸アンモニウムを得ることができ、亜硫酸アンモニウムを酸化し、蒸発結晶させて硫酸アンモニウム結晶体を得ることができる。該方法は長いプロセスフローを有し、高い投資及び高い運転コストを必要とする。
In addition, as disclosed in
更に一つの方法は、エアーストリッピング方法（air stripping method）であり、廃水を不連続相として空気と接触させ、廃水中組成の実際濃度と平衡濃度との差を利用し、アンモニア性窒素を気相に転移させて除去する方法である。廃水中のアンモニア性窒素は、通常、アンモニウムイオン（ＮＨ4 +）及び遊離アンモニアの状態でバランスを維持して存在し（ＮＨ4 +＋ＯＨ-＝ＮＨ3＋Ｈ2Ｏ）、廃水ｐＨ値をアルカリ性に調整した後、気体と溶液との接触を通じて廃水中の遊離アンモニアを空気中に吹き飛ばせる。該方法は、空気を連続して吹き込み、アルカリでｐＨ値を調整しなければならないので、処理コストが高い。 One more method is the air stripping method, in which wastewater is brought into contact with air as a discontinuous phase and the difference between the actual concentration and the equilibrium concentration of the wastewater composition is utilized to remove ammonia nitrogen. It is a method of removing by transferring to a phase. Ammonia nitrogen in wastewater usually exists in a balanced state in the state of ammonium ions (NH 4 + ) and free ammonia (NH 4 + + OH − = NH 3 + H 2 O), making the wastewater pH value alkaline. After adjustment, free ammonia in the wastewater can be blown into the air through contact between the gas and the solution. In this method, since air must be continuously blown and the pH value must be adjusted with an alkali, the processing cost is high.
本発明の目的は、上記の問題中の少なくとも一つを解決できる、原料をナトリウム塩と共に焙焼し、可溶性バナジン酸ナトリウムを浸出させ、アンモニウム塩を投入した酸性の浸出液からバナジン酸アンモニウムを析出させる工程で発生した廃水の処理方法を提供することである。 The object of the present invention is to solve at least one of the above-mentioned problems. The raw material is roasted together with sodium salt, soluble sodium vanadate is leached, and ammonium vanadate is precipitated from an acidic leachate containing ammonium salt. It is to provide a method for treating wastewater generated in a process.
本発明による廃水の処理方法は、酸化バナジウム生産のナトリウム塩法で発生した廃水の処理方法において、順番に実行する下記の段階：ａ）ｐＨ値が５．０〜６．５である廃水を９０℃以上の温度で濃縮且つ結晶化させて第１結晶スラリーを得た後、９０℃以上の温度で固液分離を行って無水硫酸ナトリウム結晶及び第１溶液を得る段階と、ｂ）第１溶液を９℃〜２０℃の温度で結晶化させた後、固液分離を行って、硫酸ナトリウムと硫酸アンモニウムとの複塩及び第２溶液を得る段階と、ｃ）第２溶液を７０℃以上の温度で蒸発濃縮させ、６０℃〜６５℃の温度で結晶化させて第２結晶スラリーを得た後、５５℃以上の温度で第２結晶スラリーに対して固液分離を行って、硫酸アンモニウムと塩化アンモニウムとの混合アンモニウム塩及び第３溶液を得る段階とを含む廃水の処理方法である。 The wastewater treatment method according to the present invention is a treatment method of wastewater generated by the sodium salt method for producing vanadium oxide. The following steps are carried out in order: a) wastewater having a pH value of 5.0 to 6.5 is 90 A step of concentrating and crystallizing at a temperature of not less than 0 ° C. to obtain a first crystal slurry, followed by solid-liquid separation at a temperature of not less than 90 ° C. to obtain anhydrous sodium sulfate crystals and a first solution; b) the first solution Is crystallized at a temperature of 9 ° C to 20 ° C, followed by solid-liquid separation to obtain a double salt of sodium sulfate and ammonium sulfate and a second solution, and c) the second solution is heated to a temperature of 70 ° C or higher. The second crystal slurry was obtained by evaporating and concentrating at a temperature of 60 ° C. to 65 ° C., followed by solid-liquid separation of the second crystal slurry at a temperature of 55 ° C. or higher, and ammonium sulfate and ammonium chloride. Mixed ammonium salt with It is a method of treating waste water comprising the steps of obtaining a third solution.
段階ａ）において、濃縮且つ結晶化する前の廃水体積と第１結晶スラリーの体積との比率は１０：１を超えないことができ、結晶化時間は少なくとも４０分であることができる。 In step a), the ratio of the volume of waste water before concentration and crystallization to the volume of the first crystal slurry can not exceed 10: 1 and the crystallization time can be at least 40 minutes.
段階ｂ）において、９℃〜１４℃の温度で第１溶液を少なくとも３時間結晶化させることができる。 In step b), the first solution can be crystallized for at least 3 hours at a temperature between 9 ° C and 14 ° C.
前記方法は、硫酸ナトリウムと硫酸アンモニウムとの複塩を段階ａ）で使用される廃水に入れる段階を更に含むことができる。 The method may further comprise the step of placing a double salt of sodium sulfate and ammonium sulfate into the wastewater used in step a).
段階ｃ）において、第２溶液と第２結晶スラリーとの体積比率は２〜２．５：１であり、結晶化時間は少なくとも２時間であることができる。 In step c), the volume ratio of the second solution to the second crystal slurry can be 2 to 2.5: 1 and the crystallization time can be at least 2 hours.
前記方法は、第３溶液を段階ｂ）に使用される第１溶液に入れる段階を更に含むことができる。 The method can further comprise placing the third solution into the first solution used in step b).
前記廃水は、１５，０００〜２４，０００ｍｇ／ＬのＮａ+、６，０００〜１０，０００ｍｇ／ＬのＮＨ4 +、５０，０００〜８０，０００ｍｇ／ＬのＳＯ4 2-及び５００〜３，５００ｍｇ／ＬのＣｌ-を含むことができる。 The waste water is composed of 15,000 to 24,000 mg / L Na + , 6,000 to 10,000 mg / L NH 4 + , 50,000 to 80,000 mg / L SO 4 2- and 500 to 3, It can contain 500 mg / L Cl − .
前記廃水は、４０〜３００ｍｇ／ＬのＶ5+、４０〜８００ｍｇ／ＬのＣｒ6+、５０〜２２０ｍｇ／ＬのＣａ2+、２００〜４００ｍｇ／ＬのＳｉＯ2及び２〜５ｍｇ／Ｌの全鉄（total Fe）を更に含むことができる。 The waste water comprises 40-300 mg / L V 5+ , 40-800 mg / L Cr 6+ , 50-220 mg / L Ca 2+ , 200-400 mg / L SiO 2 and 2-5 mg / L total. It may further contain iron (total Fe).
