EXPERIMENTAL STUDY OF COPPER AND NICKLE SULFIDE MOBILIZATION BY AQUEOUS ALKALINE FLUID AT HIGH TEMPERATURES AND 20 KB

Abstract

As proved earlier, an aqueous fluid in equilibrium with mantle minerals at pressures above 10 kb has a relatively high alkalinity. The stability of hydrosulfide complexes of chalcophile elements in such a solution at relatively low temperatures and pressures results in the high solubility of the corresponding sulfides [2]. Therefore, the hydrosulfide form of ore-component transport in high-density aqueous alkaline fluid is most likely very important, too, at higher temperatures and mantle pressures. To check this postulate, the authors ran tests in a piston-and cylinder apparatus, and were able to determine the concentrations of rock- and ore-forming elements in the fluid when copper and nickel sulfides react with water at 600° and 900°C and 20 kb in the presence of clinopyroxenes, synthesized in the system jadeite70-diopside30-water (Jd0.7-Di0.3).