201130738 六、發明說明： 【發明所屬之技術領域】 本發明之一部分係關於自含鋰溶液中回收鋰，該等含鐘 溶液為例如製造鋰離子電池中使用之進料流以及藉由自爲 於礦石之材料中提取鋰而得到之進料流。 本申請案主張2008年11月17曰申請之美國臨時申請案第 61/199’495號之權利，該案出於所有目的以全文引用的方 式併入於此。 【先前技術】 3鋰電池，由於其具有較高能量密度重量比以及相較其 他類型電池具有相對較長使用壽命，已成為多種現有及新 興應用中之較佳電池。鋰離子電池用於眾多應用中，例如 行動電話、膝上型電腦、 搏器）。 •^療器件及植入物（諸如心臟起 鋰離子電池在新型汽車(例如混合及電動車輛)的研發中 ，由於其減少排放且降低對烴201130738 VI. Description of the Invention: [Technical Field of the Invention] One aspect of the present invention relates to the recovery of lithium from a lithium-containing solution, such as a feed stream used in the manufacture of lithium ion batteries, and by self-contained A feed stream obtained by extracting lithium from the ore material. The present application claims the benefit of U.S. Provisional Application Serial No. 61/199, 495, filed on Jan. 27, 2008, which is hereby incorporated by reference in its entirety in its entirety in its entirety. [Prior Art] A lithium battery has become a preferred battery in many existing and emerging applications due to its high energy density to weight ratio and relatively long service life compared to other types of batteries. Lithium-ion batteries are used in many applications, such as mobile phones, laptops, and beaters. • Devices and implants (such as the heart from lithium-ion batteries in the development of new vehicles (such as hybrid and electric vehicles), due to its reduced emissions and reduced hydrocarbons
得電池重量相較其他電池減輕 素0 亦成為極其有用之能源選擇， 燃料之依賴，故而既環保又 外’選擇鋰離子電池供車 能量密度重量比，從而使 此為車輛製造中之重要因 鋰離子電池通常由三 三個主要部分構成：1)碳陽極，2)分 151347.doc 201130738 離器，及3)含鐘陰極材料。較佳含鐘陰極材料 包括鋰及金 氧化物材料’諸如鋰鈷氧化物、鋰鎳鈷氧化物、鋰錳氧 化物及磷酸鋰鐵，但其他鋰化合物亦可使用。 麟S文鐘鐵為用作含鐘陰極材料之尤佳化合物，因為與所 提及之其他陰極材料相比，其提供改良之安全概況、可接 丈之工作特徵及較低之毒性。相對較大之電池尺寸尤其如 此，諸如用於電動汽車中之情況。安全特徵改良係由於填 酸經鐵（亦稱為LIP)能夠避免如其他鐘離子電池一般易於過 熱。此對較大電池尤其重要。同時，up電池之電池工作 特徵與目前使用之其他化合物等同。其他鐘化合物減少了 U向’但以犧牲工作特徵為代價。碌酸鐘鐵硫酸鹽類 似於LIP，且亦用於電池中。 礦酸賴可㈣式化學法，❹含輯子之水溶液進料 流來製備’該等鐘離子係來自例如碳酸經、單水合氣氧化 裡、硝酸裡等經源。典型反應流程係由Yang等人士㈣ of Power Senses 146 (2005) 539_543描述如下進行： 3LiN03 + 3Fe(N〇3)2.«H2〇+3(NH4)2HP〇4 Fe3(P〇4)2*«H2〇+Li3P〇4+6NH3 + 9HN03 ⑴The weight of the battery is also an extremely useful energy choice compared to other batteries, and the fuel is dependent on it. Therefore, it is environmentally friendly and externally selects the energy density-to-weight ratio of the lithium-ion battery, thus making this an important factor in the manufacture of lithium. Ion batteries typically consist of three main components: 1) carbon anodes, 2) 151347.doc 201130738 separators, and 3) bell-containing materials. Preferred cathode-containing materials include lithium and gold oxide materials such as lithium cobalt oxide, lithium nickel cobalt oxide, lithium manganese oxide and lithium iron phosphate, but other lithium compounds may also be used. Lin S Wenzhong Iron is a particularly good compound for use as a cathode material containing a clock because it provides an improved safety profile, acceptable working characteristics and lower toxicity compared to other cathode materials mentioned. This is especially true for relatively large battery sizes, such as those used in electric vehicles. The improvement of the safety feature is due to the fact that the acid-filled iron (also known as LIP) can be easily overheated as other plasma batteries. This is especially important for larger batteries. At the same time, the battery function of the up battery is equivalent to other compounds currently in use. Other clock compounds reduce U-direction but at the expense of work characteristics. The acid bell iron sulfate is similar to LIP and is also used in batteries. The mineral acid lysate (four) type chemical method, which is prepared by the aqueous solution feed stream containing the series, is derived from a source such as carbonic acid, monohydrate gas, or nitric acid. The typical reaction scheme is described by Yang et al. (4) of Power Senses 146 (2005) 539_543 as follows: 3LiN03 + 3Fe(N〇3)2.«H2〇+3(NH4)2HP〇4 Fe3(P〇4)2* «H2〇+Li3P〇4+6NH3 + 9HN03 (1)
Fe3(P04)2*«H20+Li3P〇4 ^ 3LiFeP04+„H20 (II) 磷酸鋰鐵可用濕式化學法，使用含鋰離子之水溶液進料 流來製備，該等鋰離子係來自例如碳酸鋰、單水合氫氧化 鋰、硝酸鋰等鋰源。磷酸鋰鐵硫酸鹽以類似方式製備，作 151347.doc 201130738 製備需要硫酸鹽原料。舉例而言，Goodenough等人之美國 專利第5,910,382號及Armand等人之美國專利第6,5 14,640 號各描述磷酸鋰鐵之水溶液製備。一般而言，由於方法效 率低’故此等製備磷酸鋰鐵之濕式化學法產生含有大量鋰 離子以及其他雜質的水溶液流。由濕式化學法製備磷酸鋰 鐵產生之典型液流的組成如下：Fe3(P04)2*«H20+Li3P〇4^3LiFeP04+„H20 (II) Lithium iron phosphate can be prepared by wet chemical method using an aqueous solution containing lithium ions, such as lithium carbonate. A lithium source such as lithium hydroxide monohydrate or lithium nitrate. Lithium iron phosphate sulfate is prepared in a similar manner as 151, 347.doc 201130738. The preparation of a sulfate raw material is required. For example, US Pat. No. 5,910,382 to Goodenough et al. and Armand et al. U.S. Patent No. 6,5,140, each describes the preparation of an aqueous solution of lithium iron phosphate. In general, the wet chemical process for preparing lithium iron phosphate produces an aqueous solution stream containing a large amount of lithium ions and other impurities due to the low efficiency of the process. The composition of a typical liquid stream produced by the wet chemical method for the preparation of lithium iron phosphate is as follows:
由於鋰為磷酸鋰鐵材料之主要且較有價值之組分之一， 因此將而要回收任何過量鋰以在濕式化學法製造磷酸鋰鐵 151347.doc 201130738 中再使用，在生產磷酸鋰鐵產品之製造過程中提供相對大 里過篁之鋰的情況下尤其如此。自鋰電池廢料中回收並純 化鋰之方法獲知於已公開之PCT申請案wo 98/59385，但 此項技術中需要回收鋰之改良及替代方法。 【發明内容】 本發明利用雙極電滲析來達成此目的及其他目的，雙極 電滲析亦稱為用以自進料流中回收鋰之鹽裂解技術幼… splitting technology)。所回收之鋰呈氫氧化鋰溶液形式， 可使其再循環至所用進料流中以使用濕式化學法生產磷酸 鋰鐵。該過程中亦產生硫酸溶液，可將其回收並用於其他 過程中或作為商品出售》在較佳實施例中，在對進料流進 行雙極電滲析之前減少或更佳移除進料流中之任何磷酸根 離子’因為已發現’磷酸鹽易於污染膜，從而降低氫氧化 鐘之產率或完全阻止其形成◦或者，在含鋰礦石之硫酸還 原中，所得經純化之硫酸鋰液流亦可依此方式處理。其優 勢在於亦產生硫酸液流，若加以濃縮，則可用於抵消購買 所需硫酸之成本。 雙極膜電滲析利用獨立腔室及膜來產生所引入之各別鹽 溶液的酸及鹼。根據此方法，離子交換膜經由電場分離溶 液中之離子物質。雙極膜將水解離成帶正電之氫離子 (H ，在水溶液中以H3〇+(水合氫離子）形式存在）及帶負電 之氫氧根陰離子（〇Η·) 雙極膜通常由結合在一起之陰離子交換層及陽離子交換 層形成。提供水擴散層或界面，來自外部水性鹽溶液之水 151347.doc 201130738 於其中擴散。 進步提供陰離子及陽離子可選擇性滲透之膜以引導鹽 離子刀離例如必要時，鋰離子及硫酸根離子。因此，在 雙極膜電滲析中通常使用三膜系統。 來自市。來源之膜’例如Astom之ACM、CMB、AAV及 /1膜或FumaTech之FKB膜，可以其對無用離子（H+*〇H-) 回遷之抗〖生低電阻率及對所得酸與驗溶液之潛在腐蝕性 質的抗J·生、’且5使用。此等膜定位於電極，亦即陽極與陰極 之間，且電極間施加直流電（DC)。 較佳的池製造商包括Eurodia，且EUR20及EUR40為較 佳0 使用雙極膜技術自含硫㈣之液流中以氫氧化㈣式回 收H之較佳配置展示於圖4中。如圖 可渗透膜;「。」為陽離子可渗透膜β「Β」為雙=離: 離子膜允許帶負電之硫酸根離子通過，但阻止帶正電之鐘 離子通過Μ目反地’陽離子膜允許帶正電之㈣子穿過， 但阻止硫酸根負離子通過。圖中間展示預帶電之酸與驗儲 集器，所得Η+或〇Η·離子與所析出之帶負電之硫酸根離子 及帶正電之鐘離子組合。因&，產生氫氧化鐘溶液，可將 其饋入製備魏裡鐵之過程液流中。在陰極側得到硫 液。 ' 較佳的是，藉由添加適合之鹼’較佳為鹼金屬氫氧化 物，對先前所述類型之硫酸經溶液進行預處理，達到 較高阳值，通常達到丨°至"之ΡΗ值。氫氧化链、氫氧化 I51347.doc 201130738 納、氫氧化鉀尤佳。