201043581 六、發明說明： 本申請要求歐洲專利申請EP 09 1 6006 1的優先權，出 於所有目的，該申請的全部內容藉由引用結合在此。 【發明所屬之技術領域】 本發明涉及從包含用過的磷酸的廢液中、特別是在鋁 處理方法、更特別是使用磷酸的鋁蝕刻方法中產生的廢液 〇 中回收磷酸鹽有用物質。 【先前技術】 磷酸係一種廣泛使用的工業化學製品。在電子行業中 消耗了巨量的超純磷酸（“電子級”），從而導致了大量的 含磷酸鹽的廢液。尤其是，LCD行業每年使用了超過1〇〇 kT含磷酸的溶液作爲鋁蝕刻劑。電子級磷酸典型地具有 以下基本特性： 化學式 H3P〇4 分子量(g) 98.0 典型濃度(％) 80-85 P含量(％) 31.3 85%的密度(g/ml) 1.71 100% 的密度(g/ml) 1.88 mp (t )，85% 21.0 mp (°C ) 5 100% 42.3 CAS-No 7664-38-2</ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the recovery of a phosphate useful substance from a waste liquid containing waste phosphoric acid, particularly in an aluminum treatment method, more particularly, an aluminum etching method using phosphoric acid. [Prior Art] Phosphoric acid is a widely used industrial chemical. A huge amount of ultrapure phosphoric acid ("electronic grade") is consumed in the electronics industry, resulting in a large amount of phosphate-containing waste liquid. In particular, the LCD industry uses more than 1 〇〇 kT of phosphoric acid per year as an aluminum etchant. Electronic grade phosphoric acid typically has the following basic characteristics: Chemical formula H3P〇4 Molecular weight (g) 98.0 Typical concentration (%) 80-85 P content (%) 31.3 85% density (g/ml) 1.71 100% density (g/ Ml) 1.88 mp (t ), 85% 21.0 mp (°C ) 5 100% 42.3 CAS-No 7664-38-2
-5- 201043581 W02005/120675描述了 一種用於處理含磷酸、乙酸和 硝酸的蝕刻廢棄物的方法。然而這個方法應用起來似乎是 困難並且昂貴的。 【發明內容】 本發明的目的係提供一種用於從廢液中回收磷酸鹽有 用物質的方法，該方法係簡單並且有成本效益的，卻能夠 自具有低濃度磷酸及含高量不同雜質的廢液中回收再用 (valorising)碟酸鹽有用物質。 因此，本發明涉及一種從含有重金屬以及按重量計至 少25%的磷酸的廢液中回收磷酸鹽有用物質的方法，其中 使該廢液與反應物相接觸，該反應物能夠與該溶液中所包 含的磷酸反應生成不溶性磷酸鹽，將該不溶性磷酸鹽分離 出，並且將所分離的磷酸鹽進行乾燥並且回收再用（valorised) 〇 在根據本發明的方法中，該廢液包含多種重金屬。重 金屬的實例爲鋁、鎘、鉛、汞。根據本發明的方法尤其適 合於含鋁的廢液。這種廢液有利地含有按重量計至少10 p p m、較佳的是至少5 0 p p m的重金屬，特別是銘。在此推 薦它包含最多1%、較佳的是0.5%、更佳的是最多1〇〇〇 ppm的重金屬，特別是鋁。 這種廢液包含按重量計至少25%、較佳的是至少40% 、更佳的是至少50%、在某些情況下最佳的是至少60%的 磷酸。有利地，這個百分數不超過9 0%、較佳的是85%、 201043581 更佳的是8 0 %、最佳的是7 0 %。然而，根據本發明該方 '法 還可以有利地從含有小於60%，在某些情況下小於50%、 甚至小於40%的磷酸的廢液中回收磷酸鹽有用物質。 在根據本發明的方法中，使該廢液與能夠形成不溶性 磷酸鹽的反應物相接觸。在此推薦向該溶液中加入的反Μ 物的量値包括在對於該溶液中存在的所有磷酸進行反應所: 必須的化學計量的量値的0.75和I·5倍之間、較佳的是在 0 0.85和1.25倍之間。該量値較佳的是近似等於該化學計 量的量。 該不溶性磷酸鹽可以藉由任何適當的允許從液體中分 離出固體的方法被分離出，例如像過濾。然後較佳的是將 所分離的磷酸鹽進行洗滌。在可隨意的乾燥之後，將經洗 猴分離的磷酸鹽回收再用（valorised)。這種回收再用較佳 的是包括包裝以及銷售。 根據本發明的方法允許從廢液中回收一般多於8 0%、 〇 有利地多於90%、較佳的是地多於95%的磷酸鹽有用物質 〇 該方法對於從含有除磷酸之外的其他酸的廢液中回收 磷酸鹽有用物質係特別有效的。 在一有利的實施方式中，該廢液含有至少1 %、較佳 的是多於5%、更佳的是多於10%、最佳的是多於20%的 硝酸。 在另一有利的實施方式中，該廢液含有至少1 %、較 佳的是多於5%、更佳的是多於1 〇%、最佳的是多於20% 201043581 的乙酸。 在又另一有利的實施方式中，該廢液包含至少1 %的 硝酸和至少1 %的乙酸兩者。還可以有利地將以上該等實 施方式中的所有不同的硝酸和乙酸的範圍相結合。 在根據本發明的方法的一較佳實施方式中，該廢液係 由一種鋁蝕刻方法產生的。這樣的廢液係來自例如半導體 製造工廠的蝕刻過程的腐蝕性廢棄物。這種廢液包括磷酸 、硝酸和乙酸、鋁以及一些其他的金屬性雜質。在半導體 製造中，要進行幾次鈾刻過程以便完成從晶圓表面受控地 去除多層薄膜。這種蝕刻可以利用液體或氣態的蝕刻劑來 進行。液體蝕刻劑（濕法蝕刻）產生氧化反應。在金屬的濕 法蝕刻中’將金屬氧化的能力以及所產生物種的溶解性係 關鍵性的。在鋁的情況下，濕法蝕刻通常是利用磷酸 (H3P〇4)、硝酸（hn〇3)和乙酸（CH3COOH)在水中的一混合 物來進行。硝酸被用來將鋁的表面氧化。然後磷酸溶解該 氧化鋁層並且該方法可以進一步進行。乙酸和水僅僅起到 稀釋劑的作用以保持鋁鹽進入溶液中。 