JP2575706B2 - Prevention method of silica-based scale failure in pickling waste liquid system of steel material - Google Patents
Prevention method of silica-based scale failure in pickling waste liquid system of steel materialInfo
- Publication number
- JP2575706B2 JP2575706B2 JP62135616A JP13561687A JP2575706B2 JP 2575706 B2 JP2575706 B2 JP 2575706B2 JP 62135616 A JP62135616 A JP 62135616A JP 13561687 A JP13561687 A JP 13561687A JP 2575706 B2 JP2575706 B2 JP 2575706B2
- Authority
- JP
- Japan
- Prior art keywords
- waste liquid
- silica
- scale
- pickling waste
- based scale
- 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
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims description 36
- 239000007788 liquid Substances 0.000 title claims description 25
- 239000002699 waste material Substances 0.000 title claims description 24
- 239000000377 silicon dioxide Substances 0.000 title claims description 18
- 238000005554 pickling Methods 0.000 title claims description 15
- 229910000831 Steel Inorganic materials 0.000 title claims description 12
- 239000010959 steel Substances 0.000 title claims description 12
- 238000000034 method Methods 0.000 title claims description 9
- 239000000463 material Substances 0.000 title claims description 6
- 230000002265 prevention Effects 0.000 title description 4
- 150000003839 salts Chemical class 0.000 claims description 7
- XQRLCLUYWUNEEH-UHFFFAOYSA-N diphosphonic acid Chemical compound OP(=O)OP(O)=O XQRLCLUYWUNEEH-UHFFFAOYSA-N 0.000 claims description 6
- 125000000217 alkyl group Chemical group 0.000 claims description 2
- 125000004432 carbon atom Chemical group C* 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 238000012360 testing method Methods 0.000 description 8
- 239000002253 acid Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- DBVJJBKOTRCVKF-UHFFFAOYSA-N Etidronic acid Chemical compound OP(=O)(O)C(O)(C)P(O)(O)=O DBVJJBKOTRCVKF-UHFFFAOYSA-N 0.000 description 6
- 239000002455 scale inhibitor Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000010960 cold rolled steel Substances 0.000 description 2
- -1 diphosphonic acid compound Chemical class 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000001802 infusion Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
Landscapes
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） この発明は、鋼板、鋼管、線材、型鋼等の鋼材の酸洗
廃液系、ことに酸洗濃縮廃液処理系においてシリカを主
体とする軟質ないし硬質の沈澱物または付着物（以下シ
リカ系スケールという）による障害、ことに管路の詰ま
りを防止をする方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a pickling waste liquid system for steel materials such as steel sheets, steel pipes, wires, and mold steels, and particularly to a soft or concentrated pickling concentrated waste liquid treatment system mainly comprising silica. The present invention relates to a method for preventing obstacles caused by hard precipitates or deposits (hereinafter referred to as silica-based scale), particularly, clogging of pipelines.
（従来技術） 冷間圧延鋼板等の鋼材に対し、表面の検査と手入前の
予備処理として、また鋼板上のスケールや赤銹を除去す
るため、一般には塩酸による酸洗浄がおこなわれてい
る。(Prior art) In general, acid cleaning with hydrochloric acid is performed on steel materials, such as cold-rolled steel plates, as a pre-treatment before surface inspection and maintenance, and to remove scale and rust on the steel plates. .
この酸洗廃液は、多量の酸化鉄が含まているので、こ
れを濃縮した後焙焼して回収しているが、この回収工程
における酸洗廃液濃縮工程後の配管、ポンプあるいは焙
焼炉のスプレーノズル等が硬質の付着物で閉塞する障害
が発生する問題があった。Since this pickling waste liquid contains a large amount of iron oxide, it is concentrated and then roasted and recovered.However, the pipe, pump or roasting furnace after the pickling waste liquid concentrating step in this recovery step is used. There has been a problem that the spray nozzle or the like may be blocked by hard deposits.
このため従来は、高圧水洗浄や器具を取り換えたり、
あるいは配管を取り外しスケールを除去する等の処置が
行われていた。For this reason, conventionally, high pressure water cleaning and replacement of equipment,
Alternatively, measures such as removing the pipe and removing the scale have been taken.
