The wet lime-SO2 scrubbing process was investigated on a laboratory scale in support of full-scale prototype studies. The investigation consisted of laboratory scale experiments in the following areas: Measurement of the overall rate of uptake of SO2 in a stirred-pot reactor; Measurement of the relative rates of hydration of selected limestones and dolomites; Measurement of the relative rates of dissolution of selected limestone and dolomite materials; Chemical analysis of selected dolomite- and limestone-based liquors prepared at three temperatures. These experiments were designed to yield qualitative indications of the importance of individual physical and chemical processes to the overall limestone-SO2 wet scrubbing process. The results of the current experiments indicate that lime in particulate form reacts readily with various sulfur species or carbonate in solution to yield a coating which inhibits utilization of the bulk of the lime. The two primary variables studied were the flue gas and the scrubber-liquor compositions. The results indicate a strong dependence of hydration rate on the conditions of calcination of the stone and particle size. The results also indicate that the rate of the hydration process is limited by diffusion of water through the lime particle, and that over-burning of the lime markedly decreases hydration rate. Other experiments, using partically sulfated limes or solutions containing SO4(-2), showed that hydration rates are severely limited by the presence or formation of a layer of sulfate on the lime particles. Rates of dissolution of hydrated lime were determined in a well-stirred system using a calcium ion-specific electrode and a pH electrode for monitoring the concentrations of Ca(++) and OH(-) in solution. (Author)