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Objective: To analysis the distribution characteristics of coal worker's pneumoconiosis in Hubei Province during 2006-2010 (the 11th Five-Year Plan period) and 2011-2015 (the 12th Five-Year Plan period) , and its correlation with the gross domestic product (GDP) of Hubei Province from 1986 to 2015. Methods: In September 2019, the data of newly diagnosed coal worker's pneumoconiosis reported in Occupational Disease and Occupational Health Information Monitoring System from 2006 to 2015 and the GDP data from 1986 to 2015 in Hubei Province were collected. The distribution characteristics of time, region, enterprise size, industry and economic type of coal-worker's pneumoconiosis and its correlation with GDP were analyzed. Results: In 2006-2015, 3807 new cases of coal worker's pneumoconiosis were reported in Hubei Province. The time distribution generally ascended as a wave trend. The number of new cases reached its peak in 2013 (722 cases) . GDP growth continued between 1986-1995, 1996-2005 and 2006-2015, especially in 2006-2015. New cases of coal worker's pneumoconiosis were mainly distributed in Huangshi city, Yichang city and Enshi prefecture, accounting for 82.40% (3137/3807) of the total cases. The proportion of new cases in Huangshi city was higher than that in Yichang city and Enshi prefecture (χ(2)=272.66, 243.19, P <0.05) . New cases were mainly distributed in coal mining industry (3103 cases, 81.51%) , small-sized and medium (1675 cases, 44.00%) , and private enterprises (1621 cases, 42.58%) . The rank correlation (r(s)) of coal worker's pneumoconiosis in 2006-2015 with GDP in1986-1995, 1996-2005 and 2006-2015 were 0.157, 0.144, 0.200, respectively, and there were no significant differences ( P >0.05) . Conclusion: The coalworker's pneumoconiosis in Hubei Province are mostly distributed in small and medium-sized private enterprises, and the regional distribution is concentrated in Huangshi city, Yichang city and Enshi prefecture. The concentration of cases is closely related to the number and energy production of local coal mines. There is no correlation between the growth of GDP and the distribution of cases.

Objective: To analyze the incidence of pneumoconiosis among workers in the coal industry in the past 13 years in Chongqing, understand the different epidemiological characteristics of new pneumoconiosis among workers in the coal industry in the city, provide basic evidence for the prevention and treatment of pneumoconiosis. Methods: Collecting new cases of pneumoconiosis diagnosed in the coal industry in Chongqing in January 2006-May 2018, and analyze its epidemiological characteristics. Results: In January 2006-May 2018, 25329 cases of pneumoconiosis were added to workers in the coal industry in Chongqing, and 23, 328 cases were present, all male. Among the existing cases: coal workers' pneumoconiosis accounted for 89.30%, silicosis accounted for 10.70%; age distribution was 50-59 years old. The main, accounting for 45.19%, the average age of onset was 52.21±7.45 years; the actual dusting age was mainly 10-19 years, the average actual working age was 17.52±8.47 years; the distribution of the work was mainly by the main coal mining (53.20%) ; There are more new cases in enterprises, accounting for 88.86%; distributed in 36 districts and counties. Conclusion: There was a large number of new pneumoconiosis diseases in the coal industry in Chongqing. Different measures should be taken according to the characteristics of different enterprises, and relevant enterprises should be urged to take the initiative to carry out occupational health surveillance, effectively protect the health of workers, improve the coordination mechanism, improve medical security, and gradually realize government assistance and Social care is combined.

