Which of the following magnetic impurity is present in Cassiterite ore?

In the froth-floatation process,palm oil functions as:

Which of the following ores is concentrated by the froth flotation process?

In the froth flotation process for the concentration of ores,why do the ore particles float?

While extracting an element from its ore,the ore is ground and leached with dilute $KCN$ solution to form the soluble product potassium argentocyanide. The element is

$PbS$ can be separated from $ZnS$ by electrostatic separation. Which property is involved in this method?