Amongst the following , the total number of ores which may be concentrated by froth floatation process is : haematite, bauxite, galena, copper pyrites, sphalerite, cassiterite, calamine, argentite , chalocite.

Answer

4

Explanation

Galena, copper pyrites, sphalerite, chalcocite. Please note that although argentite `(Ag_2S)` is a sulphide ore, it is not concentrated by froth floatation process since its silver content is low. It is better concentrated by leaching with NaCN .