Flotation In Presence Research Articles

Depression of Arsenopyrite during Collectorless Flotation in Presence of Aqueous Metal Ions and Inorganic Compounds

Currently, the depression of arsenopyrite during the flotation of base metal mineral sulfides is being continuously studied to reduce its presence in sulfide concentrates of economic interest. In this work, the influence of aqueous metal ions (Fe2+, Cu2+, and Zn2+) in concentrations of 5, 25, and 75 g∗ton−1; mixtures of aqueous chlorides (ammonium and magnesium) and aluminum sulfate (AS)–sodium silicate (SS); and the use of only ordinary Portland cement (OPC) in all concentrations of 0.05 to 0.6 g∗ton−1 during the collectorless flotation and depression of a single-phase majority of arsenopyrite was analyzed. The results revealed a decrease in the hydrophobicity; its depression was greater with the use of OPC. At the concentration of 0.4 g∗ton−1 at alkaline pH and a pulp potential of +0.067 V, in 0.5 min, its flotation was 15.4 % w/w and the cumulative recovery at 10 min was 46.4 % w/w. The arsenopyrite depression was as follows: OPC > mixed chlorides > ASSS. Fe2+, Zn2+, Cu2+ ions activate flotation arsenopyrite. The solids obtained during the flotation were characterized using FTIR, and the functional groups responsible for the depression of arsenopyrite were identified.

Experimental and molecular dynamics simulation study on the effect of polyacrylamide on bauxite flotation

In this work, the effect of polyacrylamide (PAM) on bauxite flotation was comprehensively studied using both experimental and molecular dynamics simulation (MDS) methods. It was found that the recovery and selectivity of bauxite flotation decreased rapidly when the concentration of PAM exceeded a critical value. MDS study revealed that PAM could adsorb on diaspore and kaolinite through hydrogen bonding between the amide groups of PAM molecules and Al-OH on mineral surfaces. The hydrocarbon chains of PAM were oriented outwards at low concentration and increased the hydrophobicity of mineral surfaces, while PAM molecules entangled each other through intermolecular interaction at high concentration and reduced the hydrophobicity of mineral surfaces, which was in good agreement with the contact angle measurement results. High PAM concentration could possibly hamper the adsorption of collectors by steric hindrance. In addition, PAM could cause the unselective flocculation of diaspore and kaolinite, reducing the separation efficiency of bauxite flotation. Hexametaphosphate was able to improve the performance of bauxite flotation in presence of PAM at a proper dosage by reducing the unselective flocculation of diaspore and kaolinite.

Effect of the lattice ions on the calcite flotation in presence of Zn(II)

The effect of Zn2+ on calcite flotation and the effect of lattice ions on calcite flotation in presence of Zn2+ were investigated through microflotation tests, zeta potential measurements, and surface analysis. The results show that Zn species inhibit the interaction between the reagents and calcite through the formation of surface precipitation coating on the calcite surface, when the concentration of Zn2+ is higher than 10−5mol/L. The effect of Zn species on calcite flotation can be decreased with the increase of Ca2+, instead of CO32-. In presence of Ca2+ and CO32-, the change of floatability suggests that Zn species can be desorbed with an optimum ratio of Ca2+/CO32-. The zeta potential measurements and surface analysis show the existence of a mixture of hydrozincite and zinc hydroxide products on mineral surface, and zinc surface coating can be desorbed due to the strong chemical adsorption of Ca2+ and the formation of hydrozincite in the bulk solution.

Microbially Induced Flotation of Galena and Quartz from Pyrite

Selective separation of pyrite from galena and quartz was achieved through microbiologically induced flotation in presence of Bacillus subtilis. B. subtilis functions as a depressant for pyrite while it promotes the flotation of galena and quartz. Bacterial extracellular protein (EP) was isolated and the protein profile of bacterial cells grown in presence and absence of minerals established.

Selective separation of arsenopyrite from pyrite by biomodulation in the presence of Acidithiobacillus ferrooxidans.

Effective methods for selective separation using flotation or flocculation of arsenopyrite from pyrite by biomodulation using Acidithiobacillus ferrooxidans are presented here. Adhesion of the bacterium to the surface of arsenopyrite was very slow compared to that to pyrite, resulting in a difference in surface modification of the minerals subsequent to interaction with cells. The cells were able to effectively depress pyrite flotation in presence of collectors like potassium isopropyl xanthate and potassium amyl xanthate. On the other hand the flotability of arsenopyrite after conditioning with the cells was not significantly affected. The activation of pyrite by copper sulfate was reduced when the minerals were conditioned together, resulting in better selectivity. Selective separation could also be achieved by flocculation of biomodulated samples.

Flotation of metal-loaded clay anion exchangers. Part I: the case of chromates

Synthetic hydrotalcite-like layered materials are known for their ability to remove anions, like the chromates. These sorbents usually exist in powder form, thereby exhibiting high surface area and rapid kinetics for adsorption, but presenting appreciable problems in the subsequent solid/liquid separation process. Almost complete removals were obtained in this paper, from batchwork dispersed-air flotation in presence of a flocculant. Due to the experienced difficulty of flotation of thermally activated (at 500°C) hydrotalcite metal-loaded particles, the application of various surfactants was studied. Continuous-flow laboratory runs certified also the effectiveness of this combined process of sorptive flotation, a promising innovative treatment technology.