The function of potassium ethyl xanthate in the froth floatation process is to make the ore

Which of the following ores is best concentrated by the froth-flotation method?

Explain the froth flotation process.

$4 Ag_{(s)} + 8 CN^{-}_{(aq)} + 2 H_2O_{(l)} + O_{2(g)} \longrightarrow 4 [Ag(CN)_2]^{-}_{(aq)} + 4 OH^{-}_{(aq)}$
The above reaction represents the process of concentration of ore in the extraction of silver. This process is:

Haematite ore is concentrated by

The process which involves the treatment of the ore with a suitable reagent so as to make it soluble but not the impurities is called: