JPS60180905A - Manufacture of sulfuric acid for electronic industry - Google Patents

Abstract

PURPOSE:To manufacture high purity sulfuric acid for the electronic industry having a very low dust content in an industrially advantageous manner by filtering liq. sulfur trioxide with a filter medium having a specified pore size, gasifying the filtered liq. sulfur trioxide, and allowing the resulting gas to be absorbed in water or sulfuric acid. CONSTITUTION:Liq. SO3 is introduced into a filter 2 through a duct 1 and filtered with a filter medium having 0.01-2mum pore size such as a sintered metallic filter. The filtered liq. SO3 is introduced into a gasifier 3, where 90-60wt% of it is gasified, and the remainder is taken out through a purge pipe 5. The resulting gaseous SO3 is introduced into an absorption tower 6, 98% sulfuric acid is fed from the top of the tower 6 through a circulating sulfuric acid duct 7, and pure water is properly supplied through a pure water duct 8 to produce sulfuric acid by the absorption of the gaseous SO3. This sulfuric acid is drawn from the bottom of the tower 6 through a drawing pipe 9, and part of it is drawn through a drawing pipe 11 as a product and taken out of an outlet 13 through a filter 12.

Description

【発明の詳細な説明】 本発明は電子工業用硫酸の製造法に関するものである。[Detailed description of the invention] The present invention relates to a method for producing sulfuric acid for electronic industry.

詳しくは高純度でダスト含有量の極めて少ない電子工業
用硫酸を工業的に有利に製造する方法に関するものであ
る。Specifically, the present invention relates to an industrially advantageous method for producing sulfuric acid for the electronic industry with high purity and extremely low dust content.

液体三酸化硫黄（以下「液体Ｓ０３」と略記する）を気
化させて三酸化硫黄ガス（以下「Ｓ０３ガス」と略記す
る）とし、これを水または硫酸に吸収させるｌ硫酸の製
造法は、液体Ｓｏ３を気化させる際に、高沸点分を残す
などの方法を採ることによって精製の効果を持たせるこ
とができるので、電子工業用等の高純度硫酸を製造する
のに好ましい方法である。The method for producing sulfuric acid is to vaporize liquid sulfur trioxide (hereinafter abbreviated as "liquid S03") into sulfur trioxide gas (hereinafter abbreviated as "S03 gas") and absorb this into water or sulfuric acid. This is a preferred method for producing high-purity sulfuric acid for use in the electronics industry, etc., since it is possible to provide a purification effect by leaving a high-boiling point component when vaporizing So3.

しかしながら、電子工業用硫酸は高純度であるとともに
、実質的にダストを含まないことが要求されるので、上
記硫酸の製造法にダストの除去操作を組み込むことが必
要である。ダストの除去法としては、製品化する直前に
硫酸ｋ濾過することか、直接的で効果が太きいが、硫酸
は粘度が高いので孔径が小さい炉材を用いて濾過するこ
とは容易ではないだめ、十分なダスト除去を計ろうとし
て孔径が小さい炉材を使用す拐を交換する必要がある等
の難点を有している。However, since sulfuric acid for the electronic industry is required to be of high purity and substantially dust-free, it is necessary to incorporate a dust removal operation into the above-mentioned method for producing sulfuric acid. The most effective way to remove dust is to filter it directly with sulfuric acid immediately before commercialization, but since sulfuric acid has a high viscosity, it is difficult to filter it using a furnace material with small pores. However, in order to achieve sufficient dust removal, furnace materials with small pore diameters are used, and the pores must be replaced.

本発明者らはダストの除去法につき鋭意研究を重ねた結
果、前記した硫酸の製造法において気化させる前の液体
５ｏａｋ濾過するときは、液体Ｓｏ３は硫酸に比し粘度
が著しく小さいので濾過は容易であり、次いで液０体Ｓ
Ｏ８の気化２いうダストの同伴は考え難い工程があるた
め、かくして気化したＳＯ，ガスを水または硫酸に吸収
させて得だ硫酸はダスト含有量が少ないこと、およびそ
の結果、製品化する直前の硫酸の濾過の負荷が大巾に軽
減され、ここで使用する炉材の交換頻度２少なくするこ
とができるとと會知得して本発明を完成した。As a result of intensive research into dust removal methods, the inventors of the present invention found that when filtrating the liquid before vaporizing it in the above-mentioned sulfuric acid production method, liquid So3 has a significantly lower viscosity than sulfuric acid, so filtration is easy. , and then the liquid 0 body S
Since there is a process called vaporization of O8, which is difficult to imagine entrainment of dust, the vaporized SO gas is absorbed into water or sulfuric acid. The present invention was completed based on the knowledge that the burden of filtration of sulfuric acid can be greatly reduced, and the frequency of replacing the furnace material used here can be reduced by 2 times.

