从《三矿》看社会现实类纪录片映照现实的三个维度

纪录片如何在有限的篇幅中映照出一个复杂的、隐蔽的、行进中的现实?纪录片《三矿》以有百年历史的阳煤集团三矿即将关井为时间节点,以三位采煤队长为人物主线,展现了煤矿工人的个体命运与传统工业面临转型的大时代背景。本文通过对《三矿》的分析,从人、社会、历史三个维度,揭示纪录片是如何映照现实的,并得出结论:社会现实类纪录片以纪实的手段洞见人性的光芒、照见社会的边缘、见证时代的变迁,进而实现以影像映照现实的功能。

建构、感召、突破:纪录片《三矿》的影像塑造

纪录片《三矿》讲述了拥有111年历史、曾经产量庞大的阳煤集团三矿进入关井倒计时后怎样转型,6000多名矿工如何安置的故事。本文以蒙太奇和接受美学为理论支撑,探析纪录片《三矿》的叙事主题、情感表征、影像塑造与样态创新。纪录片《三矿》按大小时间顺序,搭建了整体影片框架,并利用平行蒙太奇等表现手段烘托情绪、营造情感氛围,让观众不仅感受到一座百年老矿风雨沧桑的历史,同时也领略了煤矿工人不畏艰险的硬骨头风采。同时,本片大量采用无声源音乐、意象性镜头以及跌宕起伏的叙事结构“召唤”观众进入自身叙事体系,带领观众体验纪录片的光影世界。纪录片《三矿》在满足受众“期待视野”的同时,着力突破以往传统主流纪录片的叙事方式,不为是传统主流纪录片样态的一次有益创新尝试。

Thermodynamics study on leaching process of gibbsitic bauxite by hydrochloric acid

For the low-grade gibbsitic bauxite,the leaching rate of alumina is very low during the Bayer process.The acid leaching method is attracting more attention,and the hydrochloric acid leaching was developed rapidly.The mineral composition and chemical composition were investigated by X-ray diffraction analysis and semi-quantitative analysis.The thermodynamics of leaching process was analyzed.The results show that the major minerals in the bauxite are gibbsite,secondly goethite and quartz,anatase and so on.The acid leaching reactions of the bauxite would be thermodynamically easy and completed.Under the conditions that ore granularity is less than-55 μm,the L/S ratio is 100：7,and the leaching temperature is 373-383 K,the leaching time is 120 min and the concentration of HCl is 10%,both the leaching rates of Al and Fe are over 95%.The main composition of leaching slag is SiO2 which is easy for comprehensive utilization.

Non-isothermal thermal decomposition kinetics of high iron gibbsite ore based on Popescu method

The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most probable thermal decomposition mechanism is the three-dimensional diffusion model of Jander equation,and the mechanism code is D3.The activation energy and pre-exponential factor for thermal decomposition of high iron gibbsite ore calculated by the Popescu method are 75.36 kJ/mol and 1.51×10-5 s-（-1）,respectively.The correctness of the obtained mechanism function is validated by the activation energy acquired by the iso-conversional method.Popescu method is a rational and reliable method for the analysis of the thermal decomposition mechanism of high iron gibbsite ore.

3D electrical structure of porphyry copper deposit:A case study of Shaxi copper deposit

Located in Lu-Zong ore concentration area, middle-lower Yangtze metallogenic belt, ShaXi porphyry copper deposit is a typical hydrothermal deposit. To investigate the distribution of deep ore bodies and spatial characteristics of host structures, an AMT survey was conducted in mining area. Eighteen pseudo-2D resistivity sections were constructed through careful processing and inversion. These sections clearly show resistivity difference between the Silurian sandstones formation and quartz diorite porphyry and this porphyry copper formation was controlled by the highly resistive anticlines. Using 3D block Kxiging interpolation method and 3D visualization techniques, we constructed a detailed 3D resistivity model of quartz diorite porphyry which shows the shape and spatial distribution of deep ore bodies. This case study can serve as a good example for future ore prospecting in and around this mining area.

