Papers by Keyword: Dump

Abstract: Detailed descriptions of the consortia present in commercial mineral processing operations have emerged in recent years, improving our understanding of the biology and the ecology of bioleaching. In spite of this progress, one of the aspects of biomining microbial ecology that remains un-tackled is that of virus-host interactions. The effects of viruses on the dynamics of the bioleaching microbial consortia and their impact in metal recovery is presently unknown. To begin addressing this issue we asked a basic question: ¿Are there viruses in industrial bioleaching econiches In this work, we answer that question experimentally, assessing the number and types of viral particles recovered in the leachates from different industrial settings, using epifluorescence and transmission electron microscopy. Findings emerging from this work point to an almost null presence of viral particles in the leachates from mineral processing operations, possibly due to structural stability issues of the particles in the extreme acidic and highly oxidant conditions favoured by their potential microbial hosts. In turn, DNA-loaded viral-size vesicles of presently unknown function are frequent and abundant in all samples analysed.

Abstract: An extremely alkaline slag dump in Germany was investigated for its mineralogy and colonization with microorganisms. The dump material originated from a metallurgical processing plant for steel production and consisted of a magnetic concentrate of cohenite, metallic iron and magnetite interwoven or associated with various slag related phases such as glasses of variable chemistry, RO-, C2F- and C4AF- phases, and phases originating from the ovens, steel additives, sand and construction fragments. After deposition, reactions in the surface layer generated a number of secondary phases such as gels (NaCO₃-rich or -poor), calcite, mirabilite, natron, and others. To explore the microbiology inside the approximately 15 m high dump, 35 samples were taken over the whole depth range via core drilling. Total cell counts were determined via acridine orange staining and living cells were enumerated on R2 agar plates for heterotrophs. Both methods allowed for the detection of microbial life on the dump surface down to about 1 m depth. In this depth range the pH values were between 8 and 12. Below, microbial life was not detected, most likely because of the high pH values of 12 and the low availability of organic carbon inside the dump. In contrast to all previously studied sulfidic dumps the interior of the alkaline slag dump did not appear to be a habitat for microorganisms.

Abstract: In this paper, xingshan iron mine as an engineering example. Based on slip field theory, numerical simulation method and limit equilibrium method for the mine slope stability research and evaluation. Meanwhile, a variety of load shedding scheme was designed and optimized design. The results showed that the final dump slope angle is 19.2, considering the most unfavorable conditions in saturated with earthquake. And ultimate load shedding scheme can guarantee the slope stability, and saves the load shedding costs is about 20 million yuan. The economic effect is remarkable.

Abstract: In view of the local conditions of Xingshan Iron Mine North Dump, an economically safe load shedding scheme was determined. Based on critical sliding field technology, the most dangerous slip surface can be searched of different waste-dump slope angles. Once the most dangerous slip surface is fixed, limit equilibrium methods can be used to analyze the stability of the slope. The corresponding slope angle of minimum allowable safety coefficient under the most unfavorable condition was defined as the optimal slope angle of this section, and the minimum optimal slope angle of all the sections of dump was determined as the final optimal slope angel of the whole dump. This method was not any practical but also extremely economical, which can ensure the absolute safety of dump and its surroundings.

Abstract: The carbon sequestration of Heidaigou opencast mining area was calculated by using carbon density method based on remote sensing technology, combined field surveys and data measured indoor. Soil bulk density, soil organic matter and other soil properties of the 63 soil samples in the Heidaigou mining area were measured. The results indicated the following conclusions. (1) The carbon sequestration of Heidaigou opencast coal mine area was 4,651,623.30 t in 2010. (2) There was a positive correlation between soil carbon density and the age of land reclamation. (3)After reclamation the carbon sequestration of Heidaigou opencast coal mine increased by 239,748.61 t. So the potential for carbon sequestration is great in this area. The results indicate that the mining area land reclamation can improve soil carbon acquisition capability and maintain the ecological balance of carbon cycle.