本発明によれば、上記の問題中の少なくとも一つを解決できる、原料をナトリウム塩と共に焙焼し、可溶性バナジン酸ナトリウムを浸出させ、アンモニウム塩を投入した酸性の浸出液からバナジン酸アンモニウムを析出させる工程で発生した廃水の処理方法を提供することができる。 According to the present invention, at least one of the above problems can be solved. The raw material is roasted with sodium salt, soluble sodium vanadate is leached, and ammonium vanadate is precipitated from an acidic leachate charged with ammonium salt. A method for treating waste water generated in the process can be provided.
以下、図面を参照しながら本発明によるナトリウム塩法で発生した廃水の処理方法を詳細に説明する。
一実施形態において、処理対象となるナトリウム塩法からの廃水には、１５，０００〜２４，０００ｍｇ／ＬのＮａ+、６，０００〜１０，０００ｍｇ／ＬのＮＨ4 +、５０，０００〜８０，０００ｍｇ／ＬのＳＯ4 2-及び５００〜３，５００ｍｇ／ＬのＣｌ-が含まれることができる。他の一実施形態において、処理対象となるナトリウム塩法からの廃水には、４０〜３００ｍｇ／ＬのＶ5+、４０〜８００ｍｇ／ＬのＣｒ6+、５０〜２２０ｍｇ／ＬのＣａ2+、２００〜４００ｍｇ／ＬのＳｉＯ2及び２〜５ｍｇ／ＬのＴＦｅ（全鉄）がさらに含まれることができる。ナトリウム塩法からの廃水中で、Ｃｒ6+はクロム酸イオンＣｒＯ4 2-及び／又は重クロム酸イオンＣｒ2Ｏ7 2-の形態で存在することができ、Ｖ5+は主にバナジン酸イオン（例えばＶＯ3 -）の形態で存在することができ、ＳｉＯ2の含有量はケイ酸イオン（例えば、ＳｉＯ4 4-、ＳｉＯ3 2-）の形態で存在するケイ素元素をＳｉＯ2に換算した含有量を指すことができる。ナトリウム塩法で発生した廃水のｐＨ値が２〜３である場合、ケイ素元素は主にケイ酸コロイドの形態で存在する。しかし、ナトリウム塩法からの廃水の成分及び含有量はこれに限定されるものではない。
Hereinafter, a method for treating wastewater generated by the sodium salt method according to the present invention will be described in detail with reference to the drawings.
In one embodiment, the wastewater from the sodium salt process to be treated includes 15,000 to 24,000 mg / L Na + , 6,000 to 10,000 mg / L NH 4 + , 50,000 to 80 , Cl of SO 4 2-and 500~3,500mg / L of 000mg / L - can be included. In another embodiment, the wastewater from the sodium salt process to be treated includes 40-300 mg / L V 5+ , 40-800 mg / L Cr 6+ , 50-220 mg / L Ca 2+ , 200 to 400 mg / L SiO 2 and 2 to 5 mg / L TFe (total iron) may further be included. In the wastewater from the sodium salt process, Cr 6+ can be present in the form of chromate ion CrO 4 2− and / or dichromate ion Cr 2 O 7 2− , V 5+ being mainly vanadic acid. ion (e.g., VO 3 -) of the can be present in the form, the content of SiO 2 is silicate ion (e.g., SiO 4 4-, SiO 3 2- ) in terms of silicon element present in the form of the SiO 2 Content. When the pH value of wastewater generated by the sodium salt method is 2 to 3, elemental silicon exists mainly in the form of colloidal silicate. However, the components and content of waste water from the sodium salt method are not limited to this.
図１は、硫酸ナトリウム、硫酸アンモニウム、塩化ナトリウム及び塩化アンモニウムの水における溶解度が温度によって変化するグラフを示す図である。図１を参照すると、硫酸ナトリウムの水における溶解度は、０℃の約５ｇから徐々に約３７℃の約５０ｇまで増加し、その後約３７℃からは徐々に１００℃の約４３ｇまで減少している。硫酸アンモニウムの水における溶解度は、０℃の約７０ｇから徐々に１００℃の約１０３ｇまで増加している。塩化ナトリウムの水における溶解度は、０℃の約３５ｇから１００℃の約４０ｇまで徐々に増加している。塩化アンモニウムの水における溶解度は、０℃の約２９ｇから１００℃の約７７ｇまで徐々に増加している。ナトリウム塩法からの廃水には大量のＮａ+、ＮＨ4 +、ＳＯ4 2-が存在し、且つ高温条件で硫酸ナトリウムの溶解度が同一温度条件における硫酸アンモニウムの溶解度よりも大きく低いので、高温条件でナトリウム塩法からの廃水に対して濃縮することで、硫酸ナトリウムを結晶化させ、硫酸アンモニウムが依然として廃水中に溶解されるようにすることができる。 FIG. 1 is a graph showing the solubility of sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride in water varying with temperature. Referring to FIG. 1, the solubility of sodium sulfate in water gradually increases from about 5 g at 0 ° C. to about 50 g at about 37 ° C., and then gradually decreases from about 37 ° C. to about 43 g at 100 ° C. . The solubility of ammonium sulfate in water gradually increases from about 70 g at 0 ° C. to about 103 g at 100 ° C. The solubility of sodium chloride in water gradually increases from about 35 g at 0 ° C. to about 40 g at 100 ° C. The solubility of ammonium chloride in water gradually increases from about 29 g at 0 ° C. to about 77 g at 100 ° C. The waste water from the sodium salt method contains a large amount of Na + , NH 4 + , SO 4 2− , and the solubility of sodium sulfate is much lower than that of ammonium sulfate at the same temperature condition at high temperature conditions. By concentrating on the wastewater from the sodium salt process, the sodium sulfate can be crystallized and the ammonium sulfate can still be dissolved in the wastewater.
