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Magnesium-rich gangue dissolution in column bioleaching of chalcopyrite

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Rare Metals 2015年第5期34卷 366-370页

作者： Xue Liu Jian-Kang Wen Biao Wu Shuang Liu national engineering labortory of biohydrometallurgy General Research Institute for Nonferrous Metals

This study is to assess the effect of magnesiumrich gangue dissolution on the ore containing chalcopyrite and carrollite from Democratic Republic of the Congo （DRC）. The ore contains 11.0 wt% magnesium and 2.4 wt% copper. When Mg^2＋ concentration is over 20 g·L^-1 after 2 months in column bioleaching, the redox potential of leachate keeps stable, much less than that when Mg2＋ concentration is below 20 g·L^-1. Meanwhile, the extractions of Cu^2＋ and Co^2＋ from chalcopyrite with carrollite obviously inhibited by Mg^2＋ concentration of over 20 g·L^-1 were investigated. The extraction of cobalt depends on chalcopyrite dissolved in column reactor. The growth and oxidation activity of bacteria are affected by high Mg^2＋ concentration （〉20 g·L^-1） in leachate of column reactor. As the rate of gangue dissolution depends on the amount of sulfuric acid, the decrease of the particle size relates to the increase of the total particle surface area and acid consumption. Therefore, the operation of pre-leaching for magnesium removal is not the most effective and economical way to solve the problem of magnesium-rich gangue minerals dissolution.

关键词： Magnesium-rich Column bioleaching Chalcopyrite Carrollite

Label Recovery and Trajectory Designable Network for Transfer Fault Diagnosis of Machines With Incorrect Annotation

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 932-945页

作者： Bin Yang Yaguo Lei Xiang Li Naipeng Li Asoke K.Nandi the Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System the School of Mechanical EngineeringXi’an Jiaotong UniveristyXi’an 710049 the Hunan Provincial Key labortory of Health Maintenance for Mechanical Equipment Hunan Univeristy of Science and TechnologyXiangtan 411201China the Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniveristyXi’an 710049China the Department of Electronic and Electrical engineering Brunel University LondonUxbridge UB83PHUK

The success of deep transfer learning in fault diagnosis is attributed to the collection of high-quality labeled data from the source ***,in engineering scenarios,achieving such high-quality label annotation is difficult and *** incorrect label annotation produces two negative effects:1)the complex decision boundary of diagnosis models lowers the generalization performance on the target domain,and2)the distribution of target domain samples becomes misaligned with the false-labeled *** overcome these negative effects,this article proposes a solution called the label recovery and trajectory designable network(LRTDN).LRTDN consists of three ***,a residual network with dual classifiers is to learn features from cross-domain ***,an annotation check module is constructed to generate a label anomaly indicator that could modify the abnormal labels of false-labeled samples in the source *** the training of relabeled samples,the complexity of diagnosis model is reduced via semi-supervised ***,the adaptation trajectories are designed for sample distributions across *** ensures that the target domain samples are only adapted with the pure-labeled *** LRTDN is verified by two case studies,in which the diagnosis knowledge of bearings is transferred across different working conditions as well as different yet related *** results show that LRTDN offers a high diagnosis accuracy even in the presence of incorrect annotation.

关键词： Deep transfer learning domain adaptation incorrect label annotation intelligent fault diagnosis rotating machines

Mechanism of Mg2+ dissolution from olivine and serpentine: Implication for bioleaching of high-magnesium nickel sulfide ore at elevated pH

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1069-1079页

作者： Jian-zhi Sun Jian-kang Wen Bo-wei Chen Biao Wu national engineering Laboratory of biohydrometallurgy GRINM Group Corporation Limited

To inhibit the dissolution of Mg^2+ during the bioleaching process of high-magnesium nickel sulfide ore, the effect of major bioleaching factors on the dissolution of Mg^2+ from olivine and serpentine was investigated and kinetics studies were carried out. The results indicated that the dissolution rate-controlling steps are chemical reaction for olivine and internal diffusion for serpentine. The most influential factor on the dissolution of Mg^2+ from olivine and serpentine was temperature, followed by p H and particle size. A novel method of bioleaching at elevated pH was used in the bioleaching of Jinchuan ore. The results showed that elevated pH could significantly reduce the dissolution of Mg^2+ and acid consumption along with slightly influencing the leaching efficiencies of nickel and cobalt. A model was used to explain the leaching behaviors of high-magnesium nickel sulfide ore in different bioleaching systems. The model suggested that olivine will be depleted eventually, whereas serpentine will remain because of the difference in the rate-controlling steps. Bioleaching at elevated pH is a suitable method for treating high-magnesium nickel sulfide ores.