（発明が解決しようとする問題点） 前記高圧水洗浄等においては、該廃液回収処理設備を
ストップして行なわねばならず、作業効率が悪化し、多
大の労力や手間がかかるという問題点を有していた。(Problems to be Solved by the Invention) In the high-pressure water washing and the like, there is a problem that the waste liquid recovery treatment equipment must be stopped and performed, and the working efficiency is deteriorated, and much labor and labor are required. Was.
前記酸洗廃液は、焙焼されるまでに濃縮、脱珪等の工
程を経て廃液の液性が変化することもあるが、水を主成
分として、下記のような物性および主要組成を示す強酸
性の特殊な廃液である。The pickling waste liquid may undergo concentration, desiliconization, etc. before the roasting, and the liquid property of the waste liquid may change.However, a strong acid showing the following physical properties and main composition, mainly containing water, It is a special waste liquid.
そして、この発明の発明者らが前記障害となる硬質の
付着物を分析した結果、シリカを主体とするものである
ことを確認した。 The inventors of the present invention have analyzed the hard deposits that become obstacles, and as a result, have confirmed that they are mainly composed of silica.
そこで、発明者らは上記酸洗廃液中にスケール防止剤
を添加して、上記シリカ系スケールによる障害を防止す
る方法について鋭意検討を行った。Therefore, the inventors have conducted intensive studies on a method of adding a scale inhibitor to the pickling waste liquid to prevent the above-mentioned silica-based scale from being damaged.
従来、一般水系でのスケール防止剤としては種々の化
合物が提案され、使用されている。しかし、これらのス
ケール防止剤は通常のカルシウム系やリン系のスケール
防止に有効であっても、シリカ系スケールの防止に有効
であるか否かは全く不明であり、むしろシリ系スケール
防止に有効なものは僅かである。ことにこの発明で用い
るジホスホン酸系の化合物は、一般水系でのリン系やカ
ルシウム系のスケール防止には有効であるが、地熱水を
対象とする試験によれば、シリカ系スケールの発生、付
着の防止にはほとんど効果がないとされている。〔地
熱,Vol,21,No.1.（Ser.No.81）1984第12頁〜第22頁，
（特に第18頁右欄下から12行目〜５行目）参照〕 さらにシリカ系スケールに有効とされている公知のス
ケール防止剤の場合でもそのスケール中のシリカ成分が
乾燥物に対し、SiO2換算70％程度より多くなるとスケー
ル防止剤による防止処理がしにくゝその対策は困難であ
るとされている。Conventionally, various compounds have been proposed and used as scale inhibitors in general aqueous systems. However, even if these scale inhibitors are effective in preventing normal calcium and phosphorus scales, it is completely unknown whether they are effective in preventing silica-based scales, but rather effective in preventing siliceous scales. Are few. Particularly, the diphosphonic acid-based compound used in the present invention is effective for preventing phosphorus-based or calcium-based scales in general aqueous systems.However, according to tests for geothermal water, generation of silica-based scales, It is said that there is almost no effect in preventing adhesion. [Geothermal, Vol. 21, No. 1. (Ser. No. 81) 1984 pp. 12-22,
(Especially, see page 18, right column, bottom line, 12th to 5th lines)] Further, even in the case of a known scale inhibitor which is considered to be effective for a silica-based scale, the silica component in the scale has a SiO. If it exceeds about 70% in 2 conversion, it is said that the prevention treatment with the scale inhibitor is difficult.
特にこの発明の対象である鋼材の塩酸酸洗廃液系のう
ち、濃縮廃液処理系に発生するシリカ系スケールは、シ
リカがSiO2換算80〜90％或いはそれ以上を占めている硬
質の緻密なスケールであり、しかもその特殊な水質を考
慮すると、従来公知のシリカ系スケール防止材を用いて
もスケール障害の防止に有効であるとは考えられなかっ
た。In particular, of the steel acid hydrochloric acid pickling waste liquid system that is the subject of the present invention, the silica-based scale generated in the concentrated waste liquid treatment system is a hard dense scale in which silica occupies 80 to 90% or more of SiO 2 in terms of SiO 2. In view of the special water quality, it was not considered that the use of a conventionally known silica-based scale preventive material was effective in preventing scale failure.
