Persistent froth is becoming more and more common in coal and mineral flotation plants and presents safety and operational challenges. No effective method has been developed to destabilise persistent froth. As a new initiative, this study examined the structural difference between persistent foam and coal froth, based on which a solution was developed to maximumly destabilise coal froth. Destabilisation test, oscillatory rheology measurement and scanning electron microscopy (SEM) analysis indicated that the coal froth was more stable than the foam due to the formation of thin capillaries and tightly arranged coal particles on bubble surfaces. Although 107 µm silicone oil droplet could completely destabilise the foam at 2 mmol/L concentration, it only destabilised less than 50% coal froth even at 6 mmol/L concentration. To maximumly destabilise the coal froth formed by −38 and −20 µm particles, 24 and 18 µm silicone oil droplets were required to pass through the thin capillaries and enter the bubble films, respectively. However, smaller silicone oil droplets could not bridge the bubble films to destabilise coal froth and therefore a critical droplet size occurred depending on the size of particles stabilising the froth.

持久性泡沫在煤和矿物浮选厂中变得越来越普遍，并带来安全和操作挑战。尚未开发出有效的方法来破坏持久性泡沫的稳定性。作为一项新举措，这项研究检查了持久性泡沫和煤泡沫之间的结构差异，在此基础上开发了一种解决方案，以最大限度地破坏煤泡沫的稳定性。失稳试验、振荡流变学测量和扫描电子显微镜 (SEM) 分析表明，由于在气泡表面形成细毛细管和紧密排列的煤颗粒，煤泡沫比泡沫更稳定。尽管 107 µm 硅油液滴可以在 2 mmol/L 浓度下完全破坏泡沫的稳定性，但即使在 6 mmol/L 浓度下，它也只能破坏不到 50% 的煤泡沫。为了最大限度地破坏由 -38 和 -20 µm 颗粒形成的煤泡沫，需要 24 和 18 µm 的硅油液滴分别穿过细毛细管并进入气泡膜。然而，较小的硅油液滴不能桥接气泡膜以破坏煤泡沫的稳定性，因此出现临界液滴尺寸取决于稳定泡沫的颗粒尺寸。