JPS6256319A - Production of high-purity silica - Google Patents
Production of high-purity silicaInfo
- Publication number
- JPS6256319A JPS6256319A JP19305085A JP19305085A JPS6256319A JP S6256319 A JPS6256319 A JP S6256319A JP 19305085 A JP19305085 A JP 19305085A JP 19305085 A JP19305085 A JP 19305085A JP S6256319 A JPS6256319 A JP S6256319A
- Authority
- JP
- Japan
- Prior art keywords
- silica
- silica gel
- slurry
- washing tower
- washing
- 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.)
- Granted
Links
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は高純度シリカの製造法に関し、更に詳しくは珪
酸アルカリと鉱酸との反応によって顆粒状シリカを生成
し、該顆粒状シリカを洗浄することにより高純度のシリ
カを製造する方法に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing high-purity silica, and more specifically, the present invention relates to a method for producing high-purity silica, and more specifically, producing granular silica by a reaction between an alkali silicate and a mineral acid, and washing the granular silica. The present invention relates to a method for producing high-purity silica.
近年、高純度化されたシリカは触媒担体、電子材料原料
などにおいて益々需要が増加して来ている。たとえば、
電子材料の１例として、半導体封止材フィラーの原料と
して用いる場合、アルカリ金属の混入は配線腐食の問題
、放射性元素の混入はソフトエラーの原因として、益々
高集積化されるＩＣ，ＬＳＩの分野に於いてシリカフィ
ラーの純度が要求されている。In recent years, demand for highly purified silica has been increasing as a catalyst carrier, a raw material for electronic materials, and the like. for example,
As an example of electronic materials, when used as a raw material for semiconductor encapsulant filler, the contamination of alkali metals causes wiring corrosion, and the contamination of radioactive elements causes soft errors in the field of IC and LSI, which are becoming increasingly highly integrated. The purity of the silica filler is required.
他方、触媒担体としてシリカを利用する場合、純度の低
下は対称触媒反応の副反応が生じ、目的とする反応の収
率、純度に影響を及ぼす原因となっている。On the other hand, when silica is used as a catalyst carrier, a decrease in purity causes side reactions in the symmetric catalytic reaction, which affects the yield and purity of the desired reaction.
この様な各分野の需要に応するためには純度の高いシリ
カが要望されているが、従来のシリカの製造法は珪酸ア
ルカリと鉱酸との反応により生成したシリカゲルのスラ
リーをデカンテーション、バッチ槽での攪拌、濾過、あ
るいに遠心分離による操作により洗浄してシリカを得る
方法が行われている。Highly pure silica is required to meet the demands of these various fields, but the conventional silica manufacturing method is to decant a slurry of silica gel produced by the reaction of alkali silicate and mineral acid, and then process it in batches. Methods of obtaining silica include washing in a tank, filtration, or centrifugation.
しかしながら、珪酸アルカリと鉱酸との反応により生成
したシリカゲルは極めて微粒子であるか、あるいは顆粒
状のシリカゲルに微粒状のシリカが同伴した性状を有す
るために、上記のいずれの洗浄方法においてもシリカの
微細粒子の損失が多く、また濾過性が悪く、時には分離
不能となることもある。さらに、遠心分離によるシリカ
ゲルのスラリーの洗浄も工業的操作としては効率的に操
作し難い問題点がある。However, since the silica gel produced by the reaction between an alkali silicate and a mineral acid is extremely fine particles or has a property in which fine silica particles are accompanied by granular silica gel, neither of the above cleaning methods can remove silica. There is a lot of loss of fine particles, and the filterability is poor, sometimes making separation impossible. Furthermore, washing the silica gel slurry by centrifugation also has the problem of being difficult to operate efficiently in industrial operations.
