SULFUR ORES TURNING TO GOOD VALUE .7. MOD ELING THE SULFUR BURNING FROM THE INDIVIDUAL PARTICLES OF THE VOLCANIC ORIGIN ORES

The previous results have demonstrated that the vaporization of sulphu r is the most important step of burning sulphur from volcanic ore It i s known at the that the afflux of vapors from a particle reduces the h eat transfer to the particle. This work presents a physical and a math ematical model for sulphur burning kinetics during the constant rate p eriod, based on the heat balance around particle, Computations show th at for the case of 10 mm ore particles, brunt in natural convection, t he mass Bow race of sulphur is close to experimental measurements for temperatures near the Sulphur boiling point. For higher temperatures a nd forced convection, the burning is accompanied by expulsion of sulph ur from particle as jets of drops and/or vapors. This phenomenon proba bly is due to the breakage of microscopical cells of barren rack, dete rmined by the rising of pressure of sulphur vapors. For this reason th e mass transport is intensified and the measured vaporization rates ar e higher, with approx. 25 - 30%, than those predicted by the model.