As part of the study of hazardous metal ion separation from industrial wastes, the extraction behavior of Hg(II) from dilute hydrochloric acid solutions with dicyclohexano-18-crown-6 (DC18C6) in 1,2-dichloroethane was investigated. For comparison, extraction studies also were carried out with 18-crown-6 (18C6), benzo-18-crown-6 (B18C6), and dibenzo-18-crown-6 (DB18C6). The extraction data were analyzed by both graphical and theoretical methods that account for aqueous phase complexation with inorganic ligands and all plausible complexes extracted into the organic phase. The results demonstrate that Hg (II) is extracted into dichloroethane as HgCl2.2Crown Ether. The HgCl2.DC18C6 solid complex was prepared and characterized by elemental analysis, and IR (infrared) and H-1-NMR (nuclear magnetic resonance) spectral studies. The possible means of extracting and separating Hg(II) from other metal ions, such as Mg(II), Ca(II), Ba(II), and Fe(III), that are present in the industrial wastes of the chlor-alkali industry is discussed. The potential of the DC18C6 for decontaminating mercury from the brine sludge of a chlor-alkali plant has been assessed.