さらに、この様な洗浄操作の因難性に加えて、反応によ
り生成したシリカゲルのスラリーには原料の珪酸アルカ
リ及び鉱酸等に起因する不純物元素として、たとえばシ
リカ（ＳｉＯ２）基準で鉄（Ｆｅ）１００ｐｐｍ以上、
ナトリウム（Ｎａ）１０％以上、ウラン（Ｕ）１００ｐ
ｐｂ以上を含有しているために、これ等の不純物元素の
含有量を各金属元素１０ｐｐｍ以下、放射性元素１ｐｐ
ｂ以下に低減せしめるためには洗浄工程において使１４
１する洗浄水を多量に、たとえばシリカ当り３０倍以上
の純水を必要とする等の問題点があった。Furthermore, in addition to the difficulty of such a cleaning operation, the silica gel slurry produced by the reaction contains impurity elements originating from the raw materials such as alkali silicate and mineral acids, such as iron (Fe) based on silica (SiO2). 100ppm or more,
Sodium (Na) 10% or more, uranium (U) 100p
Since it contains more than PB, the content of these impurity elements should be reduced to 10 ppm or less for each metal element and 1 ppm for radioactive elements.
In order to reduce the
There are problems in that a large amount of washing water is required, for example, 30 times or more of pure water per silica.
本発明者等はこの様な現状に鑑み、高純度のシリカの需
要の増大に伴ない、原料の安定供給が１１Ｔ能で安価な
珪酸アルカリを出発原料として、経済的に高純度シリカ
を工業的に製造する方法を提供することを目的として鋭
意研究を行った結果、珪酸アルカリと鉱酸との反応によ
り実質的に０．１四以上の粒径の顆粒状シリカゲルのス
ラリーを生成せしめ、次いで該スラリーを向流洗浄によ
り洗浄することにより、珪素以外の金属成分の含有率を
ＳｉＯ２当り１０ｐｐｍ以下、特に放射性元素（Ｕ。In view of the current situation, and with the increasing demand for high-purity silica, the inventors of the present invention have developed an economical method to produce high-purity silica industrially, using a stable supply of raw materials as starting material from an inexpensive alkali silicate with a capacity of 11T. As a result of extensive research aimed at providing a method for producing silica gel, a slurry of granular silica gel with a particle size of substantially 0.14 or more was produced by the reaction of alkali silicate and mineral acid, and then the By cleaning the slurry by countercurrent cleaning, the content of metal components other than silicon can be reduced to 10 ppm or less based on SiO2, especially radioactive elements (U).
Ｔｈ ’）の含有率を１ｐｐｂ以下に低減した高純度シ
リカを提供することができることを知見し本発明を完成
した。The present invention was completed based on the finding that it is possible to provide high-purity silica in which the content of Th') is reduced to 1 ppb or less.
〔問題点を解決・するための手段〕および〔作用〕すな
わち、本発明は珪酸アルカリと鉱酸との反応によってシ
リカゲルを製造する方法において、該反応によって生成
する顆粒状シリカゲルのスラリーを竪型洗浄塔の上部か
ら流下させ、その下部から洗浄水を注入して撹拌下にシ
リカゲルの充填層を形成させた状態で洗浄することを特
徴とする高純度シリカの製造法にかかるものである。[Means for solving the problem] and [Operation] That is, the present invention provides a method for producing silica gel by a reaction between an alkali silicate and a mineral acid, in which a slurry of granular silica gel produced by the reaction is washed in a vertical mold. This method relates to a method for producing high-purity silica, which is characterized in that washing water is caused to flow down from the upper part of the tower, and washing water is injected from the lower part of the tower to form a packed bed of silica gel while stirring.
以下、本発明について詳述する。The present invention will be explained in detail below.
本発明において、原料として適用される珪酸アルカリと
は８１０２７Ｍ２０ （式中ＭはＮａ又はＫを表わす）
のモル比が１乃至４の珪酸アルカリであるが鉱酸の使用
量との関係から特に３号珪酸ソーダの如きモル比の大き
い珪酸ソーダが好ましい。In the present invention, the alkali silicate used as a raw material is 81027M20 (in the formula, M represents Na or K)
The alkali silicate has a molar ratio of 1 to 4, but sodium silicate having a high molar ratio, such as No. 3 sodium silicate, is particularly preferred in view of the amount of mineral acid used.
濃度は特に限定することなく、生成するシリカの使用目
的によって自由に設定することができるが、多くの場合
、ＳｉＯ２として１０〜３０重量％の水溶液として用い
られる。The concentration is not particularly limited and can be freely set depending on the intended use of the produced silica, but in most cases it is used as an aqueous solution of 10 to 30% by weight of SiO2.
