JP3131433B2 - Method for producing high-purity phosphoric acid - Google Patents
Method for producing high-purity phosphoric acidInfo
- Publication number
- JP3131433B2 JP3131433B2 JP01329462A JP32946289A JP3131433B2 JP 3131433 B2 JP3131433 B2 JP 3131433B2 JP 01329462 A JP01329462 A JP 01329462A JP 32946289 A JP32946289 A JP 32946289A JP 3131433 B2 JP3131433 B2 JP 3131433B2
- Authority
- JP
- Japan
- Prior art keywords
- phosphoric acid
- crystallization
- purity
- tube
- crystals
- 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.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/18—Phosphoric acid
- C01B25/234—Purification; Stabilisation; Concentration
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
【発明の詳細な説明】 ［発明の属する技術分野］ 本発明は、高純度リン酸の製造方法に関する。更に言
えば、本発明方法により得られた高純度リン酸は、Fe、
Mn及びNa元素の混入が少ないために半導体製造工程にお
いて窒化珪素膜を除去するために使用した際に、微細素
子の電気特性を劣化させる不純物を実質的に含まない好
適な電子材料となる。また、本発明方法により得られた
高純度リン酸は、不純物の含有量が少ないという特徴か
ら、金属アルミニウムのエッチング液、セラミック用ア
ルミナエッチング液、光ファイバー用のリン酸ガラスの
原料としても好適に使用できる。Description: TECHNICAL FIELD The present invention relates to a method for producing high-purity phosphoric acid. Furthermore, high-purity phosphoric acid obtained by the method of the present invention is Fe,
Since it is less mixed with Mn and Na elements, when used for removing a silicon nitride film in a semiconductor manufacturing process, it is a suitable electronic material which does not substantially contain impurities which degrade electric characteristics of a fine element. Further, the high-purity phosphoric acid obtained by the method of the present invention is preferably used as a raw material for an etching solution for metallic aluminum, an alumina etching solution for ceramics, and a phosphate glass for optical fibers because of the feature that the content of impurities is small. it can.
［従来の技術］ 従来のリン酸を晶析法で精製する技術は、古くは例え
ば特公昭44−14692号公報にみられる。これによれば、
リン酸を所望純度に精製するために晶析操作、母液から
の分離操作及び融解操作からなる一連の晶析精製操作を
３回繰り返す方法が開示されている。[Prior Art] A conventional technique for purifying phosphoric acid by a crystallization method has long been found, for example, in Japanese Patent Publication No. 44-14692. According to this,
A method is disclosed in which a series of crystallization purification operations including a crystallization operation, a separation operation from a mother liquor, and a melting operation are repeated three times in order to purify phosphoric acid to a desired purity.
追村ら［東洋曹達報告:10、２、21（1966）］は、リ
ン酸を晶析操作で精製する基礎物性データである飽和溶
解度、過飽和度と成長速度の相関、リン酸半水結晶の吸
湿性、リン酸中の結晶沈降速度について明らかにした
が、析出したリン酸半水結晶粒子の純度については、定
量的には論じていない。Ooimura et al. [Toyo Soda Report: 10, 2, 21 (1966)] reported the basic physical property data for purifying phosphoric acid by crystallization, including the relationship between saturated solubility, supersaturation and the growth rate, and phosphoric acid hemihydrate crystals. Although the hygroscopicity and the crystal sedimentation rate in phosphoric acid were clarified, the purity of the precipitated phosphoric acid hemihydrate crystal particles was not quantitatively discussed.
また、例えば青山らのProceedings of a Conference
of Industrial Crystallization（1976）の第413〜420
頁には、流動層型晶析装置での応用例が示されている。
この流動層型晶析装置では、均一粗大粒子が生成するた
め、母液からの分離操作が容易になる上に、流動層部分
に設けられた外部熱交換器により溶液を冷却し、効率よ
く晶析熱を除去することにより生産速度を高くすること
ができる特徴をもっている。For example, Aoyama et al.'S Proceedings of a Conference
413-420 of Industrial Crystallization (1976)
The page shows an example of application in a fluidized bed crystallizer.
In this fluidized bed type crystallizer, uniform coarse particles are generated, so that the separation operation from the mother liquor is easy.In addition, the solution is cooled by an external heat exchanger provided in the fluidized bed, and crystallization is efficiently performed. It has the characteristic that the production rate can be increased by removing heat.
このようにリン酸を晶析操作で精製することは公知で
あるが、これらの操作によって得られたリン酸の純度に
ついては明確に記されていないうえに、リン酸を晶析操
作で精製する方法は明らかにされているものの、その方
法による効果が明示されていない。As described above, it is known to purify phosphoric acid by a crystallization operation, but the purity of the phosphoric acid obtained by these operations is not clearly described, and the phosphoric acid is purified by a crystallization operation. Although the method is clarified, the effect of the method is not specified.