將pH值調整至此範圍可移除雜質，如 沈灰物’尤其係可能干擾電滲析裝置中之電化學反應的磷 酸鹽。尤佳的是，至少自進料中移除磷酸鹽，因為已發 現，此雜質尤其會導致膜受污染，從而破壞過程進行。在 饋入雙極電滲析池中之前，自溶液令過濾此等沈澱物。接 著視需要可將溶液調整至較低pH值，例如pH丨_4，且較佳 為2 3，較佳係利用自過程中得到之酸來作調整，接著將 /合液饋入電滲析池中。如上所述，在此過程中，鋰離子穿 過陽離子膜，產生氫氧化鋰液流；且硫酸根穿過陰離子 膜，產生硫酸液流。（見圖4) 所得Li0H及硫酸液流就各別組分之莫耳含量而言為相 對較弱之液流。舉例而言，測試展示如下平均範圍：Since lithium is one of the major and valuable components of lithium iron phosphate materials, any excess lithium will be recovered for further use in the wet chemical process for the manufacture of lithium iron phosphate 151347.doc 201130738 for the production of lithium iron phosphate. This is especially the case when the product is manufactured with relatively large amounts of lithium. The method of recovering and purifying lithium from lithium battery waste is known from the published PCT application WO 98/59385, but there is a need in the art for improvements and alternative methods of recovering lithium. SUMMARY OF THE INVENTION The present invention utilizes bipolar electrodialysis to achieve this and other objects. Bipolar electrodialysis is also known as a salt cracking technique for recovering lithium from a feed stream. The recovered lithium is in the form of a lithium hydroxide solution which can be recycled to the feed stream used to produce lithium iron phosphate using wet chemical methods. A sulfuric acid solution is also produced in the process which can be recovered and used in other processes or sold as a commercial product. In a preferred embodiment, the feed stream is reduced or better removed prior to bipolar electrodialysis of the feed stream. Any of the phosphate ions 'because it has been found that 'phosphates tend to contaminate the membrane, thereby reducing the yield of the hydrazine clock or completely preventing the formation of hydrazine or, in the reduction of sulfuric acid containing lithium ore, the resulting purified lithium sulphate stream Can be processed in this way. The advantage is that a sulfuric acid stream is also produced, which, if concentrated, can be used to offset the cost of the sulfuric acid required to purchase. Bipolar membrane electrodialysis utilizes separate chambers and membranes to produce the acid and base of the individual salt solutions introduced. According to this method, the ion exchange membrane separates the ionic species in the solution via an electric field. The bipolar membrane will hydrolyze into positively charged hydrogen ions (H, in the form of H3〇+ (hydrated hydrogen ions) in aqueous solution) and negatively charged hydroxide anions (〇Η·) bipolar membranes usually combined Formed together with an anion exchange layer and a cation exchange layer. A water diffusion layer or interface is provided, in which water from an external aqueous salt solution 151347.doc 201130738 diffuses. Advancement provides an anion and cation selectively permeable membrane to direct the salt ion away from, for example, lithium ions and sulfate ions, if desired. Therefore, a three-membrane system is commonly used in bipolar membrane electrodialysis. From the city. Source membranes such as Astom's ACM, CMB, AAV and /1 membranes or FumaTech's FKB membranes can be used for the resistance of unwanted ions (H+*〇H-) to reduce the low resistivity and the resulting acid and test solution. Anti-J·, 'and 5 use of potentially corrosive properties. These membranes are positioned between the electrodes, i.e., between the anode and the cathode, with direct current (DC) applied between the electrodes. Preferred cell manufacturers include Eurodia, and EUR20 and EUR40 are preferred. A preferred configuration using a bipolar membrane technique to recover H from a sulfur (IV) stream in a sulfur (IV) stream is shown in FIG. As shown in the permeable membrane; "." is the cation permeable membrane β "Β" is double = away: The ionic membrane allows the negatively charged sulfate ions to pass, but prevents the positively charged clock ions from passing through the Μ 阳离子 cation membrane Allow positively charged (four) to pass through, but prevent sulfate negative ions from passing. The pre-charged acid and reservoir are shown in the middle of the figure, and the resulting Η+ or 〇Η· ions are combined with the precipitated negatively charged sulfate ions and positively charged clock ions. Due to &, a hydrazine hydroxide solution is produced which can be fed into the process stream for the preparation of Weili iron. Sulfur is obtained on the cathode side. Preferably, the sulfuric acid solution of the type previously described is pretreated by adding a suitable base, preferably an alkali metal hydroxide, to achieve a higher positive value, usually reaching a value of 丨° to " . Hydroxide chain, hydrogen peroxide I51347.doc 201130738 Nano, potassium hydroxide is especially good. Adjusting the pH to this range removes impurities such as ashes, especially phosphoric acid which may interfere with the electrochemical reaction in the electrodialysis unit. It is especially preferred to remove the phosphate from at least the feed, as it has been found that this impurity particularly causes the membrane to become contaminated, thereby disrupting the process. These precipitates were filtered from the solution before being fed into the bipolar electrodialysis cell. The solution can then be adjusted to a lower pH, such as pH 丨 4, and preferably 2 3 , preferably adjusted by the acid obtained from the process, and then fed into the electrodialysis cell. . As described above, during this process, lithium ions pass through the cation membrane to produce a lithium hydroxide stream; and the sulfate passes through the anion membrane to produce a sulfuric acid stream. (See Figure 4) The resulting Li0H and sulfuric acid streams are relatively weak streams for the molar content of the individual components. For example, the test shows the following average range:
LiOH . 1.6-1.85 M H2S04 ： 0.57-1.1 Μ 本發明之另—態樣係關於氫氧化鋰產物之純度，因為經 純化之氫氧化鐘產物為極其需要的。 已發現，硫酸產物濃度降低約5〇%使得氫氧化物溶液中 之硫酸根濃度下降相應的量（自啊至2⑼ppm)。另 卜隨S酉夂濃度降⑯，相對於酸產纟之電流效率增加 10% 〇 ' 上述過程之方塊圖展示於圖1中。 更特疋§之，參考圖丨，藉由將pH值調整至約10至約u 以使任何固體雜質自進料流中沈殿出，從而移除任何固體 雜質來純化含硫酸鋰之進料流’較佳為來自鋰電池組分生 之進料接著對所得經純化之硫酸鋰進料流進行雙 151347.doc 201130738 極參析’渗析前較佳用硫酸將pH值調整至約2 、高厶 、、乂5，使用 k 〇之雙極獏以自液流中分離鋰，其將以氫氧化鋰形式回 收。在一個較佳實施例中，在對硫酸鋰進料流進行雙極電 滲析之前，在純化步驟之前或可能在純化步驟期間，藉由 例如調整pH值以移除磷酸鹽或藉由使用適當離子交換犋以 自’谷液中移除磷酸鹽，藉此移除任何磷酸鹽。或者，來自 硫酸礦石提取過程之硫酸鋰液流，已按此項技術中已知之 慣例適當純化，可對之進行雙極滲析，渗析前較佳用硫酸 將pH值調整至約2·35，使用適合之雙極膜以自液流中分 離鐘’其將以氫氧化鋰形式回收。 據信’電流效率低，尤其當其涉及陽離子膜時，會導致 鄰近膜之局部pH值較高，從而在中央進料室中形成沈搬 物。亦可在池外部，藉由有意將進料之pH值升至10且允許 形成沈澱物而觀察到此情況。表丨展示自pH值已調整至 1〇，靜置隔夜並過濾之硫酸鋰進料溶液之1〇 L批料中收集 之固體的組成。總計回收到3.〇2 g固冑。將一部分固體 (0.3035 g)再溶解於⑽Μ Ηα中，以由icp2分析。 自下表1可見，沈澱物中之主要雜質似為Fe、、p、si、LiOH . 1.6-1.85 M H2S04 : 0.57-1.1 另 Another aspect of the invention relates to the purity of the lithium hydroxide product, since the purified hydrazine hydroxide product is highly desirable. It has been found that a reduction in the concentration of the sulfuric acid product of about 5% causes the sulfate concentration in the hydroxide solution to decrease by a corresponding amount (from 2 to 9 (ppm) ppm). In addition, the concentration of S酉夂 decreases by 16 and the current efficiency relative to acid production increases by 10%. 〇 'The block diagram of the above process is shown in Fig. 1. More specifically, referring to the figure, the lithium sulfate-containing feed stream is purified by adjusting the pH to about 10 to about u to cause any solid impurities to stand out from the feed stream, thereby removing any solid impurities. Preferably, the feed from the lithium battery component is then subjected to a double 151347.doc 201130738 polar analysis of the resulting purified lithium sulfate feed stream. Preferably, the pH is adjusted to about 2 sulphuric acid prior to dialysis. , 乂5, using k 〇 bipolar 貘 to separate lithium from the liquid stream, which will be recovered as lithium hydroxide. In a preferred embodiment, prior to the bipolar electrodialysis of the lithium sulfate feed stream, prior to the purification step or possibly during the purification step, for example, by adjusting the pH to remove phosphate or by using appropriate ions The crucible is exchanged to remove phosphate from the 'sap liquid, thereby removing any phosphate. Alternatively, the lithium sulphate stream from the sulphate ore extraction process has been suitably purified according to the conventions known in the art, and bipolar dialysis can be carried out. The pH is preferably adjusted to about 2.35 using sulphuric acid prior to dialysis. A suitable bipolar membrane is used to separate the clock from the liquid stream, which will be recovered in the form of lithium hydroxide. It is believed that the current efficiency is low, especially when it involves a cationic membrane, which results in a higher local pH of the adjacent membrane, thereby forming a sink in the central feed chamber. This can also be observed outside the cell by intentionally raising the pH of the feed to 10 and allowing the formation of a precipitate. The 丨 shows the composition of the solids collected from the 1 〇L batch of the lithium sulphate feed solution that has been adjusted to pH 〇 and allowed to stand overnight and filtered. A total of 3.〇2 g solids was recovered. A portion of the solid (0.3035 g) was redissolved in (10) Η Ηα for analysis by icp2. As can be seen from Table 1 below, the main impurities in the precipitate appear to be Fe, p, si,
Zn及 Mn3 〇 151347.doc 201130738 表1再溶解之固體的ICP分析（mg/L) A1 11 Ca 9.2 Cu 21.0 Fe 22.4 Li 391.0 Μη 58.4 Ni 1.2 P 351.0 S 231.0 Si 46.6 Sr 0.2 Zn 22.9 用適合之雙極膜對硫酸鋰進料流進行雙極滲析得到氫氧 化鐘溶液及硫酸溶液，分別如圖1右側及左側所示。 可回收氫氧化鋰溶液，或較佳可將其直接引入製備 LiFeP〇4或其他含鋰鹽或產物之過程中。當然’可回收氫 氧化鋰’且將其用作例如適合化學反應中之鹼或用於調整 初始進料流之pH值以移除諸如磷酸鹽之雜質。 視需要可在使用前濃縮所回收之氫氧化鋰溶液，或在必 要時對其進行其他純化步驟。 μ 現轉向圖1左側，回收硫酸溶液並出售，或將其用作適 合化學及工業過程令之酸。或者，可將其濃縮，且用於抵 消購買自含鋰礦石中以酸提取鋰所需之硫酸的相關成本。 圖2展示本發明之一個替代實施例，其中氫氧化鋰與硫 15I347.doc 201130738 酸液流均被回收且用於製造磷酸鋰鐵之過程中，此基本上 使該過程連續進行。由於在該過程中鐵以硫酸鐵之二式添 加，故使用所回收之硫酸液流形&硫酸鐵為可行的。此將 取決於硫酸鐵之純度需求以及所需之濃度水準。然而，根 據此方法，可利用替代硫酸鐵之鐵源以及提供硫酸根來源 之硫酸溶液。 更特定言之’在圖2中’如上所述’在進行電渗析之前 藉由將PH值調整至叫！，接著將pH值下調至〉3 $來純化 硫酸鋰進料流。 如同圖1，用適合之膜對純化流進行雙極電滲析以形成 硫酸水溶液流及氫氧化鋰水溶液進料流。在此實施例中， 重點在於回收硫酸與氫氧化鋰進料流且使之返回用於鋰產 品，尤其磷酸链鐵的生產中。主於圖2左側，藉由向 硫酸溶液中添加鐵源而使硫酸水溶液流轉化成硫酸鐵。鐵 源可為任何合適之來源，包括天然存在之鐵礦石中所見之 金屬鐵。由於硫酸鐵溶液已含有硫酸根離子，故硫酸鐵為 較佳鐵鹽。添加鐵得到磷酸鐵溶液，接著使該磷酸鐵溶液 最終與自雙極電滲析過程中回收之氫氧化鋰溶液以及磷酸 鹽原料混合以得到鱗酸鋰鐵。 如圖2右側所示，較佳藉由自另一來源引入氫氧化鋰或 藉由濃縮所回收之液流，將氫氧化鋰溶液調整至所需氫氧 化鋰含量。 另一較佳實施例展示於圖3中。在此選擇方案中，過程 中使用非氫氧化鋰之鋰源，例如碳酸鋰。在此實施例中， 151347.doc 201130738 使硫酸液流與預定純度之碳酸鋰反應，以產生額外硫酸鋰 溶液’接著將其添加至原始再循環溶液中，隨後饋入雙極 電滲析池中。此過程展示於圖3中之流程圖左側。因此， 可使用不同鋰源來得到可提取出氫氧化鋰之鋰溶液。 LiS〇4進料流之PH值調整步驟如上所述。 注意，根據諸如本文所述之濕式化學法，展示將硫酸鐵 添加至全部或一部分硫酸液流中以得到硫酸鐵溶液，其與 所回收之氣氧化經溶液一起用於產生填酸經鐵。 【實施方式】 實例1 對構自Euroduce之EUR-2C電滲析池進行改進，使其包 括Astom雙極膜（BP1)以及FuMaTech陰離子及陽離子膜（分 別為FAB及FKB)。向該池中通入經預處理而將阳值調整至 10之進料溶液以使磷酸鹽及其他雜質沈澱出，繼而過濾以 移除沈澱物。接著WPH值調整至1?1^3.5，隨後饋入池中。 自表2可見’電流效率為約75%時’陽離子膜產生至多 2.16 M LiOH。t流效率為4〇%時，陰離子交換膜產生〇6 Μ邮〇4產物溶液。在整個操作中平均電流密度接近㈣ mA/cm2’同時該池在25 ν之值定電壓下工作（此電壓施加 於全部七組膜及電極沖洗室之間）。在此短期工作下，池 中未觀察到㈣，此表明向池中引入進料溶液之前，藉由 預處理將PH值調整至10,與未調整阳值之進料溶液相 比，結果得到改良。 由於吾人須使用一種產物流以維持中央室中之，因 151347.doc 201130738 此池之總效率似乎由任何特定膜之最低電流效率決定。因 此，在貫例1中有必要將一些產物Li〇H回添至中央室中， 以中和自酸室回遷之質子。因此，池之總電流效率應為 40%，消除了 FKB膜之優勢。 實例2-5 實例2至5皆使用Astom膜（ACM、CMB及BPI)來操作。實 例2及3為短期實驗，其使用如前所述經預處理至pH 的 硫酸鋰進料溶液。兩個實例均得到接近於6〇%之酸及鹼電 流效率，且在短期内維持良好的電流密度，此表明預處理 與先前操作相比’結果得到改良。實例4為隔夜實驗，其 使用相同條件來操作，且顯示電流密度顯著下降，此可能 由於膜受到磷酸鹽或其他沈澱物的污染。 圖5展示全部三個操作之電流密度。125〇分鐘後，暫停 池並關閉泵以便上樣。在重啟系、統時，電流密度明顯恢 復，此表明電流下降係由於少量沈澱物，隨後將其自池中 洗去。 由於預處理至pH 1 〇可能使一些污染物殘留於進料流 中，故實例5使用經預處理至口]^ u並維持3天，接著加以 過濾之溶液。如圖6所示，電流密度維持24小時以上結 果得到明顯改良。電流最終下降據信係由於進料中之硫酸 鋰逐漸耗盡，此硫酸經以單一大批量操作。 圖6亦顯示’藉由‘&定地添加水，使酸及驗之濃度維持 相虽恆疋。因此’需要且有時有必要添加產物酸或鹼以控 制中央進料室中之阳值。為有助於控制此室，選擇較高酸 151347.doc 13 201130738 濃度’從而降低酸電流效率’使得僅藉由添加u〇H，可 將中央室中之pH值控制在3.5。形成氫氧化物之平均電流 密度為60 %左右。 圖6顯示，全部三個室中之硫酸根濃度皆隨時間變化。 中央室係以單一批量操作，且實驗結束時，濃度達到約 0.2 Μ。LiOH中之硫酸根為約400 mg/L，佔電流的約 0.85°/。》降低硫酸濃度會使LiOH中之硫酸根含量進一步下 降。 實例6-10 在實例6-10中，使用Eurodia EUR-2C電滲析池來展示硫 酸鋰之三室鹽裂解的可行性。該池裝配有七組陽離子、陰 離子及雙極膜’如圖4所示進行組態。各膜之有效面積為 0.02 m2。 咸信’由於氫氧根離子回遷，在鄰近陽離子膜之高pH值 區域中形成之磷酸鋰若出現，則為導致膜污染的主要原 因。與將pH值僅調整至1〇相比’藉由將ρί1值升至u對進 料溶液進行預處理以移除磷酸鹽及其他雜質，使得此等踏 大部分沈澱出，且得到改良結果。 貫例9為代表性實例且詳細描述如下。藉由用4 μ 將pH值升至11來對1 Μ硫酸裡起始溶液進行預處理以移心 不溶性磷酸鹽，比率為約1 L LiOH對60 L 1 M Li2SO。# 4 7ta 分混合經處理之硫酸鐘，且使沈澱物沈降隔夜，隨後經破 璃纖維濾紙（1 μπι孔徑）過濾。藉由每公升υβό*添加約 111乙4]^硫酸，將經過遽之1/丨2$〇4的]311值再調整至卩只2。 151347.doc -14- 201130738 經預處理之LijO4進料的起始體積為8 L，且預熱至約 60 C，隨後轉移至20 L玻璃進料儲集器中。初始Li〇H鹼為 來自實例8之3公升渣滓（heel)，在實驗開始時分析得到 LiOH為1.8 Μ。初始酸為亦來自實例§之2 [ H2 S 〇4清滓， 且分析得到ΗβΟ4為0.93 Μ。電極洗液為2公升5〇 mM硫 酸。將溶液以約0.5 L/小室（總流量為3_4 L/min)泵入 Eurodia池（EUR-2C-BP7)，各室上維持相等的反向壓力（3_4 psi)以防止任一膜上之壓力過大而導致内部洩漏。監測各 室之流速及壓力，以及進料溫度、進料]311值、電流、電 壓 '通過之電荷及進料體積。 電滲析於25伏恆定電壓下進行。U2S〇4進料溫度控制在 35C。系（TE-MDK-MT3，Kynar March Pump)及 ED池提供 足夠熱量來維持溫度。給2〇公升進料罐加上護套，使得當 溫度超過35t時，冷卻水可經由螺線管閥門及溫度控制器 (OMEGA CN76000)泵入護套。 池膜提供充足熱傳遞以冷卻其他室。為使此實驗連續進 行20小時，泵送補充經預處理至pH之之以。…進料，i μ LijO4進料之連續速率為1〇 mL/min。穿過膜回遷之 質子多於穿過FKB陽離子膜回遷之氫氧根，因此，中央室 之pH值通常會下降。#由使用高鈉pH值之電極及設定於 pH 2之JENCO ρΗ/ORP控制器添加4 Μ £ωΗ來控制中央室 的PH值。