他方の原料である鉱酸としては、塩酸、硝酸又は硫酸等
を用いることができ、特に高純度シリカを製造する場合
には塩酸又は硝酸が有利である。As the mineral acid, which is the other raw material, hydrochloric acid, nitric acid, sulfuric acid, etc. can be used, and hydrochloric acid or nitric acid is particularly advantageous when producing high-purity silica.
上記の珪酸アルカリと鉱酸とを反応させてシリカゲルを
生成させるに当り、反応条件は、特に限定なく、周知の
方法を適宜選択しても差支えないが、本発明において、
特に後述するような効果的な洗浄をして不純物の実質的
な除去を行うためには、反応の当初から終了まで終始、
酸性領域でシリカゲルの生成を行わせることが望ましい
。In producing silica gel by reacting the above-mentioned alkali silicate and mineral acid, the reaction conditions are not particularly limited, and well-known methods may be selected as appropriate; however, in the present invention,
In particular, in order to effectively remove impurities as described below, it is necessary to clean the entire reaction from the beginning to the end.
It is desirable to generate silica gel in an acidic region.
反応系の酸濃度としては、１規定以上の場合が適当であ
り、反応系の温度は特に限定する必要はない。The acid concentration of the reaction system is suitably 1N or more, and the temperature of the reaction system does not need to be particularly limited.
なお、本反応においては、必要に応じて多価カルボン酸
、オキシカルボン酸、アミノポリカルボン酸等のキレ−
１・剤、あるいは過酸化水素等をＳｉＯ２に対して０．
５〜５重量％添加すると、より不純物の除去に効果的で
ある場合が多い。In addition, in this reaction, clear carboxylic acids such as polyhydric carboxylic acids, oxycarboxylic acids, aminopolycarboxylic acids, etc.
1. agent or hydrogen peroxide etc. to SiO2.
Addition of 5 to 5% by weight is often more effective in removing impurities.
かくして珪酸アルカリと鉱酸との反応により生成したシ
リカゲルは、原料から随伴する不純物と共に副生ずる多
量のアルカリ金属塩を母液中に伴って不純物を多量に吸
着したスラリーとなっている。The silica gel thus produced by the reaction between an alkali silicate and a mineral acid is a slurry that adsorbs a large amount of impurities, with a large amount of alkali metal salts produced as by-products in the mother liquor along with impurities accompanying the raw materials.
従って、以下に説明する洗浄を行うに当り、シリカゲル
は微細な粒子がアグロメレートシた顆粒状の粒子として
生成することが必要であり、この点からも酸性領域での
シリカゲルの生成が優れている。また、良好な洗浄効果
を得るためにはスラリー中の顆粒状シリカゲルの粒度は
０．１■以上が好ましい。Therefore, when performing the cleaning described below, it is necessary to produce silica gel in the form of granular particles in which fine particles are agglomerated, and from this point of view as well, production of silica gel in an acidic region is superior. Further, in order to obtain a good cleaning effect, the particle size of the granular silica gel in the slurry is preferably 0.1 square centimeter or more.
通常、シリカゲルのスラリーの洗浄はデカンテーション
、バッチ槽での攪拌洗浄あるいは、遠心分離による操作
を伴って洗浄することが行われるが、シリカゲルが極め
て微細粒子であるために、かかる洗浄操作では多量の洗
浄水を要すにもかかわらず、濾布への目詰まり等のトラ
ブルが生じ易く効率的な処理を行なうことが困難である
。Usually, silica gel slurry is washed by decantation, stirring in a batch tank, or centrifugation, but since silica gel is extremely fine particles, such washing operations require a large amount of water. Although cleaning water is required, problems such as clogging of the filter cloth are likely to occur, making it difficult to carry out efficient processing.
しかして、本発明はシリカゲルのスラリーと洗浄水とを
向流接触させて撹拌下でシリカゲルの充填層を形成させ
た状態で連続的に洗浄を行うことを特徴とする。Accordingly, the present invention is characterized in that washing is performed continuously in a state where a silica gel slurry and washing water are brought into countercurrent contact with each other to form a packed layer of silica gel under stirring.
次に、この操作について第１図に基づいて詳細に説明す
る。Next, this operation will be explained in detail based on FIG.
