JPS6136107A - Preparation of solution - Google Patents

Abstract

PURPOSE:To prepare efficiently an acidic solution of oxalic or nitric acid of any of various metals having high concentration and high stability, by blending precipitate of a metal hydroxide with oxalic acid power or conc. nitric acid, adding an aqueous solution of the acid or water to the blend. CONSTITUTION:Hydroxide precipitate such as precipitate of a metal (e.g., Nb, or Ti) and hydrous precipitate, etc. of basic carbonate, etc. is blended with 0.5- 5mol based on 1mol metal atom in the precipitate of oxalic acid powder (e.g., oxalic anhydride powder) or about 1-2 times mol of the product of number of mols X valence of the metal atom of 13-15N conc. nitric acid, an aqueous solution of the same acid added before or water is added to the blend, so that an acid solution of oxalic acid or nitric acid of a metal useful as a functional ceramic having a structure of perovskite type, etc. is prepared.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、各種金属の酸性溶液の調整法例えばペロプス
カイト型構造等の機能性セラミックに用いられろ各種金
属の酸性溶液の調整法に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for preparing acidic solutions of various metals, such as methods for preparing acidic solutions of various metals used in functional ceramics such as perovskite-type structures.

（従来技術とその問題点） 従来から各種金属のシュウ酸又は硝酸の酸性溶液乞調整
する方法としては例えば（１）各種金属のシュウ酸又は
硝酸の塩乞水に溶解する方法。（２）各種金属ンシュウ
酸又は硝酸の水溶液に溶解する方法。(Prior Art and its Problems) Conventional methods for preparing various metals in acidic solutions of oxalic acid or nitric acid include (1) a method of dissolving various metals in oxalic acid or nitric acid salt solution; (2) A method of dissolving various metals in an aqueous solution of oxalic acid or nitric acid.

（３）各棟金属の水′）１１１！Ｐ／ｌの沈殿乞シュウ
酸又は硝酸の水溶液に溶解する方法等か考えられろ。(3) Metal water in each building') 111! Consider methods such as dissolving in an aqueous solution of oxalic acid or nitric acid for precipitation of P/l.

しかし、（１）の方法においてシュウ酸塩の場合水に対
する溶解度が一般的に小さいものか多く、溶解に時間か
かかると共に、そのシュウ酸塩の合成も複雑であり、又
硝厳塩の場合の場合は水に対する溶解度が犬きぐ問題は
少ないが、その硝酸塩の合成が困難である。However, in the case of method (1), the solubility of oxalates in water is generally low, and it takes time to dissolve them, and the synthesis of the oxalates is complicated. If the solubility in water is low, there are few problems, but the synthesis of the nitrate is difficult.

（２）の方法は酸との反応性の高い雀属では有勅な方法
であるが、溶解時にガスが発生したり、溶、解熱がかな
り出るので好ましくない。Although method (2) is a popular method for sparrows that are highly reactive with acids, it is not preferred because gas is generated during melting and a considerable amount of dissolution and heat dissolution occurs.

（３１の方法は例えはチタンの水昶物沈殿乞歯酸水溶液
に溶解する場合、溶解に長時間ン要し、その　　　′溶
解量も少ないので調整された溶ｌｌＩ！濃度が低く、又
調整時点では透明液であるか溶解液か不安定であるので
、時間と共に沈殿が生成する実用的ではない。(In method 31, for example, when dissolving titanium in an aqueous solution of aqueous acid, it takes a long time to dissolve, and the amount of dissolved titanium is small, so the adjusted concentration of the solution is low, and the concentration at the time of adjustment is low. However, it is not practical because it is either a transparent liquid or a dissolved liquid, and is unstable, so that a precipitate forms over time.

（問題点ケ解失するための手段） 本発明は、高ｄｉかつ安定性の高いシュウ酸又は測成の
酸性＠液の効率的な８）４整法乞提供しようとするもの
である。すなわち本発明は各種金属の水オロ物沈殿乞用
いてシュウ酸又は硝酸の酸性溶液ケ調整する際に各種金
属の水和物沈殿にシュウ酸粉末又は−硝酸ン添加混合し
た後さらにこれらに添加した同一の酸性水１谷液又は水
ビ加えろことケ脣倣とする。(Means for solving the problems) The present invention aims to provide an efficient 8)4 method for producing oxalic acid or a measuring acid solution with high di and high stability. That is, in the present invention, when preparing an acidic solution of oxalic acid or nitric acid using the hydroxide precipitate of various metals, oxalic acid powder or -nitric acid is added to and mixed with the hydrate precipitate of various metals, and then further added to these. Add one drop of the same acidic water or a glass of water.

