TWI280334B - Purifying method for the removal of depositions containing magnetit from a pressure-container of a power station - Google Patents

Abstract

This invention relates to a purifying method for the removal of depositions containing magnetit from a pressure-container of a power station, in which the depositions are processed with a purifying water solution containing a reduction-medium and heated to a higher purification temperature, so as to reduce the iron-III-ions to iron-II-ions. It is characterized in that a purifying solution is applied to the pressure-container, which contains a pre-substance, it releases the reduction-medium under the existing conditions during the purification. Preferably hexamethyl tetramine is used as pre-substance.

Description

1280334 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種由發電廠之壓力容器去除各種含有磁 鐵礦之沈積物所用的淨化方法。 【先前技術】 上述方法例如由EP 273 1 82 A1中已爲人所知。所謂壓 力容器例如是指一種傳統發電廠之蒸氣鍋爐或核能發電廠 之蒸氣產生器之二次側。在一種由優質鋼所構成的壓力容器 • 中磁鐵礦以一種固態層之形式沈積在容器內表面上，加熱管 表面上且主要是以固定在容器底部上-或固定在安靜流動區 中之鬆散型泥漿式聚集之形式而沈積著。磁鐵礦可視爲一種 由鐵-Π -和鐵-111 -氧化物所形成的混合物。爲了去除各種沈 積物，已知可在高的淨化溫度時使用複合物結合劑（例如， E D T A P爲了使鐵_ 111轉送至可容易複合之鐵· I工中，貝[j通常 使用聯胺作爲還原劑。目前就毒理學而言聯胺之操控是有問 題的。因此，此種物質中例如會顯示一種致癌作用。就防止 ® 聯胺逸出至環境中所需的措施而言，聯胺之操控需要高的費 用。就後續之一系列會由於污染和合倂所產生的事件而言，，， 聯胺事故”及人員傷害之法律上的重要性須在每次使用聯胺 之前弄清楚。 【發明內容】 由上述問題開始，本發明的目的是提供一種本文開頭所 "述形式之淨化方法，藉此可克服上述的缺點。 •上述目的就申請專利範圍第1項之淨化方法而言係以下 1280334 述方式來達成：含有一種先質（Pre-substance)之淨化溶液施 加至壓力容器中，此先質在淨化期間的主要條件（例如，高 的溫度及/或微酸性之pH-範圍）中放出一種還原劑。以此種 方式可使用一種先質，其在毒理學上是無問題的或至少傷害 性較聯胺輕微，使得在將淨化溶液供應至壓力容器中時人員 健康-和環境負載受影響之危險性可下降。 此外，本發明的方法中的設計方式是：其在二階段中進 行，在第一階段（S卩，還原階段）中，以一種含有先質之第一 • 淨化溶液I來進行處理，且在隨後之第二階段（複合階段）中 第二淨化溶液II饋入至壓力容器中，此第二淨化溶液II含 有一種以二價之鐵離子來形成可溶解之複合物所用的複合 結合劑。此種二階段之方法主要是依據以下的構想：磁鐵礦 之還原所需的反應時間較鐵-Π的複合作用多很多，這另外 之原因是由於磁鐵礦晶格會隨著還原作用而受到破壞。在還 原相位期間較大的濃度會存在複合結合劑上，特別是在酸性 溶液中加工時複合結合劑可使氧化之基本金屬侵蝕性大大 ^ 地加速，其中複合結合劑藉由氧化還原·平衡而達成之複合 作用之形成使轉入溶液中的鐵-II被去除。在此種方法中， 含有還原劑的濃液作用在磁鐵礦沈積物上直至其完全還原 爲止，此時不需擔心一種値得注意之基本金屬剝蝕作用。然 後，在還原階段中當一種含有複合結合劑之淨化溶液II饋 入至壓力容器中時，基本金屬侵蝕性一方面可藉由下述方式 ^ 來下降：大量的鐵-II可供此複合結合劑使用以作爲反應伙 -伴（partner)，使基本金屬之溶解可壓制成一種競爭-反應。另 1280334 一方面是鐵-I卜複合作用能以高的反應速率（β卩’短的時間 中）來完成，使氧化之基本金屬侵蝕性（其以較低的反應速率 來進行）在明顯的範圍內甚至不會發生。 較佳是使用上述的先質，其可釋放一種醛（特別是甲醛） 以作爲還原劑。此種物質或醛是一種適合用來使磁鐵礦還原 的還原劑，其在磁鐵礦還原時氧化成碳酸，其如以下仍將顯 示者在淨化期間可由壓力容器中去除或以其它方式未受損 地來去除且因此可防止基本金屬受到腐蝕性的侵蝕。 還原階段較佳是在微酸性至中性溶液中進行，特別是在 pH-値5至7(較佳是5.0至7.0)的範圍中進行。藉由上述措 施來考慮以下的事實：平衡線依據還原氧化-系統 Fe3 04/Fe-II在pH 6.8時之電位與pH-値座標圖而延伸。遵 循微酸性至中性或至多是微鹼性的條件下可確保：磁鐵礦之 還原能以足夠的反應速率來預先進行。此外，該複合結合劑 較佳是以某種數量添加至淨化溶液中，此數量最多是等於複 合時藉由還原所產生的鐵-II數量之10%。此種措施同樣可 使上述之氧化還原-平衡偏移至鐵-II-側，其中此複合作用可 結合二價之鐵離子且複合物由於平衡而去除。以此種方式可 促成磁鐵礦晶格之溶解。較佳是使用EDTA作爲複合結合劑。 本發明的淨化方法中一種很適當的先質是六亞甲四胺 (H exam ethylente tram in)。此種亦稱爲優洛托品（Ur otr opine) 之物質就毒理學上的觀點而言較聯胺的危險性少很多，特別 是在室溫時更是如此，淨化溶液I供應至發電廠中。六亞甲 四胺在酸性溶液中-且特別是在高的淨化溫度時釋出甲醛。 1280334 甲醒是一種無問題之無毒物質。但此種釋出作用是在壓力鍋 爐中進行’即，在封閉的系統中進行。很好的結果（特別是 具有成對的物質六亞甲四胺/EDTA)可在溫度90gc至 200QC(較佳是140GC至20(^0時達成。爲了保護基本金屬而 使用溫度敏感的腐蝕防止劑（例如，^辛炔-3-醇 (l-Octyne-3-ol))時，則較低的溫度（大約是9〇〇c至1200C) 亦是適當的。當六亞甲四胺對EDTA之莫耳比保持在3.5:1 至2 :1時’則可達成一種快速的泥漿式溶解作用且因此可使 H 基本金屬侵蝕性減低至一種未起決定作用的程度。當淨化溶 液I含有0.6至0.7莫耳/升（mole/1)六亞甲四胺和〇·ΐ7至0.36 莫耳/升EDTA時，則可達成最佳的結果。