Patent ID: 6906235

Claim:
An iron sulfide mixture comprising an iron sulfide selected from the group consisting of (a), (b), (c) and (d) below and at least one alkaline earth metal compound: (a) an iron sulfide with excellent durability having a mackinawite structure which contains FeM x N y S z 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 0.01<x≦0.5, y≦0.2 and 0.7≦z≦1.4, as an essential component; (b) an iron sulfide with excellent durability having a mackinawite structure which contains FeM′ x N y S z wherein M′ represents Ca, Mg or combination thereof, N represents an alkali metal, and x, y and z, indicating the molar proportions of the respective elements, represent numbers satisfying 0.01<x≦0.5, y≦0.2 and 0.7≦z≦1.4, as an essential component; (c) an iron sulfide with excellent durability having a mackinawite structure which contains FeM x N y S z 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 0.01<x≦0.5, y≦0.2 and 0.7≦z≦1.4, as an essential component, wherein the mackinawite structure is a denatured mackinawite structure which gives an XRD pattern wherein spacing between 001 planes has increased in c axis direction to a value of from 5.03 A to 5.53 A and the ratio of the intensity for the diffraction peak attributable to any other hkl planes to that for the diffraction peak attributable to the 001 planes is 20/100 or lower; and (d) an iron sulfide with excellent durability having a mackinawite structure which contains FeM′ x N y S z wherein M′ represents Ca, Mg or combination thereof, N represents an alkali metal, and x, y and z, indicating the molar proportions of the respective elements, represent numbers satisfying 0.01<x≦0.5, y≦0.2 and 0.7≦z≦1.4, as an essential component; wherein the mackinawite structure is a denatured mackinawite structure which gives an XRD pattern wherein spacing between 001 planes has increased in c axis direction to a value of from 5.03 A to 5.53 A and the ratio of the intensity for the diffraction peak attributable to any other hkl planes to that for the diffraction peak attributable to the 001 planes is 20/100 or lower.