The single most important operation used for the recovery and upgrading ofsulfide ores”, that’s howG. J. Jameson described thefroth flotation processin 1992. And it’s true: this process, used in several processing industries, is able to selectively separatehydrophobic fromhydrophilic materials,by taking advantage of the different categories of hydrophobicity that areincreased by using surfactants and wetting agents during the processalso applied to waste water treatment or paper recycling.

The mining field wouldn’t be the same without this innovation, considered one of the greatest technologies applied to the industry in the twentieth century. Its consequent development boosted the recovery of valuableminerals like copper, for instance. Our world, full of copper wires usedfor electrical conduction and electrical motors, wouldn’t be the same without this innovative process.

During the froth flotation process, occurs the separation of several types ofsulfides,carbonatesandoxides,prior to further refinement.Phosphatesandcoalcan also be purified by flotation technology.

During the process, four things happen:

1. Reagent conditioning happens in order to achieve hydrophobic surface charges on the desired particles
2. Collection and upward transport by bubbles in contact with air or nitrogen
3. A stable froth formates on the surface of the flotation cell
4. There’s a separation of the mineral laden froth from the bath

The flotation process has three stages:

1. Roughing
2. Cleaning
3. Scavenging

Flotation can be performed by different types of machines, in rectangular or cylindrical mechanically agitated cells or tanks, columns, aJameson Cellor deinking flotation machines. The mechanical cells are based in a large mixer and diffuser mechanism that can be found at the bottom of the mixing tank and introduces air, providing a mixing action.The flotation columnsuse airspargersto generate air at the bottom of a tall column, while introducing slurry above and generating a mixing action, as well.

Mechanical cells usually have a higher throughput rate, but end up producing lower quality material, while flotation columns work the other way around, with a lower throughput rate but higher quality material.The Jameson cell just combines the slurry with air in a downcomer: then, a high shear creates the turbulent conditions required for bubble particle contacting.

Advantages of the froth flotation process:first of all, almostallmineralscan be separatedbythis process. Then, the surface propertiescan be controlledandaltered by the flotationreagent. Finally, this technique is highly appropriate for the separation ofsulfideminerals.

Thanks & Regards

Rinkoo Gupta

AskIITians Faculty