在第二階段（即， 複合階段）中，使用EDTA作爲複合結合劑。此外，EDTA是 一種很有效的複合結合劑，價格上不貴可大量地購買，這樣 所具備的優點是：還原階段和複合階段可以相同的複合結合 劑來進行，所使用的全部化學劑之數目可較少，化學劑之間 不期望的更換作用所造成的危險性亦可下降。 ^ 該複合階段可在微酸性至微鹼性之溶液中進行，此乃因 在此種pH-値範圍中可達成特別有效且快速的複合作用。反 應溶液中較佳是保持著6至10之pH-値，特別是6.5至9.3。 若反應階段中並非整個磁鐵礦都已還原且因此在將淨化溶 液II饋入至壓力容器時仍有或多或少的殘餘物留在磁鐵礦 上，則可藉由EDTA以加速磁鐵礦之溶解或加速磁鐵礦晶格 * 之破壞，亦可使基本金屬侵蝕性加速發生作用。但這一方面 “會由於”在金屬-溶液相位鄰界區中複合反應較氧化還原反 1280334 應快很多”而受到限制。另一方面，藉由另一種措施可使PH-値不會下降至對基本金屬侵蝕性有加速作用時之太低之 値。此種措施是將三乙胺添加至淨化溶液II中。須選取此 種添加量’以保持一種微鹼性之pH-値。在作爲準（quasi)緩 衝劑用之三乙胺上沈積一種在鐵-III還原時由甲醛所形成之 蟻酸’其中所形成的物質是具有揮發性的且會在複合階段時 所存在的溫度中蒸發而可由溶液中去除。三乙胺以相同的數 量來和二氧化碳或碳酸進行反應。這在甲醛氧化至初步形成 φ 二氧化碳時會發生。 藉由添加鹼性反應性之三乙胺，則同時可使鹼性劑（例 如，氨（a m m ο n i a)或嗎啉（m 〇 r p h ο 1 i n e ))之數量減低，特別是 在嗎啉較貴時這樣是有利的。較佳是使用一種反應溶液II， 其在各別的淨化溫度時以EDTA來達成飽和且最多含有〇·5 莫耳/升之三乙胺。 【實施方式】 爲了進行本方法，須將壓力容器中已存在的水之一部份 ^ 排出，以使即將饋入的反應溶液有容納的空間存在。鍋爐水 然後加熱至一種淨化溫度（例如，14〇GC)，這可藉由導入一 種蒸氣來達成。爲了饋入各反應溶液I和Π ’則適當的方式 是使這些溶液在饋入之前同樣加熱至該淨化溫度。 進行上述二階段之淨化方法所使用的淨化溶液1和11 具有以下的成份： 1280334 六亞甲四胺 二銨-EDTA 三乙胺 需用來溶解1000 公斤之磁鐵礦 淨化溶液I 0.713莫耳/升 0.356莫耳/升 (=104g/l) 1010 升 淨化溶液II 1.369莫耳/升 (=400g/l) 最多0.469莫耳/升 (=65g/l) 9210 升1280334 IX. Description of the Invention: [Technical Field] The present invention relates to a purification method for removing various deposits containing magnetite from a pressure vessel of a power plant. [Prior Art] The above method is known, for example, from EP 273 1 82 A1. By pressure vessel is meant, for example, a secondary side of a steam boiler of a conventional power plant or a steam generator of a nuclear power plant. In a pressure vessel consisting of high-quality steel, medium magnetite is deposited as a solid layer on the inner surface of the vessel, on the surface of the heating tube and mainly on the bottom of the vessel - or in a quiet flow zone. Deposited in the form of loose mud-like aggregates. Magnetite can be considered as a mixture of iron-strontium- and iron-111-oxides. In order to remove various deposits, it is known to use complex binders at high purification temperatures (for example, EDTAP in order to transfer iron 111 to an easily recyclable iron, I [usually using hydrazine as a reduction] In the case of toxicology, the manipulation of hydrazine is problematic. Therefore, for example, this substance may show a carcinogenic effect. In terms of measures required to prevent the escape of hydrazine to the environment, hydrazine The handling requires a high cost. The legal importance of the hydrazine accident and the injury of personnel in one of the subsequent series due to contamination and collateralization must be clarified before each use of hydrazine. SUMMARY OF THE INVENTION Starting from the above problems, it is an object of the present invention to provide a purification method of the form described at the outset, whereby the above disadvantages can be overcome. • The above object is in the purification method of claim 1 of the patent application. This is achieved by the following method 1280334: a pre-substance purification solution is applied to the pressure vessel, the main conditions of the precursor