· Gold, Silver, and Sodium. Effect of Tellurium on Parting. Parting of Gold and Silver Commercially. The Gutzkow Refining Process. Pure silver is readily attacked by strong hot sulphuric acid of SG 1.815, or about 90 per cent, strength. The reaction which takes place may be represented as follows: 2Ag + 2H2 SO4 = Ag2 SO4 + 2H2O + SO2.