# General Principles and Processes of Isolation of Elements

## Chemistry

### NCERT

1   Which of the ores mentioned can be concentrated by magnetic separation method?

##### Solution :

Ores which are magnetic in nature can be separated from non-magnetic gangue particles by magnetic separation method. For ex: ores of iron such as haemetite $(Fe_2 O_3 ),$ magnetite $(Fe_3 O_4 ),$ siderite $(FeCO_3 )$ and iron pyrites $(FeS_2 )$ being magnetic can be separated from non-magnetic silica and other impurities by magnetic separation method.

2   What is the significance of leaching in the extraction of aluminium?