3D characterization and analysis of pore structure of packed ore particle beds based on computed tomography images

Methods and procedures of three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography was applied to deriving the cross-sectional images of specimens with single particle size of 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 ram. Based on the in-house developed 3D image analysis programs using Matlab, the volume porosity, pore size distribution and degree of connectivity were calculated and analyzed in detail. The results indicate that the volume porosity, the mean diameter of pores and the effective pore size （d50） increase with the increasing of particle size. Lognormal distribution or Gauss distribution is mostly suitable to model the pore size distribution. The degree of connectivity investigated on the basis of cluster-labeling algorithm also increases with increasing the particle size approximately.

Enrichment of ferric iron on mineral surface during bioleaching of chalcopyrite

In order to investigate the enrichment of ferric iron bound by extracellular polymeric substance （EPS） on the mineral surface during bioleaching of chalcopyrite, several methods including sonication, heating and vortexing were used and sonication at 48℃ was shown as a good way to extract ferric iron. Scanning electron microscope （SEM） and energy dispersive X-ray spectrometer （EDX） analysis showed that lots of cracks and pits can be found on the chalcopyrite surface after bioleaching and that iron oxide was filled in these cracks and pits. The variations of contents of ferric iron and EPS on the chalcopyrite surface were investigated. The results indicated that the content of EPS increased rapidly in the first 10 d and then maintained at a stable level, while ferric iron content increased all the time, especially in the later stage of bioleaching.

On 3D Geo-visualization of a Mine Surface Plant and Mine Roadway

Constructing the 3D virtual scene of a coal mine is the objective requirement for modernizing and processing information on coal mining production. It is also the key technology to establish a ＂digital mine＂. By exploring current worldwide research, software and hardware tools and application demands, combined with the case study site （the Dazhuang mine of Pingdingshan coal group）, an approach for 3D geo-visualization of a mine surface plant and mine roadway is deeply discussed. In this study, the rapid modeling method for a large range virtual scene based on Arc/Info and SiteBuilder3D is studied, and automatic generation of a 3D scene from a 2D scene is realized. Such an automatic method which can convert mine roadway systems from 2D to 3D is realized for the Dazhuang mine. Some relevant application questions are studied, including attribute query, coordinate query, distance measure, collision detection and the dynamic interaction between 2D and 3D virtual scenes in the virtual scene of a mine surface plant and mine roadway. A prototype system is designed and developed.

Study of 3-D Numerical Simulation for Gas Transfer in the Goaf of the Coal Mining

In order to simulate field distribution rules,mathematical models for 3-D air flows and gas transfer in the goaf of the coal mining are established,based on theories of permeability and dynamic dispersion through porous media. A gas dispersion equation in a 3-D field is calculated by use of numerical method on a weighted upstream multi-element balance. Based on data of an example with a U type ventilation mode,surface charts of air pressure distribution and gas concentration are drawn by Graphtool software. Finally,a comparison between actually measured results in the model test and the numerical simulation results is made to proves the numerical implementation feasible.

Research on microseismic activity rules in Sanhejian Coal Mine

By the microseismic (MS) monitoring system of Sanhejian Coal Mine,the detail MS activity rules in the entire mining process of 9202 strong rockburst working face were studied,following main conclusions were obtained.(1) The strong correlation between MS activity and the region stress gradient was revealed.The higher the region stress gradient, the stronger the MS signal is,and the frequency-spectrum moves to lower frequency band the amplitude begins to add gradually.(2) The different types of MS signals have the cor- responding frequency-spectrum character.Such as relieve-shot MS signal shows the wide frequency-spectrum,multi-peak high frequency character,while rockburst omen signal shows the low frequency and amplitude,the mainshock signal has relatively higher fre- quency and amplitude.(3) To monitor and recognize rockburst dangerous region,the strong consistence between the MS signal intensity and the amplitude of electromagnetic emission (EME) signal and drilling bits measured was observed.On above,the weakening and controlling technology of MS intensity was put forward.

