Removal of rubidium from brine by an integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide

A novel integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide(KCuFC/SPSG)was used for selectively extracting rubidium ion(Rb^(+))from brine.To form KCuFC/SPSG,the precursor film of sulfonated polysulfone/graphene(SPSG)was synthesized by phase conversion process,which was alternately immersed in 0.1 mol·L^(-1)CuSO_(4)/K_(4)[Fe(CN)_(6)]by in-situ adsorption coupled co-precipitation method.Various data such as nuclear magnetic resonance spectrometer,Fourier transform infrared spectroscope,X-ray photoelectron spectroscope,X-ray diffraction,scanning electron microscope,and energy dispersive spectroscopy all verified that abundant KCuFC were uniformly located on the film.The resulting KCuFC/SPSG was used in film separation system.As the solution was fed into the system,the Rb^(+)could be selectively adsorption by KCuFC/SPSG.After the saturation adsorption,0.5 mol·L^(-1)NH_(4)Cl/HCl was fed into the film cell,Rb^(+)could be quickly desorbed by ion-exchange between Rb^(+)and NH_(4)^(+)in the lattice of KCuFC.The purpose of separating and recovering Rb^(+)from the brine can be achieved after the repeated operation.The effects of pH,adsorption time,and interferential ions on the adsorption capacity of Rb^(+)were investigated by batch experiments.The adsorption behavior fits the pseudo-second order kinetic process,while KCuFC has a higher adsorption capacity(Langmuir maximum sorption 165.4 mg·g^(-1)).In addition,KCuFC/SPSG shows excellent selectivity for Rb^(+)even in complex brine systems.KCuFC/SPSG could maintain 93.5%extraction efficiency after five adsorption/desorption cycles.

Comprehensive utilization of complex rubidium ore resources:Mineral dissociation and selective leaching of rubidium and potassium

Currently,the process of extracting rubidium from ores has attracted a great deal of attention due to the increasing application of rubidium in high-technology field.A novel process for the comprehensive utilization of rubidium ore resources is proposed in this paper.The process consists mainly of mineral dissociation,selective leaching,and desilication.The results showed that the stable silicon–oxygen tetrahedral structure of the rubidium ore was completely disrupted by thermal activation and the mineral was completely dissociated,which was conducive to subsequent selective leaching.Under the optimal conditions,extractions of 98.67% Rb and 96.23%K were obtained by leaching the rubidium ore.Moreover,the addition of a certain amount of activated Al(OH)_(3) during leaching can effectively inhibit the leaching of silicon.In the meantime,the leach residue was sodalite,which was successfully synthesized to zeolite A by hydrothermal conversion.The proposed process provided a feasible strategy for the green extraction of rubidium and the sustainable utilization of various resources.

Solvent extraction of rubidium and cesium from salt lake brine with t-BAMBP-kerosene solution

The residues of salt lake brine from which potassium had been removed were used to extract Rb＋ and Cs＋ together with a sulphonated kerosene（SK） solution of 1.0 mol/L 4-tert-butyl-2-（α-methylbenzyl） phenol（t-BAMBP）. Rb＋ and Cs＋ were enriched and separated effectively by precipitating Mg2＋ before extraction and by scrubbing out K＋ and Na＋ repeatedly before stripping. The effects of the volume ratio of organic phase to aqueous extraction phase（O/A）, alkalinity of aqueous phase（c（OH）-）, interference from K＋ and Mg2＋, and ratio the volume of organic phase to aqueous scrubbing phase（O/A′） were investigated. The experimental brine was extracted optimally by 5-stage extraction with 1.0 mol/L t-BAMBP in SK, c（OH-）=1 mol/L, and O/A=1：1. The scrubbing yield of rubidium was only about 10.5% when the extraction solvent was washed 3 times with 1×10-4 mol/L Na OH at O/A′=1：0.5. After 5-stage countercurrent extraction, the final extraction yields of Rb＋ and Cs＋ reached 95.04% and 99.80%, respectively.