［発明が解決しようとする課題］ 本発明は、このような従来技術に鑑みて鋭意研究を行
った結果完成されたものであり、各種金属元素が、その
液中の状態が溶解、不溶解に拘わらず、実質的に検出で
きる限界と同程度の高純度リン酸を提供することができ
る製造方法を提供することを目的とするものである。[Problems to be Solved by the Invention] The present invention has been completed as a result of intensive studies in view of such conventional techniques, and various metal elements are dissolved or insoluble in a liquid state. Regardless, an object of the present invention is to provide a production method capable of providing high-purity phosphoric acid having substantially the same limit as the limit of detection.
［課題を解決するための手段］ すなわち、本発明は（イ）濃度70重量％以上の原料リ
ン酸中に冷媒を流通して晶析管を浸漬して浸漬管表面に
リン酸半水結晶を析出させる晶析工程、（ロ）次いで、
晶析管を原料リン酸より取り出した後、晶析管表面に析
出したリン酸半水結晶を発汗させて結晶内外に含有する
不純物を除去する精製工程、からなることを特徴とする
高純度リン酸の製造方法に係る。[Means for Solving the Problems] That is, the present invention provides (a) a method in which a crystallization tube is immersed by flowing a refrigerant through a raw phosphoric acid having a concentration of 70% by weight or more to form phosphoric acid hemihydrate crystals on the surface of the immersion tube. A crystallization step for precipitation, (b)
A purifying step of removing the crystallizing tube from the raw material phosphoric acid and then sweating the phosphoric acid hemihydrate crystals deposited on the surface of the crystallizing tube to remove impurities contained inside and outside the crystal. The present invention relates to a method for producing an acid.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明においてリン酸とは、下記の一般式 H3PO4 で表される成分とH2Oの任意の比率の混合液体であり、
その濃度はJIS Ｋ−1449に示される水酸化ナトリウム
による滴定法で測定するものをいう。In the present invention, phosphoric acid is a mixed liquid having an arbitrary ratio of a component represented by the following general formula H 3 PO 4 and H 2 O,
The concentration is measured by a titration method using sodium hydroxide shown in JIS K-1449.
一般に、リン酸は、他の鉱酸と比べて蒸気分圧が低く
蒸留法を適用して精製することは容易でなく、また、工
業的に精製することは実質的に非常に困難な化合物であ
るけれども、本発明方法により得られる高純度リン酸
は、Fe、Mn及びNaすなわち鉄、マンガン及びナトリウム
の成分含有量が少ないことを特徴とするリン酸である。Generally, phosphoric acid is a compound that has a low vapor partial pressure compared to other mineral acids, is not easy to purify by applying a distillation method, and is substantially very difficult to purify industrially. Nevertheless, the high-purity phosphoric acid obtained by the method of the present invention is a phosphoric acid characterized by a low content of Fe, Mn and Na, ie, iron, manganese and sodium.
本発明方法により得られるリン酸は、不純物量がppb
のレベルを扱うものであるところから、測定精度が実際
上問題となるので次のように定義する。The phosphoric acid obtained by the method of the present invention has an impurity amount of ppb
Since the measurement accuracy is actually a problem from the point of handling the level of 定義, it is defined as follows.
すなわち、リン酸中の不純物成分における各元素すな
わちFe、Mn及びNa等の含有量の値は、希釈率５倍（Naに
おいては100倍）に希釈した試料を炭素製加熱炉に10μ
ｌ注入し、800℃に加熱してリン酸を除去し、表１に示
す元素に応じた原子化温度において原子状となった元素
を元素によって定めた測定波長の光の吸光度を希薄塩酸
中の標準試料と比較する、いわゆるフレームレス原子吸
光光度分析法で測定評価するものをいう。また、リン酸
の純度は、単位リン酸質量当たりの元素の質量の比率と
して表す。That is, the value of the content of each element, that is, Fe, Mn, and Na, in the impurity component in phosphoric acid is determined by diluting a sample diluted 5 times (100 times in Na) into a carbon furnace.
l, and heated to 800 ° C. to remove phosphoric acid. At an atomization temperature corresponding to the element shown in Table 1, the element that became an atomic state was measured for the absorbance of light having a measurement wavelength determined by the element. It refers to what is measured and evaluated by the so-called flameless atomic absorption spectrophotometry, which is compared with a standard sample. Further, the purity of phosphoric acid is expressed as a ratio of the mass of an element per unit mass of phosphoric acid.
フレームレス原子吸光光度分析によるFe、Mn及びNaの
検出下限を表１に示す。Table 1 shows the detection lower limits of Fe, Mn and Na by flameless atomic absorption spectrometry.