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Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the deep coal mining in China, the contradiction between the mine water inrush from aquifer underling the coal seam and the decline ecological water level is more and more serious. Based on the analysis of the assemblage characteristics between the No. 5 coal seam and the aquifer(auifuge) in Chenghe mining area, the present study is to investigate the depth of destroyed floor by combining the theoretical calculation and in-situ measurement. The influence of coal seam mining on the confined water underling the coal seam has been studied from the perspective of aquifer structure, ecological water level and water quality. The results indicate that the maximum depth of destroyed floor of the No. 5 coal seam is 8-10. 8 m, and the main control factors of the depth of destroyed floor are the dip length of working face and the lithologic association of floor. And there is a positive correlation between the dip length of working face and the depth of destroyed floor, a negative correlation between lithologic association of floor and the depth of destroyed floor. Influence degree of the aquifer structure from large to small can be divided into Ⅰ,Ⅱ,Ⅲ level area, and the Ⅰ level areas are mainly distributed in the central-south and north,which covers an area of 6. 78 km2,accounting for 45． 2% of the total area; there is no obvious effect on water level and water quality. The paper puts forward a grouting reinforcement technology to protect water resources and stabilize the ecological water level in mining, and finds an effective way for the healthy development of coal industry in Weibei region. [ABSTRACT FROM AUTHOR]

The utilization pattern of coal in China is still relatively extensive, the industry scale of clean coal utilization is small, the space layout is unreasonable, and the induced efficiency and environmental problems are obvious, so there is urgent need for transformation and upgrading. Put forward the development pattern of converting from coal production to clean energy production for future coal production and utilization mode, namely the coal production by large base. The coal can be converted into oil, gas, power, chemicals and other clean fuels and raw materials on site. Analyse the basic conditions and technology requirements supporting the future clean coal utilization mode. It has important reference value for realizing clean and efficient utilization of coal and promoting Coal industry transformation and upgrading. [ABSTRACT FROM AUTHOR]

Fully-mechanized top coal caving with large mining height is the main mining method for extra-thick coal seam. However, as the height of coal cutting and coal caving increases, prominent problems such as severe mine pressure behaviour severe rib spalling in working face, low top coal recovery rate and high gas emission rate and so on emerge. Based on the analysis of the development history of the fully-mechanized top coal caving in China, taking the working face 8105 at Tashan Coal Mine as the engineering background, authors studied the movement characteristics of the top coal and roof at the fully-mechanized top coal caving face with large mining height in the 14-20 m extra-thick coal seam, successfully developed key technologies such as the comprehensive prevention and control technology for rib spalling at the fully-mechanized top coal caving face with large mining height, high-efficient coal caving technology with high recovery rate and safety guarantee technology for mining under the condition of "low gas occurrence, high gas emission", etc. The underground test showed that the recovery rate at the fully-mechanized top coal caving face with large mining height 8105 at Tashan Coal Mine reaches 88. 9% which is 5.9% higher than that at working face 8104, the average operating rate of the equipment at the working face reach 92.1 %, and the raw coal produced at the face in 2011 reach 10.849 Mt, which achieve the objective of 10 Mt coal produced at the fully-mechanized top coal caving face with large mining height using domestic equipment in a year. [ABSTRACT FROM AUTHOR]

This paper aimed at the problems such as low restoration rate of land resources and long time for subsidence land reclamation by traditional technology with the condition of final subsided status. Based on the introduction and discussion of the research history for unsteady subsidence land reclamation, the concept of concurrent mining and reclamation (CMR) was proposed. The connotation, principles, technical classifications, and key technologies of CMR for underground coal mining were presented. The advantages with high reclamation percentage of land resources for the new technology were proved based on a case study, which indicated that CMR could increase farmland reclamation percentages to 37. 59% comparing with the farmland reclamation percentage of post-mining. The scope of application and application prospects of the technology were also discussed, CMR could be used in 5 of the 14 large coal bases. It is estimated that the application of CMR could increase land area by 6 680. 8 km². [ABSTRACT FROM AUTHOR]

