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Selection of leading industries for coal resource cities based on coupling coordination of industry&
Taking the city of Qitaihe is as an example in order to provide practical methods for the selection of leading industries for coal resource cities,this paper establishes the specific operation scheme for selection of leading industries according to the actual situation of coal resource cities based on the theory of coupling coordination together with the coupling coordination for technological innovation.The results show that the degree for coupling coordination of the technological innovation for each alternative industry differentiates with the development of coal resource cities.For example,the average degree of food processing industry from agricultural produce is 0.9.Therefore,coal resource cities should develop some industries related to coal industry,such as coking industry,some chemical and medicines industry and non-metallic mineral products manufacturing,in the near future,however,some industries with greater market and influence potentials and low carbon emissions should be attached much importance to in the future....
2020-06-12 16:19:08浏览：1435
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The Influence of CO on the Carbon Isotopic Composition of CH4 in Closed Pyrolysis Experiment With Co
A low-mature coal (Ro=0.4%, from the Manjia'er depression, Tarim Basin, China) was subjected to closed system pyrolysis, in sealed gold tubes, under isothermal temperature conditions. The carbon isotopic compositions of the pyrolyst fractions (hydrocarbon, CO2, CO, etc.) at two temperature points (350°C and 550°C) were measured. The results showed that δ13CCH4 value is generally heavier at 350°C than that at 550°C, because the high abundance of CO generated at low temperature would greatly influence δ13CCH4 value, and the retention time of CO in gas chromatograph is close to that of CH4. But CO is formed through chemical reaction of the oxygen-containing functional group C=O, e.g. Lactones, ketones, ether, etc. At low temperature, while CO2 comes mainly from zecarboxylization.The carbon isotopic composition of coal gas from Lanzhou Coal Gas Works was definitely different from that of thermally pyrolysed products from coal. Theδ13CCH4 value of coal gas was abnormally heavier than δ13CCO. At the same time, the reversed sequence (δ13C-1＞δ13C-2) of δ13C1 and δ13C2 happened. The bond energy of free ions generally decides the sequence of generation of hydrocarbon fractions according to the chemical structure, whereas the stability of pyrolysate fractions and their carbon isotope fractionation are affected by the C-C bond energy....
2020-06-12 16:19:07浏览：1435
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Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam
A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law,pointing out the thickness of the conglomerate at different seam mining,and during the destruction and instability of existing state of laws.At 21141 thick seam mining,the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone,formed a stratified and hierarchical down collapse.The shape of caving area is a "triangular block",the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance,while the top layer of thick gravel layer is the overall bending subsidence trend.Tilting the direction of the face,a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance,thus forming a mutual extrusion of articulated block structure.The instability,separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident.This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock,analyzes the stope law of coupling for the pressure burst behavior law for the mining work face,and the choice of preventive measures to provide a theoretical basis and implementation....
2020-06-12 16:19:05浏览：1436
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Comparative study of electrostatic sensors with circular and probe electrodes for velocity measureme
This paper presents recent progress on the velocity measurement of pulverised coal in pneumatic pipelines using electrostatic sensors in combination with correlation signal processing techniques. A comparative study of electrostatic sensors with circular and probe electrodes was conducted on a 94 mm bore horizontal pipeline in a 4 MW furnace. The advantages and limitations of both sensors are discussed. Experimental results demonstrate that both sensors are capable of providing pulverised coal velocity measurement with excellent repeatability and dynamic response....
2020-06-12 16:19:03浏览：1422
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DEVELOPMENT OF COAL DRY BENEFICIATION WITH AIR-DENSE MEDIUM FLUIDIZED BED IN CHINA
In China more than two-thirds of available coal reserves are in arid areas, where, to beneficiate the run-of-mine coal,there is not enough water resource required by conventional processing. Developing efficient dry beneficiation technology is of great significance for efficient coal utilization in China, notably the clean coal technology (CCT). The dry coal beneficiation technology with air-dense medium fluidized bed utilizes air-solid suspension as beneficiating medium whose density is consistent for beneficiation, similar in principle to the wet dense medium beneficiation using liquid-solid suspension as separating medium. The heavy portion in feedstock whose density is higher than the density of the fluidized bed will sink, whereas the lighter portion will float, thus stratifying the feed materials according to their density.In order to obtain efficient dry separation in air-dense medium fluidized bed, stable fluidization with well dispersed micro-bubbles must be achieved to ensure low viscosity and high fluidity. The pure buoyancy of beneficiation materials plays a main role in fluidized bed, and the displaced distribution effect should be restrained. The displaced distribution effects include viscosity displaced distribution effect and movement displaced distribution effect. The former is caused by viscosity of the fluidized bed. It decreases with