以下さらに本発明の詳細な説明する。本発明において、
谷則金属の水和物沈殿とは含水酸化物沈殿（水酸化物沈
殿）及び塩基性炭酸塩等の含水塩沈殿ン含む広い範囲の
もの乞いう。本発明において用いられろ各種金属水和物
の沈殿ケ生成するには各種金属塩例えば塩化物硝酸塩、
硫酸塩等の水溶液と塩基例えばアンモニア水、水酸化ナ
トリウム等と反応させろか、もり、　＜はイオン交換樹
脂等で処理して前記各種金属基水浴液の１・１４に高め
ろなどの手段により水１０物の沈殿とし、これを蒸留水
等で充分洗浄すれはよいが、これらの方法に限定されろ
ものではない。The present invention will be further explained in detail below. In the present invention,
Hydrate precipitation of Taninori metals refers to a wide range of conditions, including hydrated oxide precipitation (hydroxide precipitation) and hydrated salt precipitation such as basic carbonates. Various metal salts such as chlorides, nitrates,
By reacting an aqueous solution of sulfate, etc. with a base such as aqueous ammonia, sodium hydroxide, etc., or by treating it with an ion exchange resin or the like to increase the concentration to 1.14% of the above-mentioned various metal-based water bath solutions. It is possible to precipitate the 10 substances and wash the precipitate thoroughly with distilled water or the like, but the method is not limited to these methods.

また各■金属の水オロ物沈殿の含水率は小さい方か高一
度浴液が得られろので好ましいが、あまり含水率が小さ
い場合にはシュウ酸粉末又は濃硝酸を添加混合し反１芯
させろ際に充分に反応が進まず、調整した酸性浴液の安
定性が低くなる欠点が現われろ場合がある。従って金属
の水イ１１物の含水率はシュウ酸粉末又は濃硝酸ン適前
加えて均一なスラリー状態となろようにすることが好ま
しい。In addition, it is preferable that the water content of the water-based precipitate of each metal is small or high, since a bath liquid can be obtained, but if the water content is too small, add and mix oxalic acid powder or concentrated nitric acid to make it dilute. In some cases, the reaction may not proceed sufficiently and the stability of the prepared acidic bath solution may become low. Therefore, it is preferable to adjust the water content of the metal water to a uniform slurry by adding an appropriate amount of oxalic acid powder or concentrated nitric acid.

本発明で用いろシュウ酸粉末としては、無水シュウ酸（
Ｈ２Ｃ２０４）、シュウ酸性水１谷液（Ｈ３Ｃ２０４・
２Ｈ２０）、などがあげられろ。またこれらに少量の水
分ン含有さぜたスラリー状のものも用いられろ。The oxalic acid powder used in the present invention includes oxalic anhydride (
H2C204), 1 trough solution of oxalic acid water (H3C204・
2H20), etc. A slurry containing a small amount of water may also be used.

又濃硝酸は１５〜１５Ｎの通常の１硝酸でよい。Further, the concentrated nitric acid may be ordinary 15-15N nitric acid.

また（濃硝酸の園用口は高い力が好ましいが、用いろ水
和！物の沈殿の件′＋１により、その濃度限界は異なる
。一般的に硝酸塩の存在する金属では比較的１戊濃度の
硝酸でも硝酸酸性溶液が祠祭ｏＴ牝であるが、例えばチ
タンの、ｔ：　５な硝酸塩の合成が困難なものでは、低
感度の硝酸では高一度で安定性の旨い（洞酸酸性溶液は
調整できない。In addition, (although it is preferable to use concentrated nitric acid at a high strength, its concentration limit differs depending on the matter of hydration and precipitation of the nitric acid. Generally speaking, metals containing nitrates have a relatively high concentration of Even with nitric acid, an acidic solution of nitric acid is suitable for the shrine, but for example, when it is difficult to synthesize a t: 5 nitrate of titanium, nitric acid, which has a low sensitivity, is stable at a high temperature. Can not.