during purification (eg, high) a reducing agent is released in the temperature and/or slightly acidic pH range. In this way a precursor can be used which is toxicologically problem-free or at least less harmful than the hydrazine, so that The risk of human health - and environmental load being affected when the purification solution is supplied to the pressure vessel may be reduced. Furthermore, the design of the method of the invention is such that it is carried out in a second phase, in the first phase (S卩, reduction) In the stage), the first purification solution I containing the precursor is treated, and in the second phase (complex phase), the second purification solution II is fed into the pressure vessel, the second purification solution II Contains a composite binder for the formation of soluble compounds with divalent iron ions. This two-stage method is based on the following concept: the reaction time required for the reduction of magnetite is better than that of iron-bismuth The effect is much more, because the magnetite crystal lattice is destroyed by the reduction. During the reduction phase, a large concentration will exist on the composite binder, especially in the acidic solution. The composite binder during processing can greatly accelerate the erosion of the basic metal of oxidation, wherein the composite bond is formed by the combination of redox and equilibrium, so that the iron-II transferred into the solution is removed. In the method, the dope containing the reducing agent acts on the magnetite deposit until it is completely reduced, and there is no need to worry about a basic metal ablation effect which is noticed. Then, in the reduction stage, when a compound contains a composite bond When the cleaning solution II of the agent is fed into the pressure vessel, the basic metal aggressiveness can be reduced by the following means: a large amount of iron-II can be used as the reaction partner-partner. So that the dissolution of the base metal can be compressed into a competition-reaction. Another 1280334 on the one hand, the iron-I complex can be completed at a high reaction rate (β卩' in a short period of time), making the basic metal corrosion of oxidation (It proceeds at a lower reaction rate) does not even occur within a significant range. It is preferred to use the above precursor which releases an aldehyde (particularly formaldehyde) as a reducing agent. Such a substance or aldehyde is a reducing agent suitable for reducing magnetite, which oxidizes to carbonic acid upon reduction of magnetite, which will still be shown to be removed from the pressure vessel during purification or otherwise Damaged to remove and thus prevent the base metal from being corroded. The reduction stage is preferably carried out in a slightly acidic to neutral solution, particularly in the range of pH - 5 to 7 (preferably 5.0 to 7.0). The above facts are considered by the above measures: the equilibrium line extends in accordance with the potential and pH-値 plot of the reduced oxidation-system