Application of Wood Char in Processing Oolitic High-phosphorus Hematite for Phosphorus Removal

Phosphorus removal from oolitic high-phosphorus hematite using direct reduction followed by melting separation was investigated.At the direct reduction stage,highly volatile wood char was prepared by carbonizing jujube wood at 673 Kfor 2hand was used as reducing agent.The results of the direct reduction tests show that at a temperature of 1 373 K,a char mixing ratio of 0.8,and a reduction time of 10-25 min,the briquettes reached a metallization degree of 80%-84% and a residual carbon content of 0.13-1.98 mass%.Phosphorus remained in the gangue as calcium phosphate after reduction.The results of the melting separation tests show that residual carbon in reduced briquette negatively affects the phosphorus content（w[P]）in hot metal.When the reduced briquettes obtained under the aforementioned conditions were used for melting separation,hot metal suitable for basic oxygen steelmaking（w[P]<0.4mass%）could not be obtained from metallic briquettes with a residual carbon content more than 1.0mass%.In contrast,it could be obtained from metallic briquettes with residual carbon content less than0.35mass% by mixing with 2%-4% Na2CO3.