Mechanical Operation Topic : Froth Flotation Techniques & its application in chemical industries Group NO:03 Mayank Chauhan Maunish Mehta Viraj Modi Tapan Patel Israulhaq Patel

Definition of Froth Flotation Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing Industries. Flotation is a selective process and can be used to achieve separation from complex or such as lead- zinc, copper-zinc etc.

Principles of flotation Before froth flotation can work, the ore to be treated as reduced to fine particles by crushing and grinding, a process known as comminution so that a various minerals exists as physically separate grains. This Process known as liberation. Here the particle size are typically less then 0.1 mm but sometimes size smaller than 7-10 micro meter required.

Various Froth Flotation Techniques 1.Column Flotation 2.Jameson cell 3.Air sparged hydrocyclone flotation

Air sparged hydrocyclone (ASH) flotation The machine combines the froth flotation principles with the flow characteristic of a hydrocyclone, leading to a fast separation of minerals. In ASH flotation the ore slurry is fed tangentially through a conventional cyclone header into porous cylinder. This develops a swirl flow in radial direction which is discharged through the annular opening located at the bottom of the ASH.

Air is sparged through the jacket porous cylinder which allows attachment of bubbles with the particles. With a reduction in the tangential velocity of hydrophobic particles these these are transported with the bubbles into a discharge as overflow product. The hydrophilic particles are discharged as an underflow product through the annulus between the porous cylinder wall.

Jameson cell A schematic fiagram of jameson cel is shown in fig

In the cell the central portion of the conventional column cell has been replaced by downcomer. The feed sluury is forced through a nozzle forming a jet of slurry which draws air into the central down comer. The aerated slurry is into a tank and froth formed is washed by jets of wash water and finally collected in concentrate launder.

The first production cell was installed in1989 in Mount Isamine for the flotation of lead slimes and the cell is now being used for the treatment of coal, copper, zinc, and also for removing organics from electrolyte solutions etc.

Froth Flotation cell Numbered triangles show direction of stream flow.

A mixture of ore and water called pulp enters the cell from the conditioner and flows to the bottom of the cell. Air is passed down a vertical impeller where shearing forces break the air stream into small bubbles the minerals concentrate froth is collected from the top of the cell while pulp flows to another cell.

Application Ferrite are mixed metal oxides containing iron oxides as their main costitutents for the manufacture of ferrites super concenteration of impurities (alumina & silica) in the concentrate. Flotation is the technique for concentration of low grade ores and fines. It has found in application in processing of low grade iron ore with siliceous gngues.

The flotation process is widely used in industrial waste water treatment plants where it removes fats, oil, grease and suspended solids from waste water. Froth flotation is one of the processes used to recover recycled paper. The target is to remove and release the hydrophobic contaminants from recycled paper.