AMF Series: Proven technology for agitation, mixing and flotation applications in industries worldwide

Process frame of minerals

Flotation

Application Introduction

What is Flotation

• Before flotation process can be used, the ore has to be reduced to fine particles by crushing and grinding. The particle are typically less than 0.1mm(100μm). But in some cases sizes smaller than 7-10 μm are required.

• Flotation is a mineral separation process done in the water medium. The ground ore is mixed with water to form a slurry and the desired mineral is rendered hydrophobic by the addition of a surfactant or collector chemical. The process is based on the difference in the surface properties of the mineral and gangue. The surface of the selected mineral is made water repellent(hydrophobic) by using selected reagents and these particles get attached to the air bubbles that are introduced in the system and collected as froth whereas wetted particles are left behind in the slurry.

• The separation process produces better results if the particles are well liberated which is achieved by grinding the ore. The recovery of the particles increases with the decrease in particle size to a limit and then it again recovery starts decreasing.

  
  

Critical points

• Mechanism keeps the slurry in motion without excessive turbulence

• Bubble and particle contact in the shear zone between the rotor and stator

• The strong shear forces produce sufficient energy for fines to break through

• The water film energy barrier on the air bubbles

• The challenge of the flotation is to keep the froth in constant motion

• To ensure high recovery or to make maximum concentrate grade

  
  

Flotation machine types

Mechanical cells

• Mechanical cells use impellers to circulate the pulp and keep the solid suspended in the solution and to draw adequate quantity of air to creat bubble. These cells can be subaeration

• self-aerating(self- air drawing) and supercharged / pneumo mechanical cells. The most common are Denver & Wemco cells.

FLSmidth flotation concept

Outotec flotation concept

Metso flotation concept