Coal Froth Flotation:  Effects of Reagent Adsorption on the Froth Structure

Abstract

The amount and quality of concentrate obtained from froth flotation of a coal are very important to determine the efficiency of the separation process. The shape and size of the bubbles in the froth directly affect the amount and purity of the concentrate overflowed during the froth flotation of the coal. The froth structure is significantly dependent on parameters such as the size of the solid particles, the surface properties of the particles, the chemical structure of surface active agents, the reagents adsorbed onto solid particles, and the reagents remaining in water. This work was performed to determine the relationship between the reagents adsorbed on the solid particles, froth structure, and froth flotation performance. The -53 µm size fraction of a bituminous coal was used to perform froth flotation experiments. The froth flotation of the coal used was performed in the presence of two nonionic surfactants, Triton x-100 (poly(ethylene glycol) tert-octylphenyl ether) and MIBC (methyl isobutyl carbinol), and an anionic surfactant, SDS (sodium dodecyl sulfate). The results showed that the adsorption of a high amount of reagent on the particles decreased the ability of separation, thus a substantial amount of mineral particles overflowed along with the hydrophobic coal particles. The use of MIBC with Triton x-100 or SDS as mixture increased solid recovery, and it was concluded that MIBC selectively adsorbed on solids acting as collector as well as a frother. Reagent adsorption has a crucial effect on the froth structure, which is strongly related to flotation performance.

An unusual synergistic adsorption of MIBC and CTAB mixtures at the air–water interface

“…Although MIBC adsorption can be examined individually (Comley et al, 2002), the mixture behavior is more relevant to flotation due to the fact that collectors, frothers and modifiers are collectively used to control the interfacial properties in the flotation systems. Most of research on binary mixtures with MIBC (Ozmak and Aktas, 2006;Strydom et al, 1983) have focused on application aspects such as solid recovery in flotation or froth stability while neglecting the fundamental adsorption (Tan et al, 2005). It is customarily assumed that collectors and frothers in their mixtures co-adsorb at the air-water interface and synergistically reduce the surface tension more significantly than the individual component surfactants.…”

In smell’s shadow: Materials and politics at the edge of perception

“…As air bubbles are introduced into the mixture, the surface-active properties of water and oil-soluble washing agents such as crude MCHM help coal stick to the bubbles rising to the surface behind mineral contaminants. It results in cleaner-burning coal (Ozmak and Aktas, 2006). Crude MCHM has helped maintain coal production in West Virginia to some extent, allowing coal to continue circulating in an economy and climate that increasingly desires and demands other forms of energy.…”

Multiscale Convolutional Network for Repairing Coal Slime Foam Images

“…These factors include the addition of flotation reagents and the amount of aeration by observing the characteristic information of the foam surface. − However, owing to subjective bias, production environment changes, and other factors, the findings of manual judgment are frequently inaccurate, causing frequent fluctuations in flotation production indicators and low utilization of mineral resources . Consequently, using machine vision to capture the characteristic information of flotation foam, to monitor and identify the foam in the flotation process in real time, and to guide the adjustment of production factors, such as reagent dosage and liquid level, affecting flotation production increases the yield and economic benefits of the flotation concentrate in a coal washing plant. − …”