Adsorption-extraction mechanism of heavy rare earth by Cyanex272-P507 impregnated resin

Instrument of IR spectrometer and methods of saturation, equimolar series change and slope were applied to study the extraction mechanism of Cyanex272-P507 impregnated resin for heavy rare earths from hydrochloric acid solution. The results show that the molar ratio of Cyanex272-P507 to rare earth in the extraction complex is 3. Chlorine ions do not participate in coordination. The extraction reaction can be expressed as RE3＋（a） ＋ 3-HA（r） ＋ 3/2HL（r）= [REA3/2L3/2]（r） ＋ 3H＋（a） （where HA represents 2 2 Cyanex272 and HL represents P507）. The synergic extractant formed in extraction chromatography is in a form ofmonopolymer and with a chemical structure of REA3/2L3/2.

Extraction of cerium(Ⅳ) using tributyl phosphate impregnated resin from nitric acid medium

Tributyl phosphate （TBP） solvent was used for impregnation into Amberlite XAD-16 nonionic polymeric resin beads using the wet method to prepare solvent impregnated resin （SIR）. Undiluted TBP in a ratio to the resin support （volume to mass） of 6.0 at room temperature （RT） in 24 h was impregnated the resin with a mass ratio of 1.944, while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88. Cerium（Ⅳ） oxide concentrate, prepared from crude Egyptian monazite sand, containing 37% cerium, 1.6% thorium and about 40% the other trivalent rare earth oxides, was used to prepare cerium（Ⅳ） nitrate solution for extraction using the prepared SIR. The impregnated resin was satisfactory for Ce（Ⅳ） extraction from nitric acid medium at room temperature. Cerium loading capacity of the impregnated resin reached 95.6% of the calculated theoretical capacity （173 g/kg （Ce/SIR）） under the conditions of 51.57 g/L cerium and 2.48 g/L thorium, 5.0 mol/L free nitric acid, solution to resin ratio of 10.0 and contacting the phases for 5.0 min. The loading capacity reached 98.75% when cerium concentration was increased to 91.43 g/L under the same conditions.

Separation of Tb^(3+) , Dy^(3+) , Ho^(3+) , Er^( 3+) with Solvent Impregnated Resins Containing Di-(2,4,4-trimethylpentyl) Phosphinic Acid

Solvent impregnated resins (SIR) with di (2,4,4 trimethylpentyl)phosphinic acid (Cyanex 571) were studied by adsorption of the extractant into Amberlite XAD 4; XAD 7; XAD 1180 polymeric adsorbents. The results shas that Cyanex 571/XAD 7 impregnated resins containing extractant of 0 35～0 45 g·g -1 resin have a favorable extractive activity in HCl medium. The rare earths (Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ ) are separated by using SIR as the column stationary phase. The better separation effect is obtained at lower load and slower elution rate.

Multiphysics Coupling Study on Impregnation Process of Hot-Melt Resin in Fiber Fabrics for Composite Material Production

Since the resin-based composite materials are of essential importance in many key engineering fields,the manufacture processes are highly worth studying and optimizing for satisfying quality control at the highest possible production rate.In this paper,combined with the impregnation theory,the flow-thermal-mechanical multiphysics coupling model is built to characterize,investigate and optimize the osmotic flow process of hot-melt resin in fiber fabrics with the uniformity and adequacy of resin impregnation as the evaluation criteria.First,the osmotic flow process is characterized by the osmotic flow front of resin,which is tracked by the phase-field method.Then,the influencing factors of roller clearance,temperature and speed are comprehensively investigated.After that,the simulation data of resin impregnation degree are fitted by polynomial curves,with accuracy up to 96.13%,for further investigation of interaction between influencing factors.Finally,based on the above results,the operation parameter combination for impregnation process is optimized with the response surface method and provided as the guidance for practical application.

Effect of Moisture on the Insulation Condition of Twisted Coils

Method IEEE 841 is used to test endurance of insulation system of stators to 100% humidity at 40 ℃ for168 h. Insulation resistance after this test between phases or between phase and frame has not been lover as 5 × 10^6 Ohm. Some producers of motors use this method for determining quality of impregation resin. On such test insulation resistance between phases was lover as between phase and frame. Because between phases is only wire insulation impregnating resins on insulation resistance of insulation system an impregnating resin we observe influence of type of wires and after humidity test. With diagnostic of insulation, the state is dealt. We compare our impregnation resin with competitive impregnation resin. We made test on twisted coils prepared after STN IEC from two parallel wires. In this test, we succeed in demonstrating that the main influence on insulation resistance of insulation system wire and impregnation resin has insulation of wire. Impregnation resin has influenced on data dispersion.

Study on the diffusion kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregnated resin

Kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregn ated resin was studied. The influences of temperature,concentration,granularit y of resin on the exchange degree were investigated by the limited bath method. The result showed that the controlling factor of RE3+/H+ diffusion on Cyanex272-P507 extraction resin was particles diffusion. The process of diffuse kinetics f itted well with the expression developed by Body model. The apparent activation energy was determined as 23.20 kJ/mol. The reaction order was 0.452. In addition,the constant of particles diffusion(D0) was 1.352×10-8 m2/S and the entropy of diffusion was-47.055 J/(mol·K).

Extractant(2,3-dimethylbutyl)(2,4,40-trimethylpentyl) phosphinic acid(INET-3) impregnated onto XAD-16 and its extraction and separation performance for heavy rare earths from chloride media

（2,3-Dimethylbutyl）（2,4,40-trimethylpentyl）phosphinic acid（INET-3） was impregnated onto dry macroporous resins XAD-16 and pretreated XAD-16 with ethyl alcohol and HCl（Pre-XAD-16） to prepare the solvent impregnated resins SIRs-INET-3/XAD-16 and SIRs-INET-3/Pre-XAD-16. The molecular weight distribution of the low molecular weight（LMW） polymers washed off by ethyl alcohol during XAD-16 pretreatment was determined by gel permeation chromatography（GPC）. The macroporous resins（XAD-16 ＆ Pre-XAD-16）, the corresponding solvent impregnated resins（SIRs-INET-3/XAD-16 ＆SIRs-INET-3/Pre-XAD-16） and the PVA coated SIRs-INET-3/Pre-XAD-16 with boric acid as cross-linking agent were characterized by FT-IR, SEM-EDS and TGA. The effects of XAD-16 pretreatment and PVA coating technology on RE（III） adsorption equilibrium time, INET-3 losses during extraction and adsorption capacity were investigated. The adsorption kinetics, selectivity and stripping behaviors of SIRs-INET-3/XAD-16 were further studied. The washed off LMW polymers had the Mn of 36,656, Mw of 40,310 and polydispersity coefficient of 1.10. The SIRs-INET-3/XAD-16 had shorter equilibrium time,less INET-3 loss and more Tm（III） adsorption capacity than the SIRs-INET-3/Pre-XAD-16. The PVA coated SIRs-INET-3/Pre-XAD-16 had less INET-3 loss and more Tm（III） adsorption capacity but longer equilibrium time than the uncoated SIRs-INET-3/Pre-XAD-16. The adsorption of RE（III） on the SIRsINET-3/XAD-16 followed the pseudo-second-order kinetic model. The Tm（III） accumulative adsorption amounts onto SIRs-INET-3/XAD-16 after eight extraction stages was 23.6 mg/g. The separation factors of adjacent heavy RE（III） β（Er/Ho）, β（Tm/Er）, β（Yb/Tm） and β（Lu/Yb） values were 1.76, 2.59, 2.56 and 1.19,respectively. The adsorbed Lu（III） onto the SIRs-INET-3/XAD-16 can be stripped completely by 1.0 mol/L H2SO4.