矿业科学学报

Evaluation of the hydrocarbon generation and hydrocarbon expulsion characteristics of coal-measure source rock in Shisanjianfang area,Tuha Basin

Wu Zhiyuan, Peng Suping, Du Wenfeng

2016, 1(2): 103-112.

Abstract(704) PDF(386)

Abstract:
The organic matter type,abundance of organic matter and maturity of organic matter of hydrocarbon of Shuixigou formation in Shisanjianfang area had been evaluated through the geochemical test data.A hydrocarbon expulsion mode of the study area has been established by hydrocarbon-generated potential method, and the hydrocarbon expulsion characteristics has been determined.The result show that, the northwest of the study area with the thick source rock, the thickness between 350-600m,the average is 480m.Higher abundance of organic matter and the thermal evolution stage is between maturation to high maturation, the organic matter types mainly for class Ⅱ and Ⅲ, has a certain hydrocarbongenerating potential.The expulsion threshold depth of coal petrography in the Shuixigou Ground of the study area is 2000m, and the biggest hydrocarbon expulsion rate is 530mg/g.In the 2500m, quickly reaching the peak of hydrocarbon expulsion, and the biggest hydrocarbon expulsion rate is 150mg/(g·hm).The expulsion threshold depth of coaly mudstones in the Shuixigou Ground of the study area is 2200m, and the biggest hydrocarbon expulsion rate is 320mg/g.In the 2800m, quickly reaching the peak of hydrocarbon expulsion, indicating that the study area has certain exploration potential.These research results have certain reference significance of the hydrocarbon expulsion study for the area which has the similar geological conditions.

Deformation monitoring of the Daguangbao landslide with time series InSAR technique

Chen Lei, Zhao Xuesheng, Tang Yixian, Zhang Hong

2016, 1(2): 113-119.

Abstract(863) PDF(479)

Abstract:
The Daguangbao landslide is located in the Gaochuan village,Anxian county in the Sichuan province,China.It is the largest coseismic landslide triggered by the Ms 8.0 Wenchuan earthquake on May 12，2008 and it caused enormous human casualties and property damage.The time series InSAR technique is utilized to retrieve the deformation characteristics of the landslide to monitor the displacement and disasters warning.In order to get the deformation and deformation rate,eleven scenes of radar images collected from Radarsat-2 satellite between 2014 and 2015 and one pair of TanDEM bi-static images are used to obtain the time series values in the study.The study shows that the landslide is in a state of dynamic balance during the observation period,and its tiny deformation is induced by precipitation and earthquakes happened around the landslide.Therefore the landslide will not cause big geological disasters.

Impact of underground coal mining on land ecology and its restoration in windy and sandy region

Hu Zhenqi, Chen Chao

2016, 1(2): 120-130.

Abstract(937) PDF(529)

Abstract:
The energy “Golden Triangle” region,most part of which locates in windy and sandy region,has been playing an important role in China`s energy development.Impact of underground coal mining on regional ecology is directly related to the sustainable development of the mining industry and local region.Based on long-term monitoring and previous research results,the impact of underground coal mining on land ecology and its restoration methods are studied systematically.The study indicates that: the monitoring method of land ecology plays a key role in revealing the impact of underground coal mining on land ecology.The method of multi-source information collection and processing dominated by underground mining information,and dynamic and long-term field monitoring are more effective.Coal mining produces certain impact on land ecology such as surface deformation,cracks,soil moisture,soil physical and chemical properties and vegetation growth in windy and sandy region.However,most of these factors are characterized by self-healing and natural restoration in a relative short period except margin cracks of subsidence basin.This region should adopt “partition” differentiated ecological restoration model,which means that the uniform subsidence region conduct “natural closure” restoration,and the differential subsidence region conduct artificial-induced restoration model which gives priority to phytoremediation supplemented with appropriate engineering restoration.Meanwhile,it should adopt the concurrent mining and reclamation model which consists of super-large working face and concurrent subsidence and ground cracks filling,aiming to reach reduction of land ecological damage and restoration in time.

