Effect of Al on the solid reaction between 3CaO·Al2O3 oxide and Fe–S–O–Al alloy at 1373 K

Diffusion couples of 3CaO·Al2O3 and Fe–S–O–(Al) alloys are prepared to investigate the transformation of calcium aluminate reacting with solid sulfurcontaining alloys. Diffusion behaviors and solid reaction between the alloy phase and the slag phase under 1373 K are studied. Product layers of 12CaO·7Al2O3 and CaS are formed at the interface. After heating for 10 h, the average thickness of CaS layer in samples with and without Al in the alloy phase is 2.10 and 0.71 μm, respectively, while it increases to 3.76 and 1.75 μm after 50 h heating. Aluminum in the alloy makes the solid reaction at the interface easier to happen, meanwhile inhibits the formation of CaS layer by promoting the formation of 12CaO·7Al2O3 layer and suppresses the diffusion of sulfur