Iron ore froth flotation has recently been used to obtain pure minerals due to the depletion of high-grade deposits. Amine collectors have often been used in cationic reverse iron ore flotation to achieve the separation with quartz impurities. The main problem associated with these collectors is related to the control of frothing properties and the high cost of amine reagents. In this paper, we report the benefits of partial replacement of amine collectors with a frother in reverse cationic flotation of hematite. Surface tension and batch flotation experimental results indicated for the first time that replacing Flotigam EDA, an etheramine collector by more than 10% improved the flotation performance in both grade and recovery of hematite. It was also noted mild hematite entrainments for lower frother dosages whilst reagents cost estimation indicated profitability per ton of iron recovered. At higher frother dosage however, higher quartz recoveries were observed as a result of entrainment which led to satisfactory results in terms of iron grade in the sink, but results showed higher costs of reagents than when collector was used alone. From observed results, it was concluded that partially replacing amine collector by a frother does improve the performance of the flotation globally regardless of pronounced entrainment that was mainly due the mineralogy of the ore with notable amounts of locked particles in the lower sizes. Finally, it would be useful to investigate these findings with alternative reagents and on minerals with different mineralogical properties.

The problem of shear stability of highly concentrated (dense) emulsions has been discussed based on treating these emulsions as viscoplastic media. Their rheological properties were characterized by the linear elastic modulus and the yield stress because these properties are responsible for the rheological properties of emulsion. The shear stability was defined as the characteristic time of the drop size decrease in emulsification. This approach is opposite to the usual characterization of shear stability of emulsions consisting of the application of the capillary number, this parameter was excluded from the discussion. The analysis was based on the experimental data for samples of various concentrations (ranging from 0.79 to 0.92 vol. %), prepared with different surfactants, four types of external phases, refined at different shear rates and using two types of emulsification devices with different types of the flow. For constructing master curves, the elasticity number (El) and the Bingham number (Bn) as...

Shear stability of water-in-oil highly concentrated emulsions was characterized by the rate of the droplet size decrease at a constant shear rate. Samples of different concentration (ranging from...

Intensive mining activities generate toxic acid mine drainage (AMD) effluents containing a high concentration of metals, including iron. The chemical synthesis of iron nanoparticles from this waste could lead to further environmental concerns. Therefore, the green synthesis of nanoparticles using plants has gained significant interest because of several benefits, including being eco-friendly. The current study reports a novel approach involving the synthesis of stabilized iron nanoparticles from AMD using rooibos tea extract. An aqueous solution of rooibos tea was prepared and titrated with AMD to reduce Fe²⁺/Fe³⁺. The samples synthesized under optimum conditions were characterized by TEM, XRD, FTIR, UV-Vis, and EDS. The results revealed that the nanoparticles had an average particle size of 36 nm with a spherical shape. These particles showed promising application as a Fenton-like catalyst for the degradation of textile dye (orange II sodium salt) with a removal efficiency of 94% within 30 min. Thus, the stabilized iron nanoparticles synthesized here performed in higher ranges than the currently reported Fenton-like catalysts regarding dye removal efficiency and reaction time.