Including explanation of answer please.

1) It is always a good idea to operate SAG mills at their critical speed to get the most efficiency in size reduction.

a) True b) False

2) In the dense media separation of scheelite (CaWO4) from calcite (CaCO3)-rich ore matrix, slimes are usually removed before the main separation stage.

a) True b) False

3) In the processing of an iron ore, the low intensity drum magnetic separation works better for recovery of hematite (paramagnetic) than that of magnetite (ferromagnetic)

a) True b) False

4) In froth flotation, bubble size should always be kept as large as possible, preferably > 2 mm, so that they can hit and capture the fine particles with a greater force and greater surface for collection.

a) True b) False