図２は、本発明によるナトリウム塩法で発生した廃水の処理方法のフローチャートである。図２を参照すると、本発明によるナトリウム塩法で発生した廃水の処理方法の一実施形態において、無機酸（例えば硫酸、塩酸）又は無機アルカリ（例えばＮａＯＨ）を使用して、廃水のｐＨ値を５．０〜６．５に調整し得る。但し、廃水のｐＨ値範囲が５．０〜６．５であれば、ｐＨ値を調整する必要はない。廃水のｐＨ値が５．０より小さいと、後続の濃縮過程中に廃水が設備に対する腐食を増加させ、設備材質に関する要求も高くなる。また、廃水のｐＨ値が５．０より小さいと、酸性度が高すぎ、溶液粘度が高くなって蒸発効率が低下する。廃水のｐＨ値が６．５より大きいと、後続の蒸発濃縮過程中にアンモニアの逸出速度が速く、アンモニアの損失が大きく、その他、凝縮水にてアンモニアの含有量が高く、凝縮水の使用に影響を与える。 FIG. 2 is a flowchart of a method for treating wastewater generated by the sodium salt method according to the present invention. Referring to FIG. 2, in one embodiment of a method for treating wastewater generated by the sodium salt method according to the present invention, an inorganic acid (eg, sulfuric acid, hydrochloric acid) or an inorganic alkali (eg, NaOH) is used to adjust the pH value of the wastewater. It can be adjusted to 5.0 to 6.5. However, if the pH value range of the wastewater is 5.0 to 6.5, it is not necessary to adjust the pH value. If the pH value of the waste water is less than 5.0, the waste water increases the corrosion of the equipment during the subsequent concentration process, and the requirements for equipment materials are high. On the other hand, if the pH value of the wastewater is smaller than 5.0, the acidity is too high, the solution viscosity is increased, and the evaporation efficiency is lowered. If the pH value of the wastewater is greater than 6.5, the escape rate of ammonia is high during the subsequent evaporation and concentration process, the loss of ammonia is large, and the content of ammonia in the condensed water is high. To affect.
他の一実施形態において、廃水のｐＨ値を５．０〜６．５に調整する前に、廃水中のバナジウム及びクロムを除去してもよい。具体的な一実施形態において、硫酸第一鉄、亜硫酸ナトリウム、硫化ナトリウム等中の少なくとも一つの還元剤を使用し、廃水中の原子価が高いバナジウム及びクロムをＶ4+及びＣｒ3+に還元することができ、その後Ｃｒ(ＯＨ)3及びＶＯ(ＯＨ)2結晶体が析出するように廃水のｐＨ値を調整してから、固液分離を行って、廃水中のバナジウム及びクロムを除去することができる。しかし、本発明はこれに限定されるものではなく、即ち、廃水中のバナジウム及びクロムを除去しなくてもよい。 In another embodiment, vanadium and chromium in the wastewater may be removed before adjusting the pH value of the wastewater to 5.0-6.5. In a specific embodiment, at least one reducing agent in ferrous sulfate, sodium sulfite, sodium sulfide, etc. is used to reduce high valence vanadium and chromium in wastewater to V 4+ and Cr 3+ . After adjusting the pH value of the wastewater so that Cr (OH) 3 and VO (OH) 2 crystals are precipitated, solid-liquid separation is performed to remove vanadium and chromium in the wastewater. be able to. However, the present invention is not limited to this, that is, it is not necessary to remove vanadium and chromium in the wastewater.
続いて、９０℃以上の温度条件で廃水を濃縮且つ結晶化させ、その後９０℃以上の温度で固液分離を行って無水硫酸ナトリウム結晶体及び溶液を得る。ここで、前記溶液は一部の硫酸ナトリウムを除去してアンモニウムイオンを富ませた廃水を意味し、以下の文章で「アンモニウム豊富液」と呼ばれる。得られた無水硫酸ナトリウム結晶体に、異物として硫酸アンモニウム、塩化ナトリウム及び／又は塩化アンモニウムが存在することを許容し、例えば、３ｗｔ％以下の硫酸アンモニウム、０．６ｗｔ％以下の塩化ナトリウム及び／又は塩化アンモニウムが存在することを許容する。濃縮且つ結晶化の温度及び／又は固液分離温度が９０℃より低いと、硫酸アンモニウムの含有量が上昇する。 Subsequently, the wastewater is concentrated and crystallized under a temperature condition of 90 ° C. or higher, and then solid-liquid separation is performed at a temperature of 90 ° C. or higher to obtain an anhydrous sodium sulfate crystal and solution. Here, the solution means waste water from which a part of sodium sulfate is removed to enrich ammonium ions, and is referred to as “ammonium rich liquid” in the following text. The obtained anhydrous sodium sulfate crystal is allowed to contain ammonium sulfate, sodium chloride and / or ammonium chloride as foreign matters, for example, 3 wt% or less ammonium sulfate, 0.6 wt% or less sodium chloride and / or ammonium chloride. Is allowed to exist. When the concentration and crystallization temperature and / or the solid-liquid separation temperature is lower than 90 ° C., the content of ammonium sulfate increases.
一実施形態において、一つの蒸発器と一つの蒸発結晶器を使用して、廃水を濃縮且つ結晶化させることができる。一実施形態にて、濃縮比率（即ち、濃縮且つ結晶化以前の廃水体積と結晶化後の結晶スラリーとの体積の比率）は１０：３〜１０：１であり、結晶化時間は４０分以上である。濃縮比率が１０：３より低い場合、無水硫酸ナトリウム結晶体の収率が低すぎることがある。濃縮比率が１０：１より高い場合、硫酸アンモニウムが過度に析出され、例えば、無水硫酸ナトリウム結晶体における硫酸アンモニウム含有量が３ｗｔ％を超えることになる。結晶化時間が４０分より短い場合、硫酸ナトリウムの析出が不完全で、アンモニウム豊富液に多すぎる硫酸ナトリウムが残留され、且つ結晶粒子が細すぎ、固液分離が難しく、無水硫酸ナトリウムの純度に影響を与える。 In one embodiment, one evaporator and one evaporation crystallizer can be used to concentrate and crystallize the wastewater. In one embodiment, the concentration ratio (ie, the ratio of the volume of waste water before concentration and crystallization to the volume of crystal slurry after crystallization) is 10: 3 to 10: 1 and the crystallization time is 40 minutes or more. It is. If the concentration ratio is lower than 10: 3, the yield of anhydrous sodium sulfate crystals may be too low. When the concentration ratio is higher than 10: 1, ammonium sulfate is excessively precipitated. For example, the ammonium sulfate content in the anhydrous sodium sulfate crystal exceeds 3 wt%. When the crystallization time is shorter than 40 minutes, the precipitation of sodium sulfate is incomplete, too much sodium sulfate remains in the ammonium-rich liquid, and the crystal particles are too thin, making it difficult to separate solid and liquid, and the purity of anhydrous sodium sulfate is reduced. Influence.
ここで、得られた無水硫酸ナトリウム結晶体は、乾燥させることができる。 Here, the obtained anhydrous sodium sulfate crystal can be dried.
