Novel iron sulfides having excellent durability and excellent treating properties
of heavy metals, processes for producing the iron sulfides, iron sulfide mixture,
a heavy metal treating agent containing either of these novel iron sulfides as
an effective component, and a method by which wastes containing various heavy metals
are treated with the heavy metal treating agent are disclosed. The iron sulfide
having a mackinawite structure which contains FeMxNySz
wherein M represents an alkaline earth metal, N represents an alkali metal, and
x, y and z, indicating the molar proportions of the respective elements, represent
numbers satisfying 0.01x0.5, y0.2 and 0.7z1.4,
as an essential component.