Effects of coal mining subsidence on the rhizosphere environment of Artemisia ordosica in Mu Us sandland,northwest China

Zhang Yanxu, Bi Yinli, Wang Zhigang, Qiu Lang, Sun Huan, Cai Yun

2016, 1(2): 131-139.

Abstract(746) PDF(280)

Abstract:
Taking the rhizosphere soil of Artemisia ordosica in Mu Us sandland as an example, the effects of soil physi chemical properties, soil microorganism and enzyme activities after 1-3 years subsidence were analyzed. The results showed that soil bulk density and field capacity decreased, and rhizosphere soil available phosphorus, potassium and nitrogen content decreased significantly (P<0.05) after subsidence, but soil pH and conductivity increased significantly compared with the un disturbance area. The quantities of bacteria and actinomycetes decreased in the depth of 0-20 cm, while the quantities of fungi increased. As compared to the un disturbance area, soil microbial quantity increased in the 20-40 cm and 40-60 cm layers. Soil acid phosphatase activity increased significantly after subsidence (P<0.05). Soil invertase activity in the surface increased significantly after 2-3 years subsidence, while there was no significant difference in the deep soil (P> 0.05).There was no significant difference on soil available phosphorus and nitrogen, the quantities of bacteria in surface soil, soil urease and invertase activity between subsidence area and the un disturbance area after 3 years. The rhizosphere environment of plants has a certain self repair capacity, but it will take a long time to reach the level of nature eco environment after mining subsidence.

Experimental and numerical study on temperature field by freezing pipe of double chambers

Sun Qiang, Yang Liyun, Chen Jun, Wang Qianxing, Liu Ju

2016, 1(2): 140-145.

Abstract(694) PDF(288)

Abstract:
In order to control the horizontal energy transfer of freezing pipe, a new type freezing pipe with two chambers was set up. The temperature field of this new freezing pipe was analyzed by model test and numerical simulation. The results show that the temperature field shape inside the 1.5 diameter of the new freezing pipe was Ushape and there was a remarkable temperature difference between the side of liquid nitrogen chamber and air chamber, which proved that the new freezing pipe would change the transfer of cool energy and have the effective capability of control freezing. On the other side, the temperature field shape outside the 1.5 diameter of the freezing pipe was circleshape, which indicated the new freezing pipe had less effective efficiency on the control freezing when it is used in a large space. In conclusion，the new freezing pipe can control the freezing effectively during short time period, and can be used in municipal rescue engineering.

The experimental research on the propagation laws of cracks in roadway surrounding rock subjected to static-dynamic load

Guo Dongming, Yan Pengyang, Xue Lei, Luo Lang, Yang Jun

2016, 1(2): 146-154.

Abstract(705) PDF(376)

Abstract:
In order to study the propagation law of the crack in surrounding rock subjected to static dynamic load, the poly methyl methacrylate (PMMA) are used to make specimens containing a single prefabricated crack and dynamic caustics experimental system with explosion load is used to conduct experimental research on the propagation laws of crack in roadway surrounding rock. Study has showed that there exists close relation among the extension displacement of the prefabricated crack, the damage degree of the specimen and confined pressure around the specimen. There is a negative correlation relationship between the extension displacement and the damage degree, which is closely associated with the confined pressure, presenting a rule of increasing firstly and decreasing later as the increasing of confined pressure. Changing the confined pressure around the specimen and keeping the explosion condition unchanged in the study, the prefabricated cracks all appear the phenomenon of alternative variation between extension and arresting, but the value of extension displacement reaches a maximum of 30.84 mm and a minimum of 10.98 mm when the value of confined pressure is 0 MPa and 0.4 MPa respectively, presenting a trend of decreasing firstly and increasing later as the increasing of confined pressure. There exists a close relation between energy release rate around the crack tip and propagation speed of the crack. When energy release rate increases, the propagation speed will increase then, but when the propagation speed decreases, energy accumulation occurs around the tip induced by the explosion stress wave, resulting in energy release rate increasing.

