TRACE-ELEMENT EMISSIONS FROM WESTERN U. S. COAL-FIRED POWER PLANTS*

The Lawrence Livermore Laboratory program to evalute the trace elements in stack emissions from coal-fired power plants is described. Stack sampling and analysis of fly ash at modern, western U. S. power plants is discussed. Scanning-electron-microscope techniques are shown to be essential for accurate sizing of stack particles sampled with cascade impactors. Particle-size distributions for volatile and nonvolatile trace elements are reported. Comparisons show that the trace elemet enrichment factors of western and eastern U. S. coal-fired power plants are significantly different.