離子交換及實例

1、離子交換方法從鎳的陽極電解液中分離銅離子交換方法從鎳的陽極電解液中分離銅報告人：張學峰報告人：張學峰參考文獻：Removal of copper from nickel anode electrolyte through ion exchange目目 錄錄實實 驗驗分分 析析致致 謝謝結結 論論摘摘 要要離子交換離子交換離子交換離子交換介介 紹紹 離子交換概述 離子交換的機理是 離子交換樹脂 離子交換的選擇性 離子交換操作過程離子交換概述離子交換概述定義：利用離子交換劑中的可交換基團與溶液中各種離子間的離子交換能力的不同來進行分離的一種方法。原理：基于物質(zhì)在固液相之間的分配。離子交換概述離子交

2、換概述離子交換樹脂的結構：1、高分子部分樹脂的主干，有一定的機械強度，不易溶解2、聯(lián)結劑把整個骨架交聯(lián)起來，使之具有三維空間的網(wǎng)狀結構3、官能團固定在樹脂上的活性基團，在溶液中能夠電離，產(chǎn)生游離的可交換離子與溶液中的離子進行交換離子交換概述離子交換概述離子交換樹脂的簡單表示：活性離子為陽離子，稱為陽離子交換樹脂，與陽離子發(fā)生交換；活性離子為陰離子，稱為陰離子交換樹脂，與陰離子發(fā)生交換。離子交換概述離子交換概述離子交換層析原理：離 子 交 換 層 析 （ I o n Exchange Chromatography簡稱為IEC）是以離子交換劑為固定相，依據(jù)流動相中的組分離子與交換劑上的平衡離子進行

3、可逆交換時的結合力大小的差別而進行分離的一種層析方法。離子交換樹脂離子交換樹脂離子交換樹脂的分類離子交換樹脂官能團陽樹脂，酸性基團陰樹脂，堿性基團活性離子氫型羥型鹽型陽離子交換樹脂 陰離子交換樹脂離子交換樹脂離子交換樹脂表1. 四類不同樹脂的比較離子交換樹脂離子交換樹脂離子交換樹脂離子交換樹脂離子交換樹脂的命名 代號代號分類名稱分類名稱骨架名稱骨架名稱0強酸性本意思系1弱酸性丙烯酸系2強堿性酚醛系3弱堿性環(huán)氧系4螯合性乙烯哌（pai）啶系5兩性脲醛系6氧化還原氯乙烯系表2. 離子交換樹脂分類代號和骨架代號離子交換樹脂離子交換樹脂離子交換樹脂的命名 X X凝膠型交聯(lián)度數(shù)值順序號骨架代號分類代號離

4、子交換樹脂離子交換樹脂離子交換樹脂的命名 大孔型順序號骨架代號分類代號大孔代號D離子交換樹脂離子交換樹脂離子交換樹脂的選擇性 離子水化半徑離子化合價溶液酸堿度交聯(lián)度，膨脹性輔助力有機溶劑摘摘 要要摘摘 要要An novel method for removal of copper from nickel anodic electrolyte through ion exchange was studied after cupric deoxidization. Orthogonal design experiments show the optimum conditions of deoxid

5、izing cupric into Cu+ in the nickel electrolyte are the reductive agent dosage is 4.5 times as the theoretic dosage and reaction time is 0.5 h at 40and pH 2.0. Ion exchange experiments show that the breakthrough capacity(Y) decreases with the increase of the linear flow rate(X): Y=1.5590.194X+0.0067

6、X2. Breakthrough capacity increases with the increase of the ratio of height to radius(RRH). The higher the initial copper concentration, the less the breakthrough capacity(BC). SO42- and nickel concentration have no obvious change during the process of sorption, so it is not necessary to worry abou

7、t the loss of nickel during the sorption process. Desorption experiments show that copper desorption from the resin is made perfectly with NaCl solution added with 4% (volume fraction) H2O2 (30%) and more than 100 g/LCuCl2 solution is achieved.Key words: nickel anode electrolyte; copper removal; cup

8、ric deoxidization; anion ion exchange; breakthrough capacity介介 紹紹It is difficult to separate copper from nickel solution due to the certain similar chemical properties.Precipitation has been widely used to separate copper from nickel electrolyte based on the different characters of copper and nickel

9、, and the method has been used widely for its simplicity. Especially for sulfide precipitation process.Precipitation has been widely used to separate copper from nickel electrolyte based on the different characters of copper and nickel, and the method has been used widely for its simplicity. Especia

