煤炭工程 ›› 2022, Vol. 54 ›› Issue (12): 170-175.doi: 10.11799/ce202212030

• 研究探讨 • 上一篇    下一篇

非磁性物对重介质悬浮液旋流稳定性及分选效果的影响

朱子祺   

  1. 1. 神华神东煤炭公司洗选中心
    2. 中国矿业大学(北京)
  • 收稿日期:2022-02-11 修回日期:2022-03-16 出版日期:2022-12-14 发布日期:2023-02-06
  • 通讯作者: 涂亚楠 E-mail:fightforrei@163.com

Effect of non-magnetic substance on the cyclone stability of dense medium suspension and separation process

Zi qiZhu1,   

  • Received:2022-02-11 Revised:2022-03-16 Online:2022-12-14 Published:2023-02-06

摘要: 低密度重介质悬浮液存在强沉降失稳趋势,可能造成旋流器分选富集镜质组的效果变差。以低灰煤泥、蒙脱石及其混配的复合煤泥作为非磁性物,进行了重介质分选试验,探讨重介质悬浮液中非磁性物含量及组成对其旋流场稳定性和实际分选效果的影响,结果表明:随非磁性物含量的提高,悬浮液底流浓缩度、溢流澄清度、浓缩效率及底溢流密度差均下降,稳定性提高,且添加复合煤泥具有更好的稳定性|仅添加蒙脱石时悬浮液的浓缩效率值和溢流澄清度均高于不添加非磁性物的悬浮液,表明悬浮液体系更加不稳定|悬浮液中复合煤泥含量为30%和40%时,可以分选得到灰分小于3%且镜质组含量高于75%的目标精煤,分选的可能偏差E值最低达到0.034g/cm3,而在其含量超过50%,或仅添加低灰煤泥或蒙脱石的悬浮液均未能达到此要求|添加过多的非磁性物后虽然可以进一步提高悬浮液稳定性,但也会对分离过程中被选煤颗粒在旋流器中的迁移运动产生更大的阻碍作用从而使分选效果变差,因此悬浮液中非磁性物含量存在最佳值。

关键词: 重介质悬浮液, 旋流器, 旋流稳定性, 沉降, 分选, 复合煤泥

Abstract: There is a strong trend of sedimentation in low density heavy medium suspension, which may worsen the effect of cyclone separation and enrichment of vitrinite in dense medium cyclone (DMC). In this study, low ash slime, montmorillonite and their mixed composite slime were used as non-magnetic materials to reveal their effects on the cyclone stability and actual separation. The results show that: 1) with the increase of non-magnetic content, the underflow concentration, overflow clarity, concentration efficiency and underflow density difference of the suspension decrease, and the stability increases. And the addition of composite slime has better stability. 2) the concentration efficiency and overflow clarity of suspension with montmorillonite and magnetite powder are higher than those without non-magnetic substance, indicating that the system is more unstable. 3) the target of concentrate with ash content less than 3% and vitrinite content higher than 75% can be obtained by using suspension with magnetic content of 30% and 40%. The lowest possible deviation E value of separation is 0.034g/cm3, but when its content is more than 50%, or the suspension with only low ash slime or montmorillonite cannot meet this requirement. 4) although the addition of too much non-magnetic material can further improve the stability of the suspension, it can also hinder the migration of the selected coal particles in the DMC and make the separation effect worse. therefore, there is an optimal value of non-magnetic content in the suspension.

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