本発明方法により得られた高純度リン酸は前記の測定
法で求めた不純物量（H3PO4の濃度を85重量％に換算し
たときの含有不純物）、特に、Fe、Mn及びNaがそれぞれ
25ppb以下、3ppb以下及び40bbp以下にあるものである。 In the high-purity phosphoric acid obtained by the method of the present invention, the amount of impurities (impurities contained when the concentration of H 3 PO 4 is converted to 85% by weight), particularly Fe, Mn and Na, are determined by the above-mentioned measuring method.
It is below 25ppb, below 3ppb and below 40bbp.
リン酸は各種金属に対する腐食性が強いため、金属等
の表面エッチング液として有用であるが、本発明方法に
より得られたものは特に上記各元素の不純物量が少ない
高純度リン酸であるため、半導体の分野その他精密工業
に用いられる金属、ガラスなどのエッチング液として最
適なものである。Phosphoric acid is highly corrosive to various metals, and thus is useful as a surface etching solution for metals and the like.However, the one obtained by the method of the present invention is a high-purity phosphoric acid having a small amount of impurities of each of the above-described elements. It is most suitable as an etchant for metals, glass and the like used in the field of semiconductors and other precision industries.
次に、本発明方法によれば、前記したように（イ）の
晶析工程と（ロ）のリン酸結晶の発汗操作による精製工
程から本質的になるプロセスにより工業的に高純度リン
酸を製造することができる。Next, according to the method of the present invention, high-purity phosphoric acid is industrially produced by a process essentially consisting of the crystallization step (a) and the purification step (ii) of the phosphoric acid crystals by a sweating operation, as described above. Can be manufactured.
本発明において適用できる原料リン酸は、特に限定は
なく、乾式法または湿式法で得られる工業用リン酸であ
り、その濃度は70重量％以上にあるものである。濃度が
70重量％未満では飽和温度が低く、晶析に際し適切な過
飽和度を得るのに多くのエネルギーを必要とし、工業的
に好ましくない。また、上限は飽和濃度（91.6重量％）
までであり、それ以上はリン酸半水結晶以外の結晶が析
出する恐れがあり、更に粘度が高くなって晶析、分離が
困難となり好ましくない。The raw phosphoric acid applicable in the present invention is not particularly limited, and is industrial phosphoric acid obtained by a dry method or a wet method, and its concentration is 70% by weight or more. Concentration
If it is less than 70% by weight, the saturation temperature is low, and a large amount of energy is required to obtain an appropriate degree of supersaturation during crystallization, which is not industrially preferable. The upper limit is the saturation concentration (91.6% by weight)
Above that, crystals other than phosphoric acid hemihydrate crystals may be precipitated, and the viscosity is further increased, which makes crystallization and separation difficult.
なお、本発明の目的上可及的に精製され且つ浮遊微粒
子を除いたリン酸を原料とすることが好ましい。For the purpose of the present invention, it is preferable to use phosphoric acid as purified as possible and excluding suspended particles.
（イ）晶析工程 この工程は、原料リン酸よりリン酸半水結晶を析出さ
せる晶析工程である。原料リン酸の温度は15〜30℃、好
ましくは18〜27℃にあり、且つ温度制御が効率的にでき
るように循環系を構成されたものがよい。(A) Crystallization Step This step is a crystallization step of precipitating phosphoric acid hemihydrate crystals from the starting phosphoric acid. The temperature of the raw phosphoric acid is 15 to 30 ° C., preferably 18 to 27 ° C., and a system in which a circulation system is configured so that the temperature can be controlled efficiently is good.
リン酸の晶析は前記したように冷媒を流通した晶析管
を原料リン酸液に浸漬せしめ、その管表面に半水結晶を
析出させるところに特徴の１つがある。One of the features of the crystallization of phosphoric acid is that the crystallization tube through which the refrigerant has been circulated is immersed in a phosphoric acid solution as described above, and hemihydrate crystals are precipitated on the surface of the tube.
晶析管としては多くの場合、例えば硬質ガラス製の二
重円筒形の中空構造をもったもので、その内部に冷媒を
流通させることにより管表面の温度を所定の過冷却温度
に調整できるようにした比較的簡単なものでよい。In many cases, the crystallization tube has a double-cylindrical hollow structure made of, for example, hard glass, and the temperature of the tube surface can be adjusted to a predetermined supercooling temperature by flowing a coolant through the crystallization tube. It can be a relatively simple one.
従って、晶析管表面の形状は特に円筒形でなければな
らないということはなく、冷媒が流通でき且つ晶析管表
面の温度が所定温度に対して±１℃、望ましくは±0.05
℃に保てるならば平面、その他の形状を採ることができ
る。Therefore, the shape of the crystallizer tube surface does not have to be particularly cylindrical, and the temperature of the crystallizer tube surface is ± 1 ° C., preferably ± 0.05 ° C. with respect to the predetermined temperature, through which the refrigerant can flow.