10、lly for sulfide precipitation process.介介 紹紹The anion exchange method in the hydrochloric acid solution has been applied for purification of Co, and the good results for separation of metallic impurities from cobalt chloride have been reported. Therefore, we may try to remove copper from anode nickel

11、 electrolyte with ion exchange. However, copper and nickel mainly exist in the form of Cu2+and Ni2+ in the solution regardless of their complexes，with chlorine. So it is difficult to separate copper with cation resin exchange. And it cannot be satisfied with demands of production if anion resin exch

12、ange is simply used for copper treatment. The anode nickel electrolyte must be dealt with before anion resin exchange is used.介介 紹紹In this work, a reductive agent was added to reduce Cu2+ into Cu+, and Cu+ can become anion complexes with chlorine but it is difficult for nickel in the nickel electrol

13、yte at Cl=7080 g/L. So nickel and Cu+ can be separated with anion exchange.實實 驗驗實實 驗驗試 劑材 料實實 驗驗步 驟1、2、The initial nickel electrolyte solutions were placed in a 500 mL cell using a water bath circulator and were regulated at a certain pH with diluted NaOH or HCl. And then sodium sulfite was added an

14、d Cu2+ was reduced to Cu+. Finally, the solutions were poured into the column with 717# strongly basic anion exchange resin and copper could be absorbed into resin from the dealt nickel electrolyte solution. When the copper concentration of the outflow from the column arrived 3*10-6mol/L, the sorpti

15、on must stop and the sorption capacity was defined as breakthrough capacity(BC). After sorption, washing the remnants in the column was needed and then desorption was made by NaCl solution with a small amount of H2O2 at low pH. Copper went into solution in the form of CuCl2 from resin. The resin can

16、 be regenerated and may be reused. The copper concentration of the outflow solution was analyzed with an atom absorption spectrophotometer AAS 1 N (Zeiss Jena, Germany).分分 析析分分 析析DeoxidizationDeoxidization of cupricOrthogonal design experimentEffect of reductive agent dosageSorptionEffect of sorptio

17、n speed on copper sorptionRRH ratio on copper sorptionEffect of initial copper concentration on BCSelectivity sorption of other ionsDesorptionDeoxidizationDeoxidization of cupricDuring the deoxidization of cupric from solution, it is found that different end points of potential(EPP) will lead to dif

18、ferent breakthrough capacity, as shown in Fig.1.Fig.1 shows that breakthrough capacity decreases with the increase of the end point of potential. When the end point of reductive potential is between 0.52 V and 0.49 V, breakthrough capacity increases by 10 times and arrives 1.39 mmol/g dry resin at 0

19、.49 V from 0.14 mmol/g dry resin at 0.52 V. When EPP is lower than 0.49V, BC increases slowly and it is only 1.41 mmol/g dry resin at 0.45 V. When the end point of potential arrives 0.72 V, there is almost nothing to exchange. With the development of cupric deoxidization, the lower the potential, th

20、e more the breakthrough capacity is.DeoxidizationDeoxidization of cupricIt is difficult for cupric to form anion complexes. It is also difficult for Ni2+ to combine anion complexes with chlorine according to the stable constants of complex from Table 2. But it is easy for the Cu+ to form anion compl

21、exes with chlorine. Especially, anion complexes of CuCl2 and CuCl3 2 are more easily formed than other ions mentioned above because lg2 and lg3 of Cu+ are 6.06 and 6.89, respectively.Thus, the end point of reductive potential has great effects on the breakthrough capacity of resin. During the proces

22、s of deoxidization, the less the potential in thesolution, the more the CuCli (i-1) is produced and the easier the anion exchange.DeoxidizationOrthogonal design experimentIn order to confirm the deoxidization conditions of cupric, factorial design experiment is needed. Some factors might have great

23、effects on the deoxidization, such as reductive agent dosage, pH of solution, time and temperature of reaction. Now orthogonal experiments were designed with the four factors and three levels with the aim value of EPP as listed in Table 3.Table 3 displays the effect sequence of the above four factor

24、s: ABCD. That is to say, the reductive agent dosage has the greatest effect on the reductive potential of cupric, pH of solution and reaction time have less effect, and reaction temperature has the least effect. It is also shown that the optimum conditions of the reductive cupric to Cu+ in the nicke