A Compact Direct Digital Frequency Synthesizer for the Rubidium Atomic Frequency Standard

A compact direct digital frequency synthesizer （DDFS） for system-on-chip implementation of the high precision rubidium atomic frequency standard is developed. For small chip size and low power consumption, the phase to sine mapping data is compressed using sine symmetry technique, sine-phase difference technique, quad line approximation technique,and quantization and error read only memory （QE-ROM） technique. The ROM size is reduced by 98% using these techniques. A compact DDFS chip with 32bit phase storage depth and a 10bit on-chip digital to analog converter has been successfully implemented using a standard 0.35μm CMOS process. The core area of the DDFS is 1.6mm^2. It consumes 167mW at 3.3V,and its spurious free dynamic range is 61dB.

The process and mechanism for cesium and rubidium extraction with saponified 4-tert-butyl-2-(a-methylbenzyl) phenol

Cesium(Cs)and rubidium(Rb)separation from brine is an important and application-oriented topic.4-tert-butyl-2-(a-methylbenzyl)phenol(t-BAMBP)has been used for Cs and Rb extraction.However,the traditional extraction technology is base and acid consumed.In the present work,an innovative process for Cs and Rb extraction with t-BAMBP is developed,which consists of saponification,extraction,scrubbing and stripping.Both infrared spectrum and electrostatic potential analysis indicate the hydrogen of phenolic hydroxyl is dissociated from t-BAMBP during saponification and the oxygen of phenolic hydroxyl is the binding site for alkali metal ions.Saponified organic phase shows an excellent extraction effect for Cs^(+)and Rb^(+).The extraction reaches equilibrium in 5 min,with 99.5%Cs^(+)and 46.7%Rb^(+)are loaded into the organic phase in the single-stage extraction.Slope method indicates the structure of the extraction complex is MOR·3ROH(M=Cs^(+),Rb^(+),K^(+)),where the electrostatic attraction between M^(+)and the oxygen of phenolic hydroxyl is dominant,and the cation–p interaction has a significant effect also.The extraction complex of MOR·3ROH dissociates in the acid environment while scrubbing and stripping is completed.The Cs^(+)and Rb^(+)are separated from the mixture phase,the proton H bonds to the phenolic hydroxyl group,and the extractant is regenerated.

Rubidium-modified bioactive glass-ceramics with hydroxyapatite crystals for bone regeneration

In order to study the influence of rubidium(Rb)addition on the phase composition,microstructure,mechanical properties and cell response of bioactive glass-ceramics,CaO−SiO2−Na2O−B2O3−MgO−ZnO−P2O5 glass system was designed with and without addition of Rb.The results show that hydroxyapatite(HA)and Mg−whitelockite(Ca18Mg2H2(PO4)14)crystalline phases are formed in the glass matrix without Rb.After the addition of Rb,only HA phase is detected.The grain size of the crystals in the glass-ceramics is larger with the addition of Rb than that of samples without Rb.Rb addition can improve the bending strength of glass-ceramics.The cultivation of human bone marrow mesenchymal stem cells(hBMSCs)on Rb-containing glass-ceramics demonstrates enhanced cell adhesion,proliferation and ALP activity.In conclusion,Rb-modified glass-ceramics exhibit good mechanical property,excellent bioactivity and biocompatibility,which have potential for bone regeneration application.

Mild and highly efficient transfer hydrogenation of aldehyde and ketone catalyzed by rubidium phosphate

Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb_3PO_4 was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb_3PO_4 lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb_3PO_4, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde> 4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb_3PO_4 and worth in industrial application.

The near-infrared spectra and distribution of excited states of electrodeless discharge rubidium vapour lamps

The population ratio between the excited states of rubidium in the electrodeless discharge rubidium vapour lamp is calculated according to the near-infrared spectra in the region of 780-1550 nm. By using a 1529 nm laser, we measure the density of natural rubidium atoms at the 5P3/2 level. The populations of different excited states are then clarified.

