title: Stabilizing conditions of metal mercury in mercury sulfurization using a planetary ball mill.
abstract: This study used a non-heating process to stabilize mercury by mercury sulfurization. Elemental mercury and sulfur were mixed using planetary ball milling under various experimental conditions and the optimal conditions were determined. The labile intermediate, mercury sulfide, was observed in the early stages of milling, and the intermediates were then pulverized into mercury sulfide powder. These phenomena were significantly influenced by the diameter of the planetary ball. A larger diameter enhanced mercury stabilization. For a ball with a 19.04-mm diameter, the toxicity characteristic leaching procedure (TCLP) and the Japanese leaching test (JLT) values were 0.263μg/L and 0.0586μg/L, respectively, suggesting that mercury leachability was strictly controlled. When the molar ratio of sulfur to mercury was 1.05, the mercury concentration in the headspace was <1μg/Nm(3) at 20°C, which was equivalent to the level in pure reagent. The stability of the planetary ball milling product at optimum conditions was either comparable or superior to that in other stabilization techniques. The running cost of this technology was estimated to be 15,360Yen (154USD)/ton-Hg. This stabilization technology is cost-effective and environmentally sound for the long-term and safe management of mercury.
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Naomichi
authors.initials: N
authors.lastname: Fukuda
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Global Ecology, Graduate School of Global Environmental Studies, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan. Electronic address: takaoka.masaki.4w@kyoto-u.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takaoka
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan; Department of Global Ecology, Graduate School of Global Environmental Studies, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Oshita
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D008628:Mercury / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy; D014961:X-Ray Diffraction
chemical_list: D013455:Sulfur; D008628:Mercury
keywords: Intermediate; Mercury sulfide; Planetary ball mill; Stabilization