Fe3 04/Fe-II at pH 6.8. It is ensured that the reduction of magnetite can be carried out in advance at a sufficient reaction rate, following a slightly acidic to neutral or at most slightly alkaline condition. Further, the composite binder is preferably added to the purification solution in an amount which is at most equal to 10% of the amount of iron-II produced by reduction upon compounding. This measure also shifts the above-described redox-equilibrium to the iron-II-side, where this complexing binds to divalent iron ions and the complex is removed by equilibrium. In this way, dissolution of the magnetite crystal lattice can be promoted. It is preferred to use EDTA as a composite binder. A very suitable precursor in the purification process of the present invention is H test ethylente tram in. This substance, also known as Ur otr opine, is much less dangerous than hydrazine from a toxicological point of view, especially at room temperature, where the purification solution I is supplied to generate electricity. In the factory. Hexamethylenetetramine releases formaldehyde in an acidic solution - and especially at high purification temperatures. 1280334 Awakening is a non-toxic, non-toxic substance. However, this release is carried out in a pressure cooker', i.e., in a closed system. Very good results (especially with the paired substance hexamethylenetetramine/EDTA) can be achieved at temperatures from 90gc to 200QC (preferably 140GC to 20). Temperature sensitive corrosion protection is used to protect the base metal. When a reagent (for example, 1-octyne-3-ol), a lower temperature (about 9〇〇c to 1200C) is also suitable. When hexamethylenetetramine is used When the molar ratio of EDTA is maintained at 3.5:1 to 2:1, a rapid mud-like dissolution can be achieved and thus the H-based metal aggressiveness can be reduced to an undetermined extent. When the purification solution I contains The best results are achieved when 0.6 to 0.7 mol/l (mole/1) hexamethylenetetramine and 〇·ΐ 7 to 0.36 mol/L EDTA. In the second stage (ie, the compound stage), EDTA is used as a composite binder. In addition, EDTA is a very effective composite binder, which is inexpensive and can be purchased in large quantities. This has the advantage that the reduction phase and the composite phase can be carried out by the same composite binder. The number of all chemicals used can be less, and the undesirable replacement between chemicals The resulting hazard can also be reduced. ^ The compounding stage can be carried out in a slightly acidic to slightly alkaline solution, since a particularly effective and rapid complexing effect can be achieved in this pH-値 range. It is preferred to maintain a pH of from 6 to 10, especially from 6.5 to 9.3. If not all of the magnetite has been reduced in the reaction stage and therefore there is still more or less when feeding the purification solution II to the pressure vessel. If the residue remains on the magnetite, the EDTA can accelerate the dissolution of the magnetite or accelerate