在20小時實驗中每分鐘進料}311值之電子數據記 錄顯示_之變化範圍為1-9至2」，因此，總計3·67 l之4 M UOH添加至進料中以中和氫氧根回冑。操作進行小 151347.doc 201130738 時之後，由於添加11.8 L LijSO4及3.7 L LiOH以及向酸中 輸送6.8 L水並向驗中輸送0.7 L水，進料體積自8 L增至 15.3 L。Zn and Mn3 〇 151347.doc 201130738 Table 1 ICP analysis of reconstituted solids (mg/L) A1 11 Ca 9.2 Cu 21.0 Fe 22.4 Li 391.0 Μη 58.4 Ni 1.2 P 351.0 S 231.0 Si 46.6 Sr 0.2 Zn 22.9 with suitable double The bipolar membrane was subjected to bipolar dialysis of the lithium sulfate feed stream to obtain a hydrazine hydroxide solution and a sulfuric acid solution, as shown in the right side and the left side of Fig. 1, respectively. The lithium hydroxide solution can be recovered, or preferably it can be directly introduced into the process of preparing LiFeP〇4 or other lithium-containing salts or products. Of course, 'recoverable lithium hydroxide' is used and used, for example, as a base suitable for chemical reactions or to adjust the pH of the initial feed stream to remove impurities such as phosphate. The recovered lithium hydroxide solution may be concentrated before use, or may be subjected to other purification steps as necessary. μ Now turn to the left side of Figure 1, recover the sulfuric acid solution and sell it, or use it as an acid suitable for chemical and industrial processes. Alternatively, it can be concentrated and used to offset the associated costs of purchasing sulfuric acid required to extract lithium from acid containing lithium ore. Figure 2 shows an alternate embodiment of the invention in which lithium hydroxide and sulfur 15I347.doc 201130738 acid streams are recovered and used in the manufacture of lithium iron phosphate, which essentially allows the process to proceed continuously. Since iron is added in the form of iron sulfate in the process, it is feasible to use the recovered sulfuric acid liquid manifold & This will depend on the purity requirements of the ferric sulphate and the level of concentration required. However, according to this method, an iron source replacing iron sulfate and a sulfuric acid solution derived from a sulfate source can be utilized. More specifically, 'in Figure 2' is as described above' by adjusting the pH to call before electrodialysis! The lithium sulfate feed stream is then purified by lowering the pH to >3 $. As in Figure 1, the purified stream is subjected to bipolar electrodialysis using a suitable membrane to form an aqueous solution of aqueous sulfuric acid and a feed stream of aqueous lithium hydroxide. In this embodiment, the focus is on recovering the sulfuric acid and lithium hydroxide feed streams and returning them for use in the production of lithium products, particularly ferric phosphate. Mainly on the left side of Fig. 2, the aqueous solution of sulfuric acid is converted into iron sulfate by adding an iron source to the sulfuric acid solution. The iron source can be of any suitable source, including the metallic iron found in naturally occurring iron ore. Since the ferric sulfate solution already contains sulfate ions, ferric sulfate is a preferred iron salt. Iron is added to obtain an iron phosphate solution, and then the iron phosphate solution is finally mixed with a lithium hydroxide solution and a phosphate raw material recovered from the bipolar electrodialysis to obtain lithium iron ateate. As shown on the right side of Figure 2, the lithium hydroxide solution is preferably adjusted to the desired lithium hydroxide content by introducing lithium hydroxide from another source or by concentrating the recovered stream. Another preferred embodiment is shown in FIG. In this alternative, a lithium source other than lithium hydroxide, such as lithium carbonate, is used in the process. In this embodiment, 151347.doc 201130738 reacts the sulfuric acid stream with lithium carbonate of a predetermined purity to produce an additional lithium sulfate solution' which is then added to the original recycle solution and subsequently fed to the bipolar electrodialysis cell. This process is shown on the left side of the flow chart in Figure 3. Therefore, different lithium sources can be used to obtain a lithium solution in which lithium hydroxide can be extracted. The pH adjustment step of the LiS〇4 feed stream is as described above. Note that, according to a wet chemical process such as described herein, it is shown that iron sulphate is added to all or a portion of the sulphuric acid stream to obtain an iron sulphate solution which, together with the recovered oxidizing solution, is used to produce acid-filled iron. [Examples] Example 1 An ethylene-2C electrodialysis cell constructed from Euroduce was modified to include an Astom bipolar membrane (BP1) and a FuMaTech anion and cation membrane (FAB and FKB, respectively). A feed solution pretreated to adjust the positive value to 10 is introduced into the cell to precipitate phosphate and other impurities, which are then filtered to remove the precipitate. The WPH value is then adjusted to 1?1^3.5 and then fed into the pool. It can be seen from Table 2 that the cation film produces up to 2.16 M LiOH when the current efficiency is about 75%. When the t-flow efficiency is 4%, the anion exchange membrane produces a 〇6 Μ 〇 〇 4 product solution. The average current density was close to (four) mA/cm2' throughout the operation while the cell was operated at a constant voltage of 25 ν (this voltage was applied between all seven sets of membranes and the electrode wash chamber). Under this short-term work, no (4) was observed in the pool, which indicated that the pH was adjusted to 10 by pretreatment before introducing the feed solution into the tank, and the result was improved compared with the feed solution without adjusting the positive value. . Since we have to use a product stream to maintain it in the central chamber, the total efficiency of this pool seems to be determined by the lowest current efficiency of any particular membrane, as 151, 347.doc 201130738. Therefore, in Example 1, it is necessary to add some product Li〇H back to the central chamber to neutralize the protons relocated from the acid chamber. Therefore, the total current efficiency of the cell should be 40%, eliminating the advantages of the FKB film. Examples 2-5 Examples 2 through 5 were all operated using Astom membranes (ACM, CMB and BPI). Examples 2 and 3 are short-term experiments using a lithium sulfate feed solution pretreated to pH as previously