Electrogenerative leaching of nickel sulfide concentrate with ferric chloride

In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduced to investigate FeCl3 leaching of nickel sulfide concentrate. Some factors influencing the electrogenerative leaching, such as electrode structure, temperature and solution concentration were studied. The results show that a certain quantity of electrical energy accompanied with the leached products can be acquired in the electrogenerative leaching process. The output current and power increase with the addition of acetylene black to the electrode. Varying the components of electrode just affects the polarization degree of anode. Increasing FeCl3 concentration results in a sharp increase in the output of the leaching cell when c（FeCl3） is less than 0.1 mol/L. The optimum value of NaCl concentration for electrogenerative leaching nickel sulfide concentrate with FeCl3 is 3.0 mol/L. Temperature influences electrogenerative leaching by affecting anodic and cathodic polarization simultaneously. The apparent activation energy is determined to be 34.63 kJ/mol in the range of 298 K to 322 K. The leaching rate of Ni2+ is 29.3% after FeCl3 electrogenerative leaching of nickel sulfide concentrate for 620 min with a filter bag electrode.

Directional hydraulic fracturing to control hard-roof rockburst in coal mines

Hard roof is the main factor that induces rock-burst.In view of the present obvious weakness of control measures for hard roof rockburst in domestic collieries,the mechanism and field application of directional hydraulic fracturing technology for rock-burst prevention have been investigated in this paper using theoretical analysis and numerical simulation.The results show that the weighting span of the main roof and the released kinetic energy as well as the total elastic energy decreased greatly after the directional fracturing of hard roof with the mining progression,thereby reducing the rockburst hazard degree to coal body.The directional hydraulic fracturing technology was carried out in 6305 working face of Jisan Coal Mine to prevent rockburst.Field practices have proved that this technology is much simpler and safer to operate with better prevention effect compared with blasting.By optimizing the operation procedures and developing a new technology of automated high-pressure delivery pipe,the maximum fracturing radius now reaches more than 9 m and the borehole depth exceeds 20 m.Additionally,drilling cutting method was applied to monitor the stress of the coal mass before and after the fracturing,and the drill cuttings dropped significantly which indicates that the burst prevention effect of directional hydraulic fracturing technology is very remarkable.The research results of this paper have laid a theoretical and practical foundation for the widespread application of the directional hydraulic fracturing technology in China.

Mineral distributions in surface sediments of the western South Yellow Sea:implications for sediment provenance and transportation

The South Yellow Sea(SYS) is strongly influenced by the substantial sediment loads of the Huanghe(Yellow)(including the modern Huanghe and abandoned old Huanghe subaqueous delta) and Changjiang(Yangtze) Rivers. However,the dispersal patterns of these sediments,especially in the western SYS,have not been clearly illustrated. In this study,we have analyzed clay minerals,detrital minerals,and grain sizes for 245 surface sediment samples(0–5 cm) collected from the western SYS. The clay minerals,on average,consist of 67% illite,14% smectite,11% chlorite,and 8% kaolinite. Clay minerals,detrital minerals,and grain size analyses of surface sediments,combined with water mass hydrology analysis,reveal that sediments in the western SYS are mainly derived from the modern Huanghe River,the abandoned subaqueous delta of the old Huanghe River,some material from the Changjiang,and coastal erosion. The clay minerals(especially illite and smectite) and quartz/feldspar ratio distribution patterns,reveal that the influence of modern Huanghe sediments can reach 35°N in the northwestern part of the study area,an influence that can be enhanced especially in winter owing to northerly winds. Conversely,sediments along the Jiangsu coast are mixed,in summer,with material from the Changjiang arriving via northward flow of Changjiang Diluted Water. The Subei Coastal Current carries the refreshed sediments northward into the western SYS. Sediment distribution and transport in the western SYS are mainly controlled by the oceanic circulation system that is primarily related to the monsoon.