If it can be kept at ° C., it can be flat or any other shape.
また、冷媒は、水及びエチレングリコールの混合溶液
であるが、操作する温度の範囲において固体が析出せず
流動性があれば、他の冷媒も同様に用いられる。The refrigerant is a mixed solution of water and ethylene glycol, but other refrigerants may be used as long as solids do not precipitate and have fluidity in the operating temperature range.
係る晶析管を原料リン酸中に浸漬させることにより管
表面が過冷却状態にあるところから、その表面に半水結
晶が析出する。By immersing such a crystallization tube in the raw phosphoric acid, the hemihydrate crystals precipitate on the surface of the tube from the supercooled state.
本発明において、この過冷却温度は−２〜−８℃の範
囲がよく、これはそのような状態の冷媒を流通させるこ
とにより保持される。ここに、過冷却温度とは、リン酸
の温度からそのリン酸の濃度に対して次式で示す飽和温
度を差し引いた値である。In the present invention, the supercooling temperature is preferably in the range of −2 to −8 ° C., and this is maintained by flowing the refrigerant in such a state. Here, the supercooling temperature is a value obtained by subtracting a saturation temperature represented by the following equation with respect to the concentration of phosphoric acid from the temperature of phosphoric acid.
飽和温度［℃］＝リン酸濃度（重量％）−63.7 ただし、リン酸濃度は（重量％）で表したものであ
る。Saturation temperature [° C.] = Phosphoric acid concentration (% by weight) −63.7 where phosphoric acid concentration is expressed in (% by weight).
従って、過冷却温度は、晶析操作においては負の値、
次の精製工程に係る発汗操作においては、正の値をと
る。Therefore, the supercooling temperature is a negative value in the crystallization operation,
In the sweating operation relating to the next purification step, a positive value is taken.
係る温度に設定した理由は、本発明者らの数多くの実
験により、高純度リン酸の収率と不純物除去の効率との
相対的関係から求められたものである。The reason for setting the temperature is determined from the relative relationship between the yield of high-purity phosphoric acid and the efficiency of impurity removal by many experiments by the present inventors.
この晶析工程により、析出したリン酸半水結晶は母液
の原料リン酸に比較するとかなりの不純物が除去された
ものであり、晶析条件の如何によっては、精製効果が著
しいものである。In the crystallization step, the precipitated phosphoric acid hemihydrate crystals have been substantially free of impurities compared to the phosphoric acid used as the mother liquor, and the purification effect is remarkable depending on the crystallization conditions.
（ロ）精製工程 この工程は、前工程で析出した半水結晶を、晶析管を
リン酸液より取り出すことにより母液と分離せしめた
後、該結晶を発汗させて結晶内外の含有不純物を除去す
ることにより、更にリン酸を精製する工程であり、本発
明の他の特徴となっている。(B) Purification Step In this step, the hemihydrate crystals precipitated in the previous step are separated from the mother liquor by taking out the crystallization tube from the phosphoric acid solution, and then the crystals are sweated to remove impurities contained inside and outside the crystals. This is a step of further purifying the phosphoric acid, which is another feature of the present invention.
ここに、発汗とは、母液より分離した結晶表面に付着
した母液の過冷却温度を所定の範囲に保持して結晶の表
面の一部を融解し、滴下させる操作をいい。この操作に
より付着母液の不純物及び結晶内部に取り込まれた不純
物が滴下液として除去される。Here, perspiration refers to an operation in which the supercooling temperature of the mother liquor attached to the crystal surface separated from the mother liquor is kept within a predetermined range, and a part of the crystal surface is melted and dropped. By this operation, impurities in the adhered mother liquor and impurities taken into the crystal are removed as a dropping liquid.
従って、このときの過冷却温度はリン酸半水結晶の歩
留まりと不純物の除去効果との相対的関係から設定さ
れ、多くの場合０〜10℃の範囲にある。Therefore, the supercooling temperature at this time is set from the relative relationship between the yield of phosphoric acid hemihydrate crystals and the effect of removing impurities, and in many cases is in the range of 0 to 10 ° C.
また、発汗操作における融解量は、析出したリン酸半
水結晶の質量に対して滴下したリン酸液量の比率で表し
たとき、10重量％以上40重量％以下の範囲であり、好ま
しくは20重量％以上35重量％以下の範囲で操作を行う。
これは、本発明者らの研究によれば、融解量が10重量％
未満では、発汗効果が不充分で高純度リン酸が得られ難
く、40重量％を超えて発汗操作を継続しても、発汗操作
の効果が飽和してしまうためである。Further, the amount of melting in the sweating operation is in a range of 10% by weight or more and 40% by weight or less, preferably 20% by weight, when expressed as a ratio of the amount of the phosphoric acid solution dropped to the mass of the precipitated phosphoric acid hemihydrate crystals. The operation is performed in the range of not less than 35% by weight and not more than 35% by weight.