described. Both examples gave acid and alkali current efficiencies close to 6〇% and maintained good current densities in the short term, indicating that the pretreatment was improved compared to previous operations. Example 4 is an overnight experiment that operates using the same conditions and shows a significant decrease in current density, which may be due to contamination of the membrane with phosphate or other deposits. Figure 5 shows the current densities of all three operations. After 125 minutes, pause the tank and turn off the pump to load. When the system is restarted, the current density is remarkably restored, which indicates that the current drop is due to a small amount of precipitate, which is then washed away from the pool. Since pretreatment to pH 1 may cause some contaminants to remain in the feed stream, Example 5 used a solution that was pretreated to the port and maintained for 3 days, followed by filtration. As shown in Fig. 6, the effect of maintaining the current density for more than 24 hours was significantly improved. The final decrease in current is believed to be due to the gradual depletion of lithium sulfate in the feed, which is operated in a single large batch. Figure 6 also shows that by adding water to the &'' site, the acid and the concentration of the test are maintained. Therefore, it is necessary and sometimes necessary to add a product acid or base to control the positive value in the central feed chamber. To help control this chamber, select a higher acid 151347.doc 13 201130738 concentration 'and thereby reduce acid current efficiency' so that the pH in the central chamber can be controlled to 3.5 by simply adding u〇H. The average current density of the hydroxide formed is about 60%. Figure 6 shows that the sulfate concentrations in all three chambers vary with time. The central chamber was operated in a single batch and at the end of the experiment, the concentration reached approximately 0.2 Μ. The sulfate in LiOH is about 400 mg/L, which accounts for about 0.85 °/ of the current. 》Reducing the concentration of sulfuric acid will further reduce the sulfate content in LiOH. Examples 6-10 In Examples 6-10, the Eurodia EUR-2C electrodialysis cell was used to demonstrate the feasibility of three-chamber salt cracking of lithium sulfate. The cell is equipped with seven sets of cation, anion and bipolar membranes as shown in Figure 4. The effective area of each film is 0.02 m2. According to the reversion of hydroxide ions, the presence of lithium phosphate in the high pH region adjacent to the cation membrane is the main cause of membrane fouling. Compared to adjusting the pH to only 1 ’, the feed solution was pretreated by raising the value of ρί1 to remove phosphate and other impurities, causing most of these steps to precipitate and improved results. Example 9 is a representative example and is described in detail below. The starting solution in 1 Μ sulphuric acid was pretreated with a shift of 1 μL LiOH to 60 L 1 M Li2SO by raising the pH to 11 with 4 μ. # 4 7ta The treated sulfuric acid clock was mixed, and the precipitate was allowed to settle overnight, and then filtered through a glass fiber filter paper (1 μm aperture). By adding about 111 B 4]^ sulfuric acid per liter υβό*, the 311 value of 丨1丨2$〇4 is adjusted to 22. 151347.doc -14- 201130738 The pretreated LijO4 feed had a starting volume of 8 L and was preheated to approximately 60 C and subsequently transferred to a 20 L glass feed reservoir. The initial Li 〇 H base was 3 liters of heel from Example 8, and the LiOH was 1.8 Μ at the beginning of the experiment. The initial acid was also obtained from the example § 2 [H2 S 〇4 clear, and the analysis gave ΗβΟ4 of 0.93 Μ. The electrode wash is 2 liters of 5 mM sulphuric acid. The solution was pumped into the Eurodia pool (EUR-2C-BP7) at approximately 0.5 L/cell (total flow rate 3_4 L/min), maintaining equal back pressure (3_4 psi) on each chamber to prevent pressure on either membrane Too large to cause internal leakage. Monitor the flow rate and pressure of each chamber, as well as the feed temperature, feed 311 value, current, voltage 'passed charge' and feed volume. Electrodialysis was carried out at a constant voltage of 25 volts. The U2S〇4 feed temperature is controlled at 35C. The system (TE-MDK-MT3, Kynar March Pump) and the ED cell provide enough heat to maintain the temperature. A 2 liter liter feed tank is jacketed so that when the temperature exceeds 35 tons, the cooling water can be pumped into the jacket via a solenoid valve and temperature controller (OMEGA CN76000). The cell membrane provides sufficient heat transfer to cool other chambers. In order to allow this experiment to continue for 20 hours, the pumping supplement was pretreated to pH. ...feed, i μ LijO4 feed continuous rate of 1 〇 mL / min. The protons that pass through the membrane are more than the hydroxide that migrates through the FKB cation membrane, so the pH of the central chamber usually decreases. # Control the pH of the central chamber by adding a high sodium pH electrode and a JENCO ρΗ/ORP controller set at pH 2 to add 4 Μ £ωΗ. The electronic data record of the 311 value per minute in the 20-hour experiment shows that the range of _ varies from 1-9 to 2", therefore, a total of 3·67 l of 4 M UOH is added to the feed to neutralize the hydrogen and oxygen. Root back. After the operation was carried out at 151347.doc 201130738, the feed volume increased from 8 L to 15.3 L due to the addition of 11.8 L LijSO4 and 3.7 L LiOH and the transport of 6.8 L of water to the acid and the transport of 0.7 L of water to the test.