第１図は本発明において使用するシリカゲルのスラリー
の洗浄装置の説明図である。シリカゲルのスラリー貯槽
１には顆粒状のシリカゲルを５〜３０重量％含有するシ
リカスラリーが撹拌下で貯蔵されている。このスラリー
の組成の１例を示すと、たとえば硝酸と３号珪酸ソーダ
との反応により生成したシリカゲルスラリーの場合、５
ｉＯ２１１，７重量％、ＮａＮＯ３１０，４重量％、Ｈ
ＮＯ３４，２重量％、Ｆｅ ３０ ｐｐｒｒｘ、 Ａｌ
４ ｓ ｐｐｍ、Ｕ２０ｐｐｂ、Ｔｈ ２５ｐｐｂ
の組成（シリカゲルスラリー有姿）を有する。なお、該
シリカゲルスラリーの粒度は０．１ ｍｍ以下５％、０
．１〜１ ｍ８２％、１ｍ以上１３％である。FIG. 1 is an explanatory diagram of a silica gel slurry cleaning apparatus used in the present invention. In the silica gel slurry storage tank 1, a silica slurry containing 5 to 30% by weight of granular silica gel is stored under stirring. To give an example of the composition of this slurry, for example, in the case of silica gel slurry produced by the reaction of nitric acid and No. 3 sodium silicate,
iO2 11.7% by weight, NaNO3 10.4% by weight, H
NO34.2% by weight, Fe30 pprrx, Al
4s ppm, U20ppb, Th 25ppb
It has the following composition (as silica gel slurry). In addition, the particle size of the silica gel slurry is 0.1 mm or less, 5%, 0
．． 1 to 1 m 82%, 1 m or more 13%.
また、竪形の洗浄塔４には攪拌機７が設けられている。Further, the vertical washing tower 4 is provided with an agitator 7.
即ち攪拌機７″に攪拌しながら洗浄塔４の下部から、一
定流速で洗浄水（純水）３を注入し、洗浄塔上部から前
記のシリカゲルスラリーを流下し、洗浄塔内にシリカゲ
ルの充填層を形成させる。That is, washing water (pure water) 3 is injected at a constant flow rate from the lower part of the washing tower 4 while stirring into the stirrer 7'', and the silica gel slurry flows down from the upper part of the washing tower to form a packed bed of silica gel in the washing tower. Let it form.
この充填層はゆっ（りとした攪拌を行ない、充填層内液
中でシリカ粒子の激しい上下動がなく、ゆっ（りとした
シリカ流動層を形成せしめることが重要である。It is important that this packed bed is stirred slowly so that the silica particles do not move violently up and down in the liquid in the packed bed, and a slow silica fluidized bed is formed.
従って、この場合所望の充填層が形成される限り、特に
操作条件を限定する必要はないが、多くの場合１２０ｒ
ｐｍ以下の攪拌状態で０．５ｍ以上の充填層が形成され
ることが望ましい。このためには洗浄水の洗浄塔内の上
昇速度（空塔換算）は１５ｃｍ／ｍｉｎ 以下にする
必要があり、シリカ充填層の洗浄塔内の下降速度は１０
ｃｍ／ｍｉｎ 以下とする必要がある。しかもかかる
条件は洗浄対象物であるシリカスラリー中のシリカゲル
の粒度によるが、平均粒径０．３ ｍ （湿式篩）のシ
リカスラリーを処理する場合、洗浄水の空塔流速が速く
１０ｃｒｎ／ｍｉｎ をこえるとオーバーフロー液と
共にシリカが系外に流出し収率低下の原因となり、また
シリカゲルの充填層が乱されて偏流が生じ、洗浄を有効
に行うことができなくなる。Therefore, in this case, as long as the desired packed bed is formed, there is no need to particularly limit the operating conditions, but in many cases 120r
It is desirable that a packed layer of 0.5 m or more is formed under stirring conditions of pm or less. For this purpose, the rising speed of the washing water in the washing tower (in terms of empty tower) must be 15 cm/min or less, and the descending speed of the silica packed bed in the washing tower must be 10 cm/min or less.
cm/min or less. Moreover, these conditions depend on the particle size of the silica gel in the silica slurry that is the object to be cleaned, but when processing a silica slurry with an average particle size of 0.3 m (wet sieve), the superficial flow rate of the cleaning water is high, up to 10 crn/min. If the amount exceeds the amount, silica flows out of the system together with the overflow liquid, causing a decrease in yield, and the packed bed of silica gel is disturbed, resulting in uneven flow, making it impossible to perform cleaning effectively.
