The froth floatation process used for the concentration of sulphide ore:

• A
  is based on the difference in wettability of different minerals.
• B
  uses sodium ethyl xanthate $(C_2H_5OCS_2Na)$ as a collector.
• C
  uses $NaCN$ as a depressant in the mixture of $ZnS$ and $PbS$,where $ZnS$ forms a soluble complex and $PbS$ forms froth.
• D
  All are correct statements.