LiOH鹼自1加侖封閉聚丙烯罐循環流經池。藉由使用固 定於LiOH表面之管自頂部排放而維持3公升體積，且使用 蠕動泵將LiOH產物收集於1 5加侖溢出容器（〇verfi〇w container)中。藉由向Li〇H罐中以17 mL/min之恆定速率添 加水，使LiOH濃度維持於ι·85 μ LiOH濃度。 硫酸自2 L玻璃錯集器循環流經池之酸室。接近儲集器 頂部之溢出口維持2.2 L HjO4之恆定體積，溢出之酸產物 流入15加侖罐中。藉由以丨6 mL/min之恆定速率添加水， 使HJO4濃度恆定地保持於19 μ。 電極洗液（50 mM Η4〇4)循環流經陽極液與陰極液末端 室且在2公升聚丙烯罐頂部於池出口處重新組合，其中在 電極處產生之〇2及％氣體流向通風櫥後部。 在實驗期間採集數個樣品，以確保水添加至酸及鹼中之 速率足以保持實驗過程中濃度恆定。在19·9小時實驗結束 時’關閉電源'，使罐排$，且量測最終產物以及最終 LkSO4及電極洗液的體積。得到總計3〇•丨乙ΐ 86 μ uoh (包括3 L渣渾）及2hl L [92 M H2S04(包括2 L渣渾）。最終 進料為15.3公升〇.28 M Li2S04，且最終電極洗液含有】5 L 67 mM H2S04。電極洗液中之〇 5 [水穿過陽離子膜輸送至 酸中。向酸及鹼中添加之水的總量分別為18.6公升及20.4 公升。通過之總電荷為975660庫侖（70·78莫耳），其中338 151347.doc -16- 201130738 莫耳Η回遷’ 2〇2莫耳〇Η·回遷，且M97莫耳Li〇H添加至 進料中。此實驗之平均電流密度為67.8 mA/cm2。基於對 酸中富集之硫酸根進行分析，H2S04電流效率為52.5% ;基 於對LiOH產物中之Li+進行分析，LiOH電流效率為 72.4%。 藉由使用配備有GP50梯度泵、AS 17分析柱、ASRS300 陰離子抑制器、CD25電導率偵測器、EG40 KOH溶離劑發 生器及AS40自動上樣儀的Di〇nex DX600來分析起始樣品 及最終樣品中之SCU2.。將25 μί樣品注射至分離柱上，在 該分離柱中，使用1 mM至30 mM ΚΟΗ之濃度梯度，5 mM/min梯度上升’以1.5 mL/min對陰離子進行溶離。藉由 使用電導率偵測所產生之峰面積相對於四點校準曲線來測 定硫酸根濃度，其處於2至200 mg/L SO42-之範圍内。藉由 類似技術，使用配備有〗C25A等度泵、CSl2a分析柱、 CSRS3 00陽離子抑制器、IC25電導率偵測器、ecg II MSA 溶離劑發生器及AS4〇自動上樣儀的Dionex DX320 1C來分 析樣品中之Li+。將25 pL樣品注射至分離柱上，在該分離 柱中，使用20 mM至30 mM甲烷磺酸（MSA)之濃度梯度， 以1.0 mL/min對陰離子進行溶離。藉由使用電導率偵測所 產生之峰面積相對於四點校準曲線來測定鋰濃度，其處於 10至200 mg/L Li+之範圍内。藉由用標準1.〇 n氫氧化鈉將 pH值滴定至pH 7來測定Ηβ〇4之酸濃度。藉由使用微滴管 (microburrete)，用標準0.50 Ν硫酸滴定至ΡΗ 7來測定驗濃 度。 151347.doc 17 201130738 表3概述以Astom ACM膜進行之電渗析實驗的結果。實 例6亦分別使用Astom CMB陽離子膜及BP1雙極膜。將硫酸 裡進料溶液預處理至pH 11，過濾’接著再調整至pH 3.5， 隨後通入池中。有關電流效率之結果與上月報告之結果相 當；然而，平均電流密度低於先前操作之電流密度，此表 明仍有一些污染。陽離子膜之pH梯度在PH值為3.5時似乎 引起沈澱問題，將進料室之pH值降至PH 2，且使用具有較 少氫氧根回遷之FuMaTech FKB陽離子膜。ρΐ(13與ACM膜） 配對意謂中央室中之pH值係由質子穿過ACM之回遷來決 定，且僅藉由添加LiOH來控制pH值。 實例7至9使用FKB/ACM/BP1組合進行重複操作，三個 批次總計進行70小時。自表1可見，此等操作之再現性極 佳’以二種不同方式量測之LiOH電流效率為71 -75%(由進 料中Li +之損失、鹼室中Li +及氫氧根離子之增加來量測）。 同樣地，由全部三種測量方法量測之酸電流效率為5〇· 52。/〇。此等實例之數據顯示平均電流密度的一致性。圖7 圖解展示此情況，其中初始電流密度彼此匹配極好。因批 次大小不同而導致各批次結束時有偏差，因此，最終硫酸 鋰濃度不同。 FKB膜之向電流效率似乎有助於避免陽離子膜之進料側 的邊界層處發生沈澱問題。過程之總電流效率係由表現最 差之膜決定。亦即，ACM膜之低效率必須藉由將鹼室中之 LiOH回添至進料室中來補償，因而總效率因陰離子膜而 151347.doc •18- 201130738 降低。為增加陰離子膜之效率，降低產物酸室中之酸濃 度。實例10使用〇. 61 Μ硫酸進行操作，其使得酸電流效率 增加了 10%至62%左右。（見表3) 實例11-12 為進一步增加酸電流效率，在實例丨丨及丨2中，用來自 Astom之AAV替代性陰離子膜對池進行改進。aAV膜為原 先可構自Ashahi Chemical之酸阻斷膜。表4展示使用 FKB、AAV及BP-1雙極膜之組合進行此等實驗之數據概 述。 此等膜之酸與鹼的電流效率與實例7_9之組合極為類 似。當使用較低酸濃度時，酸電流效率增加約丨〇%。此膜 組合之平均電流密度比使用ACM膜時略低（相同酸濃度下 及在25 V恆定堆疊電壓下操作時為約1〇mA/cm2)。外部ac 阻抗量測證實，在LijO4溶液中量測時，AAV電阻高於 ACM。 欲再循環至製備磷酸鋰鐵之過程中的氫氧化鋰產物之純 度極其重要。使用此鹽裂解技術得出Li〇H流中之主要雜 質為硫酸根離子，其自酸室穿過雙極膜輸送至鹼中。輸送 量應與酸濃度直接相關。藉由比較實例9與實例丨〇(見表 3)，及比較實例n與實例12(見表4)清楚可見。在各種狀況 下，當酸濃度自1 Μ降至0.6 Μ時，1.88 M u〇Ht之硫酸 根污染減少約一半。穩態硫酸根濃度分別為43〇卯爪及2〇〇 151347.doc 19 201130738 ppm。 由於硫酸根離子及鐘離子穿過離子交換膜進行輸送，則 因離子水合（電渗）及滲透作用，水亦發生轉移。然而，水 輸送至中央室外不足以保持濃度恆定。藉由考慮實例8中 水的轉移而說明此情況。一個鋰離子穿過陽離子膜發生轉 移，則7個水亦發生轉移。類似地，平均有18個水與硫酸 根離子一起轉移，一個硫酸鋰共有158個水。由於進料溶 液中硫酸鋰僅為丨莫耳，故每個硫酸鋰幾乎含有Μ莫耳 水’使得中央室中硫酸崎到連續稀釋。自進料室中移除LiOH base is circulated through the cell from a 1 gallon closed polypropylene tank. The 3 liter volume was maintained by draining from the top using a tube fixed to the LiOH surface, and the LiOH product was collected in a 15 gallon overflow container using a peristaltic pump. The LiOH concentration was maintained at an ι·85 μ LiOH concentration by adding water to a Li〇H tank at a constant rate of 17 mL/min. Sulfuric acid is circulated through the acid chamber of the cell from a 2 L glass misaligner. The overflow port near the top of the reservoir maintains a constant volume of 2.2 L HjO4 and the overflowed acid product flows into the 15 gallon tank. The HJO4 concentration was kept constant at 19 μ by adding water at a constant rate of 丨6 mL/min. The electrode wash (50 mM Η4〇4) circulates through the anolyte and catholyte end chambers and recombines at the top of the 2 liter polypropylene tank at the cell outlet, where the 〇2 and % gas produced at the electrode flows to the back of the fume hood . Several samples were taken during the experiment to ensure that the rate of water addition to the acid and base was sufficient to maintain a constant concentration during the experiment. At the end of the 19.9 hour experiment, 'turn off the power', the tank was drained, and the final product and the final volume of LkSO4 and electrode wash were measured. A total of 3〇•丨乙ΐ 86 μ uoh (including 3 L dross) and 2hl L [92 M H2S04 (including 2 L dross) were obtained. The final feed was 15.3 liters 〇.28 M Li2S04 and the final electrode wash contained 5 L 67 mM H2S04.电极5 in the electrode wash solution [Water is transported through the cation membrane to the acid. The total amount of water added to the acid and alkali was 18.6 liters and 20.4 liters, respectively. The total charge passed is 975,660 coulombs (70.78 mol), of which 338 151347.doc -16- 201130738 Moer's relocation '2〇2 Moer's · relocation, and M97 Moer Li〇H added to the feed in. The average current density for this experiment was 67.8 mA/cm2. Based on the analysis of the sulfate enriched in the acid, the current efficiency of H2S04 was 52.5%. Based on the analysis of Li+ in the LiOH product, the LiOH current efficiency was 72.4%. Analysis of the starting sample and finalization using a Di〇nex DX600 equipped with a GP50 gradient pump, AS 17 analytical column, ASRS300 anion suppressor, CD25 conductivity detector, EG40 KOH solvate generator and AS40 autosampler SCU2. in the sample. A 25 μί sample was injected onto a separation column in which the anion was eluted at a concentration gradient of 1 mM to 30 mM, with a gradient of 5 mM/min, at 1.5 mL/min. The sulfate concentration is determined by using a peak area generated by conductivity detection relative to a four-point calibration curve, which is in the range of 2 to 200 mg/L SO42-. Using a similar technique, Dionex DX320 1C equipped with a C25A isocratic pump, CSl2a analytical column, CSRS3 00 cation suppressor, IC25 conductivity detector, ecg II MSA eliminator and AS4 〇 automatic sampler Analyze the Li+ in the sample. A 25 pL sample was injected onto a separation column in which the anion was eluted at a concentration gradient of 20 mM to 30 mM methanesulfonic acid (MSA) at 1.0 mL/min. The lithium concentration is determined by using a peak area generated by conductivity detection with respect to a four-point calibration curve, which is in the range of 10 to 200 mg/L Li+. The acid concentration of Ηβ〇4 was determined by titrating the pH to pH 7 with standard 1. 〇 n sodium hydroxide. The concentration was determined by titration with a standard 0.50 Ν sulfuric acid to ΡΗ 7 using a microburrete. 