Method for obtaining fertilizing salts and derivatives of strontium, by wet process, starting from mineral material such as strontium sulphate which is reacted with ammonium carbonate in excess. This reaction is carried out continuously and with counter-current flows of reagents. This excess of ammonium carbonate used is recovered in order to recycle it in the process and to isolate the ammonium sulphate which may be treated continuously with a lime carbonate or oxide, recovering the gases evolved by the reaction and obtaining as final product lime sulphate (gypsum). In a second phase, strontium carbonate obtained is continuously reacted with nitric acid in order to obtain strontium nitrate, part of which is carbonated with gases (CO₂ and NH₃) producing a precipitate of strontium carbonate and a solution of ammonium nitrate.