Vapour phase refining

Explain the following (a) CO_(2) is a better reducing agent below 710 K whereas CO is a better reducing agent above 710 K . (b) Generally sulphide ores are converted into oxides before reduction. ( c) Silica is added to the sulphide ore of copper in the reverberatory furnance. (d) Carbon and hydrogen are not used as reducing agents at high temperature. (e) Vapour phase refining method is used for the purification of Ti

Benefication of the ore can be done by different ways. It is increasing the concentration of ore by removing impurities, while refining is the process by which concentration of metal is incresed in the final product. The phase principle to apply vapour phase refining is/are:

Which of the follwing are main requirements for vapour phase refining ? (i) Metal should form a volatile compound with the reagent (ii) The volatile compound should be easily decompsoable to give back pure metal (iii)Metal should be very reactive and form a stable compound with the reagent

Which of the follwing are main requirements for vapour phase refining ? (i) Metal should form a volatile compound with the reagent (ii) The volatile compound should be easily decompsoable to give back pure metal (iii)Metal should be very reactive and form a stable compound with the reagent

The statement that is NOT correct is that (1) A furnace lined with haematite is used to convert cast iron to wrought iron. (2) Collectors enhance the wettability of mineral particles during froth floatation. (3) In vapour phase refining, metal should form a volatile compound. (4) Copper from its low-grade ores is extracted by hydrometallurgy.