ELECTROCHEMICAL INVESTIGATION OF SYSTEM COPPER-SULFUR

The phase equilibria of the copper-sulfur system were investigated using electrochemical cells from 0 degree to 250 degree C over the composition range Cu/S equals 0. 95-2. 10. Vapor-saturated aqueous cupric sulfate and cuprous chloride solutions were used as the electrolytes. The two blaubleibender covellites, low digenite, tetragonal phase, and protodjurleite were found to be metastable. The Cu//1//. //9S phase was demonstrated not to be a real phase in the system. The electrochemical method used in this investigation has proved to be a reliable method for determining the phase equilibria and thermochemistry of a binary sulfide system. The method, with the proper precautions, should be applicable to other binary sulfide systems.