Froth Flotation

Question 1

a method of separating the minerals in a relatively finely divided
state. It utilizes the differences in physico-chemical surface properties of
particles of various minerals. This method can only be applied to relatively fine
particles (less than 150 μm)

Answer 1

Flotation

Question 2

• Method to make the mineral particles ____ to the air bubble.
• Method to keep the air bubble ____ when it reaches the surface of
  water. It is known that the air bubble collapses when it reaches the
  surface of water. When it is collapsed, the adhering mineral particles
  are dropped into the water. So, the air bubble must be kept ____ on
  the surface of the water for a sufficient length of time for it to be
  removed from the surface.

Answer 2

1. Adhere
2. Alive

Question 3

• This method can only be applied to relatively fine particles (less than
  150 μm).
• The mineral must be water repellent or hydrophobic.
• Air bubbles can continue to hold the mineral particles if they can
  form a stable froth.

Answer 3

Froth Flotation

Question 4

The pulp is treated with various
chemical reagents known as ____

Answer 4

Flotation Reagents

Question 5

____ are chemicals used for
treating the mineral particles to make
them to adhere to the air bubbles.

Answer 5

Collectors

Question 6

____ are the chemicals used to
increase the life of the air bubbles

Answer 6

Frothers

Question 7

____ is an angle of contact of an air bubble with the surface of a solid measured across
the water.

Answer 7

Contact Angle

Question 8

____ (hydrophobic) are
minerals that have higher affinity
for air than for water, however
most minerals are ____
(____) in their natural
state.

Answer 8

Aerophilic (hydrophobic)

Aerophobic (hydrophilic)

Question 9

substances added to the ore pulp
prior to or during flotation in
order to make it possible to float
valuable mineral particles and
not to float the gangue mineral
particles. Important ____ are collectors, frothers, depressants, activators and pH
regulators.

Answer 9

Flotation Reagents

Question 10

A ____ is a chemical reagent, either an acid, base or salt, and is heteropolar in nature; the polar part of it has an affinity towards a specific mineral and the non-polar part has an affinity towards an air bubble.

Answer 10

Collector

Question 11

• The polar part is adsorbed on to the mineral to be floated whilst the
  non-polar part is oriented outwards and makes the surface of mineral
  particles hydrophobic.
• The ____ increases the contact angle of the valuable mineral particles.
• ____ are broadly classified as anionic, cationic and oily collectors.

Answer 11

Collector

Question 12

A ____ is a chemical reagent and is heteropolar in nature; the polar part of
it has an affinity for water and the non-polar part has an affinity for gas or repulsion for water. This decreases the surface tension of water and increases the life of bubbles produced.

Answer 12

Frother

Question 13

The reagents having both frothing and collecting properties are
known as ____

Answer 13

Frother-collectors

Question 14

____ are inorganic chemicals that react chemically with the mineral
particle surfaces to produce insoluble protective coatings of a wettable nature
making them non-floatable even in the presence of a proper collector.

Answer 14

Depressants

Question 15

____ are generally inorganic compounds that can modify the surface of
non-floatable or poorly floatable mineral particles by adsorption on particle
surface so that the collector may film the particle and induce flotation.

Answer 15

Activators

Question 16

• ____ – used in the flotation of sphalerite.
• ____ - is used to activate oxide minerals of lead, zinc and copper such as cerussite, smithsonite and malachite. This is also
  a sulphidizer which imparts sulphide surface to the mineral particles
  to facilitate for collector coating. It also has both dispersing and
  depressing effects

Answer 16

1. Copper Sulphate
2. Sodium Sulphide

Question 17

____ are used to modify the alkalinity or acidity of a flotation circuit or in other words to control the pH of the pulp.

Answer 17

pH regulators

Question 18

pH regulators

• Common pH regulators are ____ and ____ for creating alkaline
  conditions, ____and ____ for creating acidic conditions.

Answer 18

(1) Lime and soda ash
(2) sulphuric and hydrochloric acids

Question 19

Types of Flotation

As a mineral is selected and floated in flotation

Answer 19

Selective Flotation

Question 20

Types of Flotation

As a required mineral is selected and floated.

Answer 20

Direct Flotation

Question 21

Types of FLotation

When an unwanted mineral is selected and
floated, in which case, sink is the required product.

Answer 21

Reverse Flotation

Question 22

Types of Flotation

When an ore contains two or more valuable
minerals, one valuable mineral is selected and floated first and
second valuable mineral is floated from the tailings.

Answer 22

Differential Flotation

Question 23

Types of Flotation

When all the valuable minerals are selected and
floated.

Answer 23

Bulk flotation

Question 24

A ____ is the equipment used to carry out flotation operation. It
provides the hydrodynamic and mechanical conditions which effect the
separation.

Answer 24

Flotation Machine

Question 25

❖ In a ____ flotation machine, a mechanically driven impeller agitates the pulp and disperses the incoming air into small bubbles. These flotation machines are often composed of several identical cells arranged in series in such a way that one cell receives the defrothed pulp (tailing of preceding cell) as feed, they are called a ____

Answer 25

Mechanical Type Bank

Question 26

❖ In ____, air is introduced through the porous bottom of the cell. The air used in these machines not only creates aeration and produces froth but also maintains suspension by circulation.

Answer 26

Pneumatic MAchine

Question 27

* A technique that uses the principle of counter current wash-water flow for better separation particularly when operating on fine materials. * Simplest form of pneumatic type flotation machine. * It consists of a tall cylindrical column having the height to diameter ratio of more than 10. * The basic advantage of ____ is the production of highgrade concentrate without the loss of recovery. * A single flotation ____ can replace five to six stages of operations involving conventional cells and yet achieve better performance

Answer 27

Column Flotation

Question 28

# DEPRESSANTS for sphalerite and pyrite

Answer 28

Sodium or Potassium Cyanide

Question 29

# DEPRESSANTS combination of ____ and ____ for zinc sulphide minerals, sphalerite, marmatite, and pyrite

Answer 29

Sodium Cyanide and Zinc Sulphate

Question 30

# DEPRESSANTS sometimes used to depress pyrite in sulphide flotation

Answer 30

Lime

Question 31

# DEPRESSANTS used to depress galena

Answer 31

Sodium or Potassium Dichromate

Question 32

# LEAD AND ZINC FLOTATION depressants for pyrite and sphalerite

Answer 32

Sodium Cyanide and Zinc Sulphate

Question 33

# LEAD AND ZINC FLOTATION collector for lead circuit to float galena

Answer 33

Potassium Ethyl Xanthate

Question 34

# LEAD AND ZINC FLOTATION zinc circuit to float sphalerite

Answer 34

Sodium Isopropyl Xanthate

Question 34

# LEAD AND ZINC FLOTATION ____ as pH regulator and ____ as frother in both Pb and Zn circuit

Answer 34

Lime and Crysilic Acid

Question 34

# LEAD AND ZINC FLOTATION activate already depressed sphalerite in zinc circuit

Answer 34

Copper Sulphate

Question 34

# LEAD AND ZINC FLOTATION used as a frother in some plants

Answer 34

Methyl Iso-Butyl Carbinol

Question 35

# COPPER FLOTATION used as the collector most of the plant

Answer 35

Sodium Isopropyl Xanthate

Question 35

# Copper Flotation used as a pH regulator

Answer 35

Soda Ash

Question 35

# COPPER FLOTATION as the frother most of the plant

Answer 35

Pine Oil