Flotation

Froth Flotation

Froth flotation is a process that relies on the application of different surface properties of materials to separate particles either in suspensions or in dry granular mixtures. It has been commonly used in mineral processing to separate valuable minerals from gangue minerals since the early 20th century. In addition, froth flotation has been used to separate hydrocarbon gases and liquids since the 1920s. Although the process has been used since the early 20th century, its use has been revived in the last 25 years due to increased focus on laboratory studies of flotation and its successful commercial application in several modern mineral processing plants.

The fundamental principles of froth flotation are relatively simple. It relies on the differences between the surface properties of the various particles in the process. This is often referred to as “collector-selectivity. These surface properties control the wettability of the particles and can be manipulated by appropriate reagents or selective adsorption on the surfaces. The flotation process involves four steps:

1. Pulp Preparation: In preparation for the froth flotation process, the ore is first crushed and ground in order to make the particles more accessible for the collection process. This involves mixing the ore with a reagent and water, and then grinding theparticles in mills.

2. Collectors: Collectors are the components of the process that render the ore surface wettable. They are typically sulfonated oils and may be cationic, anionic, or amphoteric in nature.

3. Froth: The formation of the froth is integral to the successful operation of the froth flotation process. It takes place in the final step of the process, and is the final stage where valuable minerals are separated from the rest of the particles.

4. Discharge: After the froth has been formed, the particles must be separated from the liquid phase before they can be collected. This is done by removing the froth at the top of the flotation cell and discharging it, along with the valuable minerals, at the bottom of the cell.

Froth flotation can be used in a wide range of industries, from mineral processing and industrial wastewater treatment to the recovery of oil and greases from industrial effluent. The process is usually effective and requires little to no maintenance, making it an ideal choice for relatively simple industrial processes. It is reliable, cost effective, and highly efficient for separating suspended solids and other contaminants from water or wastewater. Froth flotation is also used to separate and concentrate specific minerals during ore beneficiation processes. In this case, collectors are used to target specific minerals in the ore, allowing them to be separated more easily.