TW593766B - Method for recovering cerium from chromium etching solution - Google Patents

Abstract

This invention is to provide a method capable of efficiently recovering cerium from chromium etching solution containing cerium compound and chromium compound. The chromium etching solution is vaporized and concentrated and the cerium compound is crystallized, separated and recovered and also, the cerium in the separated solution after separating the cerium compound, is separated and recovered as oxalate. In the solution containing trivalent chromium after separating the oxalate of trivalent cerium, an alkaline hydroxide is added and the trivalent chromium is precipitated as chromium hydroxide and separated to constitute a closed system.

Description

593766 V. Description of the invention (1) [Technical field of the invention] The present invention relates to a method for recovering tritium from an etching solution used for chromium etching and the like. The third method is to use ceric ammonium nitrate and other decorative compounds and acids. After the etching solution is etched with chromium, the method of recovering rhenium from a chromium etching solution containing rhenium and chromium is related. [Conventional Technology] * In the manufacturing process of semiconductor or liquid crystal display, it usually includes the process of etching metal thin films such as electrode films. When chromium is engraved in this process, g is generally used; Chromium, G, ammonium bismuth acid, etc. I carved liquid. The chromium etching solution can be, for example, a chromium etching solution of the following compositions: (1) with beryllium nitrate and nitric acid, (2) with rhenium nitrate and nitric acid and ammonium nitrate, (3) with ammonium rhenium nitrate and high gas acid, (4) With ammonium nitrate, nitric acid and high gas acid. In the liquid t m, a chromium etching solution of any composition is used, and the used chromium is etched with 〒3, ϊ4valent 钸, and β-valent chromium. Therefore, it is necessary that both the valence and the valence of 6 are strong oxidative and harmful (environmental) substances, and these patents are removed. The treatment method is, for example, sodium sodium in chromium T6886. No. reminder, the general situation is to add hydrogen sulfite to reduce the chromium in the ammonium ammonium waste liquid and then add hydroxide each, so that there is also a method to remove the thallium and t coin gas oxides. Method. The neodymium is not removed from the original 4-valent europium and 6-valent chromium after being adsorbed on the adsorbent to be removed.

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Description of the invention (2) It is really uneconomical and it is suggested by Japanese Laid-Open Patent Publication No. 62_ 丨 9 1 422 that 3 僭 用 气化 # 丨 丨 g 巧 乡 和 八 t is emulsified into a valence of 4 and other materials are used. The nature of the 4-valent 钸 is not r '叩 刀 离, 斗 · # · ^ L}] The method of sprouting clothes, but according to this method, such as chromium etching waste liquid contains chromium, no, pure things see shame. W' 钸It is co-precipitated with chromium and cannot be separated and recovered. [Problems to be Solved by the Invention] In order to solve the above-mentioned various problems, Bagufayue provided a method capable of recovering plutonium from the chrome etching solution of '3 and Nero with good efficiency. [Method to solve the problem] In order to achieve the above-mentioned object, the method of recovering the etchant from the etchant according to the present invention (the scope of application for patent) is _ After the chromium etchant containing the samarium compound as the main component is etched by chromium, A method for recovering rhenium from an etching solution containing 5 compounds and chromium compounds, which is characterized by the following steps: ~ (a) an evaporation crystallization step of evaporating and concentrating an acid chromium residual solution containing a sieve compound and a chromium compound to precipitate rhenium compounds; ( b) a step of isolating the lutetium compound that has been precipitated; (c) a step of preparing an etching solution for the composition of chromium etching by using the separated ytterbium compound. Evaporation: An acidic chromium solution containing rhenium (compound) and chromium (compound) is used to precipitate and separate rhenium compounds. At the same time, the separated rhenium compound is used to prepare an etching solution for chromium etching, which can relatively simply evaporate and crystallize. The method recovers the plutonium from the used chromium etchant with good efficiency. Method for recovering plutonium from chromium etching solution in the scope of patent application No. 2

