Formation and Properties of Submicron Particles Generated During Pyrite Combustion

Pure pyrite was combusted in a laboratory drop tube furnace(DTF) in O2/N2 and O2/CO2,a Dekati low pressure impactor(DLPI) was used to collect submicron particles(PM1) from pyrite combustion and obtain their mass fraction size distributions.Particle samples collected were subjected to physical and chemical analysis using an X-ray fluorescence(XRF) analyzer and a scanning electron microscope equipped with energy dispersive X-ray spectrometer(SEM-EDS).The mass size distribution,concentration,elemental composition and morphology of the PM1 were investigated.The results show that pyrite combustion has an important contribution to the PM1 formation.Under the same O2 concentration,the PM1 production and its peak size for the O2/CO2 condition are smaller than those for the O2/N2 condition.In the O2/N2 or O2/CO2 condition,the PM1 production and its peak size increase with the O2 concentration.The PM1 consists mainly of sulfur(S).The O2 concentration has an important influence on the partitioning of different S-containing compounds under the O2/N2 condition.With a low O2 concentration,the S in the PM1 mainly exists in the form of the element sulfur,with a higher O2 concentration,the S mainly exists in the form of sulfuric acid and sulfate.