EXPERIMENTAL STUDIES OF GOLD AND SILVER L EACHING FROM THE ACIDIC, BASIC AND INTERMEDIATE COMPOSITION AT 200-500-DEGREES-C AND P=200-1000 BAR

The experimental studies of gold ((195)AU) and silver ((110+110)mAg) l eaching in a form of trace contents from volcanic glasses by water and solutions at 200 - 500 degrees C and pressure of 200, 500, and 1000 b ar and different oxygen fugacities has been conducted. Zones of hydrat ion, recrystallization and leaching were distinguished, The removal of gold and silver from the hydration zone and its precipitation in the recrystallization zone was observed in the majority of runs. High gold leaching ability of basaltic, andesitic, and rhyolitic glasses was fo und in all runs, In contrast the removal of silver from the hydration zone was found to increase with increasing oxygen fugacity.