*4.1.3.1 Collector*

*Colloids - Types, Preparation and Applications*

*4.1.1.1 Atomic Force Microscopic (AFM) analysis*

bubble acting like a hydrophobic surface.

*4.1.2 Effect of water chemistry*

be understood and closely monitored.

*4.1.3 Effect of reagents*

Zeta potential, electric double layer is first prescribed by Helmoltz [16]. The counter ions in an electrical double layer can exchange with ions of the same sign from the solution. In a similar way, the moment of counter ions occurs, with the application of electric field because of the concept of surface conductivity.

The bubble-particle attachment forces can be calculated by attaching a bubble to a stationary solid surface and a particle to an AFM cantilever. Strong long range attractive forces can be determined for a hydrophobic particle and an air bubble before any double-layer and van der Waals forces can be established, with the gas

The attractive hydrophobic attraction between the solid-water and the watergas interfaces is assumed to be the main driving force for film rupture and the attachment of air bubbles to hydrophobic mineral particles, taking into account the repulsive existence of electrostatic repulsion and van der Waals forces between particles and air bubbles encountered in flotation. The development of a dimple due to a hydrodynamic pressure greater than the internal bubble pressure is highly dependent on the velocity of the air bubble's approach. Although the higher bubble approach velocity leads to a more pronounced dimple, in order to evaluate the film thickness of the first dimple and the form of the film for hydrophobic solid surface systems, the surface hydrophobicity needs to be taken into account. By changing the reaction conditions such as electrochemical potential and solution pH, it is possible

As water is a polar liquid and moderate conductor of electricity, potential difference will not be observed in the absence of electric current. The chemistry of water has a great influence on the interaction forces in aqueous solution between solid surfaces. The colloidal stability of various slurry phases is influenced by various ions (monovalent, divalent, trivalent, etc.) present in the water. Cations function as a binder to bridge various charged surfaces in certain instances. If present in process water, reagents/surfactants bind with cations to minimise the amount of free cations in the liquid, are able to mitigate the undesirable effect of cations and thus promote the release of mineral particles. The water chemistry of the aqueous system where the attachment occurs is strongly influenced by bubble-particle attachment. Electrolytes in water compress the electrical double layer for the already hydrophobic particles and thus lower the energy barrier created during the collision between hydrophobic particles and air bubbles, which is advantageous for the bubble particle attachment. Knowledge about the surface properties and zeta potential is very important for flotation. The literature may define the ideal situation for different ores, but due to the presence of different interfering ions, the actual situation of different ores with varied mineralogy differs. Therefore, for flotation process effectiveness, the particle size distribution proportions of coarse and fine size groups, surface features of bulk and size fractions of different mineral species and their interactions with the reagents need to

Flotation reagents play the most important role in flotation, as the heterocoagulation that could contribute to the loss of liberated valuables in the tailings

to maximise the alteration of hydrophobicity with/without collector.

**160**

Collectors are reagents which render minerals' surface hydrophobic by adsorption. The selection of an appropriate collector is critical for selective separation of valuable minerals from gangue minerals. Collectors can be classified into non-ionic, anionic and cationic depending on their ionic charge and active ion participation.