According to the study of the present inventors, the melting amount was 10% by weight.
If the amount is less than 40%, the effect of sweating is insufficient, and it is difficult to obtain high-purity phosphoric acid. Even if the sweating operation is continued at more than 40% by weight, the effect of the sweating operation is saturated.
本発明は係るリン酸結晶の発汗により充分目的とする
高純度リン酸を得ることができるが、必要に応じこの発
汗の前後のいずれかにおいて超純水ないし製品の高純度
リン酸で晶析管表面に析出したリン酸半水結晶を置換洗
浄して不純物を除去する精製工程を付加することもでき
る。In the present invention, the desired high-purity phosphoric acid can be sufficiently obtained by the perspiration of the phosphoric acid crystals according to the present invention. A purification step for removing impurities by replacing and washing the phosphoric acid hemihydrate crystals deposited on the surface can also be added.
このように置換洗浄とは、析出したリン酸半水結晶の
表面に、超純水ないし高純度リン酸の任意の比率の混合
物を接触させ、リン酸半水結晶に付着した原料リン酸を
除去する操作であり、係る操作でより効果的にリン酸半
水結晶に含まれた不純物を可及的に除去することができ
る。In this way, the displacement washing is to contact a mixture of ultrapure water or high-purity phosphoric acid at an arbitrary ratio to the surface of the precipitated phosphoric acid hemihydrate crystal to remove the raw phosphoric acid adhering to the phosphoric acid hemihydrate crystal. In this operation, impurities contained in the phosphoric acid hemihydrate crystals can be removed as effectively as possible.
なお、この操作は多くの場合、発汗操作の後で行う方
が合理的である。In many cases, it is more reasonable to perform this operation after the sweating operation.
かくして、本発明によれば、高純度のリン酸結晶を
得、次いで必要に応じこれを超純水に溶解すれば高純度
リン酸液として工業的に有利に製造することができる。Thus, according to the present invention, a high-purity phosphoric acid crystal is obtained, and then, if necessary, is dissolved in ultrapure water to produce a high-purity phosphoric acid solution industrially advantageously.
［作 用］ 本発明によれば、原料リン酸を所定温度における過冷
却状態で半水結晶として晶析することにより一次精製さ
れたリン酸半水結晶を得、次いで、この結晶を発汗操作
させることにより結晶内部に取り込まれた不純物が結晶
表面にマイグレーションして濃縮され、この不純物と結
晶表面に付着した母液の不純物とが液滴の中にあって滴
下除去することにより第二次の精製がなされる。[Operation] According to the present invention, primary phosphoric acid hemihydrate crystals are obtained by crystallizing raw phosphoric acid as hemihydrate crystals in a supercooled state at a predetermined temperature, and then the crystals are subjected to a sweating operation. As a result, impurities taken into the crystal migrate to the crystal surface and are concentrated, and this impurity and impurities of the mother liquor adhering to the crystal surface are present in the droplets and are dropped. Done.
また、より効果的な精製は、前記二次精製の前後にお
いて、好ましくはその後で、水ないし高純度リン酸で置
換洗浄する第三次の精製を所望により施すことにより達
成され、高純度リン酸を得ることができる。Further, more effective purification is achieved by performing, if desired, a third purification, which is carried out by washing with water or high-purity phosphoric acid before and after the secondary purification, preferably thereafter, to obtain high-purity phosphoric acid. Can be obtained.
［実 施 例］ 実施例で用いる原料リン酸は次のように調製した。[Example] The raw material phosphoric acid used in the example was prepared as follows.
すなわち、公知のリン酸の製造法である乾式法で製造
したリン酸（H3PO4として89重量％）をポリテトラフル
オロエチレン（PTFE）でできた孔径0.8μｍのメンブラ
ンフィルター［東洋濾紙（株）社製:T080A047A］で濾過
することによって、0.8μｍ以上の粒子の個数を減少さ
せ、とりわけ２μｍ以上の浮遊微粒子を取り除いた。That is, a phosphoric acid (89% by weight as H 3 PO 4 ) produced by a dry method, which is a known method for producing phosphoric acid, is made of polytetrafluoroethylene (PTFE) and has a pore size of 0.8 μm [Toyo Filter Paper Co., Ltd. ) Co., Ltd .: T080A047A] to reduce the number of particles of 0.8 μm or more, and in particular, to remove suspended particles of 2 μm or more.
