Final KB Qs Module 5: Magnetic and Electrostatic Separation

Question 1

What are the 3 purposes of magnetic separators?

Answer 1

1. Concentrate a valuable mineral that is magnetic (e.g., magnetite from quartz);
2. to remove magnetic contaminants;
3. to separate mixtures of magnetic and nonmagnetic valuable minerals

Question 2

What is Paramagnetism?

Answer 2

Materials only slightly affected by magnetic field. Align in the direction of the magnetic field. Alignment “disrupted” by thermal excitation.

Question 3

What is Ferromagnetism?

Answer 3

Five ferromagnetic elements (Fe, Co, Ni, Gd, and Dy). Capable of achieving high degree of magnetic alignment despite thermal interaction until a critical temperature is reached.

Question 4

Whait is Diamagnetism?

Answer 4

Very weakly repelled by the pole of a strong magnet. When magnetic field applied the diamagnetic substance will develop a magnetic moment through induction but is in the opposite direction and is therefore repelled.

Question 5

What the 2 options for the 2 kind of magnetic separation?

Answer 5

1. Low intensity/High intensity
2. Dry Separators/Wet Separators

Question 6

Dram Ms vs H for Diamagnetic sample, Paramagnetic sample, Ferromagnetic sample

Question 7

Draw a Rare-earth magnetic roll separator

Answer 7

Question 8

How does Electrical separation work?

Answer 8

Electrical separation exploits the differences in electrical conductivity between different minerals in a feed all minerals show some difference in conductivity

Question 9

What are the 3 main methods of particle charging/electrification?

Answer 9

1. Charging by ion bombardment (corona charging)
2. Charging by induction
3. Tribocharging (frictional charging)

Question 10

Explain corona charging and the result.

Answer 10

Charging of particles as they pass between two electrodes. Mineral particles passing through this corona are bombarded with the flow of ions and develop a charge.

Conductive particles dissipate charge through a grounded surface; non-conducting particles are pinned to the grounded surface

Question 11

Explain induction charging.

Answer 11

Induction charging is the process whereby uncharged particles in an electric field assume the field polarity