increasing air flow velocity. Movement displaced distribution effect will be large when air flow rate is too low or too high. If medium particle size distribution and air flow are well controlled, both displaced distribution effects could be controlled effectively. A beneficiation displaced distribution model may be used to optimize beneficiation of feedstock with a wide particle size distribution and multiple components in the fluidized bed. The rheological characteristics of fluidized beds were studied using the falling sphere method. Experimental results indicated that the fluidized bed behaves as a Bingham fluid. The plastic viscosity and yield stress can be obtained by measurement of the terminal settling velocity of spheres and linear regression of the experimental data. Both plastic viscosity and yield stress increase with increasing size of the fluidized particles. The drag coefficient can be calculated with favorable agreement with experimental data.The first dry coal beneficiation plant with air-dense medium fluidized bed was established by CUMT with an output of 320000 t.a-1 and a probable error Ep value up to 0.05 was achieved. The plant was accepted by the Chinese government in June, 1994. Since then, new applications have been found including a 700000 t.a-1 dry coal beneficiation plant put up for commercial testing. To realize coal dry beneficiation of full size range of 300～0 mm, further research on dry coal beneficiation of different size fractions has been under way at the Mineral Processing Research Center of CUMT, leading to the following results:● Dry beneficiation technology with a vibrated air-dense medium fluidized bed for fine coal of size fraction 6～0.5 mm Ash content was reduced from 16.57% to 8.35%, with yield up to 80.20% and Ep value up to 0.065.● Coal dry beneficiation technology with a deep air-dense medium fluidized bed for ＞50 mm coal An Ep value up to 0.02 was achieved. This technology is of great value for waste removal from 300～50 mm large feedstock, especially for big surface mines in China.● Coal triboelectric cleaning technology for ＜1 mm pulverized Coal Coal is comminuted down to 320 mesh (0.043 mm) to fully liberate the embedded minerals, yielding an ultra-low ash coal (less than 2%). Currently a pilot system with triboelectric cleaning has successfully passed technical appraisal.● Three-product beneficiation technology with dual-density fluidized bedThis technology yields three products: clean coal, middling and tailing, with the following typical results: Ep value of 0.06～0.09 for the upper layer with a density of 1.5～1.54 g.cm-3 and Ep value of 0.09～0.11 for the lower layer with density of 1.84～1.9 g.cm-3....
2020-06-12 16:19:00浏览：1438
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Comparison on Non-isothermal Oxidation between Spent Catalytic Cracking Catalysts and Coal
Oxidation of coke deposited on spent catalytic cracking catalysts was compared with that of coal and coal char via the non-isothermal oxidation means, i.e. the thermal-gravimetric analysis (TGA) and the differential thermal analysis (DTA). Oxidation kinetic parameters were further investigated by model-fitting methods. The test results showed that the oxidation of spent catalysts was a quite mild process, while coal and coal char experienced sharp weight loss during oxidation. The temperature for commencement and termination of oxidation increased in the following order: coal...
2020-06-12 16:18:59浏览：1405
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水蒸气对oxy-coal燃烧中NO生成的影响
为了研究H2O对燃料N向NO转化各个阶段的影响，采用可沿程取样的沉降炉反应器，研究了一种烟煤在1273 K温度下，O2/N2、O2/CO2以及O2/CO2/H2O气氛下燃烧的燃尽与NO生成的情况。并通过在停留时间为0.2、0.3、0.5、1.1 s与O2浓度为5%、21%及30%情况下的实验来研究H2O对NO生成的影响。实验结果表明，相对于O2/CO2气氛，H2O的添加抑制了NO的生成，且该影响主要集中在燃烧初期挥发分N的氧化过程。随着O2浓度的增加，H2O添加对oxy-coal燃烧方式下NO生成影响加大。...
2020-06-12 16:18:56浏览：1407
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Supported liquid membrane extraction to treat coal gasification wastewater containing high concentra
The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium hydroxide solution as the stripping agent and PVDF as the membrane material.Factors having strong impact on the extraction efficiency were studied in detail,including the mass transfer mode,twophase flow rate,stripping phase concentration.As extraction system with 20％ TBP-kerosene,parallel flow mass transfer,stripping phase concentration 0.1 mol/L,the optimal operating conditions could be obtained.Under the optimum operating conditions,the time required to reach equilibrium for the extraction is 50 min,and extraction efficiency of phenol is 86.2％ and the phenol concentration of effluent is 98.64 mg/L....
2020-06-12 16:18:54浏览：1411
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Modularized dry coal beneficiation technique based on gas-solid fluidized bed
A 40-60 t/h modularized dry coal beneficiation process with a novel method to control the bed was designed around a gas-solid fluidized bed separator. Furthermore, the hydrodynamics of medium-solids consisting of wide-size-range magnetite powder (0.3-0.06 mm) and...
2020-06-12 16:18:54浏览：1398
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An analytic solution describing the visco-elastic deformation of coal pillars in room and pillar min
Coal pillar deformation is typically nonlinear and time-dependent.The accurate prediction of this deformation has a vital importance for the successful implementation of mining techniques.These methods have proven very important as a way to excavate coal resources from under buildings,railways,or water bodies.Elastic and visco-elastic theory are employed with a Maxwell model to formulate an analytic solution for displacement of coal pillars in room and pillar mine.These results show that the visco-elastic solution adequately predicts the coal pillar deformation over time.We conclude that the visco-elastic solution can predict the coal pillar and roadway displacement from the measured geological parameters of the conditions in situ.Furthermore,this method would be useful for mine design,coal pillar support optimization,ground subsidence prediction,and coal pillar stability analysis....