なお、この洗浄塔内におけるシリカゲルの平均滞留時間
は３０分以上であることが望ましい。従って、シリカ下
降速度は平均滞留時間を３０分以上必要とするため、装
置的な限界の面と充填層の安定化のため、上記速度を適
宜設定することが必要である。一般的にはシリカ充填層
の下降速度は洗浄水の上昇速度より遅くすることが安定
に高純度のシリカを回収する為には有効である。Note that it is desirable that the average residence time of silica gel in this washing tower is 30 minutes or more. Therefore, since the silica descending speed requires an average residence time of 30 minutes or more, it is necessary to set the above-mentioned speed appropriately in view of equipment limitations and stabilization of the packed bed. Generally, it is effective to make the descending speed of the silica packed bed slower than the rising speed of the washing water in order to stably recover high-purity silica.
攪拌はシリカ充填層の流動層を乱さない程度にシリカ中
の不純物イオンの拡散を促し、同時に偏流を防ぐ目的で
行なう。なお、洗浄塔４の所望の位置には精製薬剤貯槽
２を付設して適宜洗浄塔４への薬剤の注入ができるよう
にしている。この理由は鉱酸処理だけでは除去し難い不
純物質の除去のために、前記の珪酸アルカリと鉱酸との
反応において添加したのと同様な過酸化水素、多価カル
ボン酸、オキシカルボン酸あるいはアミンポリカルボン
酸等のキレ−１・剤をスラリーの酸性域の部分に注入し
て、不純物金属物質を可溶化させる目的で添加する。こ
の操作は必ずしも不可欠ではなく、対象のシリカスラリ
ーの性状により必要に応じて行なえばよい。Stirring is performed for the purpose of promoting diffusion of impurity ions in the silica without disturbing the fluidized bed of the silica packed bed, and at the same time preventing drift. Note that a purified chemical storage tank 2 is attached to a desired position of the cleaning tower 4 so that the chemical can be appropriately injected into the cleaning tower 4. The reason for this is that in order to remove impurities that are difficult to remove with mineral acid treatment alone, hydrogen peroxide, polycarboxylic acids, oxycarboxylic acids, or amines, similar to those added in the reaction between alkali silicate and mineral acid, are added. A cleaning agent such as polycarboxylic acid is injected into the acidic region of the slurry and added for the purpose of solubilizing impurity metal substances. This operation is not necessarily essential, and may be performed as necessary depending on the properties of the target silica slurry.
洗浄されたシリカスラリーはバルブ８を通り、洗浄シリ
カ受槽６に回収し、汚染液はオーバーフロー受槽５に回
収する。The washed silica slurry passes through a valve 8 and is collected in a washed silica receiving tank 6, and the contaminated liquid is collected in an overflow receiving tank 5.
なお、洗浄程度の監視はこのオーバーフロー液′又は／
および回収シリカスラリーのｐＨ及び電気伝導度をみな
がら行う。The degree of cleaning can be monitored using this overflow liquid' or /
This is carried out while monitoring the pH and electrical conductivity of the recovered silica slurry.
以上は１本の洗浄塔について説明したが、勿論必要に応
じ２本以上の洗浄塔を用いて洗浄を行ってもよい。例え
ば、２本の洗浄塔を用いて、第一の洗浄塔で大刀の洗浄
を行い、次いで第二の洗浄塔で完全に洗浄することもで
きる。The above description has been made regarding one cleaning tower, but of course, two or more cleaning towers may be used for cleaning if necessary. For example, it is also possible to use two cleaning towers, cleaning the long sword in the first cleaning tower and then completely cleaning it in the second cleaning tower.
他方、複数の洗浄塔を用いる場合、その中間には同様の
塔又は他の攪拌槽を設けて、顆粒状シリカゲルのスラリ
ーの酸処理を行い、不純物の可溶化を促進させた後、次
いで洗浄塔へ移行させることもできる。On the other hand, when multiple washing towers are used, a similar tower or other stirring tank is provided between them to perform acid treatment of the slurry of granular silica gel to promote solubilization of impurities, and then the washing tower You can also move to .
