Process achievement for the treatment by transferred arc of fly ashes fromwaste incenerators by on line measurement of heavy metal evaporation

This study is about the destruction of fly ashes from waste incineration. I t is performed in a laboratory sized plasma reactor (Power 30 kW). It conce rns the treatment of a waste model substance by a transferred arc plasma (s tabilized by an argon flow) in order to understand how different volatile c omponents evaporate. The preparation of the model substance from a zeolite matrix impregnated with lead or zinc salts (sulfates, nitrates and chloride s) is described. The lead, zinc and chlorine evaporation is especially stud ied by following one of their atomic lines by an ICP control on-line analys is system, which allows to measure the metal concentration in the exhaust g as, and determine the end of the treatment: typically less than 10 minutes for an initial load of 70 g. The resulting materials are an inert glass in the graphite crucible and condensed materials on the cold wall of the react or. The lead and zinc concentrations, measured in the glass by X-ray fluore scence, are lower than 10 ppm for a full treatment while zinc and lead are present in the condensed materials as oxides or chlorides if chlorine is pr esent in the matrix. For an argon plasma, the type of lead or zinc salts th e arc current, the arc length, the bath temperature and the additives to re duce the viscosity of the slag are the studied parameters.