不発明のシュウ醒塩水浴液稠製にお噛ハて水和物沈殿と
シュウ１戚紛木との混合化率はシュウ酸粉末（ろ） が多いほど安定であるがシュウ酸粉未使用量乞少なくし
たい」烏合にはシュウ酸塩水浴液中の金属イオンの性質
によって異なり、例えば錯イオン乞形成する場合にはそ
の配位数乞考慮しなければならないが、はぼ水オロ物の
沈殿中の金属原子１モルに対してシュウ酸粉末０．５〜
５モル程度が通している。The mixing ratio of the hydrate precipitate and the oxalic powder mixed with the uninvented oxalic acid salt bath liquid is more stable as the amount of oxalic acid powder increases, but the amount of unused oxalic acid powder is very small. The amount of metal ion in the oxalate solution depends on the nature of the metal ion in the oxalate solution; for example, when forming a complex ion, the number of coordinations must be taken into account. Oxalic acid powder 0.5 to 1 mole of atoms
About 5 moles are passing through.

また硝酸塩水浴液のａＩ−！ｌ製におけろ濃硝酸の使用
量は、金属原子のモル数Ｘ原子価の値の１〜２倍モル程
度以上か適している。本発明におけろスラリー状態は均
一な混合がう■能な限り含水量か少ないほどシュウ酸粉
末又は濃硝酸と水和物沈殿との反応が効率よく行なわれ
ろため好ましい。Also, the aI-! of the nitrate bath solution! The amount of concentrated nitric acid to be used in the 1-manufacturing process is suitably about 1 to 2 times the mole number of metal atoms x the value of valence. In the present invention, the slurry state is preferable as long as uniform mixing is possible and the water content is as low as possible because the reaction between the oxalic acid powder or concentrated nitric acid and the hydrate precipitate can be carried out more efficiently.

本発明の手法により調製可能なシュウ酸塩水溶ニウム、
ベリリウム、鉄、クロム、希土類、スカンジウム、セリ
ウム、チタン、ジルコニウム、トリウム、ニオブ、タン
タル、ウラン、ガリウム、インジウム、マンガン、ニッ
ケル、コバルト、亜鉛、銅１、スズ、銀、カドミウム、
ビスマスナト力あげられろ。water-soluble nium oxalate, which can be prepared by the method of the present invention;
Beryllium, iron, chromium, rare earths, scandium, cerium, titanium, zirconium, thorium, niobium, tantalum, uranium, gallium, indium, manganese, nickel, cobalt, zinc, copper 1, tin, silver, cadmium,
Bismuth Nat, boost your strength.

（実施例） 実施例１ 金属嬢度約Ｏろ５　ｍｏｌ　／−（３のニオブのフッ酸
浴液にアンモニア水ン加えニオブの１く酸化物沈殿（Ｎ
ｂ（ＯＩ−（）５４生成させ、充分水洗ろ過し金属濃度
２．５　ｍｏｌ　／　ｒｃｇの沈殿とした。該沈殿と無
水シュウ酸粉末とＹ　Ｎｂ　：　Ｈ２Ｃ２０４モル比が
１＝２となるように混合し、スラリー状態で３０分間攪
拌後攪拌しながら水馨加えてニオブのシュウ酸塩水Ｉ６
液ン調製した。このシュウ酸塩水溶液７公析したところ
、金属濃度０５８４　ｍｏｌ　／　Ｊ）であった。また
２０日間放置後も沈殿生成は見られず安定なニオブのシ
ュウ酸塩水溶液であることがわかった。(Example) Example 1 Aqueous ammonia was added to the hydrofluoric acid bath solution of niobium (3) to precipitate an oxide of niobium (N
b(OI-()54 was produced, thoroughly washed with water and filtered to obtain a precipitate with a metal concentration of 2.5 mol/rcg. The precipitate was mixed with anhydrous oxalic acid powder so that the molar ratio of YNb:H2C204 was 1=2. After stirring in a slurry state for 30 minutes, water was added while stirring to make niobium oxalate water I6.
A liquid was prepared. When this oxalate aqueous solution was analyzed, the metal concentration was found to be 0584 mol/J). Further, no precipitation was observed even after standing for 20 days, indicating that the solution was a stable niobium oxalate aqueous solution.

