Pyrolusite is MnO2. So, it is an ore of manganese. It is used in making dry batteries and also in brick industry.
Heating of pyrites in air for oxidation of sulphur is called
Roasting is generally done in case of the
Solution
In this process sulphide ores are converted into oxide ores.
2ZnS + 3O2 ⟶ 2ZnO + 2SO2↑
Which one of the following is not a sulphide ore?
Solution
The formula of magnetite is Fe3O4
Calcination is used in metallurgy for removal of
Solution
Among of the following statements the correct one is
Solution
Zinc blende is ZnS and iron pyrite is FeS.
Cassiterite is concentrated by
Solution
Cassiterite contains the magnetic impurities of FeSO4 and thus concentrated by electromagnetic separation.
Iron is obtained on large scale from Fe2O3 by
Solution
Fe2O3 + 3CO ⟶ 2Fe + 3CO2 ( in blast furnace)
Germanium of very high purity is obtained by
Solution
Metals of high purity are obtained by zone refining e.g., silicon, germanium, boron, gallium, indium.
Which one of the following ores is best concentrated by froth-flotation method ?
Solution
Galena is PbS and thus purified by froth floatation method.Froth flotation method is used to concentrate sulphideores. This method is based on the fact that the surface of sulphide ores is preferentially wetted by oils while that of gangue is preferentially wetted by water.
