Separation of Rubidium from Associated Elements by Solvent Extraction with Dibenzo-24-crown-8

Naidu

Desalination and Water Treatment

et al. 2016

A B S T R A C TRubidium (Rb) is a highly valued and economically important metal present in large quantities in many natural and wastewaters. However, its recovery is hampered by its low concentration and extracting agents' limited selectivity. A batch sorption study showed that a potassium cobalt hexacyanoferrate (KCoFC) sorbent had much higher sorption capacities for Rb and caesium (Cs) than for lithium (Li), sodium (Na) and calcium (Ca). Equilibrium sorption data at pH 7 and 24 ± 1˚C for Rb and Cs satisfactorily fitted to the Langmuir model with sorption maxima of 96 and 61 mg/g, respectively. A fixed-bed column (12 cm height) containing a mixture of 2.2 g KCoFC and 19.8 g granular activated carbon had a breakthrough sorption capacity of 61 mg/g when a solution containing 5 mg Rb/L was passed through the column at a velocity of 2.5 m/h (0.7 L/h). When 1 and 5 mg Cs/L were added to the Rb solution, Rb sorption capacity dropped to 46 and 41 mg/g, respectively. During Rb sorption, K from the KCoFC lattice was released. Leaching the column containing sorbed Rb with 0.1 M KCl for 60 min at a velocity of 10 m/h desorbed 99% of sorbed Rb. A process for recovering Rb from sea water reverse osmosis brine is presented.

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Section: Desalination and Water Treatmentmentioning

confidence: 99%

Rubidium recovery using potassium cobalt hexacyanoferrate sorbent

Naidu

Desalination and Water Treatment

et al. 2016

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“…Potential methods of alkali metal extraction from natural resources include evaporation, precipitation, use of emulsion membranes and liquid-liquid extraction techniques [9,10].…”

Section: Introductionmentioning

confidence: 99%

Selective sorption of rubidium by potassium cobalt hexacyanoferrate

Naidu

Separation and Purification Technology

et al. 2016

“…Sea water and sea water rejected brine are good sources of Rb, but its recovery from these sources is challenging due to: firstly, its low concentration; and secondly, limited selectivity of chemicals utilised for its extraction in the presence of high concentrations of other ions in sea water and the brines [6]. The methods currently employed for extracting Rb consist of ion exchange/adsorption, evaporation, precipitation, use of emulsion membranes and liquid-liquid extraction techniques [7,8]. Of these, the ion exchange/adsorption process is the most suitable and widely utilised, since it is able to selectively extract low concentrations of Rb from mixed solutions [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Removing rubidium using potassium cobalt hexacyanoferrate in the membrane adsorption hybrid system

Separation and Purification Technology

Johir

et al. 2018