特に、高純度シリカを必要とする場合には、単独の塔に
よる洗浄のみでは充分に不純物元素を除去できないこと
もあるので酸処理を行うことが必要となるが、この操作
も第一の塔で母液を分離した程度の軽い洗浄をした後、
酸処理のために同様の塔または攪拌槽へ移行させ、系内
のスラリーが１規定以上の鉱酸濃度となるように鉱酸を
注入して洗浄操作と同様の条件で酸処理を行い、次いで
第一の洗浄塔へ移行して最終的な洗浄を行つク、とがで
きる。In particular, when high-purity silica is required, it may not be possible to remove impurity elements sufficiently by washing with a single column, so acid treatment is necessary, but this operation is also performed in the first column. After a light wash to separate the mother liquor,
Transfer to a similar column or stirring tank for acid treatment, inject mineral acid so that the slurry in the system has a mineral acid concentration of 1N or more, perform acid treatment under the same conditions as the cleaning operation, and then The final cleaning can be performed by moving to the first cleaning tower.
この様にして処理された洗浄シリカは含水率１０〜４０
重量％で洗浄塔下部から回収さｉｌろ・／ｌり、これは
常法により分離、乾燥等を施して回収することができる
。The washed silica treated in this way has a water content of 10 to 40.
The filtrate is recovered from the lower part of the washing tower in weight percent, and can be recovered by separation, drying, etc. using conventional methods.
かくして得られるシリカは高純度であり、例えば多くの
場合、シリカ中の不純物含有量をシリり当り各金属元素
１０ｐｐｍ以丁が達成され、特に放射性元素はＵ 、Ｔ
ｈについて、それぞれ１ｍ）１３ｂ以下にすることがで
きる。この様に本発明によれば、工業的に有利に高純度
シリカを製造することができる。The silica thus obtained has a high purity; for example, in many cases, the impurity content in the silica is less than 10 ppm of each metal element per silica, and in particular, the radioactive elements are U, T.
h can be made 1m) or less than 13b, respectively. As described above, according to the present invention, high purity silica can be produced industrially advantageously.
次に実施例を示し、本発明をさらに具体的に説明する。 EXAMPLES Next, the present invention will be explained in more detail with reference to Examples.
実施例１ ′
硝酸２０重量％水溶液１００ ｋｇを攪拌しながら７０
℃に加温、これに３号珪酸ソーダ水溶液（Ｓｕｎ□２８
．５重量％、Ｎａ２ｐ９．１重量％） ７０ ｋｐを約
３０分かけて添加した。これを７０℃で攪拌しながら２
時間保持した。得られたシリカゲルは０．１φ■篩で篩
上９４％であった（反応スラＩＪ−１）。Example 1 ' While stirring 100 kg of a 20% by weight nitric acid aqueous solution,
℃, and add No. 3 sodium silicate aqueous solution (Sun□28
．． 5% by weight, 9.1% by weight of Na2p) was added over about 30 minutes. While stirring this at 70℃,
Holds time. The obtained silica gel had a sieve coverage of 94% when sieved through a 0.1φ■ sieve (reaction sluice IJ-1).
１５０φｗＸ １，０００ Ｈｗｓ （攪拌器付）の洗
浄塔の上部から、このスラリーを洗浄塔内に充填して約
８００Ｈ１ａｌのシリカゲル充填層を形成した。This slurry was filled into the washing tower of 150φwX 1,000 Hws (with a stirrer) from the top to form a silica gel packed bed of about 800 H1al.
次いで、３０ ｒｐｍの攪拌状態で攪拌しながら下部か
ら洗浄水７００ｄ／ｍｉｎ 、上部からシリカスラリー
７００ ｍ／／ｍｉｎ を流し、下部から充填層の高さ
が一定となるように洗浄シリカスラリーをぬき出したと
ころ、撹拌下でシリカゲルの充填層は安定して形成され
た。この定常状態における洗浄水の空塔上昇速度は約４
ａｎ ／ ｍ ｉ ｎ 、 同じくシリカ充填層下
降速度は約２．３ ｃｍ ／ ｍ ｉ ｎ であり、シ
リカ充填層のシリカ濃度２０％〜３０％であった。この
操作で下部からとり出すシリカスラリーのｐＨが４．５
．電気伝導度０．０１ｍ５／ｃｍとなるように運転した
。この間約２２０分で回収されたシリカスラリーを分析
したところ次の第１表の通りであった。Next, while stirring at 30 rpm, washing water was poured at 700 d/min from the bottom and silica slurry at 700 m/min from the top, and the washed silica slurry was drawn out from the bottom so that the height of the packed bed was constant. As a result, a packed layer of silica gel was stably formed under stirring. The superficial rising speed of the washing water in this steady state is approximately 4
an/min, similarly, the silica packed bed descending speed was about 2.3 cm/min, and the silica concentration of the silica packed bed was 20% to 30%. With this operation, the pH of the silica slurry taken out from the bottom is 4.5.