このリン酸中の金属元素の量をフレームレス原子吸光
光度分析によって測定したところ、Feは180ppb、Mnは50
ppb、Naは250ppbであった。When the amount of the metal element in the phosphoric acid was measured by flameless atomic absorption spectrometry, Fe was 180 ppb and Mn was 50 ppb.
ppb and Na were 250 ppb.
なお、85重量％の原料リン酸は、この89重量％の原料
リン酸を超純水で希釈して調製した。The 85% by weight raw phosphoric acid was prepared by diluting the 89% by weight raw phosphoric acid with ultrapure water.
実施例１〜３ 所定の濃度に調製した原料リン酸を硬質ガラス製容器
に2.5kg入れ、所定の過冷却温度となるように温度を設
定し撹拌用ポンプで原料リン酸を循環し原料リン酸の温
度及び濃度の分布を少なくした。Examples 1 to 3 2.5 kg of raw phosphoric acid adjusted to a predetermined concentration was placed in a hard glass container, the temperature was set to a predetermined supercooling temperature, and the raw phosphoric acid was circulated by a stirring pump to be mixed with the raw phosphoric acid. Temperature and concentration distributions were reduced.
他方、外径2.5cm、長さ10cmの二重円筒形晶析管を用
い、次のような操作と条件で実施した。すなわち、原料
リン酸中に晶析管を浸漬し、浸漬管内部に所定過冷却温
度の冷媒（水とエチレングリコールの混合液）を流通
し、晶析管に伝熱面表面にリン酸半水結晶を晶析した。
このときの条件を表２に示す。晶析操作の後に析出結晶
の質量を測定した結果を併せて表２に示す。On the other hand, a double cylindrical crystallization tube having an outer diameter of 2.5 cm and a length of 10 cm was used under the following operation and conditions. That is, the crystallization tube is immersed in the raw phosphoric acid, a refrigerant (a mixture of water and ethylene glycol) having a predetermined supercooling temperature is circulated inside the immersion tube, and the phosphoric acid hemihydrate is applied to the heat transfer surface of the crystallization tube. The crystals were crystallized.
Table 2 shows the conditions at this time. Table 2 also shows the results of measuring the mass of the precipitated crystals after the crystallization operation.
なお、晶析管表面へリン酸半水結晶が晶析する速度
は、冷媒の過冷却温度によって異なるが、およそ12〜16
kg・cm-2・hr-1の範囲であった。 The rate at which the phosphoric acid hemihydrate crystals crystallize on the surface of the crystallizing tube varies depending on the supercooling temperature of the refrigerant.
kg · cm -2 · hr -1 .
所定の結晶成長時間が経過した後、晶析管を取り出
し、原料リン酸を滴下させ分離した。このリン酸半水結
晶に含まれるFe、Mn及びNa等の不純物成分をフレームレ
ス原子吸光光度分析によって測定して晶析工程における
リン酸の精製の程度を調べたところ、表３の結果が得ら
れた。After a lapse of a predetermined crystal growth time, the crystallization tube was taken out, and phosphoric acid as a raw material was dropped to separate the crystallized tube. Impurity components such as Fe, Mn and Na contained in the phosphoric acid hemihydrate crystals were measured by flameless atomic absorption spectrometry to determine the degree of purification of phosphoric acid in the crystallization step, and the results in Table 3 were obtained. Was done.
次いで、晶析工程で得たリン酸半水結晶が付着した晶
析管を引き上げた後、発汗操作時の冷媒温度を表４に記
載の温度になるようにすると共にこの温度ないしは少な
くとも±２℃の範囲で一定の温度に保った気相中に保持
したところ、リン酸半水結晶の表面の一部が融解して結
晶に付着した母液と共に滴下した。晶析管の表面に析出
し付着したリン酸半水結晶の質量に対して滴下した前記
混合液量が30重量％となった後に晶析管の表面に残った
リン酸半水結晶を採取し、リン酸半水結晶に含まれるF
e、Mn及びNaの成分含有量をフレームレス原子吸光個分
析によって測定した。その結果を表４に示す。 Next, after pulling up the crystallization tube to which the phosphoric acid hemihydrate crystals obtained in the crystallization step are attached, the refrigerant temperature during the sweating operation is adjusted to the temperature shown in Table 4 and at the same time or at least ± 2 ° C. When kept in a gas phase maintained at a constant temperature in the range of, a part of the surface of the phosphoric acid hemihydrate crystal was melted and dropped together with the mother liquor attached to the crystal. The phosphoric acid hemihydrate crystals remaining on the surface of the crystallization tube were collected after the amount of the mixed solution dropped to the mass of the phosphoric acid hemihydrate crystals deposited and adhered on the surface of the crystallization tube became 30% by weight. , F contained in phosphoric acid hemihydrate crystals
The component contents of e, Mn and Na were measured by flameless atomic absorption spectrometry. Table 4 shows the results.