Designing an optimal stope layout for underground mining based on a heuristic algorithm

An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in underground mine planning practice.However,the computational complexity in developing an optimal stope layout has been a reason for limited availability of the algorithms offering solution to this problem.This article shares a new and efficient heuristic algorithm that considers a three-dimensional ore body model as an input,maximizes the economic value,and satisfies the physical mining and geotechnical constraints for generating an optimal stope layout.An implementation at a copper deposit demonstrates the applicability and robustness of the algorithm.A parallel processing based modification improving the performance of the original algorithm in terms of enormous computational time saving is also presented.

Research on dynamic updating of three dimensional geological modeling based on the OO-Solid model

The dynamic updating of the model included: the change of space border,addi- tion and reduction of spatial component (disappearing,dividing and merging),the change of the topological relationship and synchronous dynamic updating of database.Firstly, arming at the deficiency of OO-Solid model in the aspect of dynamic updating,modeling primitives of OO-Solid model were modified.And then the algorithms of dynamic updating of 3D geological model with the node data,line data or surface data change were dis- cussed.The core algorithms was done by establishing space index,following the way of facing the object from bottom to top,namely the dynamic updating from the node to arc, and then to polygon,then to the face of the component and finally to the geological object. The research has important theoretical and practical values in the field of three dimen- sional geological modeling and is significant in the field of mineral resources.

Large power analysis of switched reluctance machine system for coal mine

The conventional structures in the Switched Reluctance machines are introduced, such as three-phase 12/8 structure Switched Reluctance machine, three-phase 6/4 structure Switched Reluctance machine, four-phase 16/12 structure Switched Reluctance machine, and four-phase 8/6 structure Switched Reluctance machine. Three-phase 12/8 structure Switched Reluctance machine is the best choice for the large power Switched Reluctance machine system in coal mines. The asymmetric bridge power converter main circuit and the bifilar winding power converter main circuit are also introduced. Three-phase asymmetric bridge power converter main circuit is the best choice for the large power Switched Reluctance machine system in coal mines. The magnetic paths of the designed large power motor are given with one phase excitation and double phases excitation. The phase current waveforms are also given.

Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants

Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Datun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the special natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants.

Bubble size measurement in three-phase system using photograph technology

A special experiment setup was designed to observe the interaction between bubbles and particle in flotation cell and to analyze the bubble characteristics such as bubble size, distribution and bubble-loading efficiency. Bubbles in water-gas system and three-phase system were measured. The results indicate that with the current setup the bubbles as small as 10 μm can be easily distinguished. The average size of the bubbles generated under the given conditions in two-phase system is 410 μm at frother concentration of 0.004%, which is in good correspondence with the results of other works. The effect of frother on bubble size was probed. Increasing frother concentration from 0 to 0.004% causes a reduction of bubble size from 700 to 400 μm. The bubble loading efficiency was reported. The result indicates that the fine particle is more easily entrapped than the coarse particle. Some factors, which have effect on measurement accuracy were discussed. The aeration speed has a significant effect on the accuracy of results, if it surpasses 30 mL/s, and the image becomes unclear due to the entrapment of fine particle. Another factor, which can affect observing results, is the sampling position. At a wrong sampling position, the images become unclear.

Enrichment and separation of iron minerals in gibbsitic bauxite residue based on reductive Bayer digestion

The mineralogical characteristics of three kinds of gibbsitic high-iron bauxite and the effects of various digestion conditions on the enrichment and separation of iron minerals were investigated. The results show that adding an appropriate organic reductant such as glycerol can promote the digestion of concomitant diaspore, boehmite and alumogoethite as well as the conversion of goethite to hematite in the reductive Bayer digestion. Processing Bauxite A with A/S of 25.41 can directly produce qualified iron concentrates(TFe>56%) by the reductive Bayer digestion, and thus realize the zero red mud discharge. For Bauxite B and Bauxite C with A/S of 7.82 and 3.35, the iron recoveries of 65.13% and 79.13% can be achieved with the corresponding TFe of 52.05% and 50.16% in the iron concentrates by gravity separation, respectively, resulting in the red mud discharge reduction of ~50% or above.

Neural adaptive PSD decoupling controller and its application in three-phase electrode adjusting system of submerged arc furnace

Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting.