Dephosphorization in the Reduction and Melting Separation of High Phosphorus Hematite Carbon Bearing Pellets

Abstract

The rotary hearth furnace iron nugget process is a new technology with a huge potential to efficiently utilize high phosphorus hematite. In this paper, the influences of the basicity and additives on the phosphorus content and distribution in the iron nuggets and the slag were investigated. At first CaCO3 was added to the pellets and then Na2CO3 and CaF2 were also added in the experiments. The experimental results showed that the increase in the basicity and the addition of Na2CO3 and CaF2 were shown to be effective to inhibit the apatite reduction in high phosphorus iron ores and to reduce the phosphorus content in the nuggets. When the pellets containing 4% Na2CO3 and 4% CaF2 with the basicity at 1.4 were reduced at the temperature of 1400°C for 12 min, the phosphorus content in the iron nuggets was only 0.4% and the dephosphorization rate reached 81.2%.