Mining of chemical and fertiliser minerals

Mining of chemical and fertiliser minerals
This class includes:
- mining of natural phosphates and natural potassium salts
- mining of native sulphur
- extraction and preparation of pyrites and pyrrhotite, except roasting
- mining of natural barium sulphate and carbonate (barytes and witherite), natural borates, natural magnesium sulphates (kieserite)
- mining of earth colours, fluorspar and other minerals valued chiefly as a source of chemicals
This class also includes:
- guano mining
This class excludes:
- extraction of salt, see 08.93
- roasting of iron pyrites, see 20.13
- manufacture of synthetic fertilisers and nitrogen compounds, see 20.15