关键词： olivine serpentine high-magnesium nickel sulfide ore bioleaching shrinking core model elevated pH

Dominance of Acidithiobacillus at ore surface of Zijinshan commercial low-grade copper bioleaching heap

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中国有色金属学会会刊：英文版 2008年第6期18卷 1506-1512页

作者：刘兴宇陈勃伟温建康 national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

在 Zijinshan 商业低档铜 bioleaching 堆的矿石表面的微生物引起的社区结构被 16S rRNA 基因克隆图书馆调查。为细菌和 Archaea， 105 克隆被定序。在矿石表面在场的主导的细菌种类是 Acidithiobacillus 和 Leptospirillum，为 51.42% ... 详细信息

在 Zijinshan 商业低档铜 bioleaching 堆的矿石表面的微生物引起的社区结构被 16S rRNA 基因克隆图书馆调查。为细菌和 Archaea， 105 克隆被定序。在矿石表面在场的主导的细菌种类是 Acidithiobacillus 和 Leptospirillum，为 51.42% 和 48.57% 的财务分别地。然而为 Archaea，仅仅一个运作的分类单位(外面) 属于 Ferroplasma acidiphilum。这些结果显示在商业低档铜 bioleaching 堆的类 Acidithiobacillus 的那功能可以被低估。详细说明的更多和微生物引起的社区结构的量的信息现在随着时间的过去在调查下面。

关键词：铜生物多样性生物堆 16S rRNA基因

Feasibility study on heap bioleaching of chalcopyrite

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Rare Metals 2013年第5期32卷 524-531页

作者： Bo-Wei Chen Jian-Kang national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

Bioleaching of chalcopyrite often encountered the formation of passivation layer, which inhibited the leaching process and resulted in a low leaching rate. This inhibitory effect can be eliminated by thermophilic biole- aching. The industrial test of BioCOP technology based on thermophiles was successfully completed, which confirmed the feasibility of chalcopyrite bioleaching. However, industrial leaching rate of chalcopyrite heap bioleaching is lower. This paper described the development status and industrial test of chalcopyrite heap bioleaching technology. The reasons for the lower efficiency of chalcopyrite heap bioleaching were analyzed. The strategies for successful chalcopyrite heap bioleaching were proposed.

关键词： Chalcopyrite Heap bioleaching Thermophiles Pyrite Feasibility

Control of redox potential by oxygen limitation in selective bioleaching of chalcocite and pyrite

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Rare Metals 2014年第5期33卷 622-627页

作者： Biao Wu Jian-Kang Wen Bo-Wei Chen Guo-Cheng Yao Dian-Zuo Wang national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

Based on the bioleaching mechanism and electrochemical studies of metal sulfides, the dissolution rates of chalcocite and pyrite are controlled by redox potentials. Experiment on the bioleaching of chalcocite and pyrite under constant redox potential by sparging with nitrogen gas was demonstrated. By leaching at low and constant redox potential（〈760 mV, vs SHE）, copper recoveries of 90 %–98 % are achieved, which are 10 times more than iron recoveries. The iron-oxidizing bacterial populations are observed to continue to reduce under oxygen limitation conditions, but the Acidithiobacillus that have only sulfur-oxidizing capabilities are an attractive alternative for redox-controlled bioleaching of ***, the described redox control technique might be one of the effective approaches to balance acid and iron in Zijinshan copper bio-heap leaching practice.

关键词： Pyrite Chalcocite Bioleaching Redox potential Oxygen limitation

Sulfuric acid leaching of low-grade refractory tantalum–niobium and associated rare earths minerals in Panxi area of China

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Rare Metals 2015年第3期34卷 202-206页

作者： Biao Wu He Shang Jian-Kang Wen national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

By mineral liberation analyzer （MLA） automated quantitative system, the niobium-tantalum ore in this study was classified as refractory mineral of low-grade which was mainly composed of fergusonite, polycrase, ilmenorutile, and bastnasite. Most of niobium and rare earth metals were dis- seminated in these minerals （particle sizes of 95 % rare earth elements 〈40 μm）, which cannot be concentrated through traditional floatation process and treated by the current hydrofluoric acid leaching in industry application. It is nec- essary to develop a new approach to recovery these valuable metals. In this study, an improved method is proposed to extract these metals, which includes acid roasting and sulfuric acid leaching. The influence of mineralogy, acid concentra- tion, leaching temperature, leaching time, and liquid to solid ratio was experimentally studied. It is observed that after the ground ore （-74 μm） was roasted at 350 ℃ for 2 h with sulfuric acid （18.4 mol.L- 1） in the ore to acid mass ratio of 1：1, and then the roasting residue reacted with 25 % sulfuric acid at 90 ℃ for 2 h, the recovery rate of rare earth elements reaches 〉90 %, and the leaching extent of niobium can reach 84 %.

关键词： Niobium-tantalum Rare earth Refractory Low-grade Roasting Sulfuric acid leaching

Extraction of niobium, yttrium, and cerium from a low-grade niobium-bearing ore by roasting(NH_4)_2SO_4-Na_2SO_4-H_2SO_4 system

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Rare Metals 2014年第6期33卷 754-760页

作者： Wen-Cheng Gao Jian-Kang Wen Biao Wu He Shang national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

A novel process of extracting niobium, yttrium,and cerium from a low-grade niobium-bearing ore by the roasting（NH4）2SO4-Na2SO4-H2SO4 system was experimentally studied. The influences of various factors,such as roasting temperature, roasting time, mass ratio of agents-to-ore and particle size fraction on the extraction of valuable metals were comprehensively investigated. It is found that the roasting Na2SO4-H2SO4 system is effective to extract the niobium, yttrium, and cerium. The obtained optimum conditions for the extraction of Nb, Y, and Ce are roasting temperature of 300 °C, roasting time of 3 h, mass ratio of Na2SO4：H2SO4：Ore of 0.5：1.0：1.0, and particle size fraction of-74 lm（~95 %）. Under the optimum condition, the maximum recovery of Nb, Y, and Ce can reach90.53 %, 92.15 %, and 98.04 %, respectively. All the results generated from this study will provide the fundamentals for Nb, Y, and Ce extraction from a niobiumbearing ore with low-grade.

关键词： Extraction Niobium Yttrium Cerium Lowgrade

Effect of CO_2 and N_2 on microbial community changes during column bioleaching of low-grade high pyrite-bearing chalcocite ore

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Journal of Central South University 2015年第12期22卷 4528-4535页

作者：陈勃伟武彪刘兴宇温建康 national engineering Laboratory of biohydrometallurgy General Research Institute for Nonferrous Metals

Simulated heap bioleaching of low-grade high pyrite-bearing chalcocite ore was conducted at 40 °C with aeration of CO_2 and N_*** samples were collected at day 43,64,85,106 and subjected to microbial community analysis by 16S rRNA gene clone *** analyses of 16S rDNA fragments revealed that the retrieved sequences are mainly related to genus Acidithiobacillus,Leptospirillum and *** of CO_2 and N_2 significantly impacted the microbial community *** CO_2 was aerated,the proportion of genus Acidithiobacillus considerably increased,whereas the proportion of genus Leptospirillum and genus Sulfobacillus ***,with the aeration of N_2,the proportion of genus Acidithiobacillus and Leptospirillum increased,but genus Sulfobacillus *** there was no aeration,the microbial community was similar to the inocula with the proportion of genus Leptospirillum *** results indicated that the limitation of oxygen could change the bioleaching microbial community and the aeration of CO_2 and N_2 was favourable for the growth of sulfur-oxidizer(***) and iron-oxidizer(***) respectively,which could be used for the regulation of microorganisms' role in mineral bioleaching.

关键词： bioleaching CO2 N2 chalcocite pyrite microbial community