表2示出了 一些典型的基於磷酸的鋁蝕刻劑： 濃度 19 : 1 :1 ： 2 3:1:3:1 4:4:1:1 ..............."......... 15 : 0: 1 : 1-4 蝕刻劑 H3P〇4 ：HAc ：hno3 ：h2o H3P〇4：HAc ：hno3 ：h2o H3P04: HAc :HN03 :H20 H3PO4 ： HAc :HN〇3 ：H20 表2 201043581 H3P〇4濃度通常是在30%和65% H3P〇4之間，而鋁含 量較佳的是小於0 · 1 %、更佳的是小於5 0 0 p p m。 在根據本發明的方法中，必要的是該反應物能夠形成 不溶性磷酸鹽，該磷酸鹽可以容易地被分離。 在多個推薦的實施方式中，該反應物含鈣並且能夠與 磷酸反應形成不溶性磷酸鈣。這樣的反應物較佳的是氫氧 化鈣或碳酸鈣。在該等實施方式的較佳變體中，在根據本 〇 發明的方法中回收再用（valorised)的不溶性磷酸鈣鹽較佳 的是磷酸二鈣。磷酸二鈣（磷酸一氫鈣-CaHP04-DCP)係一 商業產品，它本身具有多種不同的應用，例如在動物飼料 中。 在所推薦的實施方式的該等較佳變體中，反應物的量 有利地是以一種受控的方式加入的，以便達到的pH至少 是4，較佳的是5。 然而這種回收再用（valorised)的不溶性磷酸鹽自身可 ❹ 具有多種用途，如特別是在D C P的情況下，在本發明的 該等最佳的實施方式中，使這種不溶性磷酸鹽（代替將其 洗滌、乾燥、並且回收再用（valorised))進一步與強酸進行 反應以產生回收的磷酸以及另一種不溶性鹽。 然而，在某些情況下，這種不溶性磷酸鹽可以有利地 在與強酸反應之前進行洗滌，以便進一步從該等鹽顆粒的 表面去除雜質。 在該等最佳的實施方式中，該廢液還有利地含有其他 酸’較佳的是硝酸和/或乙酸，尤其是在上文說明的不同 -9 - 201043581 的範圍之中。 在該等最佳的實施方式中的推薦變體中，這種強酸係 硫酸並且這種其他的不溶性鹽係硫酸鈣。 所回收的磷酸有利地藉由與離子交換樹脂類相接觸和 /或藉由熔體結晶作用而被進一步純化。 離子交換樹脂類特別允許容易地去除陽離子雜質。較 佳的樹脂包括： •強酸性樹脂類（A200 Rohm&Haas); •包括亞胺基-二-乙酸根基團的螯合性大孔樹脂類， 它們似乎尤其適合於去除銅（S 930 Purolite); •包括胺基磷酸基團的螯和性大孔樹脂類（S 950 Purolite)、尤其適合去除二價陽離子如Ca、Mg，但也適 合於Cu、Pb ; •大孔強酸性樹脂（C 1 6 0 P u r ο 1 i t e)。 熔體結晶作用係指G. F. Arkenbout所說明的純化技 術（“Melt Crystallization Technology” Technomic publishing company, 1 995 )。特別推薦使用U S 6 4 9 5 0 4 4中所說明的液 壓洗滌管柱。 該等有利的實施方式（特別是涉及利用液壓洗滌管柱 的熔體結晶作用的那些）是尤其適合於生產電子級的磷酸 〇 在表3中給出電子級磷酸的典型組成。 201043581 H3P〇4(86%) 85.0-87.0% 硝酸鹽(N〇3) 最大5 ppm 總硫似S〇4計） 最大12 ppm 氯化物(Cl) 最大1 ppm 鋁(Al) 最大0.5 ppm 銻(Sb) 最大1 ppm 砷(As) 最大 0.05 ppm 鈣(Ca) 最大1 ppm 鉻(Cr) 最大0.2 ppm 鈷(Co) 最大 0.05 ppm 銅(Cu) 最大 0.05 ppm 金(Au) 最大0.3 ppm 鐵(Fe) 最大1.0 ppm 鉛(Pb) 最大0.3 ppm 鋰(Li) 最大0.1 ppm 鎂(Mg) 最大0.2 ppm 锰(Μη) 最大0.1 ppm 鎳⑽ 最大0.2 ppm 鉀(Κ) 最大1 ppm 鈉(Na) 最大1 ppm 緦(Sr) 最大0.1 ppm 鈦(Ti) 最大0.3 ppm 鋅(Zn) 最大1.0 ppm 表3 -11 - 201043581 現在將說明的實例解釋了本發明。 【實施方式】 實例 蝕刻溶液： 已經按以下方式製備了一合成的蝕刻溶液。在一燒杯 中，將 1 4.5克的 65%硝酸（w/w)、269.5克的 85%磷酸 (w/w)以及16克的100%乙酸進行混合。這樣得到的溶液 含有（按重量計）：3 . 1 %硝酸、7 6 · 4 %磷酸、5.3 %乙酸以及 15.2 %水。 DCP 沉澱（H3P04 + Ca(0H)2-> CaHP〇4 + 2H20)(l): 已將1 50克的這種蝕刻溶液引入包括一攪拌器、一溫 度探頭以及一 pH探頭的一 2升的燒杯中。已緩慢加入每 千克含69 g鈣的一石灰乳溶液（每分鐘30到40克）。當 pH探頭顯示pH爲5時停止添加。不進行冷卻或加熱。由 於放熱反應，溫度從26°C (實驗開始）上升到69°C(實驗結 束）。使反應過程中形成的沉澱物熟化2小時。然後將其 過濾並且用去離子水洗滌。最後，在60 °C下將它乾燥。獲 得了 1 62 g乾的沉澱物，極爲接近該反應的理論的1 00% 產率（163克）。 沉澱物的分析以及沉澱後剩下的溶液（濾液）的分析顯 示該沉澱物包含等莫耳量的鈣和磷酸根（如對於C a Η P 〇 4所 期望的），其量値使得產率超過95%。 磷酸再生（CaHP04 + H2S04 + xH20 —H3P04 + CaS04.xH20)(2): -12- 201043581 將以上得到的1 40克沉澱物與3 70克水在一個一升的 攪拌燒杯中進行混合。緩慢加入105.4克的96%硫酸（w/w) 〇 30分鐘後，將反應過程中生產的沉澱物過濾並用去 離子水洗滌。然後在60°C將它乾燥。最後，得到1 54克乾 燥的沉澱物以及194克濾液。沉澱物的分析顯示該沉澱物 包含等莫耳量的鈣和硫酸根，如根據方程序（2)對於CaS04 〇 所期望的，其量値使得反應的產率（表示爲硫酸鹽沉澱）是 9 5 %以上。濾液的分析顯示該最終溶液含有在固體DCP中 原始存在的95%以上的磷酸鹽以及不超過1%的硫酸鹽。 這證實該反應的產率（表示爲磷酸鹽轉化成磷酸）係95%以 上，與對沉澱物所觀察到的結果一致。 以上說明的實例解釋了在一典型的鋁蝕刻溶液中所含 的磷酸鹽轉換成幾乎僅包含磷酸的溶液的高產率。 〇 -13--5-201043581 W02005/120675 describes a method for treating etching waste containing phosphoric acid, acetic acid and nitric acid. However, this method seems to be difficult and expensive to apply. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for recovering a phosphate useful material from a waste liquid which is simple and cost effective, but which is capable of self-containing waste having a low concentration of phosphoric acid and a high amount of different impurities. Valorising disc acid useful material in liquid. Accordingly, the present invention is directed to a method of recovering a phosphate useful material from a spent liquor comprising a heavy metal and at least 25% by weight phosphoric acid, wherein the spent liquor is contacted with a reactant, the reactant being capable of reacting with the solution The contained phosphoric acid reacts to form an insoluble phosphate, separates the insoluble phosphate, and the separated phosphate is dried and recovered (valorised). In the process according to the invention, the spent liquor comprises a plurality of heavy metals. Examples of heavy metals are aluminum, cadmium, lead, and mercury. The process according to the invention is especially suitable for waste liquids containing aluminium. Such waste liquid advantageously contains heavy metals of at least 10 p p, preferably at least 5 p p m by weight, in particular. It is recommended to contain up to 1%, preferably 0.5%, more preferably up to 1 〇〇〇 ppm of heavy metals, especially aluminum. Such waste liquid comprises at least 25% by weight, preferably at least 40%, more preferably at least 50%, and in some cases most preferably at least 60% phosphoric acid. Advantageously, this percentage is no more than 90%, preferably 85%, 201043581 is more preferably 80%, and most preferably 70%. However, according to the invention, it is also advantageous to recover the phosphate useful material from a waste liquid containing less than 60%, and in some cases less than 50%, or even less than 40% phosphoric acid. In the process according to the invention, the spent liquor is contacted with a reactant capable of forming insoluble phosphate. It is recommended herein that the amount of ruthenium added to the solution is included in the reaction for all phosphoric acid present in the solution: between 0.75 and 1.5 times the amount of stoichiometric amount required, preferably Between 0 0.85 and 1.25 times. The amount 値 is preferably an amount approximately equal to the stoichiometric amount. The insoluble phosphate can be separated by any suitable means for allowing separation of the solids from the liquid, such as, for example, filtration. It is then preferred to wash the separated phosphate. The phosphate-separated phosphate is recovered and valorised after free drying. This recycling is preferably included in packaging and sales. The process according to the invention allows recovery of generally more than 80%, hydrazine advantageously more than 90%, preferably more than 95% of the phosphate useful substance from the spent liquor. The recovery of phosphate