the destruction of the magnetite crystal lattice*, and the basic metal erosion can be accelerated. "The composite reaction in the metal-solution phase boundary zone is much faster than the redox reaction 1280334." On the other hand, by another measure, the PH-値 can not be reduced to accelerate the erosion of the base metal. The effect is too low. This measure is to add triethylamine to the purification solution II. This addition amount must be chosen to maintain a slightly alkaline pH-値. Used as a quasi buffer. Depositing a triethylamine on iron-III The formic acid formed by formaldehyde in situ is formed to be volatile and can be removed from the solution by evaporation at the temperature present in the compounding stage. Triethylamine is carried out in the same amount as carbon dioxide or carbonic acid. This occurs when the formaldehyde is oxidized to the initial formation of φ carbon dioxide. By adding a basic reactive triethylamine, an alkaline agent (for example, ammonia (amm ο nia) or morpholine (m 〇rph) can be used. The number of ο 1 ine )) is reduced, especially when the morpholine is relatively expensive. It is preferred to use a reaction solution II which is saturated with EDTA at each purification temperature and contains at most 〇·5 Moere / liter of triethylamine. [Embodiment] In order to carry out the method, a part of the water already present in the pressure vessel is discharged, so that the space in which the reaction solution to be fed is accommodated exists. The boiler water is then heated to a purge temperature (e.g., 14 〇 GC), which can be achieved by introducing a vapor. In order to feed the respective reaction solutions I and ’ ', it is appropriate to heat these solutions to the purification temperature before feeding. The purification solutions 1 and 11 used in the above two-stage purification method have the following composition: 1280334 Hexamethylenetetramine diammonium-EDTA Triethylamine is required to dissolve 1000 kg of magnetite purification solution I 0.713 mol/ 0.356 m / liter (= 104 g / l) 1010 liters of purification solution II 1.369 mol / liter (= 400g / l) up to 0.469 m / liter (= 65g / l) 9210 liters

爲了在還原階段中溶解1 000公斤的磁鐵礦，需1010升 之反應溶液I，即，〇 . 7 1 3仟莫耳之六亞甲四胺和0.3 5 6仟莫 耳之EDTA。在複合過程中需9210升之淨化溶液II，其含有 1.3 69仟莫耳/升之EDTA和最多0.469仟莫耳/升之三乙胺。 EDTA在水中只以其鹽之形式而溶解著。因此，通常使用二 銨 -EDTA 或三銨 -EDTA 或其混合物或三 -morpholine-EDTA。在淨化溶液II中可藉由三乙胺添加至 33%來節省鹼性劑NH3或morpholine。In order to dissolve 1 000 kg of magnetite in the reduction stage, 1010 liters of the reaction solution I, i.e., 1. 7 1 3 仟 mol hexamethylenetetramine and 0.3 5 6 mM EDTA are required. In the compounding process, 9210 liters of Purification Solution II is required, which contains 1.3 69 Torr/L of EDTA and a maximum of 0.469 Torr/L of triethylamine. EDTA is only dissolved in water in the form of its salt. Therefore, diammonium-EDTA or triammonium-EDTA or a mixture thereof or tri-morpholine-EDTA is usually used. In the purification solution II, the alkaline agent NH3 or morpholine can be saved by adding triethylamine to 33%.