Study of a low power dissipation,miniature laser-pumped rubidium frequency standard

This paper studies a miniature low power consumption laser-pumped atom vapour cell clock scheme. Pumping ^87Rb with a vertical cavity surface emitting laser diode pump and locking the laser frequency on a Doppler-broadened spectral line, it records a 5 × 10^-11τ-1/2 （τ〈500 s） frequency stability with a table-top system in a primary experiment. The study reveals that the evaluated scheme is at the level of 2.7 watts power consumption, 90 cm^3 volume and 10^-12τ-1/2 short-term frequency stability.

Nonradiative charge transfer in collisions of protons with rubidium atoms

The nonradiative charge-transfer cross sections for protons colliding with Rb（5s） atoms are calculated by using the quantum-mechanical molecularorbital close-coupling method in an energy range of 10-a keV-10 keV. The total and state-selective charge-transfer cross sections are in good agreement with the experimental data in the relatively low energy region. The importance of rotational coupling for chargetransfer process is stressed. Compared with the radiative charge-transfer process, nonradiative charge transfer is a dominant mechanism at energies above 15 eV. The resonance structures of state-selective charge-transfer cross sections arising from the competition among channels are analysed in detail. The radiative and nonradiative1 charge-transfer rate coefficients from low to high temperature are presented.

Content Variations of Rubidium and Bromide in Sylvite Derived from Carnallite by Leaching of Magnesium Chloride

The relationship between sylvinite and carnallite is important in the potash mine body contained carnallite,especially sylvinite overlies carnallite,the reverse of a normal depositional sequence.Trace elements are more

Preparation of Ammonium Tungstophosphate-Calcium Alginate Composite Adsorbent and the Separation of Rubidium and Potassium

As a kind of rare metals,rubidium is often used to prepare special glass,photomultiplier tubes,thermoelectric converter,organic catalysts and antidepressants.Rubidium forms no minerals of its own,hence,it often coexists with

Thermodynamics Phase Equilibria for the Salt- Water System of Potassium and Rubidium Ions

1 Introduction Brines,containing a variety of useful components,such as alkali metal(IA),alkaline earth metal(type IIA),halogen elements(such as VIIA),are naturally occurring complex electrolyte solution.Although rubidium is not the main component of the brine,while in the brine exploiting process,rubidium ion is continuously enriched in the

Cooling of rubidium atoms in pulsed diffuse laser light

This paper reports an experiment on laser cooling of STRb atoms in pulsed diffuse light, which is the key step towards a compact cold atom clock. It deduces an empirical formula to simulate the pulse cooling process based on the loading of cold atoms in cooling time and the loss in the dead time, which is in agreement with the experimental data. The formula gives a reference to select the parameters for the cold atom clock.

Design and test of the microwave cavity in an optically-pumped Rubidium beam frequency standard

We are developing a compact rubidium atomic beam frequency standard with optical pumping and detection. The cavity for microwave interrogation is an important part of the clock. The cavity in our design is a Ramsey-type, E-bend one, which is the same as the conventional method in most cesium beam clocks. Requirements for the design are proposed based on the frequency shift associated with the cavity. The basic structure of the cavity is given by theoretical analysis and detailed dimensions are determined by means of electromagnetic field simulation with the help of commercial software.The cavity is manufactured and fabricated successfully. The preliminary test result of the cavity is given, which is in good agreement with the simulation. The resonant frequency is 6.835 GHz, equal to the clock transition frequency of87 Rb, and the loaded quality factor is 500. These values are adjustable with posts outside the cavity. Estimations on the Ramsey line width and several frequency shifts are made.

Synthesis and Crystal Structure of a Rubidium Lanthanum Borate Rb_3La_3(BO_3)_4

The title compound was obtained by the flux method and its structure was determined. It crystallizes in monoclinic, space group P2/c with a = 11.0024（17）, b = 9.2979（14）, c = 14.500（2） A, β = 110.879（2）°, V = 1385.9（4） A^3, Z = 4, Mr= 908.38, F（000） = 1592, p = 19.601 mm^-1, Dc = 4.353 g/cm^3, the final R = 0.0481 and wR = 0.1257 for 2532 observed reflections with I 〉 2σ（I）, The Rb3La3（BO3）4 structure can be viewed as a 3-dimensional scaffold-like framework constructed by La-O polyhedra and BO3 groups. Two Rb＋ ions locate in a channel along the a direction and the rest one in a cavity.