実施例４、５ 実施例１〜２で得られた発汗後のそれぞれの精製リン
酸半水結晶に対して、晶析管表面の過冷却温度を５℃と
した。この晶析管表面に析出したリン酸半水結晶に超純
水及び本発明方法により得られた高純度リン酸を噴霧に
よる置換洗浄した。 Examples 4 and 5 The supercooling temperature of the surface of the crystallization tube was set to 5 ° C for each of the purified phosphoric acid hemihydrate crystals obtained after sweating obtained in Examples 1 and 2. Ultrapure water and the high-purity phosphoric acid obtained by the method of the present invention were replaced and washed by spraying the phosphoric acid hemihydrate crystals deposited on the surface of the crystallizing tube.
この洗浄操作後、表面に残ったリン酸半水結晶を採取
し、リン酸半水結晶に含まれるFe、Mn及びNaの成分含有
量を上述と同様に測定したところ、表５の結果が得られ
た。After this washing operation, the phosphoric acid hemihydrate crystals remaining on the surface were collected, and the contents of Fe, Mn, and Na contained in the phosphoric acid hemihydrate crystals were measured in the same manner as described above, and the results in Table 5 were obtained. Was done.
［発明の効果］ 以上説明したように、本発明による上記高純度リン酸
の製造方法によれば、Fe、Mn及びNa元素成分が混入して
いない高純度リン酸を容易に精製し製造できる利点を挙
げることができる。 [Effects of the Invention] As described above, according to the method for producing high-purity phosphoric acid according to the present invention, there is an advantage that high-purity phosphoric acid containing no Fe, Mn, and Na element components can be easily purified and produced. Can be mentioned.
また、本発明方法により得られた高純度リン酸は、F
e、Mn及びNa元素成分の混入が少ないために半導体製造
工程において窒素珪素膜を除去するために使用した際
に、微細素子の電気特性を劣化させる不純物を実質的に
含まない好適な電子材料となる。The high-purity phosphoric acid obtained by the method of the present invention is F
e, a suitable electronic material substantially free of impurities that degrade the electrical characteristics of the microelement when used to remove the nitrogen silicon film in the semiconductor manufacturing process due to the low mixing of the Mn and Na element components. Become.
また、更に言えば、この高純度リン酸は、不純物の含
有量が少ないという特徴から、金属アルミニウムのエッ
チング液、セラミック用アルミナエッチング液、光ファ
イバー用のリン酸ガラスの原料としても好適な材料にも
なる。Furthermore, since this high-purity phosphoric acid is characterized by a low content of impurities, it is also a suitable material as a raw material of a metal aluminum etching solution, a ceramic alumina etching solution, and a phosphate glass for an optical fiber. Become.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭54−38296（ＪＰ，Ａ) 特開 昭62−30607（ＪＰ，Ａ) 特公 昭46−3246（ＪＰ，Ｂ１) (58)調査した分野(Int.Cl.7，ＤＢ名) C01B 25/234 ＣＡ（ＳＴＮ)──────────────────────────────────────────────────続 き Continued from the front page (56) References JP-A-54-38296 (JP, A) JP-A-62-30607 (JP, A) JP-B-46-3246 (JP, B1) (58) Field (Int. Cl. 7 , DB name) C01B 25/234 CA (STN)
Claims (2)
冷媒を流通した晶析管を浸漬して浸漬管表面にリン酸半
水結晶を析出させる晶析工程、 （ロ）次いで、晶析管を原料リン酸より取り出した後、
晶析管表面に析出したリン酸半水結晶を発汗させて結晶
内外に含有する不純物を除去する精製工程、からなるこ
とを特徴とする高純度リン酸の製造方法。(A) a crystallization step of immersing a crystallization tube in which a refrigerant is circulated in a raw phosphoric acid having a concentration of 70% by weight or more to precipitate phosphoric acid hemihydrate crystals on the surface of the immersion tube; , After removing the crystallization tube from the raw phosphoric acid,
A method for producing high-purity phosphoric acid, comprising: a purification step of sweating phosphoric acid hemihydrate crystals deposited on the surface of a crystallization tube to remove impurities contained inside and outside the crystals.