首先，反應階段之期間是與待反應的磁鐵礦數量有關且 大約持續1 5分鐘至數小時。爲了使磁鐵礦反應加速，則隨 時都需使蒸氣排出。由於壓力減輕，則眾多氣泡之形成會造 成大的渦流且使泥漿捲起。饋入壓力鍋爐中的淨化溶液I屬 微酸性至中性（pH値大約5至7)，這例如可藉由特性像酸一 樣的一部份以氨（ammonia)或嗎啉（morpholine)而形成飽和 之EDTA來產生。先質六亞甲四胺在淨化溫度大約是140gC 時***成甲醛和氣（ammoniac)(反應1)。甲醛使磁鐵礦之鐵 -ΙΠ還原成鐵-II且本身氧化成蟻酸（反應2)。所形成的蟻酸 之至少一部份藉由氨來中和。 在大部份之磁鐵礦（最好是全部）已還原（這與待去除之 1280334 磁鐵礦數量以及淨化溫度可持續2 0分鐘至數小時有關）之 後，淨化溶液Π在情況需要時需預熱且施加至壓力容器中， 此時壓力容器中已存在的淨化溶液I不必像先前一樣被排 出。在理想情況下，即，在磁鐵礦已完全還原時，則複合階 段中只需藉由E D T A使鐵-11互相結合而導入溶液中即可。 還原階段中或藉由剩餘磁鐵礦之還原而在複合階段中經由 甲醛之氧化而形成的蟻酸沈積在三乙胺上，此時會形成揮發 性的化合物，其在所存在的溫度中會轉換成氣相且可藉由蒸 Φ 發而由壓力容器中去除（反應3)。須選取三乙胺之濃度或數 量，使複合過程可在微鹼性至中性的範圍（即，p Η値在8.5 至7的範圍）中進行。由六亞甲四胺所釋出之甲醛亦可氧化 成二氧化碳（反應4)。二氧化碳或由其所形成的碳·酸同樣可 在形成一種揮發性之化合物時沈積在三乙胺上。 反應1 :First, the period of the reaction stage is related to the amount of magnetite to be reacted and lasts for about 15 minutes to several hours. In order to accelerate the magnetite reaction, the vapor is required to be discharged at all times. Due to the reduced pressure, the formation of numerous bubbles creates a large eddy current and causes the mud to roll up. The purification solution I fed into the pressure boiler is slightly acidic to neutral (pH 値 about 5 to 7), which can be formed, for example, by ammonia or morpholine, which is characterized by an acid like a part. Saturated EDTA is produced. The precursor hexamethylenetetramine is split into formaldehyde and ammoniac at a purification temperature of about 140 gC (Reaction 1). Formaldehyde reduces the iron-rhenium of the magnetite to iron-II and oxidizes itself to formic acid (Reaction 2). At least a portion of the formed formic acid is neutralized by ammonia. After most of the magnetite (preferably all) has been reduced (this is related to the amount of 1280334 magnetite to be removed and the purification temperature can last for 20 minutes to several hours), the purification solution needs to be used when necessary. Preheating and application to the pressure vessel, at which point the purification solution I already present in the pressure vessel does not have to be discharged as before. Ideally, that is, when the magnetite has been completely reduced, it is only necessary to introduce iron-11 into the solution by combining E D T A in the composite stage. The formic acid formed in the reduction stage or by the reduction of residual magnetite in the composite stage via oxidation of formaldehyde is deposited on triethylamine, at which point a volatile compound is formed which will convert at the temperature present. It is in the gas phase and can be removed from the pressure vessel by steaming (Reaction 3). The concentration or amount of triethylamine must be chosen such that the compounding process can be carried out in the range of slightly alkaline to neutral (i.e., p Η値 in the range of 8.5 to 7). Formaldehyde released from hexamethylenetetramine can also be oxidized to carbon dioxide (Reaction 4). Carbon dioxide or the carbon acid formed therefrom can also be deposited on triethylamine when a volatile compound is formed. Reaction 1:

