难选褐铁矿流态化磁化焙烧—弱磁选工艺研究  

Study on Fluidized Magnetizing Roasting-Low Intensity Magnetic Separation Process for Refractory Limonite

作　　者：姜亚雄[1,2] 黄丽娟 黄恩旭 陈禄政 JIANG Yaxiong;HUANG Lijuan;HUANG Enxu;CHEN Luzheng(Kunming University of Science and Technology,Kunming 650093,China;Yunnan Gold Mining Group Co.,Ltd,,Kunming 650200,China)

机构地区：[1]昆明理工大学,昆明650093 [2]云南黄金矿业集团股份有限公司,昆明650200

出　　处：《有色金属（选矿部分）》2023年第1期64-70,共7页Nonferrous Metals（Mineral Processing Section）

摘　　要：某低品位复杂难选铁矿,铁主要以褐铁矿形式存在,褐铁矿与脉石矿物紧密共生,导致强磁选精矿铁品位偏低,难以获得合格铁精矿。通过试验发现,采用高梯度强磁选预富集—流态化磁化焙烧—弱磁选工艺可以高效利用该褐铁矿,重点考察了焙烧温度、焙烧时间、还原气氛和气量,以及焙烧产品磨矿细度、磁感应强度等参数对强磁精矿磁化焙烧指标的影响。同时,详细分析了焙烧前后试样中铁物相及嵌布特征的变化情况。结果表明,针对铁品位36.58%、粒度为-0.074 mm占83.73%的强磁精矿,在焙烧温度500℃、焙烧时间15 min、还原气体CO浓度20%、总气量600 mL/min,焙烧产品磨矿细度为-0.043 mm占90%、磁场强度0.15 T的试验条件下,采用流态化磁化焙烧—弱磁选工艺,最终获得了产率59.01%、铁品位58.69%和铁回收率85.89%的铁精矿。研究结果为该类难选铁矿资源的高效利用提供了一种新的技术途径。In a low-grade complex refractory iron ore,iron mainly existed in the form of limonite,which was closely associated with gangue minerals,resulting in low iron grade of high-intensity magnetic separation concentrate,and it was difficult to obtain qualified iron concentrate.It was found that the process of high gradient high intensity magnetic separation preconcentration-fluidized magnetizing roasting-low intensity magnetic separation can efficiently utilize the limonite.Effects of roasting temperature,roasting time,reducing atmosphere and gas quantity,as well as the grinding fineness of roasted product and magnetic induction intensity on the magnetizing roasting index of high intensity magnetic concentrate were investigated.At the same time,the changes of iron phase and embedded characteristics in the samples before and after calcination were analyzed in detail.Results showed that the optimum roasting conditions were as follows:the roasting temperature was 500℃,the roasting time was 15 min,the concentration of reducing gas CO was 20%,and the total gas flow rate was 600 mL/min.Under the conditions of grinding fineness of-0.043 mm accounting for 90%and magnetic field intensity of 0.15 T,the process of fluidized magnetic roasting-low intensity magnetic separation was adopted,and finally iron concentrate with yield of 59.01%,iron grade of 58.69%and iron recovery of 85.89%was obtained.The results provided a new technical way for the efficient utilization of this kind of refractory iron ore resources.

关 键 词：褐铁矿 流态化磁化焙烧 弱磁选 

分 类 号：TD925.7[矿业工程—选矿]