すなわち本発明は、工業的に有利に電子工業用硫酸を製
造することを目的とするものであり、この目的は、液体
５ｏ３ｅ濾過後気化させて水または硫酸に吸収させるこ
とによって達成される。That is, the object of the present invention is to industrially advantageously produce sulfuric acid for electronic industry, and this object is achieved by filtering the liquid 5o3e, vaporizing it, and absorbing it into water or sulfuric acid.

以下、本発明の詳細な説明する。The present invention will be explained in detail below.

第１図は本発明を実施する装置の一例を示す線図である
。FIG. 1 is a diagram showing an example of an apparatus for implementing the present invention.

図において、（１）は液体ＳＯ，導入管、（２）は液体
Ｓｏ３’　濾過器、（３）は気化器、（４）はＳｏ、ガ
ス導管、（５）は液体Ｓｏ、パージ管、（６）は吸収塔
、（７）は循環硫酸導管、（８）は純水導入管、（９）
は吸収後の硫酸の抜出管、（７）はポンプ、０υは製品
硫酸抜出管、（２）は製品硫酸濾過器、Ｑ、Ｉは製品硫
酸取出口を示す。In the figure, (1) is liquid SO, inlet pipe, (2) is liquid So3' filter, (3) is vaporizer, (4) is So, gas conduit, (5) is liquid So, purge pipe, ( 6) is an absorption tower, (7) is a circulating sulfuric acid conduit, (8) is a pure water introduction pipe, (9)
(7) is a pump, 0υ is a product sulfuric acid extraction pipe, (2) is a product sulfuric acid filter, and Q and I are product sulfuric acid extraction ports.

液体ＳＯ３濾過器（２）に使用する炉材としては、焼結
金属フィルター、焼結不織布フィルター、四弗化樹脂（
テフロン）フィルター、ガラスフィルター、サンドフィ
ルター、珪藻土をブレコードしたフィルター等があげら
れる。これらフがハ豹〜コμｍであることが好ましく、
目的等に応じて好適な孔径のものを選ぶとか、複数個の
炉材を直列に使用するなどの使用法を採ればよい。Furnace materials used in the liquid SO3 filter (2) include sintered metal filters, sintered nonwoven fabric filters, and tetrafluoride resins (
Examples include Teflon filters, glass filters, sand filters, and diatomaceous earth bleed filters. It is preferable that these particles have a diameter of about 100 μm,
Depending on the purpose, a suitable hole diameter may be selected, or a plurality of furnace materials may be used in series.

液体Ｓｏ３濾過器（２）の設置箇所は、液体Ｓ０３の製
造から気化までの任意の箇所でよいが、通常、液体ＳＯ
３の貯槽（図示せず）から気化器（３）に至る液体ＳＯ
３の流路、例えば液体Ｓ０３導入管（１）の途中に設け
るのがよい。液体Ｓｏ、は一般にポンプ（図示せず）に
よって移送されるが、液体ＳＯｓ　ｆｆ粘度が小さいの
で、この流路に液体ＳＯ３濾過器（２）を挿入しても、
そのためのポンプの能力増は不要かまたはわずかでよい
。The liquid So3 filter (2) may be installed at any point from the production of liquid S03 to its vaporization, but usually liquid SO3
Liquid SO from storage tank 3 (not shown) to vaporizer (3)
It is preferable to provide the liquid S03 in the middle of the flow path No. 3, for example, the liquid S03 introduction pipe (1). Liquid So is generally transported by a pump (not shown), but since the liquid SOs ff viscosity is small, even if a liquid SO3 filter (2) is inserted into this flow path,
There is no need or only a small increase in pump capacity for this purpose.

濾過した液体Ｓｏ３は気化器（３）に導入し、ｑ５〜ｔ
ＯＣに加熱して８０．ガスを発生させる。この際、導入
しだ液体Ｓｏ３の９０−４０重量％を気化させ、残余の
液体Ｓｏ、をノぐ−ジロ（５）からノぐ一部することは
、Ｓ０３ガスが精製されることになるので好ましい方法
である。The filtered liquid So3 is introduced into the vaporizer (3), and from q5 to t
Heat to OC and 80. Generate gas. At this time, by vaporizing 90-40% by weight of the introduced liquid So3 and draining a portion of the remaining liquid So from the drain (5), the S03 gas will be purified. This is the preferred method.

気化したＳＯ，ガスは、水または硫酸に吸収させる。通
常、吸収塔（６）の塔頂に循環硫酸導管（７）からｑｇ
ｑｌｒ硫酸を循環し、純水導入管（８）から適宜純水を
補給しながら、塔底部のＳｏ３ガス導管（４）からＳｏ
３ガスを導入して８０３ガス舎吸収させ、吸収後の硫酸
を塔底の抜出管（９）から抜き出す。The vaporized SO gas is absorbed into water or sulfuric acid. Normally, qg
While circulating qlr sulfuric acid and replenishing pure water from the pure water inlet pipe (8) as appropriate, the So3 gas pipe (4) at the bottom of the tower is injected with So3.
3 gases are introduced and absorbed into the gas chamber 803, and the absorbed sulfuric acid is extracted from the extraction pipe (9) at the bottom of the tower.

抜き出した硫酸はポンプ（至）を通して一部を製品硫酸
として抜出管αυから抜き出し、残りの大部製品硫酸抜
出管αυから抜き出した硫酸は、必要に応じて、空気を
流通させる脱亜硫酸ガス処理等を施した後、出荷用容器
に充填する直前に製品硫酸濾過器（６）で洗浄し取出口
ａ３から取り出す。ここで使用する炉材としては、前記
した液体８０ｓ濾過器（２）Ｋおけるのと同じ種類のも
のがあげられる。Part of the extracted sulfuric acid is passed through the pump (to) and extracted from the extraction pipe αυ as product sulfuric acid, and the remaining sulfuric acid is extracted from the product sulfuric acid extraction pipe αυ as a desulfurizing gas by circulating air as necessary. After the treatment, etc., the product is washed with a sulfuric acid filter (6) immediately before being filled into shipping containers, and taken out from the outlet a3. The furnace material used here is the same type as that used in the liquid 80s filter (2)K described above.

本発明方法によると、製品硫酸からのダスト除去の負担
を軽減することができ、製品硫酸濾過器Ｐ−ＪｆＡの交
換頻度を大巾に減少させることができ、しかも動力費等
の経費増はわずかであるから、工業的に極めて有利であ
る。According to the method of the present invention, the burden of removing dust from product sulfuric acid can be reduced, the frequency of replacing the product sulfuric acid filter P-JfA can be greatly reduced, and there is only a slight increase in expenses such as power costs. Therefore, it is extremely advantageous industrially.

以下、本発明を実施例によって具体的に説明するが、本
発明はその要旨をこえない限り以下の実施例に限定され
るものではない。EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

なお、実施例中「％」は１重量％」を示す。In addition, in the examples, "%" indicates "1% by weight".

実施例１および比較例／ 第１図に示す装置を用いて電子工業用硫酸の製造を行な
った。Example 1 and Comparative Example/ Sulfuric acid for the electronic industry was produced using the apparatus shown in FIG.

液体Ｓｏｗ　濾過器（２）として孔径０．２μｍのテフ
ロンフィルターを用い、液体Ｓ０３導入管（１）から液
体ＳＯ３ｆ　Ｊ　ｌ−ＯＡ９　／　ｈｒで通し、内容積
ｔｙｒｅの気化器（３）に４人した。A Teflon filter with a pore size of 0.2 μm was used as the liquid sow filter (2), and the liquid was passed through the liquid S03 introduction pipe (1) at a rate of SO3f J l-OA9/hr, and 4 people were placed in the vaporizer (3) with an internal volume of .

気化器（３）は内温を＜ｔｔＣに保って導入液体ＳＯ，
の６Ｊ％を気化させ、残余の液体Ｓｏ３はパーシロ（５
）から抜き出した。The vaporizer (3) maintains the internal temperature at <ttC and supplies the introduced liquid SO,
6J% of the liquid So3 is vaporized, and the remaining liquid So3 is persilo (5J%).
).