C6H12N4 + 6 Η20 4 NH3 + 6 HCOH 反應2 :C6H12N4 + 6 Η20 4 NH3 + 6 HCOH Reaction 2 :

Fe3〇4 + HCOH 3 FeO + 6 HCOOH 反應3 :Fe3〇4 + HCOH 3 FeO + 6 HCOOH Reaction 3 :

(C2H5)3N + HCOOH [(C2H5)3NH] + HCOCT 反應4 : 2Fe304 + HCOH — 6 FeO + C〇2 +H20 【圖式簡單說明】 迦Ο 【元件符號說明】 無0 -11-(C2H5)3N + HCOOH [(C2H5)3NH] + HCOCT Reaction 4 : 2Fe304 + HCOH — 6 FeO + C〇2 +H20 [Simple description] Jialu [Component Symbol Description] No 0 -11-

Claims (1)

1280334 月31曰篇量 第94139359號「由發電廠之壓力容器去除各種含有磁鐵礦之沈 積物所用的淨化方法」專利案 (2007年1月修正） 十、申請專利範圍： 1. 一種由發電廠之壓力容器去除各種含有磁鐵礦之沈積物所用 的淨化方法，各沈積物以一種含有氧化劑之加熱至高的淨化 溫度之水淨化溶液來處理，以使鐵-111-離子還原成鐵-I卜離 子，此時須將一種含有先質之淨化溶液施加至壓力容器中’ φ 此先質在淨化期間現有的條件下釋出一還原劑’此淨化方法 之特徵爲：其在二個階段中進行，其中淨化階段中以一種含 有先質之第一淨化溶液I來處理且在隨後之複合階段中添加 第二淨化溶液II，其含有一種以二價之鐵離子來形成一種可 溶解之複合化合物所用的複合結合劑。 2. 如申請專利範圍第1項之淨化方法，其中使用一種先質’其 釋出一種醛以作爲還原劑。 3 .如申請專利範圍第2項之淨化方法，其中使用一種先質，其 • 釋出一種甲醛以作爲還原劑。 4.如申請專利範圍第1項之淨化方法，其中該還原階段是在微 酸性至中性溶液中進行。 5 .如申請專利範圍第4項之淨化方法，其中在該還原階段中pH-値保持著5至7。 6.如申請專利範圍第5項之淨化方法，其中在該還原階段中pH- • 値保持著5 · 0至7.0。 7.如申請專利範圍第4，5或6項之淨化方法，其中添加某一數 l28〇334 裊之複 修正 補充 9a 1. 31 年月曰 合結合劑至該淨化溶液I中，此一數量最多等於複合時 藉由還原所產生的鐵-II數量之10%。 8·如申請專利範圍第7項之淨化方法，其中使用EDTA作爲複合 結合劑。 9·如申請專利範圍第2或3項之淨化方法，其中該先質是六亞 申四胺。 1〇·如申請專利範圍第i至6項中任一項之淨化方法，其中本方 法是在9〇QC至之溫度範圍中進行。 # 1 ^如申請專利範圍第10項之淨化方法，其中本方法是在140〇c 至2 00GC之溫度範圍中進行。 1 2.如申請專利範圍第丨i項之淨化方法，其中使用一種淨化溶液 1 ’其和EDTA在莫耳量上的比例是3 5:1至2:1。 1 3 ·如申請專利範圍第i 2項之淨化方法，其中此淨化溶液I含有 0.6至〇·7莫耳/升之六亞甲四胺和〇17至ο.%莫耳/升之 EDTA。 14·如申請專利範圍第i項之淨化方法，其中使用一種淨化溶液 11，其含有EDTA以作爲複合結合劑。 15·如申請專利範圍第14項之淨化方法，其中使用一種淨化溶液 Ϊ其只曰有以作爲複合結合劑。 16·如申請專利範圍第1項之淨化方法，其中在微酸性至微鹼性 之溶液中進行該複合階段。 •如申g靑專利範圍第丨6項之淨化方法，其中在複合階段中p H _ 値保持著6至10。 18·如申請專利範圍第17項之淨化方法，其中在複合階段中pH_ -2- 1280334 96J· 口31 修正 +月曰補充 値保持著6.5至9.3。 1 9 ·如申請專利範圍第1 6至1 8項中任一項之淨化方法，其中該 淨化溶液II中添加三乙胺。 20.如申請專利範圍第19項之淨化方法，其中該淨化溶液II以 EDTA來達成飽和且最多含有0.5莫耳/升之三乙胺。1280334, 31st issue, No. 94139359, "Purification method for removing various magnetite-containing deposits from pressure vessels of power plants" (Revised in January 2007) X. Patent application scope: 1. One type of power generation The pressure vessel of the plant removes various purification methods for deposits containing magnetite, and each deposit is treated with a water purification solution containing an oxidant heated to a high purification temperature to reduce iron-111-ion to iron-I. Bu ion, in which case a precursor containing purification solution must be applied to the pressure vessel 'φ This precursor releases a reducing agent under the existing conditions during the purification period'. This purification method is characterized in that it is in two stages. Carrying out, wherein the purification stage is treated with a first purification solution I containing precursors and a second purification solution II is added in a subsequent composite stage, which contains a divalent iron ion to form a soluble composite compound The composite binder used. 2. A method of purifying the scope of claim 1 wherein a precursor is used which releases an aldehyde as a reducing agent. 