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Zhang Y.,Central South University | Wang Y.,Central South University | Li S.,Beijing General Research Institute of Mining And Metallurgy
International Journal of Mining Science and Technology | Year: 2012

The flotation separation of scheelite from fluorite and calcite using dodecyltrimethylammonium chloride (DTAC), dodecyldimethylbenzylammonium chloride (DDBAC), or didodecyldimethylammonium chloride (DDDAC) as the collector has been investigated. The results show that the selectivity of these collectors for these three calcareous minerals falls in the order: DDDAC > DDBAC > DTAC. A significantly different flotation response of scheelite compared to the other two calcareous minerals was observed over the pH range from 7 to 8 for DDDAC as the collector. A concentrate containing 41.40% WO 3 could be produced from a feed mixture containing 23.22% WO 3 at the DDDAC concentration of 4.0 × 10 -4 mol/L. The WO 3 recovery was 92.92% under these conditions. The results of zeta potential measurements suggest that electrostatic interactions are the main forces between DDDAC and the minerals. When the concentration of DDDAC is from 2 × 10 -4 to 4 × 10 -3 mol/L large differences in adsorption density, and adsorption kinetics, of DDDAC onto scheelite, calcite, and fluorite provide desirable conditions for achieving high selectivity. © 2012 Published by Elsevier B.V. on behalf of China University of Mining & Technology.

Li Q.,Beijing General Research Institute of Mining And Metallurgy
Legislation, Technology and Practice of Mine Land Reclamation - Proceedings of the Beijing International Symposium Land Reclamation and Ecological Restoration, LRER 2014 | Year: 2015

At present the heavy metal pollution soil repair technology mainly includes physical methods, chemical methods and biological methods. The physical methods mainly includes soil replacement, soil separation, soil isolation and thermodynamics method. The chemical methods mainly includes chemical fix, soil wash and electrical repair. The biological methods mainly includes plant stable, plant volatile, plant extract, microbial repair and soil animal repair. This paper briefly introduced the principle, advantages and disadvantages, and applicability of each soil repair method. © 2015 Taylor & Francis Group, London.

Xiao Y.,Tsinghua University | Wang H.,Tsinghua University | Xu W.,Tsinghua University | Zhou J.,Beijing General Research Institute of Mining And Metallurgy
Pattern Recognition | Year: 2013

Novelty detection is a one class classification problem, and it builds up the model with only normal samples, based on which the novelty is detected. Though conventional KPCA is an effective method of building one class classification models, it is prone to being affected by the presence of outliers due to its inherent properties of L2 norm. In this paper, we propose a new optimization problem, L1 norm based KPCA, which is robust to outliers. Correspondingly, we present the algorithm and the measure of novelty. The proposed method is applied to novelty detection and performs well on the simulation data sets. © 2012 Elsevier Ltd All rights reserved.

Jiang Y.,Beijing General Research Institute of Mining And Metallurgy
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

As uncertainties inherent factors, such as temperature and wear, always exist during wet multi-disc brake's lifetime, a time-dependent model was established, which incorporating such uncertainties based on stochastic differential equation theory. The time-dependent design method for wet multi-disc brake under such external uncertainties factors was presented. This method takes the braking distance and temperature changes with time into account. It can evaluate dynamic security reliability for wet multi-disc brake products, which reflects the impact of time scale in the design. The brake that can meet the reliability requirements at any time can be designed by the new method, which can provide a reference for dynamic security assessment of brakes reliability.

Qi Z.,University of Science and Technology Beijing | Sun C.-Y.,University of Science and Technology Beijing | Sun C.-Y.,Beijing General Research Institute of Mining And Metallurgy
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2013

This study researches on the flotation behavior and mechanism of dolomite through the experiment of monomineral flotation in the use of fatty acid as collector. Results of flotation tests indicate that the agent dosage is relatively small in acidic environment with myristic acid and lauric acid as collector. When the recovery of dolomite researches 70% with myristic acid and lauric acid as collector, the difference of agent dosage under the condition of alkaline and acidic environment is 3.72 and 5.64 times, respectively. The measuring results show that: under the condition of acidic and alkaline environment, the collector is adsorbed on the surface of mineral. The measuring results of SEM show that a large amount of solid attachment is on the surface of foam product. The study of mechanism shows that the chemisorption mainly wages between collector and dolomite in an alkaline environment. In an acidic environment, the collector which belongs to fatty acid is mainly solid fatty acid which is hard to dissolve, and the solid attachment forms on the surface of mineral, giving rise to draining on the surface of mineral. That makes the dolomite have better floatability in an acidic environment.

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