Effect of Microwave Treatment Upon Processing Oolitic High Phosphorus Iron Ore for Phosphorus Removal

Study on Reduction of Oolitic Hematite by Graphite in Microwave

“…Iron minerals in oolitic hematite have a more favorable absorbability to microwave than that of the silicate [4]. It is reported that the reduction rate of iron oxide can be promoted by means of microwave heating and the useful minerals separated effectively [5][6][7][8].…”

Separation of P Phase and Fe Phase in High Phosphorus Oolitic Iron Ore by Ultrafine Grinding and Gaseous Reduction in a Rotary Furnace

“…Then the reduction products were further melted at 1823 K (1550°C), and the molten iron and slag can be separated, while about 0.2 to 0.3 wt pct of P remains in the iron and needs to be further removed. [32] As for the transformation and transmission mechanism of phosphorus during melt separation process, Tang [29][30][31] considered that the P exists in the melt as apatite inclusions. Fukagai [32] has studied the reaction of the 2CaOAESiO 2 and FeO x -CaOSiO 2 -P 2 O 5 slag at 1573 K (1300°C), and reported that the CaO-SiO 2 -P 2 O 5 solid phases with high P 2 O 5 content were surrounded with coexisting phases of FeO-CaOSiO 2 system without P 2 O 5 .…”

Concentrating of Iron, Slag and Apatite Phases from High Phosphorous Iron Ore Gaseous Reduction Product at 1473 K by Super Gravity

“…According to thermodynamic data of the reactions between the H 2 /CO and the ore phases, the iron oxide can be reduced by reducing gas at low temperature, while the apatite is hard to be reduced in the temperature range of 300 K to 1 900 K. 5,[18][19][20] L. Guo,20) Z. L. Zhao and H. Q. Tang 21,22) have investigated the gas-based reduction by H 2 /CO at the temperature of 1 073 K to 1 273 K, the results show that gaseous reduction in fluidized bed or in static state can both reach a high reduction extent of iron oxide with the phosphorus still exists in apatite. Recently, M. Omran [23][24][25] and H. Q. Tang 26) have studied the function of microwave heating on the structure of high phosphorous oolitic iron ores, and they both found that the oolitic unit generated cracks and fissures due to microwave, and the microwave treatment can improve the phosphorus separation and magnetic properties. H. Q. Tang 26) further investigated the gas-based reduction of high phosphorous iron ore after microwave treatment, and the experiment results show that microwave treatment has an intensification effect on gas-based reduction, which can further reduces the gas internal resistance and increase the chemical reaction rate.…”

“…Recently, M. Omran [23][24][25] and H. Q. Tang 26) have studied the function of microwave heating on the structure of high phosphorous oolitic iron ores, and they both found that the oolitic unit generated cracks and fissures due to microwave, and the microwave treatment can improve the phosphorus separation and magnetic properties. H. Q. Tang 26) further investigated the gas-based reduction of high phosphorous iron ore after microwave treatment, and the experiment results show that microwave treatment has an intensification effect on gas-based reduction, which can further reduces the gas internal resistance and increase the chemical reaction rate.…”

“…L. Guo 20) adopted the melt-separation of raw ore after gaseous reduction at the temperature of 1 823 K, which realizes the separation of metal and slag, while the phosphorous content in the metal phase is up to 1.22 wt%; further by adding CaO into the ore with basicity of 1.5 before melt-separation, the phosphorous content in the metal can be decreased to 0.82 wt%. Simultaneously, H. Q. Tang 26) adopted the melt-separation of the ore after microwave treatment by adding CaO and Na 2 CO 3 powders as dephosphorizing agent at 1 823 K, and the phosphorous content in the metal is still 0.31 wt%. As for the transform and transmission mechanism of phosphorus from slag phase to metal phase during the meltseparation process when there is no carbon in the gaseous reduction product, Z. L. Zhao and H. Q. Tang 21,22,26) considered that phosphorus mainly exists in the metal as apatite inclusions, L. Guo 20) inferred that phosphorus was smelted into metal due to the reactions between the Fe and P 2 O 5 , which is evidenced by the thermodynamic calculations.…”