Study on the influence of sodium oleate concentration on the stability of foam

In this study, the dynamic foam analyzer is used to study the effect of sodium oleate（NaOL） concentration as the frother on the stability of the foam. High-resolution images show that the higher the concentration of NaOL, the smaller the initial bubbles generated and the thicker the liquid film between the bubbles. The measurement results of characteristic parameters such as foam volume, average bubble radius, foam volume stability and foam liquid content during the process of foam generation and attenuation indicate that the stability order of foam generated under different NaOL concentrations is: 6×10⁻⁴ mol/L≈8×10⁻⁴ mol/L ＞1×10⁻³ mol/L ＞4×10⁻⁴ mol/L. The Laplace’s equation calculation illustrates that with the increase of NaOL concentration, the surface tension of the solution gradually decreases, and pressure difference（ΔP） gradually decreases, leading to the decrease of liquid film discharge rate and bubble merging speed, which manifested as the increase of foam stability. However, when the NaOL concentration increases to 1×10⁻³ mol/L, the liquid content of the generated foam is the largest, then gravity drainage dominates, so the stability of foam decreases. This study confirms that the concentration of frother has an important influence on the stability of foam. In actual flotation, pulp concentration and reagent dosage have a significant impact on reagent concentration. It plays a vital role in improving flotation to adjust them reasonably.