Determination of the Chemical States of Sulfur in Blast Furnace Slags by Chemical Shift (X-ray Exitation)

Abstract

Sulfur exists in blast furnace slags in such states as sulfide sulfur S^2-, elemental sulfur S⁰, thiosulfate sulfur SO^2-₃, and sulfate sulfur SO^2-₃. Chemical analysis of these states is hindered by the following problems:
(1) There is no fully established method of chemical analysis for the purpose, and the existing method is time-consuming;
(2) Sampling comes into question as the states of sulfur vary with time; and
(3) Because the sample is pulverized for analysis, the analytical results indicate an average state and the method can not be applied for local analysis of the sample surface, etc.
In order to solve these problems, we carried out chemical state analysis utilizing chemical shift (X-ray exitation), and obtained the intended results. Chemical shift measurement employs, 1) the SK_α process, and 2) the SK_β process. The former process enables the degree of sulfur oxidation to be readily determined from the ratio of S⁶⁺ to S^2- in the slag. The latter permits analyzing the ratios of S^2-, S₂O^2-₃, and SO^2-₄ that may be present. The above methods of analysis have made it possible to identify secular changes in the form of sulfur in the slag or to carry out local analysis of the surface and interior of bulk samples.