続いて、９℃〜２０℃の温度でアンモニウム豊富液を結晶化させ、その後、固液分離を行い、硫酸ナトリウムと硫酸アンモニウムとの複塩（例えば、Ｎａ2ＳＯ4(ＮＨ4)2ＳＯ4・４Ｈ2Ｏ）及び溶液を得ることができる。硫酸ナトリウムと硫酸アンモニウムとの複塩以外に、更に少量の塩化アンモニウム及び／又は塩化ナトリウムを得ることができ、例えば、５ｗｔ％以下の（５ｗｔ％を超えない）塩化アンモニウム及び／又は塩化ナトリウムを得ることができる。当該段階によって、アンモニウム豊富液におけるＮａ+含有量を更に減少させ、即ち当該段階で得られた溶液のＮａ+含有量は、アンモニウム豊富液のＮａ+含有量より少ない。したがって、当該段階で得られた溶液は、精製液と呼ばれることができ、該精製液を使用することでＮａ+含有量が十分に低い硫酸アンモニウムを得ることができる。一実施形態において、９℃〜２０℃の温度条件で、アンモニウム豊富液を３時間以上結晶化させて、硫酸ナトリウムと硫酸アンモニウムとの複塩、少量の塩化アンモニウム及び／又は塩化ナトリウム(例えば、５ｗｔ％以下の塩化アンモニウム）及び精製液を得ることができる。 Subsequently, the ammonium-rich liquid is crystallized at a temperature of 9 ° C. to 20 ° C., followed by solid-liquid separation, and a double salt of sodium sulfate and ammonium sulfate (for example, Na 2 SO 4 (NH 4 ) 2 SO 4. 4H 2 O) and solutions can be obtained. In addition to the double salt of sodium sulfate and ammonium sulfate, a smaller amount of ammonium chloride and / or sodium chloride can be obtained, for example, 5 wt% or less (not exceeding 5 wt%) of ammonium chloride and / or sodium chloride. Can do. This stage further reduces the Na + content in the ammonium rich liquid, ie the Na + content of the solution obtained in this stage is less than the Na + content of the ammonium rich liquid. Therefore, the solution obtained at this stage can be referred to as a purified solution, and ammonium sulfate having a sufficiently low Na + content can be obtained by using the purified solution. In one embodiment, the ammonium rich liquid is crystallized for 3 hours or more at a temperature of 9 ° C. to 20 ° C. to form a double salt of sodium sulfate and ammonium sulfate, a small amount of ammonium chloride and / or sodium chloride (eg, 5 wt% The following ammonium chloride) and purified solution can be obtained.
上記段階で得られた複塩は、初期廃水に再利用して、産物の収率を高めることができる。 The double salt obtained in the above step can be reused in the initial wastewater to increase the yield of the product.
上記段階において、結晶化温度が９℃より低い場合、塩化アンモニウムが急速に析出することによって、塩化アンモニウムの含有量が、例えば５ｗｔ％以上まで増加し、初期廃水に再利用する場合、システムの腐食が増加し、循環回数の増加に伴って、無水硫酸ナトリウム蒸発結晶体系の安定に影響を与える虞がある。結晶化温度が２０℃を超える場合、結晶化時間を６時間まで延長しても、精製液においてＮａ+含有量は３４ｇ／Ｌより高い可能性があり、ナトリウムを除去して精製する要求を満たさない。９℃〜１４℃の温度にて、アンモニウム豊富液を結晶化させることが望ましい。 In the above stage, when the crystallization temperature is lower than 9 ° C., ammonium chloride is rapidly precipitated, so that the content of ammonium chloride is increased to, for example, 5 wt% or more, and when it is reused for initial wastewater, As the number of circulations increases, the stability of the anhydrous sodium sulfate evaporation crystal system may be affected. When the crystallization temperature exceeds 20 ° C., even if the crystallization time is extended to 6 hours, the Na + content in the purified solution may be higher than 34 g / L, which satisfies the requirement for purification by removing sodium. Absent. It is desirable to crystallize the ammonium rich liquid at a temperature between 9 ° C and 14 ° C.
そして、７０℃以上の温度で精製液を蒸発濃縮し、６０℃〜６５℃の温度で結晶化させて結晶スラリーを得ることができ、その後、５５℃以上の条件で結晶スラリーの固液分離を行って、混合アンモニウム塩及び溶液を得ることができる。当該段階にて得られた溶液は、アンダーフロー液と呼ばれ、その組成がアンモニウム豊富液と類似するため、アンモニウム豊富液に再利用することができる。混合アンモニウム塩は、硫酸アンモニウム及び塩化アンモニウムを含み、硫酸アンモニウムと塩化アンモニウムとの合計は９２％以上まで達する。混合アンモニウム塩に含まれた硫酸アンモニウム及び塩化アンモニウムにおいて、硫酸アンモニウムが多半数で、塩化アンモニウムの重量割合は６％以下である。混合アンモニウム塩において、更に少量のＮａ+を含み、例えば２ｗｔ％以下のＮａ+を含むことができる。 The purified solution is evaporated and concentrated at a temperature of 70 ° C. or higher, and crystallized at a temperature of 60 ° C. to 65 ° C. to obtain a crystal slurry. Thereafter, solid-liquid separation of the crystal slurry is performed at 55 ° C. or higher. Can be performed to obtain mixed ammonium salts and solutions. The solution obtained at this stage is called an underflow liquid, and its composition is similar to that of an ammonium-rich liquid, so that it can be reused as an ammonium-rich liquid. The mixed ammonium salt includes ammonium sulfate and ammonium chloride, and the sum of ammonium sulfate and ammonium chloride reaches 92% or more. In the ammonium sulfate and ammonium chloride contained in the mixed ammonium salt, ammonium sulfate is majority, and the weight ratio of ammonium chloride is 6% or less. The mixed ammonium salt may further contain a small amount of Na + , for example, 2 wt% or less of Na + .
７０℃以上の温度で精製液を蒸発濃縮し、６０℃〜６５℃の温度で結晶化を行う場合、硫酸アンモニウムと塩化アンモニウムとの混合アンモニウム塩の純度（又は組成）と粒度の要求を満たすが、温度が低すぎる場合、複塩が産生する。５５℃より低い温度で固液分離を行う場合、混合アンモニウム塩における硫酸アンモニウムの純度が低すぎる。 When the purified solution is evaporated and concentrated at a temperature of 70 ° C. or higher and crystallization is performed at a temperature of 60 ° C. to 65 ° C., it satisfies the requirements for the purity (or composition) and particle size of the mixed ammonium salt of ammonium sulfate and ammonium chloride. If the temperature is too low, double salts are produced. When solid-liquid separation is performed at a temperature lower than 55 ° C., the purity of ammonium sulfate in the mixed ammonium salt is too low.
