What is the role of each of the following in froth floatation process

What is the role of each of the following in froth floatation process
(i) Collectors
(ii) Froth stabilizers
(iii) Depressants

Collectors- They increase the non-wettability of mineral particles.
Forth stabilizers- They are used to stabilize the froth formed.
Depressants- They are used to prevent certain type of particles from forming the froth.