重庆接龙铁矿悬浮磁化焙烧温度对焙烧产品性能的影响

Effect of Suspension Magnetization Roasting Temperature on the Properties of Roasted Products of Chongqing Jielong Iron Mine

菱铁矿是我国重要的铁矿石资源,悬浮磁化焙烧是处理复杂难选铁矿的有效方法。本文采用实验室小型悬浮磁化焙烧装置,针对重庆接龙铁矿,开展悬浮磁化焙烧工艺优化及焙烧温度对磁化焙烧产品性能的研究。研究结果表明,接龙铁矿预氧化产品在焙烧温度为500℃、焙烧时间为3 min,CO用量为0.2 L/min的条件下,获得了铁精矿品位56.31%,回收率92.05%的试验指标。XRD分析表明,在450~550℃范围内,还原焙烧3 min,均可实现大部分的赤铁矿转变为磁铁矿,提高温度有利于赤铁矿还原更彻底,还原温度对焙烧产品的磁性影响较小。预氧化样品经还原焙烧后,比表面积降低,存在孔结构坍塌破坏后被填充的现象,导致孔尺寸增加。孔结构的改变,可能对后续的磨矿磁选造成一定的影响。研究结果对认识悬浮磁化焙烧规律有一定的意义。

Siderite is an important iron ore resource in China.Suspension magnetization roasting is an effective method to deal with complex refractory iron ores.In this paper,a small laboratory suspension magnetization roasting device is used to carry out the research on the optimization of suspension magnetization roasting process and the effect of roasting temperature on the performance of magnetized roasted products for Chongqing Jielong iron mine.The results show that under the conditions of roasting temperature of 500℃,roasting time of 3 min and CO dosage of 0.2 L/min,the iron concentrate grade of 56.31%and recovery rate of 92.05%were obtained.XRD analysis shows that in the range of 450~550℃,most hematite can be transformed into magnetite by reduction roasting for 3 min.Increasing the temperature is conducive to the more thorough reduction of hematite,and the reduction temperature has little effect on the magnetism of roasted products.After reduction roasting,the specific surface area of the pre oxidized sample decreases,and the pore structure collapses and is filled,resulting in the increase of pore size.The change of pore structure may have a certain impact on the subsequent grinding and magnetic separation.The research results have certain significance for understanding the law of suspension magnetization roasting.