useful substances in other acid waste liquids is particularly effective. In an advantageous embodiment, the waste liquid contains at least 1%, preferably more than 5%, more preferably more than 10%, most preferably more than 20% nitric acid. In another advantageous embodiment, the spent liquor contains at least 1%, more preferably more than 5%, more preferably more than 1%, most preferably more than 20% of 201043581 acetic acid. In yet another advantageous embodiment, the spent liquor comprises at least 1% nitric acid and at least 1% acetic acid. It is also advantageous to combine all of the different ranges of nitric acid and acetic acid in the above embodiments. In a preferred embodiment of the method according to the invention, the waste liquid is produced by an aluminum etching process. Such waste liquids are derived from corrosive waste such as etching processes in semiconductor manufacturing plants. Such waste liquids include phosphoric acid, nitric acid and acetic acid, aluminum, and some other metallic impurities. In semiconductor fabrication, several uranium engraving processes are performed to effect controlled removal of the multilayer film from the wafer surface. This etching can be carried out using a liquid or gaseous etchant. A liquid etchant (wet etching) produces an oxidation reaction. The ability to oxidize metals and the solubility of the species produced is critical in wet etching of metals. In the case of aluminum, wet etching is usually carried out using a mixture of phosphoric acid (H3P〇4), nitric acid (hn〇3) and acetic acid (CH3COOH) in water. Nitric acid is used to oxidize the surface of aluminum. Phosphoric acid then dissolves the aluminum oxide layer and the process can be carried out further. Acetic acid and water act only as a diluent to keep the aluminum salt in solution. Table 2 shows some typical phosphoric acid-based aluminum etchants: Concentration 19 : 1 :1 : 2 3:1:3:1 4:4:1:1 ............. .."......... 15 : 0: 1 : 1-4 Etchant H3P〇4 :HAc :hno3 :h2o H3P〇4:HAc :hno3 :h2o H3P04: HAc :HN03 :H20 H3PO4 : HAc :HN〇3 :H20 Table 2 201043581 The concentration of H3P〇4 is usually between 30% and 65% H3P〇4, while the aluminum content is preferably less than 0 · 1 %, more preferably less than 5 0 0 Ppm. In the process according to the invention, it is essential that the reactants are capable of forming insoluble phosphate which can be readily separated. In various preferred embodiments, the reactants contain calcium and are capable of reacting with phosphoric acid to form insoluble calcium phosphate. Such a reactant is preferably calcium hydroxide or calcium carbonate. In a preferred variant of these embodiments, the valorised insoluble calcium phosphate salt in the process according to the invention is preferably dicalcium phosphate. Dicalcium phosphate (calcium monocalcium phosphate-CaHP04-DCP) is a commercial product that itself has many different applications, such as in animal feed. In these preferred variations of the proposed embodiment, the amount of reactants is advantageously added in a controlled manner so as to achieve a pH of at least 4, preferably 5. However, such valorised insoluble phosphates can be used in a variety of applications, such as in the case of DCP, particularly in the preferred embodiment of the invention, to render such insoluble phosphates (in lieu of It is washed, dried, and valorised to further react with a strong acid to produce recovered phosphoric acid and another insoluble salt. However, in some cases, such insoluble phosphate may advantageously be washed prior to reaction with a strong acid to further remove impurities from the surface of the salt particles. In these preferred embodiments, the waste liquid also advantageously contains other acids, preferably nitric acid and/or acetic acid, especially in the range of the different -9 - 201043581 described above. In the preferred variants of these preferred embodiments, the strong acid is sulfuric acid and the other insoluble salt is calcium sulfate. The recovered phosphoric acid is advantageously further purified by contact with an ion exchange resin and/or by melt crystallization. The ion exchange resins particularly allow easy removal of cationic impurities. Preferred resins include: • Strongly acidic resins (A200 Rohm &Haas); • Chelating macroporous resins including imido-di-acetate groups, which appear to be particularly suitable for copper removal (S 930 Purolite) • Chelating macroporous resin (S 950 Purolite) including aminophosphoric acid groups, especially suitable for removing divalent cations such as Ca, Mg, but also suitable for Cu, Pb; • Macroporous strong acid resin (C 1 6 0 P ur ο 1 ite). Melt crystallization refers to the purification technique described by G. F. Arkenbout ("Melt Crystallization Technology" Technomic publishing company, 1 995 ). It is especially recommended to use the hydraulic wash column described in U S 6 4 9 5 0 4 4. These advantageous embodiments, particularly those involving the use of melt crystallization of hydraulic wash columns, are particularly suitable for the production of electronic grades of strontium phosphate. The typical composition of electronic grade phosphoric acid is given in Table 3. 201043581 H3P〇4(86%) 85.0-87.0% Nitrate (N〇3) Maximum 5 ppm Total sulfur like S〇4) Maximum 12 ppm Chloride (Cl) Maximum 1 ppm Aluminum (Al) Maximum 0.5 ppm 锑 ( Sb) Maximum 1 ppm Arsenic (As) Maximum 0.05 ppm Calcium (Ca) Maximum 1 ppm Chromium (Cr) Maximum 0.2 ppm Cobalt (Co) Maximum 0.05 ppm Copper (Cu) Maximum 0.05 ppm Gold (Au) Max. 0.3 ppm Iron (Fe Maximum 1.0 ppm Lead (Pb) Max. 0.3 ppm Lithium (Li) Max. 0.1 ppm Magnesium (Mg) Max. 0.2 ppm Manganese (Μη) Max. 0.1 ppm Nickel (10) Max. 0.2 ppm Potassium (Κ) Max. 1 ppm Sodium (Na) Max 1 Ppm 缌(Sr) max. 0.1 ppm Titanium (Ti) max. 0.3 ppm zinc (Zn) max. 1.0 ppm Table 3 -11 - 201043581 The examples to be explained now explain the present invention. [Embodiment] Example Etching Solution: A synthetic etching solution has been prepared in the following manner. In a beaker, 1 4.5 g of 65% nitric acid (w/w), 269.5 g of 85% phosphoric acid (w/w), and 16 g of 100% acetic acid were mixed. The solution thus obtained contained (by weight): 3.1% nitric acid, 7 6 · 4 % phosphoric acid, 5.3% acetic acid, and 15.2 % water. DCP precipitation (H3P04 + Ca(0H)2-> CaHP〇4 + 2H20)(l): 150 grams of this etching solution has been introduced into a 2 liter including a stirrer, a temperature probe and a pH probe In the beaker. A lime milk solution (30 to 40 grams per minute) containing 69 g of calcium per kg has been slowly added. The addition is stopped when the pH probe shows a pH of 5. No cooling or heating. Due to the exothermic reaction, the temperature rose from 26 ° C (start of the experiment) to 69 ° C (end of the experiment). The precipitate formed during the reaction was aged for 2 hours. It was then filtered and washed with deionized water. Finally, it was dried at 60 °C. A precipitate of 1 62 g of dry matter was obtained, which was very close to the theoretical 100% yield (163 g) of the reaction. Analysis of the precipitate and analysis of the remaining solution (filtrate) after precipitation showed that the precipitate contained equal molar amounts of calcium and phosphate (as expected for Ca Η P 〇 4) in an amount such that the yield More than 95%. Phosphoric acid regeneration (CaHP04 + H2S04 + xH20 - H3P04 + CaS04.xH20) (2): -12- 201043581 The above obtained 40 g of the precipitate was mixed with 3 70 g of water in a one liter stirred beaker. After 105.4 g of 96% sulfuric acid (w/w) was slowly added for 30 minutes, the precipitate produced during the reaction was filtered and washed with deionized water. It was then dried at 60 °C. Finally, 1 54 g of a dry precipitate and 194 g of a filtrate were obtained. Analysis of the precipitate showed that the precipitate contained equal molar amounts of calcium and sulfate, as expected for CaS04 oxime according to the procedure (2), the amount of which caused the reaction yield (expressed as sulfate precipitation) to be 9 More than 5 %. Analysis of the filtrate showed that the final solution contained more than 95% of the phosphate originally present in the solid DCP and no more than 1% of the sulfate. This confirmed that the yield of the reaction (expressed as conversion of phosphate to phosphoric acid) was 95% or more, which was consistent with the results observed for the precipitate. The examples explained above explain the high yield of a phosphate contained in a typical aluminum etching solution converted into a solution containing almost only phosphoric acid. 〇 -13-