比較例１ 実施例１で用いた充分水洗ろ過したニオブの水酸化物沈
威ンシュウ酸の飽和水浴液中に攪拌しながら加えた。逍
明溶ｌＷとなるのに８時間かかった。Comparative Example 1 The niobium hydroxide solution used in Example 1, which had been thoroughly washed and filtered, was added to the saturated water bath solution of oxalic acid with stirring. It took 8 hours to become Shomei Solu IW.

コノニオブのシュウ酸塩水溶液乞分析したとこり金属濃
度０．０２９５　ｍｏｌ　／−１３であった。この６度
は実施例１の０．５８４　ｍｏｌ　／　Ｊ３に比べかな
り低濃度であった。さらに前記透明溶液に前記ニオブの
水酸化物沈殿ケ少量加えたところ白濁溶液どなり、１日
後には多量の沈殿が生成し、溶液かかなり不安定である
ことがわかった。またこの溶液に無水シュウ酸粉末ン加
え、２１Ｗ間攪拌したが沈殿は溶５解せず、透明溶液は
得られなかった。When an aqueous solution of oxalate of Cononiobium was analyzed, the metal concentration was 0.0295 mol/-13. This 6 degrees was a considerably lower concentration than 0.584 mol/J3 in Example 1. Furthermore, when a small amount of the niobium hydroxide precipitate was added to the clear solution, the solution became cloudy and a large amount of precipitate was formed after one day, indicating that the solution was quite unstable. Further, anhydrous oxalic acid powder was added to this solution and stirred for 21 W, but the precipitate did not dissolve and a clear solution was not obtained.

実施例２ 四塩化チタン水溶液（ａ度２．０　ｍｏｌ　／　−ｅ　
）にアンモニア水を加えチタンの水酸化物沈殿馨生成さ
せ充分水洗ろ過した。Example 2 Titanium tetrachloride aqueous solution (a degree 2.0 mol/-e
) was added with ammonia water to form a titanium hydroxide precipitate, which was thoroughly washed and filtered.

この際洗浄液が硝酸銀水溶液により塩化銀の沈殿反応を
示さなくなるまで洗浄ン行なった。得られた沈殿にシュ
ウ酸２水昶物粉末（Ｈ３Ｃ２０４・２Ｈ２０）乞Ｔｉ　
：　Ｈ２Ｃ２０４・２Ｈ２０のモル比が約１　：　１．
５となるように混合し、スラリー状態で６０分間攪拌後
攪拌しながら水を加えてチタンのシュウ酸塩水溶液を調
製した。このシュウ酸塩水溶液を分析したところ金属濃
度０．６６　ｍｏｌ　／　Ａであった。また２０日間放
置後も沈殿生成は見られず安定であった。At this time, washing was carried out with a silver nitrate aqueous solution until the washing solution showed no precipitation reaction of silver chloride. Oxalic acid dihydrate powder (H3C204.2H20) was added to the resulting precipitate.
: The molar ratio of H2C204/2H20 is approximately 1:1.
After stirring in a slurry state for 60 minutes, water was added while stirring to prepare a titanium oxalate aqueous solution. Analysis of this oxalate aqueous solution revealed that the metal concentration was 0.66 mol/A. Further, even after being left for 20 days, no precipitation was observed and the product was stable.

比較例２ シュウ酸の飽４〔１水浴液１００　ｍｌに金属チタン５
ｇン加え、１日撹拌し、て反応させｔこ。未反応物馨ろ
別後、ろ液ぞ分析したところ、金属濃度０　、　Ｏ（３
０２ｍｏｌ　／−ｅであった。この感度は実施例２のＯ
１６６ｍｏｌ　／沼にくらべ、はるかに低禰度で浜）つ
ムニ。Comparative Example 2 Oxalic acid saturation 4 [1 100 ml of water bath solution and 5 ml of metallic titanium]
Add 100 g of water, stir for 1 day, and allow to react. After filtering off the unreacted materials, the filtrate was analyzed, and the metal concentration was 0, O(3
It was 0.02 mol/-e. This sensitivity is the O of Example 2.
166mol/compared to swamps, it has a much lower mineral content than swamps.

