MONITORING PARTICLE SIZES WITH ROTATING-DISC ELECTRODES - MEASUREMENT OF THE DISSOLUTION KINETICS OF CALCITE

The presence of suspended particles in solution causes an enhancement of the mass transport to a rotating disc electrode, the magnitude of which is dependent on the volume fraction of the particulate material. By monitoring the transport limited current due to the reduction/oxidation of a suitable electroactive substrate in the presence of dissolving particles the change in the size of the latter with time may be monitored, thus allowing the rate of dissolution to be inferred. Experiments conducted on the dissolution of calcite at pH 7 are shown to give kinetic data in excellent agreement with that deduced by independent means. © 1993 Academic Press. All rights reserved.