On-line emission measurement of heavy metals in flue gas
An inductively coupled plasma atomic emission spectrometer (ICP-AES) was developed to continuously measure the heavy metals concentrations in flue gas in order to track the metal release process.The system is devoted to the thermal treatment of metal-spiked mineral matrix, coal and municipal solid wastes in fluidized bed (850℃).This method was used to study the kinetics of heavy metals release.The optimum values of the gas flows from the 1200 W power generator were 0.1 L·min~ -1 for the sample gas and 0.2 L·min~ -1 for argon.During the thermal treatment of coal and municipal solid waste,Cd and Pb were released readily,while Zn was released at a lower level than Cd and Pb.The formation of stable compounds such as ZnO·Al_2O_3 and CdO·Al_2O_3 from the reaction of heavy metals with fly ash particles could decrease heavy metals release.In all cases, the experimental setup was successfully used to monitor the heavy metal release process during coal and solid waste thermal treatment.