Eh measurements in sulphide mineral slurries

Problems in utilizing open-circuit potential (Eh) values as a measurement of the redox conditions in metallurgical systems are explored. Factors which determine the Eh when more than one redox couple is present have been illustrated by studies with platinum, gold and galena indicator electrodes in iron/oxygen and xanthate/oxygen systems. Potential measurements in galena slurries have demonstrated that smooth noble-metal electrodes are sensitive to the conditions at the mineral particle/solution interface.