Based on thirteen exploratory reports for coal mines form Bijie City, Guizhou Province, data about basic coal features such as sulphur content, ash yield, ash composition and concentration of eleven trace elements as Ge, Ga, U, Th, V, Cl, As, F, Pb, Cu and Zn was systematically analyzed and modeled, and the distribution characteristics, occurrence modes and controlling factors of those trace elements in Bijie coal were investigated. In order to obtain a relative accurate content level of those eleven trace elements in Bijie coal, a parameter called "Reserves Weight Coefficient" was applied. Results show that in Bijie coal Pb, Cu, Zn, U and V are abnormally enriched, Ga is relatively enriched, F and Th are slightly enriched while Ge and Cl are both lower than the Clarke Value, concentration of As in Bijie coal is higher than the common Chinese coal but markedly lower than the USA coal. Correlativity analysis reveals that F may occurs in carbonate minerals, Pb and Cu are probably hosted in sulphide minerals and Cu shows a certain degree of organic affinity. Evidence suggests that on the one hand enrichment of Cu, Zn and V in Bijie coal can be attributed to Emeishan basalt in terrigenous province whose content of those three elements are relatively high; on the other hand trace elements enrichment in coal are controlled by sedimentary environment, specifically some elements that migrate easily in continental sedimentation process such as Ge, Ga and Th tend to be of higher content in coal when the seawater influence is weakening. V is enriched in coal when the influence is strong. In addition, some elements' abnormal enrichment in Bijie coal is believed to be linked with the tectonic movement especially hydrothermal fluid. [ABSTRACT FROM AUTHOR]

To solve the problem of high dust concentration caused by rock tunnel excavation, in view of the characteristics of dust produced and analyzing the processes of roadheader cutting rock, the paper used Fluent software to carry on numerical simulation of dust movement and analyse the dust characteristics of motion and concentration distribution. Simultaneously, this paper designed the foam dust suppression system applied to fully mechanize large cross-section rock tunnel excavation on the principle of foam dust suppression, and put it into application at the driving face of the north main haulage roadway in Zhuxianzhuang Coal Mine, Huaibei Mining Co., Ltd. The results show that the dust concentration on the exhaust section of the driving face, reaches a maximum at the leeward side of dust source. Foam making by the foam dust suppression system can enclose roadheader's cutting head and cover palisades, reaching the results of wetting rock, reducing dust content, depressing the generation of dust and blocking the spreading alleyway. The average dust-settling effect is 86. 2% and 84. 4% for the total dust and respirable dust, and the effect is 3. 6 and 4. 6 times comparing with water spray, achieving a good effect. [ABSTRACT FROM AUTHOR]

Based on analyzing the reasons and characteristics of gas combustion under coal mine and integrating the situation of gas combustion accident which frequently occured at present, the authors built the experimental platform with the ultra fine water mist to prevent gas combustion. A series of experiments with the ultra fine water mist to prevent gas combustion was conducted. Finally, the best operation parameter to study the water mist restrained gas combustion was obtained with the methane flow of 150 mL/min, the methane concentration of 90%, the atomization quantity of 220 mL/min, and the water spray particle size of 5-30 µm. The results show that after release ultra fine watermist,a closed spray ring is formed around the gas flame, and the gas flame interact with ultra fine water mist appears the process of restrained-cut flame-restrained again-cut flame again, with the gas flame gradual becoming smaller until to extinguish. Comparing with free combustion, the temperature and oxygen concentration around gas flame all reduced with different degree, and the whole process of flame extinguish is only 90 s. [ABSTRACT FROM AUTHOR]

The field tests, which were conducted in an island longwall panel in the Tangshan Coal Mine in the city of Tangshan, China, are intended to provide researchers and mining engineers with the assessment of coal bump risk during extraction of an island longwall panel. In these tests, roadway roof displacement and electromagnetic radiation (EMR) of roadways in the panel were investigated to determine the zones of intensive roof deformation. The results of the field tests show that the roof deformation starts to occur at more than 30 m ahead of the longwall face and the deformation starts to accelerate after a distance of 10 m in front of the longwall face. Large and rapid roof deformation is considered to be an important precursor of coal bump occurrence during the extraction of an island longwall panel. It indicates that the bump-prone zones around island longwall panel and near the edge of the roadway during extraction is within 7.5 to 10. 0 m ahead of the mining face. [ABSTRACT FROM AUTHOR]