国外某铁矿氢基矿相转化—弱磁选—反浮选实验研究

Hydrogen−based Mineral Phase Transformation−low Intensity Magnetic Separation−reverse Flotation of an Iron Ore Abroad

  • 摘要: 我国铁矿石大量依赖进口,为解决进口依赖问题,各企业都在积极寻找可以利用的铁矿资源,研发自主创新技术。氢基矿相转化技术以氢气或富氢气体作为还原剂,将矿石在悬浮态和一定温度下进行化学反应,使矿石中弱磁性铁矿物转变为强磁性的磁铁矿或磁赤铁矿,再利用矿物之间磁性差异进行磁选分离。某铁矿铁品位为52.11%,铁主要以赤/褐铁矿的形式存在,占全铁的85.54%,主要脉石矿物为石英,含量为20.87%。为确定该矿石的合理利用工艺,进行了氢基矿相转化—弱磁选—反浮选实验研究。结果表明,在还原温度为540 ℃、还原时间为20 min、还原气体体积浓度为25%,还原气氛V(CO)∶V(H2)=1∶3,磨矿细度−0.074 mm含量占72%、磁场强度为1600 Gs的条件下,可以得到磁选精矿铁品位65.55%、铁回收率98.14%的指标;磁选精矿中铁主要存在于磁性铁中,赤/褐铁矿的含量降为0.20%,说明原矿经氢基矿相转化后,弱磁性的赤/褐铁矿物被还原为强磁性的磁铁矿,在弱磁选过程中铁矿物得到有效回收。将磁选精矿磨细至−0.074 mm含量为88%,经一次粗选一次精选一次扫选反浮选实验可以获得铁品位68.47%、回收率97.48%的最终精矿,SiO2含量为3.06%,比原矿降低约18百分点。通过“氢基矿相转化—弱磁选—反浮选”工艺实现提铁降杂,该工艺是处理该矿石的适宜工艺,具有巨大的经济、社会和环境效益,提升了矿产资源高质量利用能力、资源持续保障能力和市场风险防范能力。

     

    Abstract: China's iron ore is heavily dependent on imports.In order to solve the problem of import dependence,enterprises are actively looking for available iron ore resources and developing independent innovation technologies.The hydrogen−based mineral phase conversion technology uses hydrogen or hydrogen−rich gas as a reducing agent to chemically react the ore in a suspended state and at a certain temperature,so that the weakly magnetic iron minerals in the ore are converted into strong magnetic magnetite or maghemite,and then magnetic separation is performed using magnetic differences between minerals.The iron grade of an iron ore is 52.11%. Iron mainly exists in the form of hematite/limonite,accounting for 85.54% of total iron.The main gangue mineral is quartz,with a content of 20.87%.In order to determine the reasonable utilization process of the ore,the experimental study of hydrogen−based mineral phase transformation−low intensity magnetic separation−reverse flotation was carried out.The results show that when the reduction temperature is 540 ℃,the reduction time is 20 min,the reduction gas volume concentration is 25%,the reduction atmosphere CO∶H2=1∶3,the grinding fineness −0.074 mm content accounts for 72%,and the magnetic field strength is 1600 Gs,the magnetic concentrate iron grade is 65.55%,and the iron recovery rate is 98.14%.The iron in the magnetic separation concentrate mainly exists in the magnetic iron.Compared with the iron content in the magnetic iron of the raw ore,the iron content in the magnetic iron increases by about 58%,and the content of hematite/limonite decreases to 0.20%,indicating that the weak magnetic hematite/limonite minerals are reduced to strong magnetic magnetite after the conversion of the raw ore by the hydrogen−based mineral phase,and the iron minerals are effectively recovered during the weak magnetic separation process.The magnetic separation concentrate was ground to −0.074 mm content of 88%.After one roughing,one cleaning and one scavenging reverse flotation test,the final concentrate with iron grade of 68.47% and recovery rate of 97.48% was obtained.The SiO2 content was 3.06%,which was about 18 percentage points lower than that of the raw ore.In this paper,through the process of ' hydrogen−based mineral phase transformation−low intensity magnetic separation−reverse flotation ',the experimental research on iron extraction and impurity reduction is completed.It is a suitable process for treating the ore.The process has great economic, social and environmental benefits,and improves the high−quality utilization of mineral resources. Ability, resource sustainability and market risk prevention capabilities.

     

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