CHEMICAL-REACTION OF SULFUR-DIOXIDE WITH A CALCIUM-OXIDE AEROSOL-PARTICLE

The chemical reaction between a single electrodynamically levitated microparticle of calcium oxide and sulfur dioxide and water vapor in a nitrogen stream was examined by means of microparticle Raman spectroscopy and gravimetric measurement. The reaction was carried out at room temperature and ambient pressure. The double-ring electrodynamic reactor is described, and the results of experiments are presented. In the presence of humid nitrogen the reaction proceeded slowly to form hemi-hydrated calcium sulfite. Raman spectra obtained during the course of the reaction show the formation of calcium hydroxide as water is taken up by the particle and the formation of calcium sulfite by reaction of sulfur dioxide with the hydroxide. It appears that either pore-plugging or the formation of a coated layer on the particle prohibited the reaction from going to completion. Microparticles of the order of 100-mu-m were used in the experiments.