抄録
The possibility for the production of solid iron containing little phosphorus from molten iron oxide containing phosphorus oxide was examined experimentally.
Molten iron oxide containing phosphorus, lime and silica was reduced by CO gas in an iron crucible. The samples containing 20 and 60% FeO were used as “model” substances for steelmaking slag and iron ore, respectively, in the case of smelting reduction.
Reduction temperature were at 1350 and 1450°C. Phosphorus contents of produced iron are always below 0.2%. Lower phosphorus content of produced iron can be obtained, with the sample containing 60% FeO than with that containing 20% FeO, with the sample with CaO/SiO2 ratio of 0.5 than with unity.
The reduction of iron oxide in the sample begins after an incubation period of a few minutes while that of phosphorus oxide in the sample has no incubation period. Namely, at very early stage of the reduction, phosphorus oxide alone is reduced. The reduced phosphorus is diluted with produced iron after beginning of reducing of iron oxide. The content of phosphorus increases again when the reducing rate of the iron oxide decreases.
The reduction rates of oxides of iron and phosphorus can be described as time-linear equations.
It is speculated that the rate determining step of the reduction is the transport process of the substances through the molten oxide.
