Surface nanobubbles on the hydrophobic surface and their implication to flotation

Li, Chenwei; Li, Danlong; Li, Xin; Xu, Ming; Zhang, Haijun

doi:10.1007/s12613-021-2279-1

Cited by 7 publications

(2 citation statements)

References 43 publications

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“…Slipping (inaccurate observance of a boundary condition of the sticking-slipping of a liquid stream over a solid surface) is associated with the presence on a hydrophobic surface of a layer of reduced viscosity (formed due to a stratification of a saturated gasliquid solution during thinning an interphase gap (Figure 8a) [46][47][48][49]) or microcavities (submicrocavities) containing gas bubbles 10 −4 -10 −2 cm in size retained by surface tension forces (with a rough surface (Figure 8b) [50,51]). Macroscopic slipping on such a surface is a consequence of reduced friction between a liquid and a gas.…”

Section: Theoretical Provisionsmentioning

confidence: 99%

Studying Flotation of Gold Microdispersions with Carrier Minerals and Pulp Aeration with a Steam–Air Mixture

Evdokimov,

Golikov,

Pryalukhin

et al. 2024

Minerals

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This work is aimed at obtaining new knowledge in the field of interactions of polydisperse hydrophobic surfaces in order to increase the extraction of mineral microdispersions via flotation. The effect of high velocity and the probability of aggregating fine particles with large ones are used to increase the extraction of finely dispersed gold in this work. Large particles act as carrier minerals, which are intentionally introduced into a pulp. The novelty of this work lies in the fact that a rougher concentrate is used as the carrier mineral. For this purpose, it is isolated from three parallel pulp streams by mixing the rougher concentrate, isolated from the first stream of raw materials, with an initial feed of the second stream; accordingly, the rougher concentrate of the second stream is mixed with the initial feed of the third stream, and the finished rougher concentrate is obtained. In this mode of extracting the rougher concentrate, the content of the extracted metal increases from stream to stream, which contributes to the growth in its content in the end product. Moreover, in order to supplement forces involved in the separation of minerals with surface forces of structural origin in the third flotation stream, the pulp is aerated for a short time (about 15%–25% of the total) with air bubbles filled with a heat carrier, i.e., hot water vapor. Within this accepted flotation method, the influence that the surface currents occurring in the wetting film have on its thinning and breakthrough kinetics is proposed to be in the form of a correction to a length of a liquid slip in the hydrophobic gap. The value of the correction is expressed as a fraction of the limiting thickness of the wetting film, determined by the condition of its thickness invariability when the streams are equal in an interphase gap: outflowing (due to an action of the downforce) and inflowing (Marangoni flows and a thermo-osmotic stream). Gold flotation experiments are performed on samples of gold-bearing ore obtained from two deposits with conditions that simulate a continuous process. Technological advantages of this developed scheme and a flotation mode of gold microdispersions are shown in comparison with the basic technology. The purpose of this work is to conduct comparative tests on the basic and developed technologies using samples of gold-bearing ore obtained from the Natalka and Olimpiada deposits. Through the use of the developed technology, an increase in gold extraction of 7.99% and in concentrate quality (from 5.09 to 100.3 g/t) is achieved when the yield of the concentrate decreases from 1.86 to 1.30%, which reduces the costs associated with its expensive metallurgical processing.

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Section: Theoretical Provisionsmentioning

confidence: 99%

Studying Flotation of Gold Microdispersions with Carrier Minerals and Pulp Aeration with a Steam–Air Mixture

Evdokimov,

Golikov,

Pryalukhin

et al. 2024

Minerals

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“…An obvious (but technically far from being simple) solution to the problem of fine particle flotation is the use of nanobubbles [20][21][22][23]. Another promising direction in the flotation of fine particles is their preliminary aggregation [24,25].…”

Section: Introductionmentioning

confidence: 99%

Studying the Flotation of Gold-Bearing Ores Using Carrier Minerals

Evdokimov,

Golikov,

Zadkov

et al. 2024

Minerals

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This work is aimed at the analysis of the development of flotation technology by applying carrier minerals. Based on the concepts of continuum mechanics, a theoretical analysis of the influence of the carrier minerals (wall) on the motion of a single solid particle is provided, taking into account their hydrodynamic interaction (in the case of low Reynolds numbers). A correction was obtained in the form of a ratio of the particle size to its distance from the wall to take into account the influence of the wall on the hydrodynamic force acting on the particle. The influence of the wall is manifested through a rapid approximation of the liquid vortex flow in the gap between the solid wall and the particle to the steady-state mode, accompanied by the suppression of the transverse movement of particles. When the liquid slides along a wall-mounted gas–liquid layer with a reduced viscosity, the liquid flow increases in the interfacial gap, which can be analyzed by a dimensionless correction that includes values describing the properties of a continuous medium (dynamic viscosity) and a disperse phase (geometric particle size). The reason for the decrease in the induction time when gold grains adhere to each other is assumed to be due to the forces of hydrophobic attraction (when the grains have a mirror-smooth surface) and the sliding of the flow along the hydrophobic surface of the particles along the gas layer (when the grains have a rough surface). When polydisperse particles are aggregated, the threshold energy of the fast coagulation was established to be lower than that arising during the interaction of monodisperse particles, whose aggregation requires a large depth of the potential pit. Performing natural experiments on the ore using a rougher concentrate as a carrier material showed that the concentrate yield decreases by 20.52% rel. In the second case, the gold extraction was higher by 4.69% abs. While maintaining the achieved level of gold extraction, the double mixing of the rougher concentrate and the initial feed increased the gold content in the rougher concentrate from 4.97 to 6.29 g/t.

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A novel cationic collector for silicon removal from collophane using reverse flotation under acidic conditions

Tao

et al. 2023

Int J Miner Metall Mater

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Surface nanobubbles on the hydrophobic surface and their implication to flotation

Cited by 7 publications

References 43 publications

Studying Flotation of Gold Microdispersions with Carrier Minerals and Pulp Aeration with a Steam–Air Mixture

Studying Flotation of Gold Microdispersions with Carrier Minerals and Pulp Aeration with a Steam–Air Mixture

Studying the Flotation of Gold-Bearing Ores Using Carrier Minerals

A novel cationic collector for silicon removal from collophane using reverse flotation under acidic conditions

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