冷却方式对磁铁矿冷却产物的磁性影响研究

磁化焙烧工艺已成为处理难选铁矿资源的主要手段，焙烧产品冷却方式是影响磁化焙烧产品选别指标的重要因素。以海南某赤铁矿纯矿物为研究对象，考察了其磁化焙烧后惰性气氛、水淬冷却和空气气氛冷却方式对焙烧产品磁铁矿氧化程度的影响。结果表明：惰性气氛可以有效防止磁铁矿发生氧化反应，产品单位质量磁矩最大，为74.2 A?m2/kg；水淬冷却过程中发生轻微的氧化反应，产品单位质量磁矩为72.5 A?m2/kg；而空气冷却方式下，磁铁矿冷却过程中部分氧化为赤铁矿，焙烧产物的单位质量磁矩仅为37.6 A?m2/kg。空气气氛冷却受冷却初始温度影响较大，随着冷却初始温度的降低，冷却产物FeO含量逐渐增加，单位质量磁矩逐渐增加，比磁化系数逐渐增加。试验结果可以为难选铁矿石磁化焙烧过程优化提供参考。

Effect of Cooling Mode on Magnetic Properties of Cooling Product

Magnetization roasting technology has become the main mean for efficient development and utilization of refractory iron ore. Cooling mode are important factors affecting the separation results of roasted products. The effect of inert atmosphere cooling， water cooling and air atmosphere cooling mode on the oxidation degree of roasted products magnetite was investigated. The results showed that the inert atmosphere cooling can effectively avoid magnetite being oxidized， and the saturation magnetization is maxmum， it’s 74.2 A?m2/kg. The cooling product in water cooling occurred slight oxidation reaction， and the saturation magnetization can reach to 72.5 A?m2/kg. In air atmosphere， part of magnetite was oxidized into hematite and the saturation magnetization of cooled product is only 37.6 A?m2/kg. In air atmosphere cooling process， the results were greatly influenced by the initial cooling temperature. With the decrease of initial cooling temperature， the FeO content of cooled products gradually increased， the saturation magnetization of the cooled products gradually increased， and the specific susceptibility of the cooled products gradually increased. The experiment results can provide theoretical basis for the process optimum of refractory iron ore magnetic roasting.