Timeliness analysis on organization intervention of miners’unsafe behavior

Tong Ruipeng, Chen Ce, Liu Dapeng

2016, 1(2): 155-161.

Abstract(774) PDF(404)

Abstract:
In order to investigate the effect and the timeliness of the organization intervention of miners’ unsafe behavior, the organizational intervention system which covers the entire coal mine system was constructed combining with the actual coal mine. The system dynamics model of organization intervention of miners’ unsafe behavior was constructed based on the analysis of miners unsafe behavior organization intervention method set and the principle of system dynamic. Dynamic simulation with different length and different intervention coefficients was carried out by using Vensim simulation software. At the same time, the objective of the conclusion was verified by comparing the simulation results with the actual data. The result shows that the effect of organizational intervention is obvious in the short term, however, it can not make the level of unsafe behavior continue to reduce in a longer period of time. The effectiveness of organizational intervention will be significantly improved through continuous optimizing intervention measures and improving the intensity of intervention.

Research on influences on gas emission characteristic of coal seam caused by penetration partings

Zhao Hongbao, Zhang Huan, Wang Feihu, Ju Nansong

2016, 1(2): 162-171.

Abstract(808) PDF(391)

Abstract:
Based on a self developed coal seam gas emission test device, taking briquette samples containing penetration partings as the research object, and taking gas emission speed and gas cumulative emission amount of coal sample as study parameters, the influences caused by penetration partings on coal seam were studied systematically, and the mechanism of gas emission of coal seam with penetration partings was discussed. The results show that the gas emission speed of all briquette specimens presents power function decay over time, and the cumulative emission amount presents an upper limit monotone increase over time. Both gas emission initial speed and cumulative emission amount of coal samples increase with the increase of adsorption equilibrium pressure. Under the same adsorption equilibrium pressure, the gas emission speed of specimens containing penetration partings is faster than the ordinary specimens in the initial stage, but two emission speed curves appear intersection from 30 min to 90 min, while the cumulative emission amount of specimens containing penetration partings is more than that of the ordinary specimens in the former 120 min. Penetration partings can improve the permeability of coal seam, provide migrations path for gas emission of coal seam, and create favorable conditions for the gas emission, so the gas emission efficiency is improved.

The breaking characteristics of thick The breaking characteristics of thick hard roof and determination of support capacity in fully mechanized caving facehard roof and determination of support capacity in fully mechanized caving face

Cheng Zhanbo, Kong Dezhong, Yang Jinghu

2016, 1(2): 172-180.

Abstract(856) PDF(415)

Abstract:
It is difficult to determine the first roof weighting interval of hard roof on fully mechanized caving face. Based on the working face 8301 of Dongzhouyao coal mine, a model of two edges fixed in thick and hard roof was established by using energy method. According to the model, the horizontal stress distribution in the main roof and the analytic formula for the first roof weighting interval of the main roof were obtained. The characteristics of roof breaking and working resistance of the support were analyzed by using numerical simulation. And the working resistance of support in different positions of the working face under different advance distance was attained based on field observation. The results showed that mine pressure behaviors were more intense under the condition of thick and hard roof, with larger the first roof weighting interval and higher working resistance of support as compared to general conditions. To be specific, the first roof weighting interval was about 58 m in working face 8301, while the periodic roof weighting length ranged from 15 to 20 m. The rated working resistance of support was 13,000 kN, but the observed maximum working resistance was 11 000 kN, only 78.7% of the rated value. It is believed that safety and efficiency of coal mining under the condition of thick and hard roof can be achieved.

A novel mine mobile communication system of blackout environment in the coal mine

Zhang Fan, Guan Zenlun

2016, 1(2): 181-187.

