Distribution coefficient anion-exchange resin

Figure 12 Volume-distribution coefficients in hydrochloric acid for various elements on the strong-base anion-exchange resin Dowex 1 X-10 (after Krause and Moore, ref. 359)...

Pilot plant studies (flow rates, 1 cm/s) with the SB-1 anion exchange resin (column diameter, 0.3-0.7 cm) yielded distribution coefficients of the order D = 400 cmVg. The boron sorption process was shown to be film diffusion controlled. The equilibrium values of boron loading were reached in 6-8 hr [280]. Boron elution and resin regeneration were carried out with 0.1 M NaOH. The complete elution of boron required 10 column volumes at 10 BV and yielded concentrates of 100 mg/L. This facilitated the eventual reduction to solid concentrates of alkali metal borates [281]. 

Figure 5. Pu(IV) Distribution Coefficients for Three Anion Exchange Resins as a Function of pH.

The feasibility of the alternative process using heterogeneous catalysis was investigated by screening several anion-exchange resin catalysts [16] and optimizing the reaction conditions for the aldolization of butyraldehyde and propionaldehyde with formaldehyde the phase distribution coefficients of the... 

Impregnated resins for the selective adsorption of noble metal ions obtained [108] by loading TOA onto macroreticular hydrophobic resins were proposed. Au(lll), Pt(lV), and Pd(Il) are adsorbed on the resins as anionic chloro complexes. The adsorption efficiency of the resin was closely related to the specific surface area, the hydrophobic property of the resin matrix, and the amount of TOA loaded. The distribution coefficients of the resin for Au(lll), Pt(lV), and Pd(ll) are higher than 10 in 1 M HCl solutions. The selective recovery of gold and platinum by column operation from the acid-leaching solutions of industrial scraps has been demonstrated. Different from the case of conventional anion exchangers, the adsorbed chloro complexes were readily released from the resin as ion pairs with TOAH" by elution with 4-methyl-2-pentanone. 

Variation of the distribution coefficient, Ka, of Zr and Hf on the anion-exchange resin CA08Y as a function of the initial HF concentration. The linear relation with a slope of -3.0 0.1 is indicated by a dotted line. The insert shows the variation of [HF], [H" ], [F ], and [HF2 ] as a function of [HFlini (Reprinted with the permission from (Haba et al. 2004). Copyright (2009) American Chemical Society)... 

Distribution coefficients Ka of Db, Nb, Ta, and Pa on the anion-exchange resin CA08Y as a function of [HF]jni. The values of Db and Ta obtained from online column experiments are indicated by the closed symbols, while those of Nb, Ta, and Pa from batch experiments are shown by the open symbols. The Ka values of Rf, Zr, and Hf taken from (Haba et al. 2004) are also plotted (Reproduced with the permission of Oldenbourg Wissenschaftsverlag, Munchen, (Tsukada et al. 2009))... 

Fig. 13 Distribution coefficients (ATj) for Rf, Zr, and Hf on the anion-exchange resin CA08Y as a function of Hp2 concentration. The data from the 1.6 mm i.d. X 7.0 mm and 1.0 mm i.d. X 3.5 mm columns are depicted by open and closed symbols, respectively [2, 53]. Adapted from [53]...

Fig. 27 Variation of the distribution coefficient, K, of Db, Nb, Ta, and Pa on the anion-exchange resin CA08Y as a function of The...

Fig. 28 Distribution coefficients, K, of Nb, Ta, Pa, and Db on the anion-exchange resin in HF/0.1 M HNO3 depending on the fluoride ion concentration. Adapted from [86]...

Farls has reported the adsorption of elements from hydrofluoric acid solutions with Dowex-1 anion exchange resin (xlO 200 mesh). His results are shown In figure 68. Uranium (Vl) adsorption Is strong from dilute HP solutions and decreases with increased acid concentration. Separation from elements exhibiting no or strong adsorption from HP solutions may be achieved by proper selection of the acid concentration. Elements such as Be, B, 3c, Tl, Zr, Ho, Sn, Te, Hf, Ta, W, Re, and Hg have adsorption curves similar In shape to that of uranium (VI). Separation from these elements using an HP system should prove difficult to almost Impossibly depending upon the distribution coefficients Involved. 

The distribution of uranium and other elements between Dowex-2 anion exchange resin and phosphoric acid solutions is represented in figure 73.Marcus has studied the Dowex 1-uranyl idiosphate system. His distribution coefficients are lower by factors of 2 to 50 at O.IM H POjj and 2M H POj, respectivelythan those shown In figure 73. 

Cobalt from acidified sea water is extracted by anion exchange on the strongly basic resin Amberlite CG 400 (SCN ) after complexation of Co2+ with thiocyanate. Distribution coefficients of cobalt(II) up to 1.9 x 104 are attainable in solutions of 1 M NH4SCN and 0.1 M HC1. Cobalt sorbed on the resin column is stripped by elution with 2 M perchloric acid 74). 

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