CARBON AND SULFUR ANALYSIS OF HOT METAL FOR THE DESULFURIZATION AND CONVERTER PROCESSES

Objective. There is a growing need for a more precise and faster metho d of determining carbon and sulphur levels when analysing hot metal so as to improve the control of the hot metal desulphurisation and decar burisation processes. At Salzgitter AG it has, for this reason, been a ttempted to develop the most automated method possible for such high-s peed analysis, For orientation purposes, trials involving the use of O E and XRFA spectroscopy have been conducted and modifications made whe re the sampling is concerned. Summary. The trials to use OE and XRFA s pectroscopy and improve the homogeneity did not lead to the desired re sults. As a consequence, the more elaborate technique of combustion an alysis was resorted to. In order to ensure that no more segregations o ccur, and to guarantee easy automation, the lest pieces were produced to have pins which can be easily cut off. This technique has highlight ed the small analysis scatters Chat are required. The carbon analysis hereby achieves a scatter of 1s = 0.02%, also when carbon levels are s ome 4.7% in production samples. For elevated sulphur levels of 0.07% t he standard deviation is 1s = 0.002 %,and for low sulphur levels of 0. 005% it is 1s = 0.0005%, The introduced automation has made it possibl e to achieve analysis times of around 5 minutes after receipt of the s amples in the laboratory. In-house-produced hot metal has been remelte d and modified for test purposes in order to have standard samples for these high carbon levels when analysing the hot metal.