title: Ultrafine particles derived from mineral processing: A case study of the Pb-Zn sulfide ore with emphasis on lead-bearing colloids.
abstract: Although mining and mineral processing industry is a vast source of heavy metal pollutants, the formation and behavior of micrometer- and nanometer-sized particles and their aqueous colloids entered the environment from the technological media has received insufficient attention to date. Here, the yield and characteristics of ultrafine mineral entities produced by routine grinding of the Pb-Zn sulfide ore (Gorevskoe ore deposit, Russia) were studied using laser diffraction analysis (LDA), dynamic light scattering (DLS) and zeta potential measurement, microscopy, X-ray photoelectron spectroscopy, with most attention given to toxic lead species. It was revealed, in particular, that the fraction of particles less that 1 μm in the ground ore typical reaches 0.4 vol. %. The aquatic particles in supernatants were micrometer size aggregates with increased content of zinc, sulfur, calcium as compared with the bulk ore concentrations. The hydrodynamic diameter of the colloidal species decreased with time, with their zeta potentials remaining about -12 mV. The colloids produced from galena were composed of 20-50 nm PbS nanoparticles associated with lead sulfate and thiosulfate, while the surface oxidation products at precipitated galena were largely lead oxyhydroxides. The size and zeta potential of the lead-bearing colloids decreased with time down to about 100 nm and from -15 mV to -30 mV, respectively. And, conversely, lead sulfide nanoparticles were mobilized before the aggregates during redispersion of the precipitates in fresh portions of water. The potential environmental impact of the metal-bearing colloids, which is due to the large-scale production and relative stability, is discussed.
authors.affiliation: Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036, Russia. Electronic address: yumikh@icct.ru.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Mikhlin
authors.affiliation: Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036, Russia; Siberian Federal University, Svobodny pr. 79, Krasnoyarsk, 660041, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Vorobyev
authors.affiliation: Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Romanchenko
authors.affiliation: Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Karasev
authors.affiliation: Institute of Chemistry and Chemical Technology of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036, Russia.
authors.forename: Anton
authors.initials: A
authors.lastname: Karacharov
authors.affiliation: Siberian Federal University, Svobodny pr. 79, Krasnoyarsk, 660041, Russia; Kirensky Institute of Physics of the Siberian Branch of the Russian Academy of Sciences, Akademgorodok 50/38, Krasnoyarsk, 660036, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Zharkov
mesh_terms: D003102:Colloids; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D008906:Mining; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D010316:Particle Size; D012426:Russia; D013440:Sulfides / Q000032:analysis* / Q000737:chemistry; D013499:Surface Properties; D017967:Zinc Compounds / Q000032:analysis* / Q000737:chemistry
chemical_list: D003102:Colloids; D004785:Environmental Pollutants; D013440:Sulfides; D017967:Zinc Compounds; C018391:lead sulfide; D007854:Lead; C032722:lead sulfate; C031238:zinc sulfide
keywords: Aquatic nanoparticles; Lead sulfide; Lead-zinc ore; Ultrafine particles