$ 5 pages

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V. Description of the invention (3) The steamed compound in item i (a) of the scope of the patent application is characterized by money. Precipitation Generally, ammonium osmium nitrate is used as the erbium compound in the chromium etching solution, and the ammonium osmium nitrate can be separated and recovered with good efficiency by the crystallization method. The method for recovering rhenium from chromium etching solution according to item 3 of the patent application is a method for recovering rhenium from an etching solution containing rhenium compound and chromium compound after chromium etching using an etching solution containing rhenium compound as a main component. The characteristics are as follows: :

(a) Evaporation and crystallization step of precipitating rhenium compounds by evaporation of acid chromium etching solution containing rhenium compounds and chromium compounds; (b) step of separating precipitating rhenium compounds; (c) separating and recovering the above steps with oxalate (B) A step of (remaining) plutonium in the separation solution after the plutonium compound is separated. The chromium etching solution is concentrated by evaporation to separate, recover and recover the rhenium compound. At the same time, the oxalate in the separation solution (remaining) after the erbium compound is separated and recovered can recover approximately the entire amount of the chromium etching solution, so that The recovery rate is greatly improved, making the present invention more practical.

Method for recovering decoration from chrome recording and engraving liquid according to item 4 of the scope of patent application, which is characterized by adding trivalent hydroxide (metal) after separation and recovery of oxalate after step 3 (c) of the scope of patent application. In a chromium solution, trivalent chromium is precipitated and separated as chromium hydroxide. 2. After step 3 (c) in the scope of Shenqing Patent, the precipitate containing oxalate trivalent as the main component is separated, and then add hydroxide test (metal) to each solution containing trivalent chromium to make 3 Valence chromium is precipitated and separated by chromium hydroxide to form dense

Page 6 593766 V. Description of the invention (4) Closed circuit) The system's harmful substance chromium will not be discharged out of the system, while the valuable substance 钸 is recovered with good efficiency, so it is extremely meaningful. There are h H spears: the method of recovering rhenium from chromium etching solution in item 5 of the scope is Ml salt separation. The step in the night is characterized by the following steps: (a) the step of adding oxalic acid to the above-mentioned separation solution to separate the trivalent europium and precipitating as oxalate; φ reduction (b) adding the test to the precipitation c {槽 你Trivalent chromium does not precipitate on the philosophical substance: the step of precipitation of ΪΛ 钸; the hardness of the emulsified product, and then the trivalent hydrazone is separated by oxalate (C) in steps (a) and (b). Precipitation of ingredients. Early 八 πMa main eight: After the HUr step (C) separation of the sieve compound separated from the knife's liquid 'addition of reducing valence of 3 valence 3 料 3 valence and insoluble salt of oxalic acid, so that chromium ㈣ solution Zhi ^) ^ 3 valence and oxalate precipitation, at the same time add alkali to neutralize to the extent that the valence of trivalent complex hydroxide is precipitated, and then make the trivalent bromide After the acid salt is not separated, the main reason for the separation of the trivalent oxalate is as follows: the chromate solution containing ^ = after the sieve compound is precipitated in the crystallization step, and is separated with good efficiency, which is almost free of patent applications. The method of recovering cerium from the chromium etching solution in the scope of item 6 is characterized in that in step 5 (b) of the scope of the patent application, the inspection should be added when neutralization is added.

Page 7 5. Description of the invention (5) Test until pH is about 4. Because the pH is about 4 in the scope of the patent application, it is possible to apply for a patent by adding a base while neutralizing the trivalent amidine with oxalate at the time of neutralization in step (b) and preventing the precipitation of chromium with hydroxide. The seventh range of ^ = can improve the efficiency of 钸. It is characterized by having the following steps: a method for recovering tritium from a chromium etching solution; the oxalate salt of trivalent tritium is the main component of the patent application scope; V step (C) is separated and recovered for precipitation to generate hydrogen; The precipitant of the arsenic oxide is prepared by using alkali hydroxide (metal) as the hydroxide base.

The step of 钸, and 氧化剂 oxidize the generated hydroxide to concentrate the metal to precipitate the metal.) The oxidant ammonium acid is used in conjunction with the Shi Xiao cycle to make it oxidatively shrink] nitrate i: ί :: chemical reaction with nitric acid and ammonium nitrate. ) After separation and recovery to generate ytterbium hydroxide, the ytterbium nitrate can be heated and concentrated to generate ytterbium nitrate. The nitrate and nitrate can be used to prepare a new route agent. ：： It is a method for recovering dysprosium from oxidized oxyhydroxide and dysprosium hydroxide.: == The chromium range #etching solution

The ammonium osmium nitrate produced by the crystallization step in the patent application scope No. 2 ammonium osmium nitrate and the patent application range is used for the chromium fetching of the ammonium osmium nitrate produced by the f7 item to adjust the use of evaporation crystallization: ΐ:;: 余 刻液 的 步骤。 Liquid steps. Item 2) and the ammonium osmium nitrate of the scope of patent application (please request the scope of the patent to be used with the exact composition of the engraved predetermined composition, so as to make the entire amount of the engraving solution 'recyclable and recoverable' as an etching solution, Make the present invention more practical. Wang Li [Forms of Implementing the Invention] The following describes the features of the present invention in detail by using the present and the following embodiments.

In this embodiment, the chromium etching solution containing ammonium osmium nitrate and nitric acid is used to etch chromium, and then the rhenium is recovered from the used chromium etching solution containing tetravalent europium, hexavalent chromium, nitric acid, and the like. In this embodiment, a chromium contact etching solution containing a europium compound and a chromium compound in the following ratio is used as the used chromium I insect solution. Rhenium content (in CeO ^ f): 48.6g (48.6g / kg) Chromium content (in Cr): 682ppm (682mg / l) [1] Evaporation and crystallization: First, evaporate and concentrate Used chromium I insect solution (1000 g), on the one hand, the crystallized praseodymium compound (ammonium phosphonium ammonium nitrate) is separated and recovered, and on the other hand, the separated liquid, namely the crystallized mother liquor ( Saturated solution of ammonium ammonium nitrate) The concentrated solution is continuously taken out of the system at a predetermined ratio. Specifically, the operations described below are performed to crystallize ammonium ammonium nitrate, crystallization, solid-liquid separation, recovery of nitric acid, and the like.

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V. Description of the invention (Ό (1 -1) The used chromium etching solution containing rhenium and chromium in the above ratio is continuously supplied to the evaporation part of the evaporation crystallization device to evaporate and condense the chromium etching solution (Fig. 1, step 1 ( S1)). (1-2) Precipitation and growth of tritium compounds in the crystallization part of the evaporation crystallization device: · (ammonium phosphonium nitrate) crystals (Fig. 1, step 2 (S 2)), and a telecentric separator ： Isosolid liquid separator separates and recovers the growing crystals (Figure 1, Step 3 (S3)). * (1-3) Secondly, the separated ammonium osmium nitrate crystals are washed, and the supporting liquids attached to the crystals are removed. (Chromium-containing concentrate) The main part (Figure 1, steps

4 (S4)). (1-4) On the other hand, the steam generated in the above-mentioned evaporation and concentration step is condensed to recover nitric acid water (Fig. 1, step 5 (S5)). (1-5) Secondly, the separation liquid from step 3 (S3) and the washing liquid from step 4 (S4) are recovered (Fig. 1, step 6 (S6)). The recovery of 钸 in this step 6 (S6) is performed through steps 11 (S11) to 21 (S21) shown in the flowchart of FIG. 2. The above embodiment is described in the case of continuous evaporation, concentration, and crystallization. However, evaporation concentration in a batch mode can also be used. The concentrated solution is cooled to crystallize and separate ammonium hafnium nitrate, and then recover the radon from the separation liquid. the way. [2] Recovery of 钸 from the separation liquid and washing liquid: The method for recovering 钸 from the separation liquid of step 3 (S3) and the washing liquid of step 4 (S4) will be described below. (2-1) Add the combined solution of the oxalic acid aqueous solution in step 3 (S3) and the washing liquid in step 4 (S 4) to reduce the 4-valent sieve to 3-valent bromine, and the 3-valent rule

Page 10 593766 5. Description of the invention (8) Precipitation with oxalate (Fig. 2, step 11 (Sll)). In this step, the hexavalent chromium existing in the chromium etching solution is reduced to trivalent chromium. (2-2) Next, add sodium hydroxide aqueous solution to neutralize until "" is 4 · 〇, so that the osmium which is not precipitated in the above step (2-1) is precipitated as oxalate (Fig. 2, step 12 (S12) ). (2 -3) The precipitated gadolinium oxalate is separated by filtration (Fig. 2, step 13 (S13)). (2-4) adding a potassium hydroxide aqueous solution having a potassium hydroxide concentration of 70 g / 70 ml, and separating and recovering the oxalate oxalate filter cake in the above step (2-3) (FIG. 2, step 1 4 (S1 4)) ) To decompose osmium oxalate to form osmium hydroxide. (2-5) Next, the oxidant sodium hypooxygenate is added to oxidize osmium hydroxide to generate rhenium hydroxide (Fig. 2, step 15 (S1 5)). (2-6) Separation of thorium hydroxide by filtration (Fig. 2, step 16 (S16)). Thus, a rhenium hydroxide wet cake (83 · 7 g) containing Ce02 (48.5 g) was recovered. In this step, 99.9% 钸 in the used chromium etching solution can be separated and recovered (calculated by Ce02 as 48 · 6g). (2-7) Add nitric acid and ammonium nitrate to the recovered thorium hydroxide and heat it to concentrate to produce ammonium rhenium nitrate (Figure 2, step Π (S1 7)). (2-8) Evaporating, condensing and crystallizing the ammonium ammonium nitrate solution using a crystallization device, and separating and dehydrating the precipitated ammonium ammonium nitrate crystals (Fig. 2, step 18 (S18)). (2-9) A new chromium etching solution is prepared by mixing and dissolving nitric acid and the like with ammonium osmium nitrate at a predetermined ratio (FIG. 2, step 1 9 (S1 9)).

Page 11 593766 V. Description of the invention (9) (2-1 〇) On the other hand, add the aqueous solution of sodium hydroxide in the above step (2-3) to separate the filtrate containing trivalent chromium after the oxalate oxalate, and adjust its pH to 8 The trivalent chromium was precipitated as chromium hydroxide (Fig. 2, step 20 (S20)). (2 -1 1) The chromium hydroxide is separated and removed by a filtration method (Fig. 2, step '· step 21 (S21)). The chromium concentration in the filtrate after filtering the II chromium oxide was 10 ppb, and the concentration was 100 ppb or less. In this step, the solution after filtering and neutralization can be used to separate and remove more than 99.9% of the chromium in the used chromium etching solution. In this embodiment, 'in step (2-2), the base is neutralized to a pH of about 4. Sodium hydroxide may be used as a base, but other bases such as potassium hydroxide may be used. In step (2-4), a potassium hydroxide aqueous solution is added to the separated and recovered oxalate broth cake ', but other alkaline aqueous solutions such as sodium hydroxide may also be used. Another step (2-5), the oxidant sodium hypochlorite is added to oxidize sulfonium hydroxide to form sulfonium, but other oxidants such as hydrogen peroxide can also be used. Step 2 and step (2-10), add sodium hydroxide aqueous solution to the filtrate after separating the oxalate oxalate to precipitate 3 彳 chrome with hydroxide, but other bases can also be used

A ★ and ^ ^ Implementation mode 'condensate and crystallize the solution containing ammonium ammonium nitrate using a crystallization device (step (2-8)), but depending on the circumstances, it is not particularly carried out. The use of ammonium osmium nitrate in solution state for the preparation of new inventions is not limited by the above embodiments in other aspects.

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V. Description of the Invention (ίο) Various applications and changes can be made within the scope of the invention. [Effects of the Invention] As described above, the method for recovering radon from the chromium etching solution of the present invention is to evaporate and condense the acid chromium etching solution containing radon and chromium to precipitate and separate the radon compound =, and use the separated decorative compound to prepare and use the chromium contact. The engraved insect engraved the liquid, so <> the simpler evaporation crystallization method with good efficiency from the used glutamate to the liquid recovery pupae. 〆

In the chromium etching solution, ammonium osmium nitrate is usually used as the erbium compound. At this time, the ammonium osmium nitrate is precipitated with good efficiency by evaporation crystallization to separate and recover (the second in the scope of patent application). 77 Another method of recovering thallium from chromium etching solution of the present invention (item No. 3 of the scope of application for patent) is to evaporate and condense the chromium etching solution to separate and recover thallium compounds, and at the same time to separate and recover thallium compounds with oxalate. After the separation of the remaining (remaining) plutonium, about a full amount of the plutonium in the chromium etching solution can be recovered, which greatly improves the recovery rate and makes the present invention more practical. Another example is the method of recovering rhenium from the chromium etching solution in the scope of the patent application. In step 3 (c) of the scope of the declared patent, the trivalent oxalate is separated: ^ The trowel's precipitate is added with alkali hydroxide. (Metal) here contains trivalent chromium

Substances are very meaningful because they will not be discharged out of the system with good quality chromium but have a ratio of ^ = I. Method, in the application] in the scope of item 5 of the recovery solution of the chromium etching solution from the chromium solution, the third step (c) of the siege compound is separated and precipitated in the name of the compound 具 with a reduction of 4 valence materials 3 valance Reduction and Health 4

593766, Description of the invention (11) — 3-The degree of hydroxide of valence chromium :: two make: and to substantially 'precipitate 3' The oxalate with 3 valence as the main re == after the oxalate is precipitated ' The liquid is separated and returned with good efficiency; == chromium compounds of chromium compounds. Method, which can be suppressed until item 5 of the scope of patent application + the solution of recovery of the etch solution is about 4, which can be restrained "; (b) adding neutralizers during neutralization can make 3 scales and 7 scales thinner — To prevent the precipitation of chromium as gas oxides, and at the same time as the second method, in the scope of the patent application, item 5i; Chromium residual etching liquid recovery method to generate the gas 4 彳 b: # 成 刀 的 结 物 用 OH The action of alkali (metal) causes the formation of money hydroxide, and the oxidation and oxidation of the oxidant oxidant heats and concentrates the formation of her ";; milk:" when nitric acid and ammonium nitrate interact and-^ e _ ^. ^ ^ P bismuth, the resulting ammonium osmium nitrate can be Combined with nitric acid, etc .; Γ ϊ rice carving liquid, can be used for recycling with good efficiency. Niu You: — ° Month replies to the 8th step of the 巳 etching solution from the chrome etching solution to recover the 钸 ammonium sulphate ammonium nitrate precipitated in the 2nd step. (The ammonium osmium nitrate generated in the seventh paragraph of the patent application system is used to adjust the etching solution of ± * AU ^ ^,,, and can be recycled and reused. The king sets Jin as ㈣ &amp; to make the invention more practical. .

593766 Brief Description of Drawings Fig. 1 is a flow chart showing the steps of evaporation, concentration, and crystallization in a method for recovering plutonium from a chromium etching solution in accordance with an embodiment of the present invention. FIG. 2 is a flowchart of a step of recovering rhenium with oxalate in a method for recovering rhenium from a chromium etching solution according to an embodiment of the present invention.

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Claims (1)

593766 VI. The precipitation of the scope of the patent application (c2) The analysis of the main components 3 · Rushen method, in which the step of separation after receiving oxalate 4. Rushen method, in which the method in 5. Rushen method The step of the step of precipitation, the step of this life; and the step of the ammonium hydroxide nitrate, and the step of (a2), (b2) from the step of the valence of oxalate with trivalent amidine. The method of recovering the chromium from the chromium etching solution in item 2 of the Qing patent includes the step (cl) of adding a hydroxide test (metal) to separate and return 3 3 {Below solution to precipitate trivalent chromium as chromium hydroxide. Step 2 (b2) of the method of recovering decoration from chrome | insect engraved liquid by adding alkali during neutralization, and adding alkali until the pH is about 4 during neutralization. The following steps are included in the recovery of the chromium etching solution from the second or fourth item of the patent patent: (&quot; c 2) The knife is separated and recovered, and the trivalent oxalate is mainly used as the hydroxide. The action of alkali (metal) causes the step of generating rhenium hydroxide to form oxyhydroxide, which acts as an oxidant to generate oxychloride, oxidizes rhenium oxide with nitric acid and ammonium nitrate, and heats and concentrates to produce the step.