Papers by Keyword: Gold Mine

Abstract: In this work we report the metagenome-derived draft genomic sequence of an enrichment culture dominated by A. ferrooxidans obtained from an airlift bioreactor inoculated with the microbial consortium recovered from the “Relave Viejo” tailing. The genome of this culture was assembled de-novo and by reference, generating a consensus assembly of 3.0 Mb. On the basis of 16S rRNA (100 % identity), average nucleotide identity analysis (99.33% identity) and in silico DNA-DNA hybridization against A. ferrooxidans ATCC 23270^T (97.9%), the recovered genome is confirmed to pertain to A. ferrooxidans species. Comparative genomics results are presented to uncover the genetic traits of the variant surviving lime treatment and to further explore the genomic diversity of these model iron oxidizing species.

Abstract: The design and adhibition of a new fashioned portable pneumatic cutting sampling machine used in the sap of the mine which use the compressed air as the source of power is introduced in this article and the problem of inefficient and large labour intensity which exist for a long time in the cutting sampling in the sap of the mine is solved in this article.

Abstract: In order to have a comparative investigation of the pollution and speciation characteristics of heavy metals between the gold and iron mine tailings of the upstream areas of Miyun Reservoir, the tailing samples from the typical gold and iron mines were analyzed. The total metal concentration is determined by acid digestion and the chemical fractionation of metal by the Tessier sequential extraction method. It is found that compared to background values of Beijing, the heavy metal in both gold and iron mine tailings is higher, while the heavy metal in gold mine tailings is higher than that of iron mine tailings, with Mn as an exception. Mercury is the most serious pollution element in gold mine tailings. Results of the sequential extraction suggest that the exchangeable of Cd exhibits the highest percentage of total metal in gold and iron mine tailings（15% and 6.5% of the total metal, respectively) among Cd, Mn, Zn, Cu, Pb, Cr. In the majority of iron mine tailing samples collected, large amounts of Cu were mainly associated with the organic form. The percentage of the bioavailable metals in both gold and iron mine tailing samples follows the order: Cd>Mn>Zn>Cu>Pb>Cr.

Abstract: Based on system modeling, including ore reserves model, mineral processing model and comprehensive technical economic analysis model, the major economic indexes of Cangshang Gold Mine were multi-objective optimized by fuzzy comprehensive evaluation. After optimization, the total profits, gold output and NPV were improved.

Abstract: Submarine mining is unprecedented in China. XinLi Mining area, affiliated to Sanshandao Gold mine, is the first metal mining carrying out submarine mining exploitation in domestic. No occurrence of uniform settlement, cracking and collapse is the key point during the mining exploitation. According to the mining choosing principle and combining the production practice and relevant experience of Sanshandao Gold mine, the representative schemes are put forward. Two representative test stopes of 63# and 71# are chosen. After the comprehensive comparison and analysis, high-drift back-filling method is adopted to research the safety of submarine mining. Industrial test results show that the high-drift back-filling method has the significant advantages of safety mining, low ore dilution and so on. The mining production ability is improved greatly, obtaining remarkable effect and realizing the key points of higher efficiency and lower loss rate of ores.

Abstract: The gold mine discharges tailings massively every day,which results in gold and useful metal draining,simultaneously brings the enormous harm to the environment The approach to comprehensive utilization of tailings of gold mines, including recycle of usable mineral and direct use of ore tailings,is analyzed in the paper, laying a foundation for continuous development of gold mines，comprehensive utilization of resource，and protection of environment.

Abstract: The aim of this review report was to summarize knowledge about arsenic-metabolizing bacteria isolated from Zloty Stok (SW Poland) gold mine and determine their potential role in mobilization of arsenic. Three physiologically different groups of arsenic metabolizing microorganisms (arsenite oxidizers, dissmiliatory arsenate reducers and arsenic resistant microbes) were isolated from the deepest section of Gertruda Adit in Zloty Stok (SW Poland) gold mine. Twenty two strains were isolated from the rock biofilms and seven from arsenic-rich bottom sediments. Analysis of the 16S rRNA gene sequence of isolated bacteria revealed them to be members of the genera: Aeromonas, Arthrobacter, Bacillus, Brevundimonas, Chryseobacterium, Desemzia, Microbacterium, Micrococcus, Paracoccus, Pseudomonas, Rhodococcus, Serratia, Shewanella, Sinorhizobium, Sphingomonas, Stenotrophomonas and Streptomyces. All of the isolated bacteria were resistant to both inorganic arsenic species: arsenate [As(V)] and arsenite [As(III)]. One of the bottom sediments isolates (Sinorhizobium sp. M14) was able to grow on minimal salt medium using arsenite as a source of energy, and was able to release arsenic from arsenopyrite. Two strains (Shewanella sp. O23S and Aeromonas sp. O23A) isolated from bottom sediments were able to grow in the absence of oxygen, by As (V) respiration coupled with lactate oxidation. Based on arsenic metabolic activity of isolated bacteria two different mechanisms of arsenic mobilization from natural minerals (arsenopyrite FeAsS) and secondary ferrous arsenate minerals (scorodite FeAsO4) were proposed.