2020-06-12 16:18:52浏览：1437
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Vertical variation of trace elements and its relation to the water-bearing capacity of Ordovician st
We tested for fourteen trace elements in samples collected from the Ordovician strata in Datun coal field. The vertical concentration variation of these trace elements is reported. The relationship of the variation to the water-beating capacity of the Ordovician strata is discussed. The minimum concentration of eleven (of 14 total) trace elements appears in the lower Majiagou formation. The maximum concentrations mainly appear in the Badou and Jiawang formations: eight maxima are located in Badou and four more are in Jiawang. The study of karst development and the water-bearing capacity of Ordovician strata shows that karst is well developed in the Majiagou formation and there is a consequent high water-beating capacity in this formation: Badou and Jiawang formations are contrary to this situation. The results illustrate that the minimum concentrations of most trace elements within certain Ordovician formations can be taken as strong evidence for the existence of a well developed karst and a high wa-ter-bearing capacity....
2020-06-12 16:18:50浏览：1420
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The characteristic curve of methane adsorbed on coal and its role in the coalbed methane storage res
Based on the adsorption potential theory, this paper processes and analyzes the isothermal adsorption data at different temperatures of four coal samples with different ranks. The research results indicate that the adsorption characteristic curve of methane adsorbed on the coal sample is a single curve, and the mathematical expression of the methane adsorption capacity, temperature and pressure is achieved from the characteristic curve. According to the calculating routine and method presented, the adsorption capacity at other equilibrium conditions can be calculated from the adsorption data of one temperature. The results of this paper are a significant contribution to the research on the storage mechanism of the coalbed methane....
2020-06-12 16:18:49浏览：1449
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Non-harmonious deformation controlling of gob-side entry in thin coal seam under dynamic pressure
The behavior of gob-side entry under dynamic pressure is totally different from the one driven after the movement of overlying strata above the adjacent coalface goaf. The gob-side entry will experience severe roof lateral structural adjustments caused by adjacent coalface mining. Thus the deformation and failure characteristics of narrow coal pillar along the gob should be carefully considered. On the basis of the data of the gob-side entry obtained in a thin coal seam under dynamic pressure, the measures to reinforce the narrow coal pillar are put forward. In addition, the non-harmonious controlling of the rock structures and non-equilibrium gob-side entry deformation is proposed to avoid potential failure. Field practices show that the supporting problems of the gob-side entry under dynamic pressure can be well addressed, which could be used in other similar mining cases....
2020-06-12 16:18:49浏览：1424
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Influence of liquid water on coalbed methane adsorption: An experimental research on coal reservoirs
Using Isothermal Adsorption/Desorption System Model IS-100 and Electrohydraulic Servo Rock System Model MTS815 as the main apparatuses and collecting samples from the major coal reservoirs in the south of Qinshui Basin, a hot point region of coalbed methane exploration, the paper carries out systematical comparisons of the isothermal adsorption experimental data for injection water coal sampies, equilibrium moisture samples and dry coal samples,probes and establishes an experimental method of injection water coal sample preparation and isothermal experiment to simulate real reservoir conditions, and then summaries the experimental regulations and discusses the mechanism of liquid water influencing coal methane adsorption. Results of the experiment indicate that: The Langmuir volume of injection water coal samples is notably larger than that of equilibrium moisture samples, as well as larger than or equivalent to that of dry coal samples; the Langmuir pressure of injection water coal samples is the highest, the next is equilibrium moisture samples, while the dry samples is the lowest, of which the experimental results of injection water samples to simulate real reservoir conditions are more close to the fact.Under the conditions of in-position reservoirs, liquid water in coals has evident influence on methane adsorption ability of coal matrix, which can increase the adsorbability of coal and make the adsorption regulation fit to Langmuir model better.Its major reason is the increase of wetting coal matrix adsorbability. The above experimental results overthrow the conventional cognition that liquid water has no influence on coalbed methane adsorption, which may lead to an improvement of the coalbed methane isothermal adsorption experimental method and of the reliability of coalbed methane resource evaluation and prediction....
2020-06-12 16:18:48浏览：1407
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Failure characteristics of surface vertical wells for relieved coal gas and their influencing factor
Based on data from through-hole and logging, we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors. The results show that the damaged positions of drainage wells are mainly located at the thick clay layer in the low alluvium and the lithological interface in the upper section of bedrock in west mining area. The failure depth of casing is 244-670 m and concentrates at about 270-460 m deep. These damaged positions are mainly located in the bending zone according to three zones of rock layers in the vertical section above the roof divided. Generally, the casing begins to deform or damage before the face line about 30-150 m. Special formation structure and rock mass properties are the direct causes of the casing failure, high mining height and fast advancing speed are fundamental reasons for rock mass damage. However, the borehole configuration and spacing to the casing failure are not very clear....
2020-06-12 16:18:47浏览：1395
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