In froth flotation the effectiveness of an air bubble to adhere to a particle is based on how hydrophobic the particle is. Hydrophobic particles have an affinity to air bubbles, leading to adsorption. Collectors are the main additives used to improve particle surfaces.

Froth flotation is a widely used process in the mining industry to separate valuable minerals from their ores. It relies on the differences in the surface properties of the minerals to be separated. Various chemicals are used in the froth flotation process to enhance the separation efficiency. The chemicals involved in the process can be classified into three main categories: collectors, depressants, and activators.

Collectors:
Collectors are chemicals that selectively bind to the surface of the desired mineral, making it hydrophobic or water-repellent. This hydrophobicity allows the mineral to attach to air bubbles and float to the surface, forming a froth. The collectors used in froth flotation can be organic compounds, such as xanthates, dithiophosphates, or fatty acids. These collectors have functional groups that interact with the mineral surface, promoting attachment to the air bubbles.

Depressants:
Depressants are chemicals that are used to selectively inhibit the flotation of unwanted minerals. They work by adsorbing onto the surface of these minerals and preventing their interaction with the collectors. Common depressants used in froth flotation include inorganic salts, such as sodium cyanide or sodium silicate, and organic polymers, such as starch or guar gum. These depressants help to separate the valuable minerals from the gangue or unwanted minerals.

Activators:
Activators are chemicals that are used to enhance the flotation of specific minerals. They work by increasing the reactivity of the mineral surface, making it more amenable to attachment with collectors. Activators are often used in combination with collectors to improve the flotation performance. Examples of activators include metal salts, such as copper sulfate or lead nitrate, which can activate the flotation of minerals like sphalerite or galena.

In conclusion, the froth flotation process involves the use of collectors, depressants, and activators to selectively separate valuable minerals from their ores. Collectors enhance the attachment of the desired mineral to air bubbles, depressants inhibit the flotation of unwanted minerals, and activators increase the reactivity of specific minerals. By carefully selecting and controlling these chemicals, the efficiency of the froth flotation process can be optimized, leading to the recovery of valuable minerals.