SOx emissions from glass manufacturing: Decomposition of sodium sulfate asinfluenced by carbon

degreesa(2)SO(4), which is added as a fining agent in silicate glass batche s, has been identified as a source of SOx and particulate emission. Interac tion between Na2SO4 and carbon in silicate glass batches influences the dec omposition behavior of Na2SO4. Na2SO4 and Na2SO4 + C decomposition experime nts are undertaken in inert and On-rich atmospheres. Decomposition of Na2SO 4 alone is observed to initiate at similar to 1100 degreesC. Carbon promote s decomposition at lower temperatures, indicated by the presence of lower-t emperature decomposition regions at similar to 500 degreesC in O-2 and simi lar to 850 degreesC in N-2. SOx is released at temperatures as low as 500 d egreesC in O-2 SO(g) and SO2(g) are the decomposition products in O-2 In N- 2, SO2(g) is the sole decomposition product. For Na2SO4 + C in O-(2) over l eft arrow, the concentration of SO(g) at 500 degreesC is 230 ppmV, with a S O/SO2 peak ratio of 1.23. Decomposition mechanism of Na2SO4 can be describe d by a surface reaction, in which SOx is formed via rearrangements of activ e S-O complexes on Na2SO4 melt surface. Isothermal decomposition of Na2SO4 + C in N-2 at 1200 degreesC exhibits a rapid mass-loss during the heating-u p period, and a region of higher decomposition rate at shorter times. At lo nger times, the decomposition rate is similar to that of Na2SO4 alone.