．． It was operated so that the electrical conductivity was 0.01 m5/cm. The silica slurry collected during this period for about 220 minutes was analyzed and the results were as shown in Table 1 below.
第 １ 表 シリカ洗浄によるロスは８％であった。Table 1 The loss due to silica washing was 8%.
実施例２゜
実施例１と同じ操作で得た反応スラリー１を実施例１と
同一の洗浄塔で反応スラリーのシリカ充填層下降速度及
び洗浄水空塔上昇速度を変えて洗浄した。Example 2 The reaction slurry 1 obtained in the same manner as in Example 1 was washed in the same washing tower as in Example 1 by changing the rate of descent of the reaction slurry into the silica packed bed and the rate of rise of the washing water in the superficial column.
洗浄結果を第２表に示す。The washing results are shown in Table 2.
第 ２ 表
（支）Ｎａ２−３※は、洗浄初期より、過酸化水素（３
５重量％）及び５０重量％蓚酸溶液をＳｉＯ２に対し、
それぞれ０．５重量％の割合となるような添加条件で、
洗浄塔中段装入口から注入した。Table 2 (sub) Na2-3* shows that hydrogen peroxide (3
5 wt%) and 50 wt% oxalic acid solution to SiO2,
Under addition conditions such that the ratio of each is 0.5% by weight,
It was injected from the middle charging port of the washing tower.
実施例３゜
１１．７重量％塩酸１２０ ｋｆを攪拌しながら７０℃
に昇温し、これに３号珪酸ソーダ水溶液４２ｋｆを１５
分で添加し、７０℃で攪拌しながら２時間保持した。こ
のものの０．１ｍ篩上は９２％であった。（反応スラリ
ー２）
実施例１と同一の洗浄塔で、前記反応スラリー２をシリ
カ充填層下降速度及び洗浄水空塔上昇速度を変え洗浄し
た。Example 3 120 kf of 11.7% by weight hydrochloric acid was heated at 70°C while stirring.
42 kf of No. 3 sodium silicate aqueous solution was added to this at 15
The mixture was added in 1 minute and kept at 70° C. with stirring for 2 hours. The 0.1 m sieve coverage of this product was 92%. (Reaction Slurry 2) In the same washing tower as in Example 1, the reaction slurry 2 was washed by changing the descending speed of the silica packed bed and the rising speed of the washing water superficial column.
洗浄結楽を第３表に示す。Table 3 shows the cleaning process.
本発明の製造法によれば操作性が良好で、洗浄水量も少
なく、設備が容易で連続して安定に工業生産が可能な洗
浄システムが達成出来、これによって各金属元素不純物
含有ｆｆ１ｌＯｐｐｒｎ以下で、放射性元素の含有量１
ｐｐｂ以下の高純度のシリカゲルを有利に製造すること
ができる。According to the manufacturing method of the present invention, a cleaning system with good operability, a small amount of cleaning water, easy equipment, and continuous and stable industrial production can be achieved. Radioactive element content 1
Silica gel with high purity of ppb or less can be advantageously produced.
第１図は本発明において使用するシリカゲルのスラリー
の洗浄装置の説明図である。FIG. 1 is an explanatory diagram of a silica gel slurry cleaning apparatus used in the present invention.
Claims (2)
を製造する方法において、該反応によって生成する顆粒
状シリカゲルのスラリーを竪形洗浄塔の上部から流下さ
せ、その下部から洗浄水を注入して撹拌下シリカゲルの
充填層を形成させた状態で洗浄することを特徴とする高
純度シリカの製造法。(1) In a method for producing silica gel by the reaction of an alkali silicate and a mineral acid, a slurry of granular silica gel produced by the reaction is allowed to flow down from the top of a vertical washing tower, and washing water is injected from the bottom and stirred. A method for producing high-purity silica, which is characterized in that washing is carried out in a state in which a packed layer of lower silica gel is formed.
