Copper Recovery from Water of Soryinskoye Tailing Pond

The large volume of recycling waters from the Soryinskoye tailing pond (up to 1300 m3/h) offers interesting possibilities for processing concentrates despite the low copper content (5.2-16.4 mg/l). Sulfides precipitation is the most efficient method of heavy metal ions removal from water. In this study, a sulfur solution in sodium hydroxide was used as a sulfidizing agent for precipitation. Commercial liquid alkali (NaOH – 46) and commercial sulfur were the initial agents. Due to the concentrated alkali, dissolution could be carried out at 115-120∘С, which is higher than the melting point of sulfur. Stable solutions were obtained at a weight ratio of NaOH: S = 1: 1 and a sulfur concentration of 350 g/l. During the laboratory and scale-up laboratory tests, the optimal consumption of sulfidizing agent was determined (110% of the stoichiometry for the formation of Cu2S, and copper extraction into the precipitate from the solution was more than 90.0% with high selectivity towards Zn and Fe). An extended analysis of the composition of the sediment (x-ray fluorescence spectrometer SPECTRO XEPOS) obtained during pilot trials showed that the main elements are, %: sulfur 58.4; oxygen 16.2; copper 8.9; iron 5.7; calcium 4.7 and arsenic 3.8. The total fraction of impurity elements does not exceed 2.3%. This study assumes use of the product conditioning to obtain concentrate with increased copper content and sulfur return to sulfidation stage. Keywords: acid mine drainage, copper recovery, chemical treatment, sulfide precipitation

Тепловое расширение ограниченных полупроводниковых твердых растворов Ag-=SUB=-x-=/SUB=-Pb-=SUB=-1-x-=/SUB=-S

Single-phase powders of AgxPb1-xS cubic solid solutions with a maximum relative silver content up to x = 0.12 were synthesized from aqueous solutions of lead acetate and silver nitrate in the presence of a sulfidizing agent, complexing and stabilizing agents. Thermal expansion of synthesized semiconductor solid solutions AgxPb1-xS was measured for the first time by dilatometry in the temperature range of 295-580 K. It is shown that the replacement of lead atoms by silver atoms in AgxPb1-xS leads to a small decrease in the thermal expansion coefficient associated with a change in the anharmonicity of atomic oscillations.

Influence of Flotation Reagents on Utilization of Complex and Refractory Lead Oxide Ores

The study aimed to explore appropriate flotation reagents to utilize lead minerals from complex and refractory lead oxide ores in Yunnan. Based on the research on the properties of the material, the reagent regime was investigated and a technological flowsheet consisting of one roughing flotation, two scavenging flotation and two concentrate flotation was adopted to perform the closed circuit flotation experiment. The optimum regulator of flotation experiment was determined as sodium silicate, sulfidizing agent as Na2S and collector as isoamyl xanthogenate. Under such a condition of reagent types and their appropriate reagent dosages, a lead recovery of 76.55% with a concentrate grade of 58.67% was obtained, which effectively improved utilization of lead resource.