151347.doc 17 201130738 Table 3 summarizes the results of electrodialysis experiments performed on Astom ACM membranes. In Example 6, Astom CMB cationic membrane and BP1 bipolar membrane were also used, respectively. The sulphuric acid feed solution was pretreated to pH 11, filtered and then adjusted to pH 3.5 and subsequently passed to the cell. The results for current efficiency are comparable to those reported last month; however, the average current density is lower than the current operating current density, indicating that there is still some contamination. The pH gradient of the cationic membrane appeared to cause precipitation problems at a pH of 3.5, the pH of the feed compartment was lowered to pH 2, and a FuMaTech FKB cation membrane with less hydroxide reversion was used. The pairing of ρΐ (13 with ACM film) means that the pH in the central chamber is determined by the relocation of protons through the ACM, and the pH is controlled only by the addition of LiOH. Examples 7 through 9 were repeated using the FKB/ACM/BP1 combination, and the three batches were totaled for 70 hours. As can be seen from Table 1, the reproducibility of these operations is excellent. The LiOH current efficiency measured in two different ways is 71 -75% (Li + loss from the feed, Li + and hydroxide ions in the alkali chamber) Increase to measure). Similarly, the acid current efficiency measured by all three measurement methods was 5 〇·52. /〇. The data for these examples shows the consistency of the average current density. Figure 7 illustrates this situation where the initial current densities match each other very well. Due to the different batch sizes, there is a deviation at the end of each batch, so the final lithium sulfate concentration is different. The current efficiency of the FKB film appears to help avoid precipitation problems at the boundary layer on the feed side of the cation membrane. The total current efficiency of the process is determined by the worst performing film. That is, the inefficiency of the ACM film must be compensated by adding the LiOH in the alkali chamber back to the feed chamber, so the overall efficiency is reduced by the anionic membrane 151347.doc •18-201130738. To increase the efficiency of the anion membrane, the acid concentration in the acid compartment of the product is reduced. Example 10 was operated using 61.61 Μ sulphuric acid which increased the acid current efficiency by about 10% to about 62%. (See Table 3) Examples 11-12 To further increase the acid current efficiency, in the examples 丨 and 丨2, the pool was modified with an AAV replacement anion membrane from Astom. The aAV film is an acid blocking film which can be originally constructed from Ashahi Chemical. Table 4 shows an overview of the data for these experiments using a combination of FKB, AAV, and BP-1 bipolar membranes. The current efficiency of the acid and base of these membranes is very similar to the combination of Examples 7-9. When a lower acid concentration is used, the acid current efficiency is increased by about 丨〇%. The average current density of this film combination was slightly lower than when using an ACM film (about 1 〇 mA/cm 2 at the same acid concentration and at a constant stack voltage of 25 V). The external ac impedance measurement confirmed that the AAV resistance was higher than ACM when measured in LijO4 solution. The purity of the lithium hydroxide product to be recycled to the process of preparing lithium iron phosphate is extremely important. Using this salt cracking technique, the major impurity in the Li〇H stream is the sulfate ion, which is transported from the acid chamber through the bipolar membrane to the base. The amount of transport should be directly related to the acid concentration. It is clearly seen by comparing Example 9 with the example 丨〇 (see Table 3), and comparing Example n with Example 12 (see Table 4). Under various conditions, when the acid concentration decreased from 1 0.6 to 0.6 ,, the sulfate contamination of 1.88 M u〇Ht was reduced by about half. Steady-state sulfate concentrations were 43 pawls and 2〇〇 151347.doc 19 201130738 ppm, respectively. Since sulfate ions and clock ions are transported through the ion exchange membrane, water is also transferred due to ion hydration (electroosmosis) and osmosis. However, the delivery of water to the central outdoor is not sufficient to maintain a constant concentration. This is illustrated by considering the transfer of water in Example 8. When one lithium ion is transferred through the cation membrane, 7 water is also transferred. Similarly, an average of 18 waters are transferred together with sulfate ions, and one lithium sulfate has a total of 158 waters. Since the lithium sulphate in the feed solution is only 丨mol, each lithium sulphate contains almost Μmol water, so that the sulphate in the central chamber is continuously diluted. Removed from the feed chamber
水可控制此連續稀釋’且可藉由例如進行反向滲透^ 控制。 X 本文引用之所有參考文獻皆出於所有目的以全文引用的 I51347.doc 201130738 表2 BPED操作概述 硫酸鋰電滲析之分析數據（EUR-2C-7BP池） 實驗 1 2 3 4 5 膜 FAB/FKB/ BP1 ACM/CMB /BP1 ACM/CMB /BP1 ACM/CMB iB?l ACM/CM B/BP1 起始/最終進料S042XM) 1.14/0.76 1.14/0.72 1.11/0.65 1.07/0.44 1.13/0.20 起始/最終進料Li+(M) 2.33/1.48 2.31/1.43 2.28/1.3 2.34/0.88 2.33/0.41 起始/最終酸，h2so4(m) 0.57/0.62 0.57/0.61 0.58/0.65 0.61/0.79 0.73/1.1 起始/最終鹼，LiOH(M) 1.77/2.16 1.77/2.29 1.72/1.82 1.75/1.77 1.69/1.96 LiOH中之起始/最终S042-(mg/L) 56/155 171/270 260/232 247/252 322/396 S042_向UOH中輸送形成之電荷 % 0.47% 0.55% 0.51% 0.63% 0.85% 電荷(mol，e') 20.7 19.0 20.8 69.7 95.3 回遷H+，mol 12.76 7.67 8.25 31.9 46.3 回遷OH-，mol 4.84 7.81 8.41 27.8 40.5 添加至進料中之OH_，mol 7.49 0.06 0.12 3.06 6.6 平均 CD，mA/cm2 61.9 55.5 57.3 50.6 68.9 Li+ CE(來自驗） 74.3 59.4 62.4 58.4 60.4 LiOHCE(鹼中形成之ΟΗ·) 76.7 58.9 59.7 60.2 57.5 Li+CE(基於進料損失） 81.6 60.1 61.1 63.0 61.4 S042· CE(來自酸） 41.4 60.0 59.7 53.3 50.5 H+CE(產生之酸） 40.9 59.6 60.4 54.2 51.4 so42-ce(基於進料損失） 41.1 61.0 58.9 56.7 51.7 輸送至酸中之水(mol/mol S〇42_) 0.70 2.97 3.06 3.18 5.11 輸送至驗中之水(mol/mol Li) 8.4 7.8 7.3 7.9 7.3 溫度3 5°C，恆定電壓=25，進料pH值控制在3.5。 151347.doc -21 · 201130738 表3使用ACM陰離子膜進行之BPED操作概述 硫酸鋰電滲析之分析數據（EUR-2C-7BP池） 實驗 6 7 8 9 10 膜 ACM/CM B/BP1 ACM/FKB /BP1 ACM/FKB /BP1 ACM/FKB /BP1 ACM/FKB /BP1 起始/最終進料so42xm) 1.12/0.68 1.16/0.10 1.15/0.17 1.15/0.28 1.16/0.13 起始/最終進料Li+(M) 2.24/1.34 2.31/0.20 2.31/0.29 2.33/0.50 2.3/0.27 穩態酸，h2so4(m)* 0.80 0.90 1.0 0.95 0.61 穩態鹼，LiOH(M)* 1.60 1.90 1.90 1.85 1.83 LIOH中之硫酸根(mg/L)* 350 400 380 450 200 SO,向LiOH中輸送形成之電荷 % 0.93% 1.2% 1.2% 0.93% 0.47% 進料pH值 3.5 2.0 2.0 2.0 2.0 電荷(mol，e_) 52.6 82.3 94.6 70.8 75.5 回遷H+，mol 27.9 39.2 46.7 33.8 28.5 回遷OH—，mol 23.3 23.7 26.3 20.2 20.4 添加至進料中之OH_，mol 4.26 17 20.7 15.0 9.5 平均 CD，mA/cm2 43.5 62.2 68.3 67.8 62.7 Li+ CE(來自鹼） 58.5 75.6 74.7 72.4 76.4 LiOH CE(鹼中形成之ΟίΤ) 55.8 71.2 72.2 71.5 73.0 Li+CE(基於進料損失） 59.6 73.7 74.6 75.5 75.2 S042· CE(來自酸） 48.7 52.1 51.9 525. 60.3 H+CE(產生之酸） 47.1 52.4 50.6 52.3 62.3 S042_CE(基於進料損失） 47.3 52.9 51.7 52.6 63.0 輸送至酸中之水(mol/mol S〇42) 4.46 2.3 1.8 1.9 1.4 輸送至驗中之水(mol/mol Li) 7.1 7.3 7.0 6.7 7.95 *穩態濃度。 溫度35°(：，恆定電壓=25，進料卩11值控制在3.5/2.0。 