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在浮选过程中,由于气泡的结合、破裂及泡沫过载而使泡沫相中的疏水颗粒从气泡上脱落。当某些脱落的颗粒返回到矿浆中时,另有一部颗粒可能会选择性地再附着于从泡沫中上升的气泡上。这样可能形成泡沫中品位变化的特性。虽然这过程未经详细研究,但定性的数据表明,这种现象出现在较深的、载荷小的泡沫中,正如浮选柱过程所出现的情况那样。已研究出一种描述上述过程的数学模型,这种模型考虑了气泡表面被可浮颗粒复盖的程度以及随着矿浆-泡沫界面上方的高度增加时泡沫特性的变化情况。通过实验室型浮选柱的试验定性地验证了模型。结果表明,随着颗粒疏水性的增加以及充气频率和充气量的增加,附着的几率也增大。当气泡表面因有过多的细粒可浮物料而使表面复盖率增大时,附着的几率就减小。同时还表明,当要求产生选择性附着时,泡沫中的水与疏水固体之间应有一个临界比值。
During flotation, hydrophobic particles in the foam phase are released from the bubbles due to the binding of gas bubbles, cracking and foam overloading. When some of the exfoliated particles are returned to the slurry, another particle may be selectively re-attached to the bubble rising from the foam. This may create a change in grade in the foam. Although this process has not been studied in detail, qualitative data indicate that this phenomenon occurs in deeper, less loaded foams, as is the case with the flotation column process. A mathematical model describing the above process has been developed that takes into account the extent to which the surface of the bubble is covered by the buoyant particles and the variation of the foam characteristics as the height above the slurry-bubble interface increases. The model was qualitatively verified by experiments on laboratory flotation column. The results show that with the increase of particle hydrophobicity and the increase of inflation frequency and inflation, the attachment probability increases. When the surface of the bubble due to excessive flotation of the material surface coverage increases, the probability of attachment decreases. It has also been shown that there should be a critical ratio between water and hydrophobic solids in the foam when selective attachment is required.