The invention relates to the use of aryliodonium and/or arylsulfonium salts of the tetrakis(perfluoro-t-butyloxy)aluminate anion of the following formula (I):

##STR00001##

as cationic initiators cleavable by light and/or free radicals for polymerizing cationically polymerizable monomers.

The invention relates to the use of aryliodonium and/or arylsulfonium salts of the tetrakis(perfluoro-t-butyloxy)aluminate anion of the following formula (I):

##STR00001##

as cationic initiators cleavable by light and/or free radicals for polymerizing cationically polymerizable monomers.

In particular, in alternative embodiments, the invention provides for a method to recover silicofluoride and phosphate species from wastewaters, or barometric condenser waters, that are typically utilized in wet-process phosphoric acid facilities. The species are recovered via a continuous ion exchange approach that allows for economic recovery of the materials and especially with the silicofluoride component allows for the production of valuable industrial materials such as hydrofluoric acid and other fluoride salts as well as industrial-grade precipitated silica materials. Return of the treated waste water to the phos-acid plant allows for optimization of reagent usage.

In particular, in alternative embodiments, the invention provides for a method to recover silicofluoride and phosphate species from wastewaters, or barometric condenser waters, that are typically utilized in wet-process phosphoric acid facilities. The species are recovered via a continuous ion exchange approach that allows for economic recovery of the materials and especially with the silicofluoride component allows for the production of valuable industrial materials such as hydrofluoric acid and other fluoride salts as well as industrial-grade precipitated silica materials. Return of the treated waste water to the phos-acid plant allows for optimization of reagent usage.