"Rapid procedures, suitable for control and many other purposes, are described for the determination of silicon in electric furnace slags and associated materials and in ores and their mixtures. After sample dissolution by hydrofluoric acid in a Teflon bomb or after a sodium peroxide fusion and subsequent acidification, silicon is determined by an atomic absorption procedure. Other elements may be determined on the same solution as the silicon because no chemical separations have been made. Atomic absorption and chemical results are compared, and the precision found for the atomic absorption procedures is shown. The effectiveness of two atomizer-burner systems is compared and it is shown to be necessary, in one of these systems, to add a major contaminant to the comparison standard in order to obtain suitable accuracy"--Summary, p. i.