Abstract
For the first time, the possibility of synthesizing zinc oxide nanoparticles during the processing of galvanic sludge using microemulsion leaching and subsequent precipitation of nanoparticles in this microemulsion has been demonstrated. Using model systems with ZnO and Zn(OH)2, the leaching of zinc into reverse microemulsions is studied in the system sodium dodecyl sulfate – butanol-1 – kerosene – water, containing extractants di-(2-ethylhexyl)phosphoric acid, caproic acid or a mixture of tributyl phosphate and acetic acid. The best leaching results are observed for microemulsion with di-(2-ethylhexyl)phosphoric acid. Using the model system “zinc hydroxide contaminated with iron (III) hydroxide,” the possibility of selective extraction of zinc into a microemulsion is shown. A method for the synthesis of nanoparticles has been developed, which includes microemulsion leaching of zinc, separation of unreacted solid phase, precipitation of ZnO nanoparticles from the microemulsion with an aqueous NaOH solution, separation of the precipitate, washing and drying. Using a model system with ZnO, spherical nanoparticles with a diameter of 34 ± 9 nm (according to transmission electron microscopy) were synthesized by this method; X-ray diffraction analysis showed that ZnO was obtained.