3. A method of purifying the scope of claim 2, wherein a precursor is used which releases a form of formaldehyde as a reducing agent. 4. The purification method of claim 1, wherein the reduction stage is carried out in a slightly acidic to neutral solution. 5. The purification method of claim 4, wherein the pH-値 is maintained at 5 to 7 in the reduction stage. 6. The purification method according to claim 5, wherein the pH- • 値 is maintained at 5·0 to 7.0 in the reduction stage. 7. For the purification method of claim 4, 5 or 6, wherein a certain number of l28 〇 334 复 is added to supplement the 9a 1. 31 month hydrazine binding agent to the purification solution I, the quantity It is at most equal to 10% of the amount of iron-II produced by reduction. 8. The purification method of claim 7, wherein EDTA is used as a composite binder. 9. The method of purifying the second or third aspect of the patent application, wherein the precursor is hexamethylenetetramine. 1) A method of purifying according to any one of claims 1 to 6, wherein the method is carried out in a temperature range from 9 〇 QC. # 1 ^ The purification method of claim 10, wherein the method is carried out in a temperature range of 140 〇 c to 200 GC. 1 2. The purification method according to the scope of claim ii, wherein a ratio of the purification solution 1 ′ to the EDTA in the molar amount is from 3 5:1 to 2:1. 1 3 . The purification method according to item i 2 of the patent application, wherein the purification solution I contains 0.6 to 7·7 mol/liter of hexamethylenetetramine and 〇17 to ο.% mol/liter of EDTA. 14. A method of purifying the scope of claim i, wherein a purification solution 11 is used which contains EDTA as a composite binder. 15. A method of purifying the scope of claim 14 wherein a purification solution is used which is only used as a composite binder. 16. The purification method of claim 1, wherein the recombination phase is carried out in a slightly acidic to slightly alkaline solution. • Purification method according to item 6-1 of the patent application, wherein p H _ 値 is maintained at 6 to 10 in the composite stage. 18. The purification method according to item 17 of the patent application, wherein pH_ -2- 1280334 96J· mouth 31 correction + month 曰 supplementation 値 is maintained at 6.5 to 9.3 in the compounding stage. The purification method according to any one of claims 1 to 18, wherein triethylamine is added to the purification solution II. 20. The purification method of claim 19, wherein the purification solution II is saturated with EDTA and contains at most 0.5 moles per liter of triethylamine. -3--3-