実施例６ 塩化ジルコニル水溶液（濃度１．６ｍｏ１．　／　Ａ　
）にアンモニア水を加え、ジルコニウムの水酸化物沈殿
ケ生成させ充分水洗ろ過した。この踪洗／′？液か硝酸
銀水溶液により塩化銀の沈殿反応ケ示さなくなるまで洗
＃ン行なった。得られた沈蝦にシコーウ１峻２水第１」
物（Ｉ−Ｔ２Ｃ，０４，−２Ｈ３Ｏ）粉末Ｙ　Ｚｒ　：
　Ｈ２Ｃ２０４・’２Ｈ３Ｏのモル比が約１　：　２．
５となるように混合しスラリー状態で６０分間攪拌後、
攪拌しなから水ぞ加えてジルコニウム・のシュウ酸塩水
浴散ン調製した。このシュウ酸塩氷浴液ン分析したとこ
ろ金属一度０．４２　ｍｏｌ　／　Ａであった。また２
０日間放置後も沈殿生成は見られず安ｔｌであった。Example 6 Zirconyl chloride aqueous solution (concentration 1.6 mo1./A
) was added with ammonia water to form a zirconium hydroxide precipitate, which was thoroughly washed and filtered. This disappearance/'? The solution was washed with an aqueous silver nitrate solution until no silver chloride precipitation reaction occurred. Add 1 water to the obtained shrimp.
Product (IT2C,04,-2H3O) powder Y Zr:
The molar ratio of H2C204.'2H3O is approximately 1:2.
After mixing in a slurry state for 60 minutes,
A zirconium oxalate water bath powder was prepared by adding water while stirring. Analysis of this oxalate salt in an ice bath revealed that it contained 0.42 mol/A of metal. Also 2
Even after standing for 0 days, no precipitate formation was observed and the temperature was low.

比較例６ 実施例６で用いた充分水洗ろ過したジルコニウムの水酸
化物沈殿ンシュウ酸の飽昶水溶散中に攪拌しながら加え
たところその溶解には６時間かかった。このジルコニウ
ムのシュウ酸塩水溶／ｌ！７分析したところ金属濃度０
．１２　ｍｏｌ　／−ｅであった。Comparative Example 6 When the hydroxide precipitate of zirconium used in Example 6, which had been thoroughly washed and filtered, was added to the dissolution of oxalic acid in saturated water with stirring, it took 6 hours to dissolve. This zirconium oxalate water soluble/l! 7 Analysis showed metal concentration 0
．． It was 12 mol/-e.

この感度は実施例乙の０．４２　ｍｏ］、　／　、８に
比べてかなり低濃度であった。This sensitivity was considerably lower than that of Example B, which was 0.42 mo], / , 8.

実施例４ 実施例２と同一のチタンの水酸化物沈殿に濃硝酸（濃度
１ろ規定）ケＴ１：ＨＮＯ３０モル比が約１−５となる
ように添加しスラリー状態で１５分間攪拌後、攪拌しな
がら水ン加えてチタンの硝酸酸性溶液とした。このチタ
ンの硝酸酸性溶液は金属濃度０．７５　ｍｏｌ　／　Ａ
、硝酸濃度は約４規定であり６０日間放置後も沈殿生成
は見られず安定であった。Example 4 Concentrated nitric acid (concentration: 1 filtration) was added to the same titanium hydroxide precipitate as in Example 2 so that the molar ratio of T1:HNO30 was approximately 1-5, and after stirring in a slurry state for 15 minutes, the mixture was stirred. While doing so, water was added to form a titanium solution in nitric acid. This acidic solution of titanium in nitric acid has a metal concentration of 0.75 mol/A.
The nitric acid concentration was approximately 4N, and the product was stable with no precipitation observed even after being left for 60 days.

比較例４ 実施例４と同一のチタンの水酸化物沈殿ン４規定の硝酸
水浴液中に攪拌しながら溶解した。溶解には約２時間要
し、た。このチタンのｌｉＩ’ｌ酸酸性浴液酸性浴液度
は０．７５　ｍｏｌ　／−ｅであった。この浴液は１日
間放置し１こところ、白色沈殿物が生成した、このよう
にして得られた溶液は実施例４と比較して非常に不女尾
であった。Comparative Example 4 The same titanium hydroxide precipitate as in Example 4 was dissolved in a 4N nitric acid water bath with stirring. It took about 2 hours to dissolve. The acidic bath liquid concentration of this titanium was 0.75 mol/-e. This bath solution was allowed to stand for one day, after which a white precipitate was formed.The solution obtained in this way was very thin compared to Example 4.

