Turnover intention among generation Y: a study of coal sector

Mar 2018 / by Ankita Anshul, Pramod Pathak and Saumya Singh

The modern workplace is undergoing a constant change as the new generation that is generation Y is replacing the previous generations rather fast. This generation has a different mind-set from the earlier one which were more loyal to the organisation. With more and more generation Y entering the coal industry a new trend has been observed that turnover rates is rising significantly. The present paper is an attempt to investigate the relationship between job satisfaction, job stress, job characteristics on the one hand and employee turnover intention on the other among generation Y employees in the coal sector. Survey respondents include 267 frontline executives and the nonexecutives working in coal industry in Dhanbad region, India, who were selected by simple random sampling method. Results derived from structural equation modelling (SEM) and AMOS showed that job satisfaction and job stress have significant impact on employee turnover intention whereas job characteristics does not have any significant impact on employee turnover intention.
Keywords: Job satisfaction, job stress, job characteristics, employee turnover intention, coal sector

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Evolution of applicability of robotics in underground mine services

Mar 2018 / by Subhash Kumar, P. K. Mishra, Jitendra Kumar and Sandeep Prasad

Mining is one of the most hazardous and hostile occupations in the world. Even though a lot of hazards are associated with this industry, mining of both fuel and mineral based deposit from earth is necessary for the economic growth of the nation, maintaining a low cost of production by avoiding import and gaining independence from other mineral rich and technologically advanced nation for its day to day requirements of minerals. But, the industry must keep in mind that it should adopt the policy of safety first than production in the context of a large number of dangers which are associated with mining activity and must take necessary action to avoid such unwanted events from happening. Though safety standards in current mining industry scenario have improved by providing training sessions to miners regarding safe and better work practices and using better machines for stabilization of mining structure and extraction. But still disaster tends to happen in mines worldwide and rescue of miners and mining machinery is the first task that is performed by industry by sending rescue team without prior knowledge about underground mine environmental condition since post-disaster installed mine environment monitoring is either damaged or destroyed. Subsequently, sending mine rescuers will be dangerous and may cause even bigger disaster from happening which is evident in past. Therefore, the mining industry is now relying upon robotics for mine disaster rescue management to assist human rescuers and avoid further exposure to dangerous post-disaster underground mine environment. This paper gives an overview of applicability of robotics in mine disaster rescue management.
Keywords: Robotics, WSN, RFID, underground mines

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Research and application of technology of gob-side entry retaining by roof cutting pressure relief in Jiaozishan coal mine

Mar 2018 / by Guo Hongjun, Ji Ming, Zhang Kun, Wang Huiqin and Liang Aoxiang

Combined the mechanism of gob-side entry retaining by roof cutting pressure relief and the geological conditions of Jiaozishan coal mine, the influence of gob-side entry retaining from the depth of blasting bore in the process of roof cutting pressure relief was studied by the method of FLAC3D numerical simulation. When the depth of blasting bore was 4m, it was most significant that the surrounding rock stress of roadway transferred to the roadway deep; meanwhile, the surrounding rock deformation was also the minimum. And the result was applied to an industrial practice in the intake airflow roadway of the 9706 working face. When the working face was mined, the surrounding rock deformation was basically identical between the coalside entry in front of the working face and the gob-side entry behind the working face, which met the requirements of retaining roadway and production next working face. It successfully reduced the difficulty of protecting roadway and the loss of coal pillar, and achieved remarkable economic and social benefits.
Keywords: Roof cutting pressure relief; gob-side entry retaining; numerical simulation; surrounding rock control; ground pressure monitoring

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Regular pattern effect of negative pressure on spontaneous combustion in gob

Mar 2018 / by Zhang Jiuling, Zhu Zhuang and Li Zhi

To Kailuan Group Lv Jiatuo mine 5877Y working face gob as the research background, and using the method of numerical simulation and field experiment, the effect of different drainage pressure on spontaneous combustion “three zones” under the condition of the buried pipe in the gob was studied. Results show that after the negative pressure is added, the spontaneous combustion zone width of the gob is smaller and then increases. Based on the analysis of the data obtained from field beam tube, the simulation results agree well with the simulation results, which proves the validity of the simulation of spontaneous combustion in gob, and provides a reasonable reference for the gas drainage in the similar condition. Fire and gas are the two major disasters that restrict the safety and efficient development of coal mine, spontaneous combustion in gob is the current coal enterprises especially the great disaster of coal seam spontaneous combustion tendency exists. At present, many mines adopt gas drainage method with high suction roadway to control gas overrun, this method also has great influence on the air leakage field in gob, increase the probability of spontaneous combustion of residual coal. Therefore, it is of important and practical significance to prevent spontaneous combustion of abandoned coal in gob and avoid fire accidents under pumping condition. Based on the study of the mechanism of spontaneous combustion of coal, the theory of gas drainage and the theory of three zones of spontaneous combustion, the application and research status at home and abroad are summarized. To Kailuan Group Lv Jiatuo mine 5877Y working face gob as the research background, and using the method of numerical simulation and field experiment, the effect of different drainage pressure on spontaneous combustion “three zones” under the condition of the buried pipe in the gob was studied. Results show that the distribution of oxygen concentration field under the condition of no buried gas drainage was simulated by establishing the mathematical model of spontaneous combustion in gob and using COMSOL numerical simulation software. The rationality of the model is confirmed by comparing the experimental data and the simulation analysis of the beam tube monitoring, Then, under the condition that other conditions and parameters remain unchanged, the negative pressure of buried pipes with 10kPa, 20kPa and 30kPa sizes is set. The range and influence law of “three zones” of spontaneous combustion in gob under different pumping negative pressure are obtained; When the negative pressure is added to the gob, the width of the spontaneous combustion zone in the gob becomes smaller and then increases. The data obtained from the monitoring of the beam tube on the spot coincide with the results of the simulation. The validity of the spontaneous combustion simulation in the gob is well verified, The research results provide theoretical support and basis for mastering the heating law of spontaneous combustion of abandoned coal in the gob and preventing and controlling the spontaneous combustion of coal seam.
Keywords: Numerical simulation, field experiment, negative pressure, spontaneous combustion

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Anjan hill mine explosion: human failures resulting 14 fatalities

Mar 2018 / by Suresh Chandra Suman and Pramod Pathak

Energy is essential for development of a nation and its people. India is home to a large population and coal is dominant fuel for its growth. A sizeable coal reserve of the nation is at greater depth for which underground mining is feasible and economically viable technology. Underground coal mining is fraught with explosion hazard. Explosion in a mine is catastrophic and takes toll. Human factors are an important issue in coal mine accidents. In 2010, Anjan hill mine, an underground coal mine in Central India coalfields, experienced an explosion with multiple fatalities. Human factors analysis and classification system developed by Shappell and Weigman (2003) was used to identify human errors leading to the mishap. Human errors with higher level system deficiency were found to be causal factors. The study identified critical human errors which contributed explosion hazard in the coal mine.
Keywords: Underground coal mine; explosion; human errors; human factor analysis and classification system (HFACS)

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Experimental partition and numerical simulated “three-zone” of spontaneous combustion in the gob

Mar 2018 / by Wang Yue-hong, Wu Yi and Li Zhi

Based on the mechanism of spontaneous combustion of coal, the theory of gas drainage and the theory of three zones of spontaneous combustion, the application and research status are summarized at home and abroad.The preliminary understanding of gas drainage and spontaneous combustion in gob is expounded. And research status and the source of subject of spontaneous combustion and gas drainage in gob in domestic and foreign on influence of spontaneous combustion is introduced in detailed. The application study of spontaneous combustion of abandoned coal in gob of numerical simulation is mainly studied. The research background that is based on 5242Z working face in gob in lvjiatuo coal of Kailuan group, it introduces duct monitoring system that is established in 12# coal seam of 5242Z working face. Beam tube monitoring is the main method in the experiment.Through the beam tube are arranged reasonable in gob, the gas bladder with regular sampling was analyzed by gas chromatography. It has achieved continuous monitoring to spontaneous combustion in gob and has measured the distribution situation of oxygen concentration of different locations inside the gob. To measure the “three zones” division of spontaneous combustion more accurate, by setting the parameters under the same conditions, the COMSOL numerical simulation software is used to solve the mathematical model of oxygen concentration and the field distribution of oxygen concentration in mined out area can be obtained. According to the simulated results, the range of three spontaneous combustion zones in goaf is determined, and the accuracy of the division of “three zones” is ensured. According to the oxygen concentration index, the result is that the heat dissipation zone is mainly distributed in the coal wall 0~15m area from the working face, the spontaneous combustion zone is mainly distributed in the coal wall 15~45m area from the working face and the suffocation zone is mainly distributed in gob outside the coal wall 45m of the working face, which provides a reference for the formulation of the technical scheme for mine fire prevention and control in the later period. The comparison between the measured and simulated the actual results of the monitoring of the beam pipe in the mined out area shows that the actual measurement coordinate points essentially coincide with the contour lines that are processed by simulation results. There is little difference in the division of “three zones” of spontaneous combustion in gob to monitoring results and simulation calculation results of beam and tube in mined out area. Therefore, the validity of the numerical simulation is verified.
Keywords: Duct monitoring system; three zones of spontaneous combustion; numerical simulation; oxygen concentration

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Determining method of backfill strength based on damage constitutive model

Mar 2018 / by Qiu Jingping, Yang Lei, Xin Jun and Sun Xiaogang

Backfill strength and ratio determining is one of the key for the stage of open stoping with subsequent filling mining method. Since some problems occur when adopting traditional method to determine filling strength, it is necessary to explore a more scientific approach to study reasonable match between backfill strength and rock mass. ZhongGuan iron mine’s backfill were subjected to laboratory mechanics test, and their stress-strain curves were obtained, backfill’s damage constitutive models before peak stress were established by using damage mechanics. According to the principle that the peak deformation energy of backfill should be corresponded to releasing energy from excavated rock mass, the optimum backfill strength and ratio of ZhongGuan iron mine were determined, which plays a significant role in fill mining production on site.

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Programming for sustainable mining projects

Mar 2018 / by B. K. Samanta

Many new and reorganized projects from existing mines have to be made profitable by methods and system study with techno-economic analysis. The author has developed about 14 computerized data-based models on field investigations in a coal company with methods which can be fruitful for planning, scheduling and monitoring for the benefit of the mining industry. Based on field investigations, prevalent cost data, projected cost-benefits have been determined with computer programming models. Advanced management methods have been applied as formidable problems are there for standardization, because of differing mining methods, depending on the type of reserve. Based on field investigations, prevalent cost data, projected cost-benefits have been determined with computer programming models. The researcher has developed about 14 computerized data-based models on field investigations in a coal company. Methods are found fruitful for planning, scheduling and monitoring for sustainable mining industry. This paper has attempted to find innovative techno-economic solutions for continued viability in mining industry with model programmes. Researchers have studied more than 300 scheduling, project, portfolio related software and developed his own programme.

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