▎ 摘　　要

NOVELTY - Preparing sulfonated polysulfone/graphene/ferrous cyanide copper composite film comprises e.g. (i) obtaining the sulfonated polysulfone/oxidized graphene composite film; and (ii) placing the sulfonated polysulfone/oxidized graphene composite film in an aqueous solution of inorganic copper salt, chelating and adsorbing copper ions, taking out, washing, placing it in an aqueous solution of potassium ferrocyanide, carrying the in-situ co-precipitation reaction to produce copper ferrocyanide, repeating the above method and alternately soaking in inorganic copper salt aqueous solution and potassium ferrocyanide aqueous solution to react to obtain sulfonated polysulfone/graphene/ferrous cyanide copper composite film, repeating the above method, soaking alternately in inorganic copper salt aqueous solution and potassium ferrocyanide aqueous solution to react to obtain the sulfonated polysulfone/graphene/ferrous cyanide copper composite film. USE - The method is useful for preparing sulfonated polysulfone/graphene/ferrous cyanide copper composite film is useful for separating and recycling rubidium in salt lake brine (claimed). ADVANTAGE - The method adopts phase inversion technology and in-situ immersion adsorption coupling coprecipitation technology to prepare sulfonated polysulfone/graphene/ferrous cyanide copper composite film with selective separation performance for rubidium ion thus separates and recovers rubidium in salt lake brine. DETAILED DESCRIPTION - Preparing sulfonated polysulfone/graphene/ferrous cyanide copper composite film comprises (i) adding coupling agent into graphene oxide suspension, ultrasonic dispersing evenly, adding sulfonated polysulfone, stirring and dispersing evenly to obtain mixture A, placing the mixture A on a glass plate, spreading it into a film, placing it in the film cleaning solution quickly, and washing to obtain the sulfonated polysulfone/oxidized graphene composite film; and (ii) placing the sulfonated polysulfone/oxidized graphene composite film in an aqueous solution of inorganic copper salt, chelating and adsorbing copper ions at a certain pH, time and temperature, taking out the sulfonated polysulfone/oxidized graphene composite film, washing it with secondary water, placing it in an aqueous solution of potassium ferrocyanide under a certain pH, time and temperature, carrying the in-situ co-precipitation reaction to produce copper ferrocyanide, repeating the above method and alternately soaking in inorganic copper salt aqueous solution and potassium ferrocyanide aqueous solution to react to obtain sulfonated polysulfone/graphene/ferrous cyanide copper composite film, repeating the above method, soaking alternately in inorganic copper salt aqueous solution and potassium ferrocyanide aqueous solution to react to obtain the sulfonated polysulfone/graphene/ferrous cyanide copper composite film. An INDEPENDENT CLAIM is also included for application of sulfonated polysulfone/graphene/ferrous cyanide copper composite film, comprising (i) using a membrane separation system, assembling sulfonated polysulfone/graphene/ferrous cyanide copper composite film sequentially in series, and using sulfonated polysulfone/graphene/ferrous cyanide copper composite film to separate rubidium in salt lake brine, specifically pumping the pretreated salt lake brine into the separation system under certain adsorption conditions and the dynamic adsorption of rubidium ion reaches saturation, emptying the salt lake brine after absorbing rubidium ion, passing through the secondary water to clean the impurities that are simply adsorbed on the membrane surface, pumping the desorption liquid into the rubidium ion film separation system for dynamic desorption treatment, carrying ion exchange and desorbing the rubidium ion on the sulfonated polysulfone/graphene/ferrous cyanide copper composite film and repeating the above steps of adsorption and desorption to desorb rubidium in the same desorption solution to obtain rubidium purification solution.