水厂铁矿细碎产品干式预选设备升级研究

水厂铁矿采用CT-0812型永磁磁力滚筒对TFe品位为23.80%的细碎产品进行干式预选,TFe品位仅提高2.10个百分点,抛尾产率仅为11.32%,尾矿mFe品位达2.38%,干式预选效果不理想。为改善预选效果进行了不同新型干选机预选效果对比试验,对预选效果较好的新型干选机进行了现场工艺参数条件试验,并对新老干选机的工业生产指标进行了对比。结果表明:①在实验室条件下,TFe品位为21.45%的水厂铁矿细碎产品,XDG65-50型多级吸出-吸住联合干式预选机可抛出产率达16.63%、TFe品位为6.16%、mFe品位为1.63%的尾矿;CTX0812型旋转磁场干式磁选机可抛出产率达39.83%、TFe品位为5.45%、mFe品位为1.02%的尾矿,预选效果较理想。②在现场工业试验参数范围内,CTX0812型旋转磁场干式磁选机对磁系运转频率和分料板位置不敏感,但对给料皮带运行速度较敏感,皮带运行速度提高,尾矿TFe品位和mFe品位呈先慢后快的上升趋势;在磁系运转频率为70Hz,皮带运行速度为3.2 m/s,分料板距滚筒中心水平距离为300 mm情况下处理TFe品位为22.95%的给矿,可获得TFe品位为26.93%的干式预选精矿,抛尾产率达19.60%,尾矿mFe品位为2.05%。③在给矿品位相当、干选机工艺参数均最佳的情况下,CTX0812型旋转磁场干式磁选机可抛出产率达18.78%、TFe品位为6.87%、mFe品位为2.06%的尾矿,精矿TFe品位达28.69%,提高幅度达4.02个百分点;CT-0812型永磁磁力滚筒可抛出产率为14.21%、TFe品位为7.45%、mFe品位为2.58%的尾矿,精矿Fe品位仅为26.95%,提高幅度仅为2.25个百分点。④CTX0812型旋转磁场干式磁选机通过高频次的磁翻转和磁搅动以及高磁场强度,能实现磁性物料和非(弱)磁性颗粒的高效分离,适合用于水厂铁矿细碎产品的高效干式预选抛废。

Study on Upgrading of Dry Preselection Equipment for Fine Crushing Products in Shuichang Iron Mine

The CT-0812 type permanent magnetic drum was used in the dry preconcentration of the fine crushing products with TFe grade of 23.80% in Shuichang Iron Mine. TFe grade can only be improved by 2.10 percentage points and the discarding tailing yield was only 11.32%. The mFe grade of the tailings reached 2.38%， which means unsatisfactory effect of the dry preselection. In order to improve the pre-selection effect， the comparative tests of pre-selection effect of different new dry separator were carried out， and then condition tests of the process parameters on site were conducted with the equipment which has better pre-selection effect. The industrial production indexes of the new and old dry separator were compared. The results showed that: ①In the condition of laboratory and the TFe grade of 21.45% of the Shuichang Iron Mine fine products， the tailing with yield of 16.63%， TFe grade of 6.16% and mFe grade of 1.63% was obtained after the treatment of the XDG65-50 multi-stage suction-holding combined dry pre-concentration machine. The tailing with yield of 39.83%， TFe grade of 5.45% and mFe grade of 1.02% was obtained after the preselecting of CTX0812 dry magnetic separator with rotating magnetic field， which means the ideal preselecting effect. ②In industrial test parameter range on site， the CTX0812 dry magnetic separator with rotating magnetic field is not sensitive to the running frequency of the magnetic system and the position of the distribution board， but it is sensitive to the running speed of the feeding belt. The TFe grade and mFe grade of tailings show an upward trend of first slow then fast with the running speed of the belt increasing. When the magnetic system runs at a frequency of 70 Hz， the belt runs at a speed of 3.2 m/s， and the feed with a TFe grade of 22.95% is treated with a horizontal distance of 300 mm from the center of the cylinder， dry preselected concentrate with a TFe grade of 26.93%， tailing with yield of 19.60% and mFe grade of 2.05% can be obtained. ③Under the condition of equal grade of feeding and optimum technological parameters of dry separator， the tailing with yield of 18.78%， TFe grade of 6.87% and mFe grade of 2.06%， and the concentrate with TFe grade of 28.69%， increased by 4.02 percentage points was acquired using the CTX0812 dry magnetic separator with rotating magnetic field. The tailing with yield of 14.21%， TFe grade of 7.45% and mFe grade of 2.58%， and the concentrate with TFe grade of 26.95%， only increased by 2.25 percentage points was acquired using CTX0812 permanent magnetic drum. ④The CTX0812 dry magnetic separator with rotating magnetic field can achieve efficient separation of magnetic materials and non(weak) magnetic particles through high frequency magnetic turnover， magnetic agitation and high magnetic field intensity， which is suitable for highly efficient dry discarding of fine crushing products in Shuichang Iron Mine.