Patent ID: 7101429

Claim:
A method of resisting corrosion of metals in concrete comprising: introducing into concrete having metal elements at least one compound capable of sequestering chloride ions, the compound having the formula 3Me(II)O·(R, R′) 2 O 3 ·Me(II)(anion) 2 ·nH 2 O, where at least one of R and R′ is present; R and R′ are different and are independently selected from the group consisting of Al, Fe Cr, and not present; anion is selected from the group consisting of NO 2 , NO 3 and OH; n is 0 to 24; and Me(II) is a cation and is selected from the group consisting of Ca, Ba, Sr, Mn, and Zn; and combinations thereof; and wherein at least one precursor to the compound is provided from acid mine drainage sludge.