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Yunsen W.,Northeastern University China | Shuai X.,Northeastern University China | Yuexia Z.,Bureau of Geology and Mineral Exploration
Journal of the Balkan Tribological Association | Year: 2015

It is well known that ordinary filling materials have some difficulties in roof contact. As a result, this paper proposed a novel method that addition of a foaming agent into filling slurry led to foaming expansion of the filling slurry through chemical reaction, thus achieving roof contact. The filling material was prepared by mix ordinary portland cement, mine tailings and hydrogen peroxide in a certain ratio. Its basic physical properties, structure, slump, swelling and mechanical properties were characterised. The results show that the slump of the filling slurry increases with concentration decreasing. At 67 ' 73% solid concentration, the slurry flow ability is best. The presence of a small amount of hydrogen peroxide can effectively prevent the slurry settlement and increase bleeding. The slurry expansion rate is positively correlated with addition amount of hydrogen peroxide. In the absence of hydrogen peroxide, the slurry bleeding rate gradually decreases with concentration increasing. However, the residual water in the filling body due to the existence of porosity lowers its strength. Therefore, the content of the cement- sand in a predetermined ratio is desired to be as high as practical to enhance the slurry strength. Source

Han T.,Chinese Academy of science | Zhu X.,Chinese Academy of science | Li K.,Bureau of Geology and Mineral Exploration | Jiang L.,Bureau of Geology and Mineral Exploration | And 3 more authors.
Ore Geology Reviews | Year: 2015

Total organic carbon content (TOC), trace element and platinum-group element (PGE) concentrations were determined in the black shales of the Lower Cambrian Niutitang Formation in the Nayong area, Guizhou Province, South China, in order to study the polymetallic Ni-Mo-PGE mineralization. The results demonstrate that numerous elements are enriched in the polymetallic ores compared to those of the nearby black shale, particularly Ni, Mo, Zn, TOC and total PGE, which can reach up to 7.03. wt.%, 8.49. wt.%, 11.7. wt.%, 11.5. wt.% and 943. ppb, respectively. The elemental enrichment distribution patterns are similar to those in the Zunyi and Zhangjiajie areas except that the Nayong location is exceptionally enriched in Zn. Whereas positive correlations are observed between the ore elements of the polymetallic ores, no such correlations are observed in the black shale. These positively correlated metallic elements are classified into three groups: Co-Ni-Cu-PGE, Zn-Cd-Pb and Mo-Tl-TOC. The geological and geochemical features of these elements suggest that Proterozoic and Early Palaeozoic mafic and ultramafic rocks, dolomites and/or Pb-Zn deposits of the Neoproterozoic Dengying Formation and seawater could be the principal sources for Co-Ni-Cu-PGE, Zn-Cd-Pb, and Mo-Tl-TOC, respectively. Furthermore, the chondrite-normalized patterns of PGEs with Pd/Pt, Pd/Ir and Pt/Ir indicate that PGE enrichment of the polymetallic ores is most likely related to hydrothermal processes associated with the mafic rocks. In contrast, PGE enrichment in the black shale resembles that of the marine oil shale with terrigenous and seawater contributions. Our investigations of TOC, trace elements and PGE geochemistry suggest that multiple sources along with submarine hydrothermal and biological contributions might be responsible for the formation of the polymetallic Ni-Mo-PGE mineralization in the black shales of the Lower Cambrian Niutitang Formation across southern China. © 2014 Elsevier B.V. Source

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