Oxidation of Sulfur in B. F. Slags to Sulfate
Kimihisa ITO, Hitoshi MORISHITA, Nobuo SANO, Gaku WATANABE, Yukio MATSUSHITA
In order to remove the deteriorating effects of B. F. slag caused by the presence of sulfide, an investigation has been made of the oxidation of sulfide in B. F. slags to sulfate for samples in the form of planes or fluidized powders at 870 to 1200 °C.
The results obtained are as follows:
1) The optimum temperature to oxidize the sulfide to sulfate with suppressing the evolution of SO2 is 1100 to 1200 °C for slag planes, and is 900 °C for slag powders, the difference between the two being due to the sintering during the oxidation for the latter.
2) The rate of oxidation of sulfide to sulfate is controlled by the diffusion of oxygen in the slag.
3) The dissolution of S= into water from treated B. F. slags can be prevented when more than 90% of sulfur exists as sulfate.
4) To achieve the result indicated in 3), it is estimated that slag powders of-200 mesh should be treated in the air for 2 hours at 870 °C, for example.