一実施形態において、濃縮比率（即ち、精製液と結晶化後の結晶スラリーの体積との比率）は２：１〜２．５：１であり、結晶化時間は２時間以上である。濃縮比率が２：１より低い場合、結晶量が少なく、収率が低くなる一方、濃縮比率が２．５：１より高い場合、硫酸ナトリウムの含有量が高くなる。 In one embodiment, the concentration ratio (i.e. the ratio between the purified solution and the volume of the crystal slurry after crystallization) is 2: 1 to 2.5: 1, and the crystallization time is 2 hours or more. When the concentration ratio is lower than 2: 1, the amount of crystals is small and the yield is low. On the other hand, when the concentration ratio is higher than 2.5: 1, the content of sodium sulfate is high.
本発明のナトリウム塩法で発生した廃水の処理方法において、蒸発濃縮して得られた蒸気を凝縮させることができ、得られた凝縮水のアンモニア含有量は低い。 In the method for treating wastewater generated by the sodium salt method of the present invention, the vapor obtained by evaporation and concentration can be condensed, and the ammonia content of the obtained condensed water is low.
従って、本発明によるナトリウム塩法で発生した廃水の処理方法は、以下の長所中のうちの少なくとも一つの長所を具備する。一番目は、製造した無水硫酸ナトリウム結晶体の品質が安定し、中国国家規格ＧＢ／Ｔ６００９−２００３三類一等品の標準より優れ、化学工業原料として直接販売することができる。二番目は、製造した混合アンモニウム塩がバナジウム酸塩析出用アンモニウム塩の要求を満たし、例えば、その中の硫酸アンモニウムと塩化アンモニウムとの合計が９２％になり、酸化バナジウム生産過程において、アンモニウム塩のリサイクルを実現することができる。三番目は、凝縮水中のアンモニア含有量を減少させ、例えば、その中のＮＨ4 +≦１５０ｍｇ／Ｌ、Ｃｌ-≦５０ｍｇ／Ｌであり、再利用過程中アンモニア逸出による二次的汚染を防ぐことができる。 Accordingly, the method for treating wastewater generated by the sodium salt method according to the present invention has at least one of the following advantages. First, the quality of the manufactured anhydrous sodium sulfate crystal is stable, which is superior to the standard of Chinese national standard GB / T6009-2003 Class III, etc., and can be directly sold as a chemical industry raw material. Secondly, the manufactured mixed ammonium salt satisfies the requirements for ammonium salt for vanadate precipitation. For example, the total amount of ammonium sulfate and ammonium chloride in the mixed ammonium salt becomes 92%, and in the process of producing vanadium oxide, ammonium salt is recycled. Can be realized. The third is to reduce the ammonia content in the condensed water, for example NH 4 + ≦ 150 mg / L, Cl − ≦ 50 mg / L, thereby preventing secondary contamination due to ammonia escape during the recycling process. be able to.
本発明により、バナジウムが抽出された廃水の処理コストを大幅に減少させ、ナトリウム塩法でバナジウムを抽出する工程の無公害生産を実現することができる。 According to the present invention, it is possible to significantly reduce the processing cost of wastewater from which vanadium has been extracted, and to realize pollution-free production in the process of extracting vanadium by the sodium salt method.
以下、具体的な実施例を参照しながら、本発明によるナトリウム塩法で発生した廃水の処理方法についてより詳細に説明する。
＜実施例１＞
１０００Ｌのバナジウム及びクロムが除去されたナトリウム塩法で発生した廃水（ｐＨ値８〜９．５）を取って濾過し、濃度が５０％である工業用硫酸でそのｐＨ値が５．６になるように調整し、試験装置にて１０Ｌ／ｈの処理速度で、本発明の処理方法によって処理を行った。
主な処理条件は次のとおりである。
Hereinafter, a method for treating wastewater generated by the sodium salt method according to the present invention will be described in more detail with reference to specific examples.
<Example 1>
Waste water (
The main processing conditions are as follows.
常圧にて、硫酸ナトリウム結晶体の蒸発且つ結晶化温度を１０３〜１０７℃、攪拌速度を３８０ｒｐｍ、濃縮比率を９．２：１、結晶化時間を１時間、保温下吸引濾過の温度を９２℃として、無水硫酸ナトリウム及びアンモニウム豊富液を得た。
アンモニウム豊富液を１３℃まで冷却し、恒温で自然的に４．５時間結晶化させた後、吸引濾過を行って複塩スラグ及び精製液を得た。複塩スラグを直接初期廃水格納装置に入れて溶解させた。
At normal pressure, the evaporation and crystallization temperature of the sodium sulfate crystal is 103-107 ° C., the stirring speed is 380 rpm, the concentration ratio is 9.2: 1, the crystallization time is 1 hour, and the temperature of suction filtration with heat retention is 92. An anhydrous sodium sulfate and ammonium rich liquid was obtained at a temperature of ° C.
The ammonium-rich liquid was cooled to 13 ° C. and crystallized naturally at a constant temperature for 4.5 hours, followed by suction filtration to obtain a double salt slag and a purified liquid. The double salt slag was directly dissolved in the initial waste water storage device.
常圧にて精製液を蒸発濃縮した。このとき、蒸発温度を１０６℃、濃縮比率を２．３：１とした。続いて６２℃温度で恒温結晶化させた。このとき、攪拌速度を５０ｒｐｍ、結晶化時間を２．５時間とした。６０℃の恒温条件で結晶スラリーを吸引濾過し、硫酸アンモニウム及びアンダーフロー液を得た。アンダーフロー液とアンモニウム豊富液とを混合してリサイクルした。
無水硫酸ナトリウム（温度１０５℃で４時間乾燥する）を約６０．５ｋｇ生産し、回収率は９６％近くになり、硫酸アンモニウムを２８．５ｋｇ回収し、回収率が９２％近くになった。
製品組成の分析結果を表１、表２、表３、表４にまとめる。
The purified solution was evaporated and concentrated at normal pressure. At this time, the evaporation temperature was 106 ° C., and the concentration ratio was 2.3: 1. Subsequently, constant temperature crystallization was performed at a temperature of 62 ° C. At this time, the stirring speed was 50 rpm, and the crystallization time was 2.5 hours. The crystal slurry was suction filtered under a constant temperature condition of 60 ° C. to obtain ammonium sulfate and an underflow liquid. The underflow liquid and ammonium rich liquid were mixed and recycled.
About 60.5 kg of anhydrous sodium sulfate (dried at 105 ° C. for 4 hours) was produced, the recovery rate was close to 96%, 28.5 kg of ammonium sulfate was recovered, and the recovery rate was close to 92%.
