The entry of air and water into spoil heaps may cause weathering processes which transform sulphides into dissolved acid.
(The entry of air and water into spoil heaps; may cause; weathering processes which transform sulphides into dissolved acid) (weathering processes; transform; sulphides; into dissolved acid)
The entry of air and water into spoil heaps weathering processes
may cause transform
weathering processes which transform sulphides into dissolved acid
sulphides into dissolved acid