Abstract(785) PDF(410)

Abstract:
To address the problems of mine mobile communication system existing poor anti nterference and anti disaster ability, and easy to form a large number of signal strength blind spots or dead zones and other issues, the genesis mechanism of wireless communications blind zones in the mine tunnel is clarified based on the electromagnetic wave theory, and a novel mine mobile communication system without blind zones is developed. A dual bus shaped network structure for mine mobile communication system is proposed, and the antenna structure considering distributed antenna and leakage is presented. Also, the working principle of the system is clarified, and the working frequency design is proposed. The results demonstrate that the system have wide network coverage, as well as ant failure and anti interference ability, which can eliminate the blackout of mine wireless communications in the coal mine, and meet mine production scheduling, emergency communications and relief, as well as whole mine mobile communication requirements.

Mineral resources evaluation model research based on BP neural network and TSVM algorithm

Zhao Xuejun, Li Yuzhen, Wu Wenbin

2016, 1(2): 188-195.

Abstract(813) PDF(809)

Abstract:
In the study of mineral resources evaluation model, the problem that the number of positive samples must be specified in the TSVM in the unlabeled samples. Then this article applied the improved algorithm to the evaluation of mineral resources, and the algorithm is TSVM based on BP neural network and BP-TSVM for short. The SVM is applied to studying the discernment and classification of labeling samples. We will annotate the plus or minus of unlabeled data within the boundary of already classified by utilizing BP neural network. The labeling samples as learned by SVM in the next iteration. The new algorithm will avoid decreased classified ability. TSVM can have more accurate estimates of number of plus of labeled data. Also, the number of training samples can reduce training times. The experimental result proves that compared with conventional SVM,TSVM and BP neural network the BP-TSVM is more accurate in evaluation of mineral resources.

Experimental study on working parameters optimization of vacuum pressure swing adsorption technology for ventilation air methane in coal mine

Zhu Tao, Liu Entong, Wang Yanxia, Ma Mingfeng, Li Ranran

2016, 1(2): 196-202.

Abstract(926) PDF(290)

Abstract:
In order to realize ventilation air methane in coal mine recycling, the vacuum pressure swing adsorption technology was adopted. The single factor experiment and orthogonal experiment were carried out in view of the variable experimental parameters in the pressure swing adsorption system. The influences of desorption pressure, feed gas concentration and the height to diameter ratio of adsorption tower were analyzed. The experimental results show that the volume fraction of desorption methane gas is higher with the lower of the desorption pressure, and the lifting ratio is smaller with the higher of the feed methane gas. The influence of different factors has an order: desorption pressure > feed methane gas > lifting ratio. The best experimental working parameters are desorption pressure of 0 kPa, and methane volume fraction of feed methane gas of 0.1%, and the height to diameter ratio of adsorption tower of 10.33, and the biggest lifting ratio of 1.68.

Study on the high precision frequency measurement algorithm in the mine intelligent power supply system

Yuan Shiliang, Xu Zhiqiang, Dong Jie, Zhu Qichen

2016, 1(2): 203-208.

Abstract(766) PDF(112)

Abstract:
To solve the problem of the error of frequency measurement algorithm with timevarying frequency in mine power supply system, an improved software zerocrossing algorithm is proposed. The relationship among the phase angle, the time and the frequency of the voltage of the system is established. The relation formula between the realtime frequency and the period of zerocrossing point is derived when rate of frequency variation is not zero according to the relationship between two adjacent with the direction of the zerocrossing phase difference of 2π. The exact calculation formula of the period is obtained by using the Newton three interpolation polynomial, the Newton iteration method and the Qin Jiushao algorithm. Hence, the frequency and rate of frequency variation can be obtained. A variety of situations ,including signals without harmonics, signals with harmonics and random noise, as well as the frequency rapid decline process in system failure, are simulated using MATLAB, The simulation results show that the algorithm of this paper can accurately measure the realtime frequency of the system and rate of frequency variation in above situations, and this method is superior to conventional zerocrossing algorithm in measurement accuracy, instantaneity and computation. This algorithm is suitable for application of protection, control and monitoring devices and automation equipment in mine intelligent power supply system.

2016 Vol. 1, No. 2