question_answer 48)

    Which of the following statements is correct about the role of substances added in the froth floatation process? (a) Collectors enhance the non-wettability of the mineral particles. (b) Collectors enhance the wettability of gangue particles. (c) By using depressants in the process two sulphide ores can be separated. (d) Froth stabilisers decrease wettability of gangue.

Answer:

                    (a, c) Froth floatation process is used to extract metal from sulphide ore. This method utilises collectors and depressants whose functions are as follows (i) Collectors enhance the non-wettability of the mineral particles. (ii) By using depressants in the process two sulphide ores can be separated, e.g., sodium cyanide is used as a depressant to separate lead sulphide ore from zinc sulphide ore.