Extraction of Cesium and Rubidium with 4-tert-butyl-2-(α-methylbenzyl) phenol from Salt Lake Brine

This work shows the extraction of cesium (Cs^+) and rubidium (Rb^+) from salt lake brine containing potassium (K^+) and magnesium (Mg^2+). The results show that 4-tert-butyl-2-(α-methylbenzyl) phenol ( t -BAMBP) diluted in sulfonated kerosene (SK) has an excellent extraction effect. Infrared spectroscopic studies indicate that polymerize to form the dimer in the t -BAMBP when Cs^+ or Rb^+ were extracted. The effects of K^+, Mg^2+, t -BAMBP concentration, the volume ratio of organic phase to aqueous phase (O/A) and the alkalinity (pH) of aqueous phase were investigated. The K^+ and Mg^2+ should be eliminated through precipitating before the extraction and separation of Cs^+ and Rb^+.The optimum extraction conditions of the experimental brine were as follows: 0.8 mol/L t -BAMBP diluted in SK, pH≥13, a phase ratio of 1:1, and an extraction contact time of 2 min at room temperature. The optimal extraction yields of Cs^+ and Rb^+ were as high as 100% and 85.8%, in addition, 8.76% of K^+ was co-extracted. Further work would increase the extraction yield and selectivity of Rb^+ and realize the efficient separation of Cs^+ and Rb^+ from brine.

Spectral filtering of dual lasers with a high-finesse length-tunable cavity for rubidium atom Rydberg excitation

We propose and demonstrate an alternative method for spectral filtering and frequency stabilization of both 780-nm and 960-nm lasers using a high-finesse length-tunable cavity(HFLTC).Firstly,the length of HFLTC is stabilized to a commercial frequency reference.Then,the two lasers are locked to this HFLTC using the Pound–Drever–Hall(PDH)method which can narrow the linewidths and stabilize the frequencies of both lasers simultaneously.Finally,the transmitted lasers of HFLTC with each power up to about 100μW,which act as seed lasers,are amplified using the injection locking method for single-atom Rydberg excitation.The linewidths of obtained lasers are narrowed to be less than 1 k Hz,meanwhile the obtained lasers'phase noise around 750 k Hz are suppressed about 30 d B.With the spectrally filtered lasers,we demonstrate a Rabi oscillation between the ground state and Rydberg state of single-atoms in an optical trap tweezer with a decay time of(67±37)μs,which is almost not affected by laser phase noise.We found that the maximum short-term laser frequency fluctuation of a single excitation lasers is at~3.3 k Hz and the maximum long-term laser frequency drift of a single laser is~46 k Hz during one month.Our work develops a stable and repeatable method to provide multiple laser sources of ultra-low phase noise,narrow linewidth,and excellent frequency stability,which is essential for high precision atomic experiments,such as neutral atom quantum computing,quantum simulation,quantum metrology,and so on.

Production of Rubidium Bose-Einstein Condensate in an Optically Plugged Magnetic Quadrupole Trap

We experimentally produce the rubidium Bose-Einstein condensate in an optically plugged magnetic quadrupole trap. A far blue-detuned focused laser beam with a wavelength of 532nm is plugged in the center of the magnetic quadrupole trap to increase the number of trapped atoms and to suppress the heating. An rf evaporative cooling in the magneto-optical hybrid trap is applied to decrease the atom temperature into degeneracy. The atom number of the condensate is 1.2（0.4）× 10^5 and the temperature is below lOOnK. We also study characteristic behaviors of the condensate, such as phase space density, condensate fraction and anisotropic expansion.

The Delayed Images in a Hot Rubidium Atomic Vapor

We report an experimental realization of the delayed images in a hot rubidium atomic vapor. With a rubidium atomic vapor cell as slow light medium, the image quality of the experiment could be improved greatly, compared with the results without a slow light medium. By analyzing the results about the image visibility of the slow light imaging system under three different conditions, the image visibility becomes better with the increment of the temperature, during the time that the wavelength of the laser is within dispersion range.