The analysis results of the product composition are summarized in Table 1, Table 2, Table 3, and Table 4.
＜実施例２＞
２０００Ｌのナトリウム塩法で発生した酸性廃水を取って濾過し、濃度が３０％である水酸化ナトリウム水溶液でそのｐＨ値が６．２になるように調整し、試験装置にて１５Ｌ／ｈの処理速度で、本発明の処理方法によって処理を行った。
主な処理条件は次のとおりである。
負圧にて、硫酸ナトリウム結晶体の蒸発且つ結晶化温度を９５〜１００℃、攪拌速度を３８０ｒｐｍ、濃縮比率を９．２：１、結晶化時間を１時間、保温下吸引濾過の温度を９３℃として、無水硫酸ナトリウム及びアンモニウム豊富液を得た。
アンモニウム豊富液を１１℃まで冷却し、恒温で自然的に４．５時間結晶化させた後、吸引濾過を行って複塩スラグ及び精製液を得た。複塩スラグを直接初期廃水格納装置に入れて溶解させた。
<Example 2>
Acidic wastewater generated by the 2000 L sodium salt method is taken and filtered, adjusted to a pH value of 6.2 with a 30% aqueous sodium hydroxide solution, and treated at 15 L / h with a test device. Processing was carried out at a speed by the processing method of the present invention.
The main processing conditions are as follows.
At a negative pressure, the evaporation and crystallization temperature of the sodium sulfate crystal is 95 to 100 ° C., the stirring speed is 380 rpm, the concentration ratio is 9.2: 1, the crystallization time is 1 hour, and the temperature of suction filtration with heat retention is 93. An anhydrous sodium sulfate and ammonium rich liquid was obtained at a temperature of ° C.
The ammonium-rich liquid was cooled to 11 ° C. and crystallized naturally at a constant temperature for 4.5 hours, followed by suction filtration to obtain a double salt slag and a purified liquid. The double salt slag was directly dissolved in the initial waste water storage device.
真空にて精製液を蒸発濃縮させた。このとき、蒸発温度を７０℃〜８０℃、濃縮比率を２．４：１とした。続いて６０℃温度で恒温結晶化させた。このとき、攪拌速度を５０ｒｐｍ、結晶化時間を２．５時間とした。６０℃の恒温条件で結晶スラリーを吸引濾過し、硫酸アンモニウム及びアンダーフロー液を得た。アンダーフロー液とアンモニウム豊富液とを混合してリサイクルした。
無水硫酸ナトリウム（温度１０５℃で４時間乾燥する）を約１４０ｋｇ生産し、回収率は９６％近くになり、硫酸アンモニウムを７２．８ｋｇ回収し、回収率が９３％近くになった。
製品組成の分析結果を表５、表６、表７、表８にまとめる。
The purified solution was evaporated and concentrated in vacuo. At this time, the evaporation temperature was 70 ° C. to 80 ° C., and the concentration ratio was 2.4: 1. Subsequently, constant temperature crystallization was performed at a temperature of 60 ° C. At this time, the stirring speed was 50 rpm, and the crystallization time was 2.5 hours. The crystal slurry was suction filtered under a constant temperature condition of 60 ° C. to obtain ammonium sulfate and an underflow liquid. The underflow liquid and ammonium rich liquid were mixed and recycled.
About 140 kg of anhydrous sodium sulfate (dried at 105 ° C. for 4 hours) was produced, and the recovery rate was close to 96%. 72.8 kg of ammonium sulfate was recovered, and the recovery rate was close to 93%.
The analysis results of the product composition are summarized in Table 5, Table 6, Table 7, and Table 8.
＜実施例３＞
１０００Ｌのバナジウム及びクロムが除去されたナトリウム塩法で発生した廃水（ｐＨ値は７．８〜９）を取って濾過し、濃度が４０％である工業用硫酸でそのｐＨ値が５．１になるように調整し、試験装置にて１０Ｌ／ｈの処理速度で、本発明の処理方法によって処理を行った。
主な処理条件は次のとおりである。
常圧にて、硫酸ナトリウム結晶体の蒸発且つ結晶化温度を９１〜９７℃、攪拌速度を３８０ｒｐｍ、濃縮比率を８．５：１、結晶化時間を５０分、保温下吸引濾過の温度を９０℃として、無水硫酸ナトリウム及びアンモニウム豊富液を得た。
アンモニウム豊富液を９℃まで冷却し、恒温で自然的に３時間結晶化させた後、吸引濾過を行って複塩スラグ及び精製液を得た。複塩スラグを直接初期廃水格納装置に入れて溶解させた。
<Example 3>
Waste water (pH value 7.8-9) generated by the sodium salt method from which 1000 L of vanadium and chromium were removed was filtered and the pH value was adjusted to 5.1 with industrial sulfuric acid having a concentration of 40%. It adjusted so that it might become, and it processed by the processing method of this invention with the processing speed of 10 L / h with the test device.
The main processing conditions are as follows.
At normal pressure, the evaporation and crystallization temperature of the sodium sulfate crystal is 91 to 97 ° C., the stirring speed is 380 rpm, the concentration ratio is 8.5: 1, the crystallization time is 50 minutes, and the temperature of suction filtration with heat retention is 90. An anhydrous sodium sulfate and ammonium rich liquid was obtained at a temperature of ° C.
The ammonium-rich liquid was cooled to 9 ° C. and crystallized naturally at a constant temperature for 3 hours, followed by suction filtration to obtain a double salt slag and a purified liquid. The double salt slag was directly dissolved in the initial waste water storage device.
常圧にて精製液を蒸発濃縮した。このとき、蒸発温度を８０℃、濃縮比率を２．０：１とした。続いて６５℃温度にて恒温結晶化させた。このとき、攪拌速度を５０ｒｐｍ、結晶化時間を３．５時間とした。５５℃の恒温条件で結晶スラリーを吸引濾過し、硫酸アンモニウム及びアンダーフロー液を得た。アンダーフロー液とアンモニウム豊富液とを混合してリサイクルした。
無水硫酸ナトリウム（温度１０５℃で４時間乾燥する）を約７０ｋｇ（９６％）生産し、回収率は９５％近くになり、硫酸アンモニウムを３５．７ｋｇ（９３％）回収し、回収率が９１％近くになった。
製品組成の分析結果を表９、表１０、表１１、表１２にまとめる。
The purified solution was evaporated and concentrated at normal pressure. At this time, the evaporation temperature was 80 ° C. and the concentration ratio was 2.0: 1. Subsequently, constant temperature crystallization was performed at a temperature of 65 ° C. At this time, the stirring speed was 50 rpm, and the crystallization time was 3.5 hours. The crystal slurry was suction filtered under a constant temperature condition of 55 ° C. to obtain ammonium sulfate and an underflow liquid. The underflow liquid and ammonium rich liquid were mixed and recycled.