分以上である特許請求の範囲第１項記載の高純度シリカ
の製造法。(2) Average residence time of silica gel in the washing tower is 30
The method for producing high-purity silica according to claim 1, wherein the production time is at least 1 minute.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19305085A JPS6256319A (en) | 1985-09-03 | 1985-09-03 | Production of high-purity silica |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19305085A JPS6256319A (en) | 1985-09-03 | 1985-09-03 | Production of high-purity silica |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6256319A true JPS6256319A (en) | 1987-03-12 |
| JPH0323488B2 JPH0323488B2 (en) | 1991-03-29 |
Family
ID=16301344
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19305085A Granted JPS6256319A (en) | 1985-09-03 | 1985-09-03 | Production of high-purity silica |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6256319A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2622565A1 (en) * | 1987-11-04 | 1989-05-05 | Rhone Poulenc Chimie | SILICA FOR DENTIFRING COMPOSITIONS COMPATIBLE IN PARTICULAR WITH ZINC |
| EP0409167A2 (en) * | 1989-07-18 | 1991-01-23 | Nkk Corporation | High purity silica and method for producing high purity silica |
| US5286478A (en) * | 1987-11-04 | 1994-02-15 | Rhone-Poulenc Chimie | Dentifrice-compatible silica particulates |
| US5342598A (en) * | 1989-07-03 | 1994-08-30 | Rhone-Poulenc Chimie | Precipitated silica particulates having controlled porosity |
| US5413844A (en) * | 1988-06-01 | 1995-05-09 | Rhone-Poulenc Chimie | Process for the preparation of zinc/dentifrice-compatible silica particulates |
| US6146533A (en) * | 1998-08-31 | 2000-11-14 | Director-General Of Agency Of Industrial Science And Technology | Method of treating wastewater containing chemical substances by use of supercritical fluid and treating apparatus |
| JP2006052108A (en) * | 2004-08-11 | 2006-02-23 | Nuclear Fuel Ind Ltd | Method for producing fuel particles for high-temperature gas-cooled reactor |
| JP2009517324A (en) * | 2005-12-01 | 2009-04-30 | イ− アンド ビ− ナノテク カンパニー リミテッド | Nanoporous silica production apparatus and production method thereof |
-
1985
- 1985-09-03 JP JP19305085A patent/JPS6256319A/en active Granted
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2622565A1 (en) * | 1987-11-04 | 1989-05-05 | Rhone Poulenc Chimie | SILICA FOR DENTIFRING COMPOSITIONS COMPATIBLE IN PARTICULAR WITH ZINC |
| US5286478A (en) * | 1987-11-04 | 1994-02-15 | Rhone-Poulenc Chimie | Dentifrice-compatible silica particulates |
| US5413844A (en) * | 1988-06-01 | 1995-05-09 | Rhone-Poulenc Chimie | Process for the preparation of zinc/dentifrice-compatible silica particulates |
| US5342598A (en) * | 1989-07-03 | 1994-08-30 | Rhone-Poulenc Chimie | Precipitated silica particulates having controlled porosity |
| US5968470A (en) * | 1989-07-03 | 1999-10-19 | Rhone-Poulenc Chimie | Precipitated silica particulates having controlled porosity |
| EP0409167A2 (en) * | 1989-07-18 | 1991-01-23 | Nkk Corporation | High purity silica and method for producing high purity silica |
| US6146533A (en) * | 1998-08-31 | 2000-11-14 | Director-General Of Agency Of Industrial Science And Technology | Method of treating wastewater containing chemical substances by use of supercritical fluid and treating apparatus |
| JP2006052108A (en) * | 2004-08-11 | 2006-02-23 | Nuclear Fuel Ind Ltd | Method for producing fuel particles for high-temperature gas-cooled reactor |
| JP4540047B2 (en) * | 2004-08-11 | 2010-09-08 | 原子燃料工業株式会社 | Method for producing fuel particles for HTGR |
| JP2009517324A (en) * | 2005-12-01 | 2009-04-30 | イ− アンド ビ− ナノテク カンパニー リミテッド | Nanoporous silica production apparatus and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0323488B2 (en) | 1991-03-29 |
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