Mg2+is extracted from ammonium dihydrogen phosphate (NH4H2PO4) solution by an
emulsion liquid membrane (ELM) using mono-(2-ethylhexyl) 2-ethylhexyl
phosphonate (HEHPEHE)as a carrier, sulfonated liquid polybutadiene (LYF) as
a surfactant and kerosene as a solvent. To study the extraction efficiency
and advantages of the ELM process in the separation of Mg2+,the effects of
various operating conditions on the extraction -HEHPEHE volume fraction,
reaction temperature, treat ratio (emulsion phase / external phase), phase
ratio (membrane phase / internal phase), agitation speed, extraction time,
internal phase concentration, surfactant LYF concentration and initial pH of
NH4H2PO4 solution are experimentally investigated and discussed. The results
show that Mg2+ in NH4H2PO4 solution can be effectively removed by the ELM
process. An extraction efficiency of more than 83.1% is attained at the
optimized parameters and superior-grade NH4H2PO4can be obtained by two
levels of extraction.