25、l electrolyte are: the reductive agent dosage is 4.5 times as the theoretic dosage and reaction time is 0.5 h at 40and pH 2.0.DeoxidizationOrthogonal design experimentDeoxidizationEffect of reductive agent dosageThe effect of reductive agent dosage on the end point of reductive potential is shown in

26、 Fig.2. It can be seen that EPP decreases with the increase of reductive agent dosage. The more the reductive agent dosage, the lower the end point of potential is.SorptionEffect of sorption speed on copper sorptionCopper sorption speed may be defined by linear flow rate, which can decide the breakt

27、hrough capacity, as shown in Fig.3. It can be seen from Fig.3 that the breakthrough capacity decreases with the increase of the linear flow rate. Complexes have no time to replace chlorine of the resin with too high linear flow rate. The more the linear flow rate, the less the time for copper to exc

28、hange with resin is, and the less the breakthrough capacity is. It is harmful for copper sorption with too high linear flow rate. But it will reduce the production efficiency with too slow linear flow rate. A suitable rate is needed. There is a relationship between the linear flow rate and the break

29、through capacity by fitting as shown in Fig.3.SorptionRRH ratio on copper sorptionIn order to improve removal copper productivity, it is necessary to check the effect of RRH of resin exchanger column. Anion exchange experiments were done on condition that RRH was changed at the linear flow rate of 5

30、 cm/min. The relationship among the mass of dry resin (mr), amount of substance of copper (nCu) and breakthrough capacity is listed in Table 4.From Table 4, we can see that the ratio of breakthrough capacity increases with the increase of RRH. When RRH reaches 48.08, the breakthrough capacity has li

31、ght change. So the optimum value of RRH might be considered to be more than 48.08, but it is easy for resin to be crushed with so high RRH. Fortunately, it can be solved by the way that resin exchanger column might be jointed in tandem.SorptionEffect of initial copper concentration on breakthrough c

32、apacityWhen the initial copper concentrations are changed at resin volume of 39.25 mL, the resin breakthrough capacities are shown in Fig.4. It can be seen that resin breakthrough capacities decrease with the increase of initial copper concentrations. That is to say, the higher the initial copper co

33、ncentration, the more difficult for the resin to absorb copper from solution under the stable linear flow rate.SorptionSelectivity sorption of other ionsThere are other ions with high concentration in the electrolyte solution except CuCl2 -and CuCl3 2-Before sorption, the initial SO4 2- and nickel c

34、oncentrations were 80 and 75 g/L, respectively. It is necessary to check the concentration change of SO4 2- and nickel after sorption.Fig.5 shows that SO42 - and nickel concentrations in the outflow decrease only by 0.5 g/L with the increase of outflow volume during the process of sorption. This sho

35、ws that there is no obvious change in the concentration of SO4 2- and nickel during the process of copper sorption. So it is not necessary to worry about the loss of nickel during the sorption process.DesorptionCopper desorption from the resin was made perfectly by 3 mol/L NaCl solution with 4% (vol

36、umefraction) H2O2 (30%) at the desorption rate of 10 cm/min when pH=4.55.5. Copper went into solution in the form of CuCl2 from resin with copper and more than 100 g/L CuCl2 solution was achieved, which could be used to produce copper salt or electrolyte copper as listed in Table 5. The concentratio

37、n of NaCl has little effect on the CuCl2 concentration when it is between 3.0 and 4.0 mol/L. The CuCl2 concentration is affected greatly by the H2O2 concentration. If H2O2 concentration is not enough, some Cu+ ions can not oxidate into Cu2+ ions and become CuCl deposition. CuCl deposition will cover

38、 the surface of the resin and block the desorption. Only when CuCl deposition is oxidated by oxidant like H2O2 into CuCl2, could copper enter into water in the form of ions.DesorptionHowever, too much H2O2 (20% volume fraction) will damage resin and it is not helpful for production. According to the

39、 reaction (6), pH has a great effect on the desorption because H+ is consumed in the process. Reaction (6) goes on rightward at lower pH and copper is desorpted fully. When CuCl(s) deposition is oxidated into soluble CuCl2, the reaction (6) goes on rightwards and copper desorption is perfectly accom

40、plished. So, only when solution is acidic and pH is less than 6, can CuCl be oxidated adequately by H2O2 into soluble CuCl2 with more than 100 g/L.Moreover, the resin can be regenerated after washing and may be reused.結結 論論結結 論論1、Orthogonal design experiments show that the effect sequence of the four factors is reductive dosage pHreaction timereaction temperature. This shows that the optimum conditions of the reductive c