Approximately 70 kg (96%) of anhydrous sodium sulfate (dried at 105 ° C. for 4 hours) is produced, the recovery rate is close to 95%, and 35.7 kg (93%) of ammonium sulfate is recovered, and the recovery rate is close to 91% Became.
The analysis results of the product composition are summarized in Table 9, Table 10, Table 11, and Table 12.
＜実施例４＞
２０００Ｌのナトリウム塩法で発生した酸性廃水を取って濾過し、濃度が３５％である水酸化ナトリウム水溶液でそのｐＨ値が６．５になるように調整し、試験装置にて１５Ｌ／ｈの処理速度で、本発明の処理方法によって処理を行った。
主な処理条件は次のとおりである。
負圧にて、硫酸ナトリウム結晶体の蒸発且つ結晶化温度を９３〜１００℃、攪拌速度を３８０ｒｐｍ、濃縮比率を７．５：１、結晶化時間を１．２５時間、保温下吸引濾過の温度を９５℃として、無水硫酸ナトリウム及びアンモニウム豊富液を得た。
アンモニウム豊富液を１８℃まで冷却し、恒温で自然的に６時間結晶化させた後、吸引濾過を行って複塩スラグ及び精製液を得た。複塩スラグを直接初期廃水格納装置に入れて溶解させた。
<Example 4>
2000 L of acidic waste water generated by the sodium salt method is taken and filtered, adjusted to a pH value of 6.5 with a sodium hydroxide aqueous solution having a concentration of 35%, and treated at 15 L / h with a test apparatus. Processing was carried out at a speed by the processing method of the present invention.
The main processing conditions are as follows.
Evaporation and crystallization temperature of sodium sulfate crystals at 93-100 ° C., stirring speed 380 rpm, concentration ratio 7.5: 1, crystallization time 1.25 hours, temperature of suction filtration under heat retention at negative pressure Was set to 95 ° C. to obtain a solution rich in anhydrous sodium sulfate and ammonium.
The ammonium-rich liquid was cooled to 18 ° C. and allowed to crystallize naturally at constant temperature for 6 hours, followed by suction filtration to obtain a double salt slag and a purified liquid. The double salt slag was directly dissolved in the initial waste water storage device.
真空にて精製液を蒸発濃縮させた。このとき、蒸発温度を７０℃〜７５℃、濃縮比率を２．５：１とした。続いて６３℃温度で恒温結晶化させた。このとき、攪拌速度を５０ｒｐｍ、結晶化時間を３時間とした。６５℃の恒温条件で結晶スラリーを吸引濾過し、硫酸アンモニウム及びアンダーフロー液を得た。アンダーフロー液とアンモニウム豊富液とを混合してリサイクルした。
無水硫酸ナトリウム（温度１０５℃で４時間乾燥する）を約１０４ｋｇ生産し、回収率は９６％近くになり、硫酸アンモニウムを５４ｋｇ回収し、回収率が９１％近くになった。
製品組成の分析結果を表１３、表１４、表１５、表１６にまとめる。
The purified solution was evaporated and concentrated in vacuo. At this time, the evaporation temperature was set to 70 to 75 ° C., and the concentration ratio was set to 2.5: 1. Subsequently, constant temperature crystallization was performed at a temperature of 63 ° C. At this time, the stirring speed was 50 rpm, and the crystallization time was 3 hours. The crystal slurry was suction filtered under a constant temperature condition of 65 ° C. to obtain ammonium sulfate and an underflow liquid. The underflow liquid and ammonium rich liquid were mixed and recycled.
About 104 kg of anhydrous sodium sulfate (dried at 105 ° C. for 4 hours) was produced, the recovery rate was close to 96%, 54 kg of ammonium sulfate was recovered, and the recovery rate was close to 91%.
The analysis results of the product composition are summarized in Table 13, Table 14, Table 15, and Table 16.
Claims (8)
ａ）ｐＨ値が５．０〜６．５である廃水を９０℃以上の温度で濃縮且つ結晶化させて第１結晶スラリーを得た後、９０℃以上の温度で固液分離を行って無水硫酸ナトリウム結晶及び第１溶液を得る段階と、
ｂ）第１溶液を９℃〜２０℃の温度で結晶化させた後、固液分離を行って、硫酸ナトリウムと硫酸アンモニウムとの複塩及び第２溶液を得る段階と、
ｃ）第２溶液を７０℃以上の温度で蒸発濃縮させ、６０℃〜６５℃の温度で結晶化させて第２結晶スラリーを得た後、５５℃以上の温度で第２結晶スラリーに対して固液分離を行って、硫酸アンモニウムと塩化アンモニウムとの混合アンモニウム塩及び第３溶液を得る段階と
を含む廃水の処理方法。 In the method of treating wastewater generated by the sodium salt method of vanadium oxide production, the following steps are carried out in sequence:
a) Waste water having a pH value of 5.0 to 6.5 is concentrated and crystallized at a temperature of 90 ° C. or higher to obtain a first crystal slurry, followed by solid-liquid separation at a temperature of 90 ° C. or higher and anhydrous Obtaining sodium sulfate crystals and a first solution;
b) Crystallizing the first solution at a temperature of 9 ° C. to 20 ° C., followed by solid-liquid separation to obtain a double salt of sodium sulfate and ammonium sulfate and a second solution;
c) The second solution is evaporated and concentrated at a temperature of 70 ° C. or higher, crystallized at a temperature of 60 ° C. to 65 ° C. to obtain a second crystal slurry, and then the second crystal slurry is heated at a temperature of 55 ° C. or higher. A method for treating wastewater, comprising solid-liquid separation to obtain a mixed ammonium salt of ammonium sulfate and ammonium chloride and a third solution.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110340963 CN102502900B (en) | 2011-11-02 | 2011-11-02 | Treatment method of sodium-roasted-leached-acid ammonium salt vanadium precipitation waste water |
| CN201110340963.2 | 2011-11-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2013094780A JP2013094780A (en) | 2013-05-20 |
| JP5466749B2 true JP5466749B2 (en) | 2014-04-09 |
Family
ID=46215051
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012242387A Active JP5466749B2 (en) | 2011-11-02 | 2012-11-02 | Vanadium oxide production wastewater treatment method |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP5466749B2 (en) |
| CN (1) | CN102502900B (en) |
| ZA (1) | ZA201208219B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104437042A (en) * | 2013-09-25 | 2015-03-25 | 攀钢集团攀枝花钢钒有限公司 | Treatment method of acid mist generated in acidic precipitation of vanadate-leaching solution |
| CN103979576A (en) * | 2014-05-21 | 2014-08-13 | 中国科学院生态环境研究中心 | Method for evaporating and crystallizing salt slag from ammonium sulfate-containing organic wastewater |
| CN104528855B (en) * | 2014-12-10 | 2017-01-25 | 攀钢集团攀枝花钢钒有限公司 | Evaporation concentration method of molybdenum precipitation wastewater |
| CN105384293B (en) * | 2015-11-16 | 2019-02-22 | 河钢股份有限公司承德分公司 | A kind of processing method of the vanadium wastewater after the deamination that cleans |