おいて、晶析管表面に析出したリン酸半水結晶を超純水
あるいは高純度リン酸で置換洗浄し、不純物を除去する
精製工程を付加する請求項１記載の高純度リン酸の製造
方法。2. A purification method in which the phosphoric acid hemihydrate crystals deposited on the surface of the crystallization tube are replaced and washed with ultrapure water or high-purity phosphoric acid to remove impurities before or after the purification step (b). The method for producing high-purity phosphoric acid according to claim 1, wherein a step is added.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01329462A JP3131433B2 (en) | 1989-12-21 | 1989-12-21 | Method for producing high-purity phosphoric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01329462A JP3131433B2 (en) | 1989-12-21 | 1989-12-21 | Method for producing high-purity phosphoric acid |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18131299A Division JP3382561B2 (en) | 1999-06-28 | 1999-06-28 | High purity phosphoric acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03193614A JPH03193614A (en) | 1991-08-23 |
| JP3131433B2 true JP3131433B2 (en) | 2001-01-31 |
Family
ID=18221647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01329462A Expired - Lifetime JP3131433B2 (en) | 1989-12-21 | 1989-12-21 | Method for producing high-purity phosphoric acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3131433B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6861039B1 (en) * | 1998-12-28 | 2005-03-01 | Toyo Boeski Kabushiki Kaisha | Method for purification of phosphoric acid high purity polyphosphoric acid |
| FI105909B (en) | 1999-03-24 | 2000-10-31 | Kemira Chemicals Oy | Process for improving the quality of phosphoric acid |
| CN1312030C (en) * | 2005-06-09 | 2007-04-25 | 北京泓远迪绿色技术有限公司 | Method for purifying wet-process phosphoric acid by crystallization |
| JP4873894B2 (en) * | 2005-06-27 | 2012-02-08 | 下関三井化学株式会社 | Method for producing high purity purified phosphoric acid |
| JP2008247733A (en) * | 2007-03-14 | 2008-10-16 | Niro Process Technology Bv | Purification of phosphoric acid rich stream |
| CH701939B1 (en) * | 2007-09-06 | 2011-04-15 | Sulzer Chemtech Ag | Method and apparatus for the purification of aqueous phosphoric acid. |
| CN102616761A (en) * | 2012-04-10 | 2012-08-01 | 瓮福（集团）有限责任公司 | Automatic temperature control system for crystallized phosphoric acid production |
| CN102602903A (en) * | 2012-04-10 | 2012-07-25 | 瓮福（集团）有限责任公司 | Temperature control system for crystal phosphoric acid production |
| CN103771374B (en) * | 2013-12-30 | 2016-04-20 | 广西明利化工有限公司 | A kind of electron-level phosphoric acid baffle crystallization device |
| CN105366655B (en) * | 2015-12-10 | 2018-01-02 | 四川蓝海化工（集团）有限公司 | The preparation method of capacitor stage phosphoric acid crystal |
-
1989
- 1989-12-21 JP JP01329462A patent/JP3131433B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03193614A (en) | 1991-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3131433B2 (en) | Method for producing high-purity phosphoric acid | |
| RU2171229C2 (en) | Method of dissolving and purifying tantalum pentaoxide (variants) | |
| EP1640340B1 (en) | High purity phosphoric acid and process for producing the same | |
| US5165907A (en) | Method of production of high purity silica and ammonium fluoride | |
| JP3382561B2 (en) | High purity phosphoric acid | |
| JP3103360B2 (en) | High purity phosphoric acid and method for producing the same | |
| KR101516601B1 (en) | Purification of Phosphoric Acid Rich Streams | |
| JP6728731B2 (en) | Method for recovering hydrofluoric acid and nitric acid | |
| KR101267638B1 (en) | Method for producing high purity caustic potash | |
| KR100454101B1 (en) | Purification method and equipment for phosphoric acid | |
| RU2424188C1 (en) | Method of producing high-purity calcium fluoride | |
| JP7345728B2 (en) | How to purify lithium carbonate | |
| US3458279A (en) | Process for preparing sodium metaphosphate | |
| US3340002A (en) | Method of manufacturing germanium-containing products substantially free of fluorinefrom liquids containing fluorine and germanium | |
| JP2547500B2 (en) | How to reduce tantalum | |
| JP4635314B2 (en) | Method for producing sodium sulfate | |
| KR100593833B1 (en) | Separation and recovery method of ultra-high purity phosphoric acid from semiconductor waste etching solution | |
| JP3137226B2 (en) | Production method of high purity strontium chloride | |
| JP4457575B2 (en) | Zeolite-modified soil production method, zeolite-modified soil production system, and zeolitic-modified soil | |
| RU2103400C1 (en) | Method of processing baddeleyite | |
| RU2583956C2 (en) | Method of obtaining extraction phosphoric acid | |
| JP3613324B2 (en) | Method for producing tantalum oxide and / or niobium oxide | |
| JPS62153111A (en) | Production of high-purity silica | |
| SU1723040A1 (en) | Method of potassium heptafluorotantalate synthesis | |
| JP3907449B2 (en) | Method for purifying fluorine-containing benzoic acid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081117 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081117 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091117 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101117 Year of fee payment: 10 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101117 Year of fee payment: 10 |