（問題点を解決するための手段） この発明の発明者らは、この問題点を解決するために
鋭意研究した結果、驚くべきことに、シリカ系スケール
防止に効果がないとされていた前記特定のジホスホン酸
系化合物が該酸洗濃縮廃液処理系においてはシリカ系ス
ケール発生防止に顕著な効果を示す事実を現場実験に基
づいて見出した。(Means for Solving the Problems) The inventors of the present invention have conducted intensive studies to solve the problems, and as a result, surprisingly, it has been found that the above-mentioned identification which has been found to be ineffective in preventing silica-based scale is not effective. The fact that the diphosphonic acid compound of the formula (1) has a remarkable effect on the prevention of generation of silica scale in the pickling concentrated waste liquid treatment system was found based on field experiments.
かくしてこの発明によれば、 鋼材の酸洗廃液に対し、 下記一般式（Ｉ）： （但し、Ｒは炭素原子数１〜５のアルキル基を示す） で表わされるヒドロキシアルキリデンジホスホン酸また
はそれらの水溶性塩を1mg/〜20mg/添加することを
特徴とする鋼材の塩酸酸洗廃液の濃縮処理系に発生する
シリカ系スケール障害防止方法が提供される。Thus, according to the present invention, the following general formula (I) is used for the pickling waste liquid of steel. (Wherein R represents an alkyl group having 1 to 5 carbon atoms) 1 to 20 mg / hydroxyalkylidene diphosphonic acid or a water-soluble salt thereof represented by the formula: To provide a method for preventing a silica-based scale failure generated in a concentration treatment system of the above.
この発明において、一般式（Ｉ）で表わされるヒドロ
キシアルキリデンジホスホン酸またはそれらの水溶性塩
としては、１−ヒドロキシエチリデン−1,1−ジホスホ
ン酸（以下、HEDPと記す。）または、HEDPのアルカリ金
属塩、アンモニウムアミン塩、アンモニウム塩あるいは
低級アルカノールアミン塩等が代表的な化合物として挙
げられる。また、これらヒドロキシアルキリデンジホス
ホン酸またはそれらの水溶性塩の廃液に対する添加量
は、酸洗される鋼材の種類や廃液の濃縮度にも左右され
るが、通常1mg/〜10mg/で充分であり、より好まし
くは5mg/〜20mg/である。上記添加量が1mg/以下
では、スケール防止効果が低く、実用に供さないため好
ましくない。また、添加量が20mg/以上であっても、
その経済的損失に見合うスケール防止効果が得られれな
い。In the present invention, the hydroxyalkylidene diphosphonic acid represented by the general formula (I) or a water-soluble salt thereof is 1-hydroxyethylidene-1,1-diphosphonic acid (hereinafter referred to as HEDP) or an alkali of HEDP. Representative compounds include metal salts, ammonium amine salts, ammonium salts and lower alkanolamine salts. The amount of the hydroxyalkylidene diphosphonic acid or the water-soluble salt thereof added to the waste liquid depends on the type of steel material to be pickled and the concentration of the waste liquid, but usually 1 mg / to 10 mg / is sufficient. , More preferably 5 mg / -20 mg /. If the amount is 1 mg / min or less, the effect of preventing scale is low, and it is not practical because it is not preferable. Also, even if the addition amount is 20 mg / or more,
A scale prevention effect commensurate with the economic loss cannot be obtained.
これらヒドロキシアルキリデンジホスホン酸またはそ
れらの水溶性塩は通常希釈水溶液としてポンプ等を用い
て該廃液系に添加される。These hydroxyalkylidene diphosphonic acids or their water-soluble salts are usually added to the waste liquid system as a dilute aqueous solution using a pump or the like.
（実施例） 以下、この発明を下記する実施例により例示する。(Examples) Hereinafter, the present invention will be exemplified by the following examples.
実施例1. 某製鉄所において冷間圧延鋼板の塩酸酸洗廃液焙焼処
理工程における濃縮酸貯槽より焙焼炉に至る４系列の送
液管のうち３系列を使用して、１系列づつ薬剤無添加、
薬剤7mg/注入、同15mg/注入の系列として190日間試
験を行った。Example 1. In a steel mill, three out of four lines of liquid supply pipes from a concentrated acid storage tank to a roasting furnace in a process of roasting hydrochloric acid and pickling waste liquid of a cold-rolled steel sheet were used, and one line was used for each chemical. Additive-free,
The test was conducted for 190 days as a series of 7 mg / injection and 15 mg / infusion.
試験後、ストレーナ入口および出口の配管を外し、フ
ランジ面より20cm奥までの配管内付着物をかき出し、10
5℃にて恒量まで乾燥後その重量を測定した。その後各
配管内に圧力水を注入して洗浄を試みた。なお、薬剤の
注入は濃縮酸貯槽出口配管中へそれぞれ行った。試験期
間中の平均的な塩酸酸洗濃縮廃液の水質を第１表に、薬
剤無添加の配管に付着したスケールの分析結果を第２表
に、試験結果を第３表にそれぞれ示す。After the test, remove the pipes at the inlet and outlet of the strainer, and scrape off any deposits in the pipe to a depth of 20 cm from the flange surface.
After drying to a constant weight at 5 ° C., the weight was measured. Thereafter, pressure water was injected into each pipe to attempt cleaning. The chemicals were injected into the concentrated acid storage tank outlet piping. Table 1 shows the average water quality of the concentrated hydrochloric acid pickling waste liquid during the test period, Table 2 shows the analysis results of the scale attached to the pipes to which no chemical was added, and Table 3 shows the test results.
なお、この際にこの発明の効果を阻害しない限り、他
の添加剤、例えば他のスケール防止剤、スケール分散
剤、防食剤等が併用添加されてもよい。In this case, other additives, for example, other scale inhibitors, scale dispersants, anticorrosives, and the like may be added together as long as the effects of the present invention are not impaired.
備考） 試験終了後、薬剤無添加の系列の配管に3kg/cm
2の高圧水洗浄を試みたが、スケールは硬質であり、ほ
とんど除去されなかった。それに比較して、HEDPを7mgo
、15mg/添加の系列の配管のスケールにおいては2kg
/cm2（通常の水道水圧力）の水洗浄で容易に除去でき
た。従って、HEDPはスケール発生を抑制又は防止するの
みならず、生じうるシリカ系スケールの軟質化する作用
も有することが判った。 Remarks) After the test, add 3kg / cm to the piping of the series without chemicals.
A high pressure water wash of 2 was attempted, but the scale was hard and hardly removed. In comparison, HEDP is 7mgo
, 2 kg on a 15 mg / addition series piping scale
/ cm 2 (normal tap water pressure) was easily removed by washing with water. Therefore, it was found that HEDP not only suppresses or prevents the generation of scale, but also has a function of softening the silica-based scale that may occur.
実施例2. 実施例1.と同様の塩酸酸洗廃液焙焼処理工程における
濃縮酸貯増出口配管中へ、HEDPを7mg/添加して、１年
間試験を行った。試験前１年間の薬剤無添加時との比較
を第４表に示す。Example 2 HEDP was added in an amount of 7 mg / h to the concentrated acid storage outlet piping in the same hydrochloric acid pickling waste liquid roasting treatment step as in Example 1, and a test was conducted for one year. Table 4 shows a comparison with the case where no drug was added for one year before the test.
（発明の効果〕 この発明によれば、鋼材の酸洗廃液ことに酸洗濃縮廃
液が流れる配管やノズル等に付着するシリカ系スケール
量が顕著に減少されるため、長期間にわたり運転が可能
となる。また、生じうるスケールも軟質となるため、簡
単な水洗で洗浄することが出来るという効果を有する。 (Effects of the Invention) According to the present invention, the amount of silica-based scale adhering to the pipes and nozzles through which the pickling concentrated waste liquid and the pickled concentrated waste liquid flow is significantly reduced, so that the operation can be performed for a long period of time. In addition, since the scale that can be generated is also soft, there is an effect that the scale can be washed by simple washing with water.
フロントページの続き (72)発明者 高木 堅志 倉敷市水島川崎通１丁目（番地なし） 川崎製鉄株式会社水島製鉄所内 (56)参考文献 特開 昭62−65798（ＪＰ，Ａ) 特開 昭59−59298（ＪＰ，Ａ) 特開 昭57−12895（ＪＰ，Ａ)Continuation of the front page (72) Inventor Kenshi Takagi 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi Kawasaki Steel Corporation Mizushima Works (56) References JP-A-62-65798 (JP, A) JP-A-59 -59298 (JP, A) JP-A-57-12895 (JP, A)
Claims (2)
それらの水溶性塩を1mg/〜20mg/添加することを特
徴とする鋼材の塩酸酸洗廃液の濃縮処理系に発生するシ
リカ系スケール障害防止方法。1. A pickling waste solution for steel materials, which is represented by the following general formula (I): (Where R represents an alkyl group having 1 to 5 carbon atoms) 1 to 20 mg / hydroxyalkylidene diphosphonic acid or a water-soluble salt thereof represented by the following formula: A method for preventing a silica-based scale failure generated in a waste liquid concentration treatment system.