気化したＳｏ、ガスは導管（４）を通し−Ｃ吸収塔（６
）の塔底部に導入した。吸収塔（６）は直径θ、３ｍ。The vaporized So gas passes through the conduit (4) to the -C absorption tower (6
) was introduced into the bottom of the tower. The absorption tower (6) has a diameter θ and 3 m.

高さ１１ｍで、塔頂に循環硫酸導管（７）から９ざチ硫
酸す、ｏθθｋｙ／　ｈｒを循環し、純水導入管（８）
から純水グθＡｉＦ／ｈｒｆｒ：導入しつつＳＯ，ガス
の吸収を行なった。With a height of 11 m, 90% sulfuric acid, oθθky/hr is circulated from the circulating sulfuric acid conduit (7) at the top of the tower, and the pure water inlet pipe (8)
SO and gas were absorbed while introducing pure water θAiF/hrfr.

吸収塔（６）の塔底からは吸収後の硫酸を抜出管（９）
から抜き出し、ポンプ（至）を通した後、製品硫酸抜出
管ａυから硫酸コ／　Ｏｋｆ／ｈｒを抜き出し、上記し
た液体ｓｏｓ　濾過器（２）と同じテフロンフィルター
を使用した製品硫酸濾過器（２）を通して、ダスト含有
ｆｉｔ（１００ｍｌ中の、２４μｍ以上のダストの数）
５００個の電子工業用硫酸を製造した。A pipe (9) extracts the absorbed sulfuric acid from the bottom of the absorption tower (6).
After passing through the pump (to), the sulfuric acid/Okf/hr is extracted from the product sulfuric acid extraction pipe aυ, and the product is passed through the product sulfuric acid filter (2) using the same Teflon filter as the liquid SOS filter (2) described above. ) through the dust-containing fit (number of dust larger than 24 μm in 100 ml)
500 pieces of sulfuric acid for electronic industry were produced.

濾過器の炉材は、製品硫酸濾過器（２）が７７月毎に１
回、液体Ｓｏ、濾過器（２）が７７月毎に７回の頻度で
交換が必要であった。The furnace material of the filter is 1 every 77 months for the product sulfuric acid filter (2).
The liquid So filter (2) needed to be replaced 7 times every 7 months.

比較のため、液体ＳＯ，の濾過を行なうことなく、他は
全く同様に操作して同品質の電子工業用硫酸を製造した
ところ、製品硫酸テ過器＠の炉材は７週間毎に交換が必
要であった。For comparison, we produced sulfuric acid for the electronic industry of the same quality using exactly the same procedure without filtration of liquid SO, and found that the furnace material of the product sulfuric acid filter @ had to be replaced every 7 weeks. It was necessary.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明を実施する装置の一例を示す線図である
。 （１）液体Ｓｏ、導入管 （２）液体ｓｏｓ　濾過器 （３）気化器 （４Ｊ　Ｓｏ３ガス導管 （５）液体Ｓｏ、パージ管 （６）吸収塔 （７）循環硫酸導管 （３）純水導入管 （９）吸収後の硫酸の抜出管 （至）ポンプ αυ　製品硫酸抜出管 （２）製品硫酸濾過器 ０３　Ｍ品硫酸取出口FIG. 1 is a diagram showing an example of an apparatus for implementing the present invention. (1) Liquid So, introduction pipe (2) Liquid SOS filter (3) Vaporizer (4J So3 gas pipe (5) Liquid So, purge pipe (6) Absorption tower (7) Circulating sulfuric acid pipe (3) Pure water introduction Pipe (9) Sulfuric acid extraction pipe after absorption (to) Pump αυ Product sulfuric acid extraction pipe (2) Product sulfuric acid filter 03 M product sulfuric acid extraction port

Claims (1)

【特許請求の範囲】[Claims] （１）液体三酸化硫黄を濾過後気化させて水または硫酸
に吸収させることを特徴とする電子工で濾過することを
特徴とする特許請求の範囲第（１）項記載の電子工業用
硫酸の製造法。(1) The sulfuric acid for the electronic industry according to claim (1) is filtered using an electronic device that vaporizes liquid sulfur trioxide after filtration and absorbs it into water or sulfuric acid. Manufacturing method.