Ceria, zirconia and mixed cerium-zirconium mesoporous oxides were synthesized and 12 used as supports for sulfur and gold species. The materials were characterised using selected 13 advanced techniques (ICP-OES, elemental analysis, XPS, XRD, N2 adsorption and desorption 14 isotherms, UV-vis, ATR-FTIR, TPR-H2, TG-DTA) which allowed monitoring of the oxidation state 15 of metals (cerium and gold)...

Typomorphic features of placer gold conglomerates the Ortokinskaya formation Early Permian age (P1or) Sololiy Uplift Olenek High and modern channel alluvium Ortoku Eekit river, which drains these deposits, are studied. It is found that extremely heterogeneous composition complex inner structure typical vast majority conglomerates. There several stages different fineness (from 251‰ to 999‰) with...

Abstract The paper comprises new analytical data on the nature and occurrence of gold in solid pyrobitumen, closely associated with main gold-bearing sulfide arsenic ores Bakyrchik deposit (Kazakhstan), related to post-collisional magmatic-hydrothermal origin. Gold mineralization occurs mainly form an “invisible” type structures arsenian pyrite arsenopyrite, gold-organic compounds pyrobitumen c...

Pyrite and arsenopyrite are known to be the most common gold-bearing sulfide minerals in refractory gold ores. Traditionally, these have been first oxidized by roasting, acidic pressure oxidation or bio-oxidation release gold, after which is dissolved subsequent cyanide leaching step. The chloride (chloride-bromide) solution presents an alternative cyanide-free media, able not only leach minera...

Plasmonic metal/semiconductor heterostructures show promise for visible-light-driven photocatalysis. Gold nanorods (AuNRs) semi-coated with TiO2 are expected to be ideally structured systems for hydrogen evolution. Synthesizing such structures by wet-chemistry methods, however, has proved challenging. Here we report the bottom-up synthesis of AuNR/TiO2 nanodumbbells (NDs) with spatially separat...

The enrichment of polymetallic sulfide ore is a complex task. Fine grinding carried out to reveal useful minerals, resulting in the formation microparticles. It difficult achieve floatation microparticles and fine minerals are lost with flotation tailings. problem microparticle can be solved by using air bubbles smaller than 50 µmin for process. Water-air microemulsion (WAME)of frothersolution ...

Gold mining and processing is an activity with large environmental impact due to the low concentration of gold in ore deposits chemical resistance most chemicals. Over 75% leached from ores using cyanide, however less toxic lixiviants have been proposed literature. Thiosulfate one these alternative reagents, but high reagent consumption has slowed acceptance operations. Reducing cost thiosulfat...

We coupled an in situ electrochemical analyzer to a CTD to conduct high-resolution, real-time profiling of redox species across the oxic–anoxic transition zone of the Black Sea water column. Voltammetry was performed using gold–amalgam working electrodes to measure simultaneously soluble oxygen and sulfur species (H2S/HS , S x , S8) at a resolution of greater than one measurement per meter. In ...

This review describes the historical development and current state of metals leaching and sulfide mineral biooxidation by the minerals industries. During the past 20 years commercial processes employing microorganisms for mineral recovery have progressed from rather uncontrolled copper dump leaching to mineral oxidation and leaching in designed bioheaps for oxidation of refractory gold ores and...