リデンジホスホン酸が、１−ヒドロキシエチリデン−1,
1−ジホスホン酸である特許請求の範囲第１項記載の障
害防止方法。2. The method of claim 1, wherein the hydroxyalkylidene diphosphonic acid represented by the general formula (I) is 1-hydroxyethylidene-1,
The method according to claim 1, wherein the method is 1-diphosphonic acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62135616A JP2575706B2 (en) | 1987-05-30 | 1987-05-30 | Prevention method of silica-based scale failure in pickling waste liquid system of steel material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62135616A JP2575706B2 (en) | 1987-05-30 | 1987-05-30 | Prevention method of silica-based scale failure in pickling waste liquid system of steel material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63302997A JPS63302997A (en) | 1988-12-09 |
| JP2575706B2 true JP2575706B2 (en) | 1997-01-29 |
Family
ID=15155972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62135616A Expired - Lifetime JP2575706B2 (en) | 1987-05-30 | 1987-05-30 | Prevention method of silica-based scale failure in pickling waste liquid system of steel material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2575706B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5944119B2 (en) * | 1980-06-26 | 1984-10-26 | 栗田工業株式会社 | water treatment agent |
| CA1207211A (en) * | 1982-09-27 | 1986-07-08 | Dionisio G. Cuisia | Composition and method for inhibiting scale |
| JPS6265798A (en) * | 1985-09-17 | 1987-03-25 | Mitsubishi Heavy Ind Ltd | Scale antisticking agent |
-
1987
- 1987-05-30 JP JP62135616A patent/JP2575706B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63302997A (en) | 1988-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3996062A (en) | Method for removing scale from metallic substrates | |
| US5024783A (en) | Boiler and boiler water treatment system | |
| US3522093A (en) | Processes of cleaning and passivating reactor equipment | |
| JP5800044B2 (en) | Descaling method and descaling agent for steam generating equipment | |
| US4789406A (en) | Method and compositions for penetrating and removing accumulated corrosion products and deposits from metal surfaces | |
| US3308065A (en) | Scale removal, ferrous metal passivation and compositions therefor | |
| JPS6039119B2 (en) | How to clean metal by spraying method | |
| US3460989A (en) | Method of treating ferrous metal surfaces | |
| JP5691039B2 (en) | Corrosion inhibitor composition for acid cleaning | |
| JPS58177479A (en) | Method of controlling corrosion and sedimentation in aqueous system and composition therefor | |
| US20170051194A1 (en) | Fluoro-inorganics for acidification or neutralization of water systems | |
| US5492629A (en) | Method of cleaning scale and stains in water systems and related equipment | |
| US3634257A (en) | Method of removing beer stone milk stone and railway carriage encrustations using a diphosphonic acid | |
| US5183573A (en) | Multipurpose scale preventer/remover | |
| EP0121631B1 (en) | Method of removing scale | |
| JPH0132313B2 (en) | ||
| JP7483576B2 (en) | Fluoro-inorganics for inhibiting or removing silica or metal silicate deposits | |
| US5733859A (en) | Maleic acid-based aqueous cleaning compositions and methods of using same | |
| US3067070A (en) | Cleaning method for industrial systems | |
| JP2575706B2 (en) | Prevention method of silica-based scale failure in pickling waste liquid system of steel material | |
| EP0094822A1 (en) | Scale-inhibiting compositions and process for inhibiting scale in systems exposed to water | |
| JPH0373359B2 (en) | ||
| CN1075164A (en) | Efficient and multi-purpose liquid detergent | |
| EP1808428B1 (en) | Descaling solutions comprising EDDH | |
| CA2852729A1 (en) | Synthetic acid compositions and uses thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071107 Year of fee payment: 11 |