| CN107265737A (en) * | 2017-08-14 | 2017-10-20 | 东莞东元环境科技股份有限公司 | A kind of industrial high-salt wastewater evaporative crystallization Zero discharging system and method |
| JP6653736B2 (en) * | 2017-08-28 | 2020-02-26 | 中国石油化工股▲ふん▼有限公司 | Equipment for treating wastewater containing ammonium salts |
| JP6686210B1 (en) * | 2019-04-26 | 2020-04-22 | 株式会社神鋼環境ソリューション | Wastewater treatment method and wastewater treatment facility |
| CN110482740B (en) * | 2019-08-16 | 2023-09-01 | 联峰钢铁（张家港）有限公司 | Sewage acid treatment method |
| CN111547918A (en) * | 2020-04-15 | 2020-08-18 | 苏州乔发盐化工设备科技有限公司 | Recycling treatment method for sodium sulfate and ammonium sulfate wastewater |
| CN112429750A (en) * | 2020-11-19 | 2021-03-02 | 中国中轻国际工程有限公司 | Process for producing sodium sulfate and ammonium sulfate from vanadium extraction waste residues |
| CN112499650B (en) * | 2020-12-01 | 2022-09-16 | 郑州中科新兴产业技术研究院 | Method for separating ammonium sulfate and ammonium chloride |
| CN114644358A (en) * | 2022-03-21 | 2022-06-21 | 四川省银河化学股份有限公司 | Method for comprehensively utilizing ammonium salt-containing wastewater after vanadium extraction |
| CN115557558A (en) * | 2022-09-27 | 2023-01-03 | 上海晶宇环境工程股份有限公司 | Vanadium precipitation wastewater treatment method and system |
| CN115594361A (en) * | 2022-11-11 | 2023-01-13 | 攀钢集团攀枝花钢铁研究院有限公司（Cn） | Method for cooperatively treating coal gas desulfurization waste residue and sodium-modified vanadium precipitation wastewater |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2164220C1 (en) * | 1999-11-22 | 2001-03-20 | Васильев Виталий Иосифович | Method of treating vanadium-containing sulfate sewage |
| CN1127452C (en) * | 2000-08-02 | 2003-11-12 | 山东新华工贸股份有限公司 | Method and equipoment for treating inidustrial effluent containing ammonium sulfate |
| CN101092248A (en) * | 2006-06-22 | 2007-12-26 | 邓镇炎 | Technique for producing vanadium pentoxide |
| CN101161596B (en) * | 2007-05-14 | 2010-05-26 | 中国科学院过程工程研究所 | A method for resource processing non-ferro metals processing wastewater containing ammonia and sulfate radical |
| CN101092272A (en) * | 2007-08-06 | 2007-12-26 | 攀枝花新钢钒股份有限公司 | Method for treating wastewater from production of vanadium oxide |
| CN100569675C (en) * | 2008-04-17 | 2009-12-16 | 武汉科技大学 | A kind of treatment process of deposition vanadium mother liquid |
| CN101948211B (en) * | 2010-09-20 | 2012-04-04 | 攀钢集团钢铁钒钛股份有限公司 | Method for treating vanadium oxide production wastewater |
-
2011
- 2011-11-02 CN CN 201110340963 patent/CN102502900B/en active Active
-
2012
- 2012-11-01 ZA ZA2012/08219A patent/ZA201208219B/en unknown
- 2012-11-02 JP JP2012242387A patent/JP5466749B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN102502900A (en) | 2012-06-20 |
| NZ603075A (en) | 2012-12-21 |
| ZA201208219B (en) | 2013-07-31 |
| JP2013094780A (en) | 2013-05-20 |
| CN102502900B (en) | 2013-08-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5466749B2 (en) | Vanadium oxide production wastewater treatment method | |
| KR101973479B1 (en) | Manufacturing Method of High Purity Lithium Carbonate with Controlled Size, Size Distribution And Shape | |
| US8048314B2 (en) | Method for treating chlorine-containing waste | |
| CN108698827B (en) | Process for producing phosphorus products from wastewater | |
| CN103145187B (en) | Production technology of harmless high-purity vanadium pentoxide | |
| JP5800436B2 (en) | Boric acid recovery method and recovery apparatus | |
| RU2736539C1 (en) | Method of producing vanadium oxide of a battery grade | |
| CN108862335B (en) | Method for preparing lithium carbonate from lithium phosphate | |
| CN104261607A (en) | Processing method of complex raffinate | |
| CN104357671A (en) | Method for separating and recovering vanadium and chromium from vanadium-chromium slag | |
| CN108359815A (en) | A kind of preparation method containing vanadium solution | |
| CN113073202B (en) | Method for comprehensively treating liquid after vanadium precipitation of acidic ammonium salt in vanadium slag extraction | |
| CN104843789A (en) | Method for purifying vanadium pentoxide | |
| CN111170373A (en) | Preparation method of ferrous chloride tetrahydrate | |
| CN106396163B (en) | A kind of method of rare-earth smelting amine wastewater of sulphuric acid comprehensive treatment reuse | |
| CN103014378B (en) | Vanadium liquid purification method | |
| CN111847527A (en) | Method for deeply purifying titanium white copperas | |
| CN105366722A (en) | Normal temperature extraction method for producing high-purity vanadium pentoxide | |
| CN103014377B (en) | Vanadium liquid purification method | |
| CN107162935B (en) | The recovery method of phosphorus-containing compound in useless chemical polishing agent | |
| CN102320990B (en) | Method for recovering oxytetracycline from oxytetracycline hydrochloride waste liquid | |
| CN211733872U (en) | Impurity removing device for soluble manganese salt solution | |
| CN113772707A (en) | Treatment method of fluorine-containing potassium chloride | |
| CN113023751A (en) | Method for recovering lithium, sodium, potassium, magnesium and calcium from chloride brine | |
| CN111186863A (en) | Impurity removal device and method for soluble manganese salt solution |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140114 |
|
| 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: 20140121 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140124 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5466749 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |