TW572851B - Recovery of cerium from solution containing both chromium and cerium - Google Patents

Description

572851 V. Description of the invention (1) [Detailed description of the invention] [Technical field to which the invention belongs] The present invention relates to a solution containing chromium and bromine, in particular, a solution containing hexavalent and tetravalent europium, The method of recovering amidine as ammonium ammonium nitrate (NH4, (N0)). In particular, the present invention relates to a solution containing hexavalent chromium, tetravalent and trivalent europium discharged from a process for etching a nitric acid recording solution containing a chromium-containing metal, and can be used as a chemical for etching. Method for recycling high-purity shi Xiao acid decoration. "〇 [Previous technology]

In the manufacturing process of semiconductor and liquid crystal display, the etching process mostly contains ammonium hafnium nitrate solution containing chromium metal. The waste liquid discharged from this project contains hexavalent chromium and tetravalent and trivalent europium. Therefore, this waste liquid is strongly oxidizing, so it is necessary to remove these substances from the waste liquid. For example, it is described in this waste liquid that the addition of sulfurous acid ^ Naring S, also. The method of adding lice calcium oxide to humans to remove chromium and tadpoles in the form of hydroxide. Further, in Japanese Patent Application Laid-Open No. 9_85264, it is written that ", after reduction of valent chromium and tetravalent europium, is adsorbed and removed on an adsorbent. [Problems to be Solved by the Invention] '° However, in these methods, the final Because it is obsolete, it is desirable to recycle it as much as possible. In particular, if the high purity ammonium osmium nitrate type of the second engraving solution is returned, the name is the name of the project, the household is equal to = the acid solution is given as m: in the waste solution of the valence, eight you ·,

Method for recovering ammonium ammonium nitrate of intermediate purity. 7 钸 L

89107975.ptd Page 4 572851 V. Description of the invention (2) [Means to solve the problem] According to the present invention, the rhenium hydroxide recovery process for recovering the hydroxide # can be performed from a solution containing chromium and rhenium. The washing process of washing the rubidium hydroxide sinking material obtained by the rubidium hydroxide recovery project, adding nitric acid and ammonia source to the rubidium hydroxide after the washing process, the ammonium nitrate decoration crystallizing process, And ammonium osmium nitrate recovery project, which recovers the ammonium osmium acid crystals produced by the crystallization process of ammonium oxalate, and recovers high purity ammonium osmium nitrate from a solution containing chromium and rhenium. In detail, 'reducing agent is sequentially added to a solution containing hexavalent chromium and tetravalent europium under pH 2 to reduce the hexavalent chromium and tetravalent europium to trivalent chromium and trivalent europium, respectively. Adding alkali to the solution obtained in the reduction process removes the chromium from the trivalent chromium Shen Dian. Adds a test oxidant to the solution obtained from the chromium removal process to make it pH 8 or more, and the hydroxide is precipitated in the form of a tetravalent europium hydroxide.钸 Precipitation project, washing process to wash the Shen Dianwu obtained from the 钸 precipitation project, dissolve the precipitate after the washing process in Xiao Wenwen and add ammonia source to the resulting nitric acid decoration solution to make Shi Xiao acid 钸 Qian Han The fine crystallization of ammonium osmium nitrate precipitation crystallization process, and the recovery of ammonium osmium nitrate from the ammonium osmium nitrate crystals produced by the crystallization process of ammonium osmium nitrate, and the recovery of ammonium osmium nitrate can be performed by using hexavalent chromium and High purity ammonium osmium nitrate was recovered from the solution. [Implementation mode of the invention] 2 is the solution of the target of the recovery of the europium of the present invention, if it contains chromium and cerium, it is better to have hexavalent chromium and tetravalent europium, and it may also contain = shop.

89l7975.pld Page 5 572851 Description of the invention (3) ^ Ammonium osmium nitrate solution containing chromium-containing metal, hexavalent chromium and tetravalent shellfish's grain solution are suitable for the treatment object of the present invention. ^, Ming first recovered from this solution. The recovery of thorium hydroxide is preferably the recovery of chromium from this solution (chromium recycler :, the recovery of thorium hydroxide from the solution after chromium recovery (the thorium hydroxide precipitation process is performed in sequence. In addition, the chromium recovery process is based on reduction Engineering and removal = constituted by engineering, and preferably carried out in this order. ≪ Reduction engineering > will ί $ η: This: the volume of the solution is reduced to less than 2 and reduced with a reducing agent, or all the tetravalent sieve is reduced The trivalent bromide is better. This reduction reaction is better than PH2. The waste liquid discharged from the process is usually this type; the other kind / the treatment of the present invention. Put a note, so it can be used as it is. Hydrogen peroxide. Hydrogen peroxide acts as a reducing agent. The reducing agent is used; for the full amount of hexavalent chromium and tetravalent bromine, & don't reduce it to trivalent. 4. The necessary amount of m 钸. In this project, the three valences A = 钸 did not contain the original, then the chromium was removed next, so you can get back 降 ^ reduce the remaining four valence 钸 to precipitate The type is eliminated, and if the tetravalent europium remains, the chromium removal rate tends to increase. Because ^ 々 In the case of the high chromium removal rate in the second chromium removal project, the recovery rate of samarium is also sacrificed, and the original project is also wanted to be raised. This reduction project is ^ = it can make some residual valence of tetravalent chromium to be returned, "& A solution with raw materials hexavalent chromium and tetravalent europium

: ^ Add hydrogen peroxide and stir easily at room temperature. The progress of the reaction can be tracked by measuring the redox potential of the solution < the process of removing chromium > In the gluten solution which is still τ avoidance, ，, 钬 4, your original work ^ r Then add alkali to make the pH Rise, and make D wash. The resulting Shen Dianwu will be removed by appropriate means such as 滹 # 未 / 愿 Centrifugation. The precipitation of chromium is performed at a pH of 2 or higher. If the pH is low, the concentrations of 1 remaining in the solution increase. On the contrary, if PΗ is high in the second song, the decoration becomes sunk. Therefore, & ~ 7, surname w c. > This process of removing the network is better than ρΗ2 可可 Aϋ

Metal θ ^ ^ 碱 Alkaline earth of milk emulsion, lice calcium oxide, etc. ‘Emulsion of lice, ammonia, etc., but Tongdang helmet is preferably sodium hydroxide. It is better to use an alkali metal hydroxide than the < Hydrogen hydroxide precipitation process > The solution after the chromium removal process is preferably P10 or more, and the alkali added with two oxides to make P8 or more, which is more expensive. The trivalent tritium in the manufacturing order solution is oxidized to tetrazine. The test is the same as the process of removing chromium.

Alkali gold that is a hydroxide, calcium hydroxide, etc., and potassium hydroxide can also be used. Usually, alkali metal hydroxides, metal hydroxides, ammonia, etc. are used. Sodium hydroxide. If ammonia is used as a base, the alkali metal f ^ in the ytterbium hydroxide produced by the removal of chromium has nitrogen and has a low cost for waste liquid treatment. However, the waste liquid contains a hydroxide as a hydroxide. Alkali. And kung fu problems, so alkali gold horse emulsifiers are usually used. Hydrogen peroxide is

In addition, it is preferable to use hydrogen peroxide 572851. V. Description of the invention (5) The action is a reducing agent under strong conditions, but it acts as an oxidizing agent in the middle of J4 Shiren. If it is removed from neutral to alkaline, it is decorated with oxidant and is decorated with f-oxide type, but its order of addition is arbitrary. With the emulsifier, the trivalent fork that was not removed by the previous project in Fen / Night was temporarily inspected and temporarily # 一 1 员 t, can be precipitated by the emulsifier type of Chengfeng, but by the bomber seven, Hexavalent chromium is produced and re-produced ^ 1 ,, and re-oxidation is carried out by the lice agent. This ίΓ oxidized decoration Shen Dian project is better than PH10 in the emulsification of π ΤΓ Μ 4 / cloth and chromium. Oxidation can also be added to the solution and stirred under hunger.苴 Emulsified tablets 丨 J, Substances, can be properly recovered by 遽 = centrifugation, centrifugation, etc. ^ = Oxidation bromide is deposited in the scourge of today's accident-Ge Zhoutian Yunu and recovered from Luoye. Compound Shen Dian: I think the hydroxides and hydrogen peroxide are used in the follow-up; Because it becomes a complex with lice in husband 1 M, if dissolved in nitric acid I, it becomes a strong acidic solution less than PZ2, which causes the peroxygen agent and tetravalent europium to be returned. Its simplest Ϊ =. Removal of hydrogen peroxide from the complex. 'As early as to heat the Shen plant, decomposing hydrogen peroxide into water and oxygen, <washing process> Water: Shen Dezhi Shen Dianwu contains a large amount of alkali metals, so proceed to "kidney: alkali metal Reduced washing process. Water washing usually involves the alkali metal content of PDm #. It is 2000 weight on a dry basis, and 600 weight in particular. It is less than 100% by weight and less than ppm by weight. Material suspended in water to form a slurry. Page 8 89107975.ptd 572851 V. Description of the invention (6) After being washed and washed back by centrifugation or centrifugation, it can be washed efficiently. The number of water washings is to increase the number of washings at room temperature to 80. However, if it is too low, the washing efficiency will be deteriorated, and j will be removed by washing, so even if it is repeated several times = Inner: The metal inspection rate included is greatly reduced to dryness. It is also difficult to make the base metal contain the water used in the standard washing, which is usually a grade of pure water. Pure water in washing. It is the &lt; Ammonium osmium nitrate precipitation crystallization process with a conductivity of 1 s / cm or less &gt; The alkali metal is dissolved in nitric acid after washing process, preferably over Amount = reduced precipitate, which can completely dissolve the dissolved form, followed by the contamination, and the crystals are concentrated and precipitated in the nitric acid solution of thallium nitrate. By this means, the ammonium nitrate is made less acidic, and Crystals can be precipitated. The alkali metal content can be significantly changed. The temperature of nitric acid is easy to dissolve. The temperature of nitric acid used for dissolution is usually 62 ° C, so the hydroxide C and the concentration of nitric acid are usually 50%. 70 ° C., preferably 7 5 to 8 5 is 60 to 70% by weight (highest azeotropic concentration 0 ^^ azeotropic concentration), preferably 100%, and more preferably 95 to 15 loo. X. In addition, the purity of nitric acid is 80 ~. If the source of ammonia is ammonium nitrate obtained from ammonium nitrate such as ammonium nitrate and ammonia, and there are 3 ammonium ions, it is ~ 30% and the purity is ~ 丨. 〇% 的 物。 And in other words,-it is better to use the nitric acid concentration in the system to react with nitric acid and generate heat, so if you use & ammonia as the ammonia source, it can be reconciled and the necessary heating energy can be reduced. The produced ammonium osmium nitrate is dissolved 572851 5. Description of the invention (7) Ammonium osmium nitrate is precipitated from the nitric acid solution of osmium nitrate It can be carried out according to a known method, for example, the method described in Patent No. 2 8 4 4 3 68. The solubility of nitric acid in nitric acid is higher as the concentration of nitric acid is lower or the temperature is lower. Therefore, in nitric acid Add Shen Dian hydroxide, which removes water as much as possible, and dissolve it. Then add an ammonia source to generate acid solution and then completely dissolve it. By completely dissolving the ammonium phosphonium nitrate produced, the precipitation can be obtained. The purity of ammonium ammonium oxalate is increased. In order to completely dissolve ammonium ammonium nitrate, it is usually heated at 60 ~ 85 ° C and stirred for 30 ~ 120 minutes after adding an ammonia source. After that, it is concentrated as needed It is preferable to cool after the operation so that ammonium osmium nitrate precipitates and crystals. &lt; Ammonium phosphonium ammonium nitrate recovery process &gt; The crystallized ammonium phosphonium ammonium nitrate precipitate can be recovered from the solution by appropriate means such as filtration and centrifugation. After partially recovering the crystallized ammonium ammonium nitrate, the mother liquor is usually concentrated by evaporation to make the ammonium ammonium nitrate more precipitated and recovered. After the mother liquor is dissolved in a nitric acid type that dissolves thallium hydroxide, it is better to reuse a part of it . &lt; Cleaning process of nitric acid &gt; The ammonium osmium nitrate recovered from the mother liquor is to remove the impurities other than the attached alkali metal with nitric acid to improve the purity of the ammonium osmium nitrate. Washing with nitric acid, which is effective for several times. After the ammonium hafnium nitrate precipitate is suspended in nitric acid to form a slurry, it is filtered or centrifuged to separate the precipitate and the method of washing wastewater. The number of times of nitric acid washing can be appropriately selected according to the concentration of impurities in ammonium osmium nitrate and the concentration of impurities required as a product. The temperature of the nitric acid cleaning is usually carried out near normal temperature. If the temperature is too high, the solubility of ammonium osmium nitrate will increase and the loss will increase. Also, nitric acid

572851, description of the invention (8) L 'contention !! If the acid concentration used is low, then the solubility of the acid continues to increase and the di-loss increases, so the nitric acid concentration is usually 50 ~ 70% (the highest azeotropic concentration) , Wide, 65 ~ 70% (highest azeotropic concentration). In addition, the higher the purity of nitric acid, the greater the cleaning effect of thion, so the purity of nitric acid is usually 80 ~, preferably 95 ~ 100%. The ammonium osmium nitrate used in the preparation of the etching solution of chromium metal requires an alkali metal content of 3% or less, preferably the following: In the case of satisfying this requirement, the precipitated crystals of ammonium osmium nitrate are It is better to start in mother liquors with an alkali metal content of 35 ppm or less, particularly 300 ppm or less. If

Therefore, precipitation and crystallization in the mother liquor of this alkali metal content rate, the alkali metal content rate of the obtained crystals of Shi Xiaoyu under ammonium, even after washing with nitric acid, is difficult to be less than 1 ppm. The alkali metal content rate in the mother liquor is 35 ppm In the following, when the mother liquor after crystallization is separated and reused as the nitric acid used to dissolve the thorium hydroxide, it must be discharged out of the system to prevent the alkali metal from accumulating in the system. However, if there is a large amount of discharge outside the system, the loss of dissolved plutonium will increase. Therefore, the discharge is preferably performed at 300 ppm, especially 200 to 250 ppm, of the alkali metal from which the crystallized mother liquor is precipitated. According to the present invention, the etching solution containing ammonium osmium nitrate is used to recover the waste solution discharged from the chromium etching process, and the rhenium is recovered as a high-purity cerium II ammonium sulphate which can be prepared as an etching solution. [Examples] &lt; Examples &gt; 2% by weight of ammonium phosphonium nitrate, 38% by weight of nitric acid, and 2% by weight of peroxyacid were included.

89107975. ptd Page 11 572851 V. Description of the invention (9), The etching solution, the hexavalent chromium discharged from the process of etching the chromium thin film is 0.02 mol / liter, and the tetravalent 钸 〇.〇70 mol / Liter, trivalent 钸 278 mol / liter of excess, liquid (ρ Η 0 · 2) 1 330 liters, at room temperature under stirring, will be used as hydrogen peroxide, 35% by weight hydrogen peroxide aqueous solution, Add about 0.4 times Mohr's to tritium and reduce chromium and tritium to trivalent. The end point of the reaction was detected by measuring the redox potential of the solution. Next, in this solution, a 25% by weight aqueous sodium hydroxide solution was added to the lower chamber / chamber to make the liquid μ to be 6.0. The resulting precipitate was removed by filtration, and the filtrate was stirred and warmed, and a hydrogen peroxide aqueous solution was added to 钸 · 7 times moles to oxidize 钸, and thereafter, 25% by weight of hydroxide was added. Aqueous sodium solution makes the solution: ph is ίο. Stir at room temperature! After 8 hours, heat at 8 ° C and stir for another 2 hours. Filter to obtain a thin yellow precipitate of rhenium hydroxide. The recovery of rhenium is 90%. The sodium content of this precipitate is 12% by weight on a dry basis ·, Suspend it in pure water on a dry basis of 0.1 g / liter, repeat the operation of filtering 5 times after stirring. The sodium content of the precipitate is 6000 ppm by dry weight. On a dry basis, add 85.1 kg of the above precipitate to 5 ^ kg of 70% nitric acid, and heat and hold for 2 hours at 84 t. The precipitate is completely dissolved. 48 kg of 29% ammonia water is added to it And, under stirring for 84 hours. Next, cool down to room temperature at a rate of ^ c / hr, take 152 kg of = = ^ crystals. The sodium content of the mother liquor after crystal separation is about 80 ppm by weight. This crystal is washed and dried with 70% nitric acid of the same weight as the crystal. The purity of the crystal is 99.0%, and the content of the metal containing sodium is less than 1% by weight.

572851

ppm. At this time, with respect to the &lt; Comparative Example &gt; recovery rate of 66% of the rhenium hydroxide in the waste etching solution, hold it for 2 hours &lt; and stir it to room temperature to crystallize the purely recovered nitrate after filtering, again: 1 / manufactured, recycle the hydroxide decoration from waste recording night. The obtained: without washing the ground, as it is, dry weight of basic phase kilograms of hydrogen and oxygen was added to 70% of 520 kilograms of oxalic acid, and at 84. . Heat and keep the precipitate completely dissolved. Add 48 kg of ammonia water at 84 C under the condition of 2 hours. Next, it was cooled at 60 ° C / hr to obtain 5 1 kg of crystals of ammonium osmium nitrate. In order to reach 99.0%, this crystal was repeatedly washed with 70% nitric acid and dried. As a result, the nitric acid required for washing was 348 kg, and 136 kg of ammonium phosphonium crystals were obtained. The recovery rate of plutonium in waste etching solution was 58%.

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89107975.ptd Page 14

Claims (1)

572851 Announcement VI. Scope of patent application 1.-Recovery method of species 钸 It is characterized by collecting by a solution containing chromium and 钸 Φ ^ ^ 钸 Hydroxide 钸 recovery process that recovers lice oxidation 钸 in the rescue, hydrogen Rhenium hydroxide precipitates obtained from the Rhenium oxide recovery project are washed with water. The cleaning process of the Rhenium hydroxide that has been washed is to add nitric acid and an ammonia source to cause ammonium rhenium nitrate to crystallize. Each project is composed of a process and an ammonium osmium nitrate recovery project in which ammonium osmium nitrate crystals generated by the ammonium nitrate precipitation and crystallization process are recovered. 1-2. The method of recovering radon as described in item 1 of the scope of the patent application, wherein each of the hydroxide #recovery workers is a chromium recovery process for removing chromium from a solution containing chromium and thallium, and removing the residues from Luo Gongqiu Hydroxide decoration precipitation process that makes the hydroxide decoration splash. 3. The method of recovering tritium as described in item 1 of the scope of the patent application, wherein the solution containing the melamine and ornament is a solution containing hexavalent chromium and tetravalent tritium.口 4. The method of recovering tritium as described in item 3 of the scope of the patent application, in which the chromium recovery process is a reduction process of reducing hexavalent chromium and tetravalent thorium to trivalent chromium and trivalent thorium respectively, and a reduction process An alkali is added to the obtained solution, and the trivalent chromium is removed by precipitation. 5. The method of recovering tritium as described in item 4 of the patent scope of Shenjing, which also includes a process of adding a reducing agent containing chromium and tritium to a solution of less than pH 2 〇89 川 7975.ptd page 15 572851 6. Scope of patent application 6. If the recovery method of the planted crickets described in item 2 of the scope of the patent application, the pot: "__ Project is the process of adding Erdian to the solution obtained from the chromium removal project. Material type Shen 7, as described in the patent application scope of the first method of recovery of radon, ammonium acid sieve ammonium precipitation process, in order to dissolve the tritium hydroxide in the light, and add ammonia to the solution to make the tritium nitrate Project for the precipitation of ammonium crystals. 8. The recovery method of the decoration as described in item 7 of the scope of patent application, which is to dissolve n oxide m in the process of shixiao acid and dissolve it in excess of shixiao acid. 0 t = sieve ^ Recovery method, which is characterized by adding hexavalent chromium and quaternary ornaments to less than p Η 2 of the> Valley solution added reduction check, 丨 person &gt; $ &amp; m 〇T j 刀 迓 原 M, order six Valence chromium and tetravalent 钸, respectively, v ^ ^ ^, 祆, add 4 recharge trivalent chromium to the solution obtained by the reduction process Shen Dian removes the smelting agent, adds the test oxidant to the Luo solution paid for the chrome removal project to make it pH 8 or more, so that the sulphate hydroxide is precipitated by the quaternary hydroxide type,殿 The Shen Dianwu obtained from the precipitation process is given as follows: 1. The washing process of 7 d M water washing. The immersed plate after the washing process is dissolved in the shi Xiao acid, #, 〆 広 人 丄, * 月 〇 欠 Τ, The cyanide source is added to the generated ytterbium nitrate solution to concentrate the ammonium osmium nitrate. The crystallization process of ammonium osmium ammonium nitrate from the crystallization of osmium® crystals, and the crystallization process of ytterbium nitrate to precipitate the crystals ρ, ^ ^ ^ Λ 10. The ammonium nitrate recovery project of the ammonium ammonium nitrate crystals that are generated to be recovered. 10. If the scope of the patent application is 7th to 9th, the recovery method of any of the 9 items described in 不 is described, in which Nitric acid is used to precipitate the molluscs. The heart of the war is the mother liquor after the ammonium crystallization is recovered, and you also use α as the nitric acid used in the precipitation crystallization process. 572851 VI. At least-part of the scope of application for patents, first application of the tf patent scope of the J or 9 items-^ Washing work is carried out until the record in the item I + 20 20 weight nn 1 alkali metal Including the right woman's collection method, the hair set below P⑽ is Qiu. Probability is based on the amount of dry matter, 隹, .σ. The scope of the patent application scope is "precipitated crystallizer of acid bromide": ^ Remembering the decoration of the ~ ~ in the solution below the Qing, eight for the hunting in the alkali metal Contains the text method, which is as follows: 1 · Shen Shizhu Zhi A 7 Xiao Xing's ammonium precipitates, it is 3 5 0% Yin Yin% of the patent scope and the 5th day of the patent. The weight t meets the θ of the eight battles used in the original project仏 14 · If Yin Wangzhuan is the agent of hydrogen peroxide. The method, the patented patent No. 6 or q, makes the cerium hydroxide precipitation worker—, the recovery of the 5 载 载 岁 oxidant used in Method I 5. If the scope of the patent application is [] or 9 = hydrogen hydride., There is a recovery method of ammonium acetic acid recovery industrial halberdine decoration, dragon washing of Shi Xiao acid cleaning process. Nitrogen is used for cleaning. 6. The alkali metal content of ammonium sulphate ammonium nitrate is described in item 15 of the scope of the patent application, and the nitric acid is washed on a dry basis. The method of recovering radon as described in the first or 91th member of the scope of patent application for H, wherein the solution containing chromium and radon recovered by kt and radon, It is a waste liquid discharged in the process of etching with an acid solution of ammonium osmium nitrate containing a chromium-containing metal. Page 17 89107975.ptd