Top IPC subclasses
1
|
B01J
|
4
|
Chemical or physical processes, e.g. catalysis, colloid chemistry; their relevant apparatus
|
2
|
C02F
|
3
|
Treatment of water, waste water, sewage, or sludge
|
3
|
B01D
|
1
|
Separation
|
4
|
C01C
|
1
|
ammoniacyanogencompounds thereof
|
5
|
C01D
|
1
|
compounds of alkali metals, i.e. lithium, sodium, potassium, rubidium, caesium, or francium
|
6
|
C01F
|
1
|
compounds of the metals beryllium, magnesium, aluminium, calcium, strontium, barium, radium, thorium
|