151347.doc -22- 201130738 表4使用AAV膜之數據概述 硫酸鋰電滲析之分析數據（EUR-2C-7BP池） 實驗 11 12 膜 AAV/FKB/BP1 AAV/FKB/BP1 起始/最終進料S042XM) 1.14/0.37 1.13/0.27 起始/最終進料Li+(M) 2.3/0.72 2.34/0.49 穩態酸，h2so4(m)1 1.1 0.57 穩態鹼，LiOH(M)1 1.85 1.85 LiOH中之硫酸根(mg/L)1 430 200 S042·向LiOH中輸送形成之電荷％ 1.25% 0.44% 進料pH值 2.0 2.0 電荷(mol，e) 83.9 73.7 回遷H+，mol 40.8 27.7 回遷OH-，mol 24.7 22.0 添加至進料中之〇H_，mol 16.6 8.14 平均 CD，mA/cm2 57.1 51.6 LiOH CE(IC-Li+分析） 72.8 71.8 LiOH CE(鹼中形成之OH·) 70.6 70.1 Li+CE(基於進料損失） 71.7 73.7 H2S04 CE(來自 IC-S04 分析） 51.3 61.8 H2S04CE(基於產生之酸） 51.4 62.4 S042—CE(基於進料損失)· 51.5 61.1 輸送至酸中之水(mol/mol S〇42-) 4.05 2.33 輸送至鹼中之水(mol/mol Li) 7.7 8.62 151347.doc -23- 1 穩態濃度。 溫度35°C，恆定電壓=25，進料pH值控制在3.5/2.0。 201130738 【圖式簡單說明】 圓1 :用於將氫氧化鋰與硫酸鋰再循環至製造磷酸鋰鐵 之過程中的簡化硫酸鋰雙極電滲析再循環過程之方塊圖。 圖2.用於將氫氧化鋰與硫酸再循環至製造磷酸鋰鐵之 過程中的硫酸鋰雙極電滲析再循環過程之方塊圖。 圖3:使用再循環之氫氧化鐘、硫酸及由另—裡源產生 之氫氧化鋰製造磷酸鋰鐵的硫酸鋰雙極電滲析再循環過程 之方塊圖》 圖4:用於自含硫酸經之液流中以氫氧化锂形式回收链 之雙極電滲析池的示意圖。 圖5:在將預處理至pH 10之進料溶液通入帶有八伽膜 之電渗析池的過程中，電流密度隨時間變化之曲線圖。 圖6:在將預處理至ρΗ η之進料溶液通入電渗析池的過 程中’電流密度以及酸與驗產物之濃度隨時間變化之曲線 圖。 圖7 :在將進料溶液通入怪定電壓下操作之Eur〇dia EUR-2C電滲析池的過程中，電流密度隨時間變化之曲線 圖0 151347.doc -24-Water can control this serial dilution' and can be controlled, for example, by reverse osmosis. X All references cited herein are for all purposes and are quoted in full by I51347.doc 201130738 Table 2 BPED Operation Overview Analytical data for lithium sulphate electrodialysis (EUR-2C-7BP pool) Experiment 1 2 3 4 5 Membrane FAB/FKB/ BP1 ACM/CMB /BP1 ACM/CMB /BP1 ACM/CMB iB?l ACM/CM B/BP1 Start/Final Feed S042XM) 1.14/0.76 1.14/0.72 1.11/0.65 1.07/0.44 1.13/0.20 Start/Last Feed Li+(M) 2.33/1.48 2.31/1.43 2.28/1.3 2.34/0.88 2.33/0.41 Starting/final acid, h2so4(m) 0.57/0.62 0.57/0.61 0.58/0.65 0.61/0.79 0.73/1.1 Start/final Base, LiOH(M) 1.77/2.16 1.77/2.29 1.72/1.82 1.75/1.77 1.69/1.96 Start/final in LiOH S042-(mg/L) 56/155 171/270 260/232 247/252 322/396 S042_ Charge generated by transport to UOH% 0.47% 0.55% 0.51% 0.63% 0.85% Charge (mol, e') 20.7 19.0 20.8 69.7 95.3 Relocation H+, mol 12.76 7.67 8.25 31.9 46.3 Relocation OH-, mol 4.84 7.81 8.41 27.8 40.5 OH_,mol added to the feed 7.49 0.06 0.12 3.06 6.6 Average CD, mA/cm2 61.9 55.5 57.3 50.6 68.9 Li+ CE (from inspection) 74.3 59.4 62.4 58.4 60.4 LiOHCE (alkali Formation ΟΗ·) 76.7 58.9 59.7 60.2 57.5 Li+CE (based on feed loss) 81.6 60.1 61.1 63.0 61.4 S042· CE (from acid) 41.4 60.0 59.7 53.3 50.5 H+CE (acid produced) 40.9 59.6 60.4 54.2 51.4 so42 -ce (based on feed loss) 41.1 61.0 58.9 56.7 51.7 Water delivered to the acid (mol/mol S〇42_) 0.70 2.97 3.06 3.18 5.11 Water delivered to the test (mol/mol Li) 8.4 7.8 7.3 7.9 7.3 Temperature 3 5 ° C, constant voltage = 25, the feed pH is controlled at 3.5. 151347.doc -21 · 201130738 Table 3 BPED operation using ACM anion membrane Overview Analytical data of lithium sulphate electrodialysis (EUR-2C-7BP pool) Experiment 6 7 8 9 10 Membrane ACM/CM B/BP1 ACM/FKB /BP1 ACM/FKB /BP1 ACM/FKB /BP1 ACM/FKB /BP1 Start/final feed so42xm) 1.12/0.68 1.16/0.10 1.15/0.17 1.15/0.28 1.16/0.13 Start/final feed Li+(M) 2.24/ 1.34 2.31/0.20 2.31/0.29 2.33/0.50 2.3/0.27 Steady-state acid, h2so4(m)* 0.80 0.90 1.0 0.95 0.61 Steady-state base, LiOH(M)* 1.60 1.90 1.90 1.85 1.83 Sulfate in LIOH (mg/L ) * 350 400 380 450 200 SO, the charge formed by transport to LiOH % 0.93% 1.2% 1.2% 0.93% 0.47% Feed pH 3.5 2.0 2.0 2.0 2.0 Charge (mol, e_) 52.6 82.3 94.6 70.8 75.5 Relocation H+, Mol 27.9 39.2 46.7 33.8 28.5 Reversion OH-, mol 23.3 23.7 26.3 20.2 20.4 OH_, mol added to the feed 4.26 17 20.7 15.0 9.5 Average CD, mA/cm2 43.5 62.2 68.3 67.8 62.7 Li+ CE (from alkali) 58.5 75.6 74.7 72.4 76.4 LiOH CE (形成 Τ formed in the base) 55.8 71.2 72.2 71.5 73.0 Li+CE (based on feed loss) 59.6 73.7 74.6 75.5 75.2 S042· CE (from acid) 48.7 52.1 51.9 525. 60.3 H+CE (acid produced) 47.1 52.4 50.6 52.3 62.3 S042_CE (based on feed loss) 47.3 52.9 51.7 52.6 63.0 Water delivered to the acid (mol/mol S〇 42) 4.46 2.3 1.8 1.9 1.4 Water delivered to the test (mol/mol Li) 7.1 7.3 7.0 6.7 7.95 * steady state concentration. Temperature 35° (:, constant voltage = 25, feed 卩 11 value is controlled at 3.5/2.0. 151347.doc -22- 201130738 Table 4 Data using AAV film Overview of analytical data for lithium sulphate electrodialysis (EUR-2C-7BP pool) ) Experiment 11 12 Membrane AAV/FKB/BP1 AAV/FKB/BP1 Initial/Final Feed S042XM) 1.14/0.37 1.13/0.27 Initial/Final Feed Li+(M) 2.3/0.72 2.34/0.49 Steady-State Acid, h2so4 (m)1 1.1 0.57 Steady-state base, LiOH(M)1 1.85 1.85 Sulfate in LiOH (mg/L) 1 430 200 S042·Characteristic charge formed by transport to LiOH 1.25% 0.44% Feed pH 2.0 2.0 Charge (mol, e) 83.9 73.7 Relocation H+, mol 40.8 27.7 Relocation OH-, mol 24.7 22.0 Add to the feed 〇H_, mol 16.6 8.14 Average CD, mA/cm2 57.1 51.6 LiOH CE (IC-Li+ analysis) 72.8 71.8 LiOH CE (OH· formed in the base) 70.6 70.1 Li+CE (based on feed loss) 71.7 73.7 H2S04 CE (from IC-S04 analysis) 51.3 61.8 H2S04CE (based on acid produced) 51.4 62.4 S042—CE (based on Material loss) · 51.5 61.1 Water delivered to the acid (mol/mol S〇42-) 4.05 2.33 Water transported to the base (mol/mol Li) 7.7 8.62 151347.doc -23- 1 State concentration. The temperature was 35 ° C, the constant voltage was 25, and the feed pH was controlled at 3.5/2.0. 201130738 [Simple description of the diagram] Circle 1: A block diagram of a simplified lithium sulfate bipolar electrodialysis recycling process for recycling lithium hydroxide and lithium sulfate to the process of manufacturing lithium iron phosphate. Figure 2. Block diagram of a lithium sulfate bipolar electrodialysis recycle process for recycling lithium hydroxide and sulfuric acid to the manufacture of lithium iron phosphate. Figure 3: Block diagram of a lithium sulfate bipolar electrodialysis recycle process using recycled iodine clock, sulfuric acid, and lithium hydroxide produced from another source to produce lithium iron phosphate. Figure 4: For self-sulfuric acid A schematic diagram of a bipolar electrodialysis cell in which the chain is recovered in the form of lithium hydroxide in the liquid stream. Figure 5: A graph of current density as a function of time during the passage of a feed solution pretreated to pH 10 into an electrodialysis cell with an eight gamma membrane. Figure 6: A graph of current density and concentration of acid and test product as a function of time during the passage of the feed solution pretreated to pH η into the electrodialysis cell. Figure 7: Current density versus time curve during the Eur〇dia EUR-2C electrodialysis cell operated with the feed solution operating at a strange voltage. Figure 0 151347.doc -24-