Finely divided platinum extraction - from platinum azide complexes with sulphuric acid at high temp and reducing the platinum

摘要

Finely divided Pt is obtd. by treating Pt azide complexes, pref. K tetranitroplatinate or Pt dinitrodianine with aq. sulphuric acid, 40 to 50% conc. for the former and 80 to 90% for the latter, and then reducing the resulting Pt aquasulphate with hydrazine hydrate in a molar ratio 10:1 or with an aq. alkali of 10 to 30% concn. Alternatively, the Pt aquasulphate may be treated with a 5% aq. alkali soln. and the resulting Pt hydroxosulphate dissolved in water and then pptd. onto activated carbon. The process time is reduced and more highly specific surface sizes obtained.