Abstract A foam sol clay (FSC) mixture, mainly composed of fly ash (FA), surfactant (n-amylamine) and polyethylene oxide (PEO), was proposed for coal dust control. The FA surface, modified by a FSC solution, stability and foamability were investigated. It was found that the FA surface in alkaline solution was deprotonated to form a negative charge, which could be adsorbed by the polar head group of n-amylamine via electrostatic interactions. As a result, with increasing surfactant, the particles gradually converted from hydrophilic to hydrophobic and attached at gas-liquid interfaces so that the contact angle, zeta potential, froth stability and foamability increased. At a surfactant concentration (ca) of 35 g/L, a monolayer three-dimensional network was formed and the maximum foamability and half-life were obtained. Upon further increasing ca, a bilayer and particle clusters were formed by surfactant chain-chain interaction, resulting in particles becoming hydrophilic again, and the FSC solution having stronger mechanical resistance against flowing, so that the viscosity rapidly increased and the diffusion of free surfactant molecules was hindered at the froth surfaces. Thus, the contact angle, froth stability and foamability decreased. PEO could bond sodium dodecyl sulfate and water to form a dual adsorption layer and hydrogen, respectively, which enhanced the wettability of the FSC on coal dust surfaces. PEO could adsorb and curl FA particles to form a thin layer of armor after froth air-drying. It was concluded that the froth generated by the FSC solution, including 200 g/L FA, 35 g/L ca and 1 g/L PEO, could control coal dust with a long-term effect.

中文翻译：

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泡沫溶胶泥防治煤尘的特性

摘要 提出了一种主要由粉煤灰（FA）、表面活性剂（正戊胺）和聚环氧乙烷（PEO）组成的泡沫溶胶粘土（FSC）混合物用于煤尘控制。研究了由 FSC 溶液改性的 FA 表面、稳定性和发泡性。发现碱性溶液中的 FA 表面去质子化形成负电荷，可以通过静电相互作用被正戊胺的极性头基吸附。结果，随着表面活性剂的增加，颗粒逐渐从亲水性转变为疏水性并附着在气液界面，从而使接触角、zeta电位、泡沫稳定性和起泡性增加。在表面活性剂浓度（ca）为 35 g/L 时，形成单层三维网络并获得最大发泡性和半衰期。在进一步增加 ca 时，表面活性剂链-链相互作用形成双层和粒子簇，使粒子重新亲水，FSC溶液对流动具有更强的机械阻力，使粘度迅速增加，游离表面活性剂分子的扩散在泡沫处受阻表面。因此，接触角、泡沫稳定性和发泡性降低。PEO可以结合十二烷基硫酸钠和水，分别形成双吸附层和氢气，增强了FSC对煤尘表面的润湿性。PEO可以吸附和卷曲FA颗粒，在泡沫风干后形成一层薄薄的装甲。结果表明，FSC 溶液产生的泡沫，包括 200 g/L FA、35 g/L ca 和 1 g/L PEO，可以长期控制煤尘。