比較例５ 実施例４と同一のチタンの水酸１ヒ物沈殿を１６規定の
濃硝酸に徐々に加えていった。このときスラリー状帽と
ならないように少量つつ加えた。溶解には約２１守間要
した。この、溶液に水ン加えて、硝酸感度４Ｊ金属磯度
［１，７５ｍｏｌ　／沼のチタンの硝を俊酸Ｙ４−溶液
ン得た。この溶液は１日間６！置１〜だところ、白色沈
殿物が生成した。Comparative Example 5 The same titanium hydroxide monoarsenide precipitate as in Example 4 was gradually added to 16N concentrated nitric acid. At this time, a small amount was added so as not to form a slurry. It took about 21 hours to dissolve. Water was added to this solution to obtain a nitric acid Y4-solution with a nitric acid sensitivity of 4J metallurgy [1.75 mol/Numa's titanium nitrate]. This solution lasts 6 days! A white precipitate was formed from position 1 onward.

これも比較ツ１］４と同僚であり、非常に不−な定な溶
液であった。This was also a colleague of Comparison 1]4, and was a very inconstant solution.

（発明の効果） 本発明の方法によれば極めて効率的に、高＄度で安定性
の筒い名桟金属のシュウ、１グヅ性溶ｌイｉ又は硝酸酸
性耐液が調製されろ。(Effects of the Invention) According to the method of the present invention, a high-strength and stable cylindrical metal solution or nitric acid-resistant solution can be prepared very efficiently.

特許出願人　市気化学工業株式会社 手続補正書 昭和５９年９月３日 特許庁長官　　志　賀　　　学　殿 １、事件の表示 昭和５９年特許願第１５６２９３号 ２　発明の名称 溶液の調整法 ろ　補正をする者 事件との関係　　特許出願人 住所　東京都千代田区有楽町１丁目４番１号明細書の発
明の詳細な説明の欄 ５　補正の内容 ５−１）明細書第２頁において、第６行「の場合」を削
除、第１６行「生成する」と「実用的」との間に１ので
」を加入する。Patent Applicant: Ichiki Kagaku Kogyo Co., Ltd. Procedural Amendment September 3, 1980 Director General of the Patent Office Manabu Shiga 1, Indication of the Case 1982 Patent Application No. 156293 2 Name of the Invention Method for Preparing a Solution Amendment Relation to the case filed by the person who filed the patent application Address of the patent applicant: 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Column 5 of the detailed description of the invention in the specification Contents of the amendment 5-1) On page 2 of the specification, line 6 “ ``In the case of'' is deleted, and in line 16, ``1 so'' is added between ``generate'' and ``practical''.

５−２）明細書第６頁において、第１２行「塩化物」と
「硝酸塩」との間に１、」を加入、第１６行「塩基」を
「沈澱剤」と訂＋Ｅ、第１３行から第１４行「水酸化ナ
トリウム」と１等」との間に、「炭酸アンモニウム」を
加入する。5-2) On page 6 of the specification, ``1'' was added between ``chloride'' and ``nitrate'' in line 12, ``base'' in line 16 was revised to ``precipitant,'' +E, line 13. Add "ammonium carbonate" between "sodium hydroxide" and "1st grade" in line 14.

５−６）明細書第６頁第７行「（Ｎｂ（ＯＨ）５」を「
（Ｎｂ（ＯＨ）５　）　Ｊと訂正、第９行「１２」をｒ
ｌ：２．７Ｊど訂正する。5-6) Replace “(Nb(OH)5)” on page 6, line 7 of the specification with “
(Nb(OH)5) J and corrected, 9th line “12” is r
l:2.7J will be corrected.

Claims (1)

【特許請求の範囲】[Claims] 各棟金属の水和物沈殿を用いてシュウ酸又は硝酸の酸性
溶液を調整する際に、前記各種金属の水和物沈殿にシュ
ウ酸粉末又は濃硝酸を添加混合した後、さらにこれらに
添加した酸と同一の酸性水溶液又は水を添加することを
特徴とする各種金属の酸性溶液の調整法。When preparing an acidic solution of oxalic acid or nitric acid using the hydrate precipitates of various metals, oxalic acid powder or concentrated nitric acid was added to and mixed with the hydrate precipitates of the various metals, and then added to these. A method for preparing acidic solutions of various metals, characterized by adding the same acidic aqueous solution as the acid or water.