نتایج جستجو برای: coal mining

تعداد نتایج: 114364  

2015
Yongjiang Zhang

In the deep mining, the disaster dynamic of coal petrology and gas becomes increasingly serious, dynamic coupling of coal gas disaster grows in number. However the traditional method of predicting is limited. In order to evaluate the dynamic disaster hazard level of the coal face in the deep mine, a fuzzy hierarchy comprehensive evaluation model of the coal petrology dynamic disaster on the coa...

2017
Pengfei Wang Jingli Zhao Yoginder P. Chugh Zhiqiang Wang

As more easily mined deposits are depleted, the reserves are becoming more limited and less favorable. Deposits of coal or trona that are being longwall mined are deep and are getting deeper. Coal bursts and bumps frequently occur within development entries in longwall mining of deep mines due to high stresses. This paper presents a novel patented longwall mining layout “Longwall Mining with Sp...

2000
Thomas M. Stoker Ernst R. Berndt A. Denny Ellerman Susanne M. Schennach

We analyze labor productivity in coal mining in the United States using indices of productivity change associated with the concepts of panel data modeling. This approach is valuable when there is extensive heterogeneity in production units, as with coal mines. We ̄nd substantial returns to scale for coal mining in all geographical regions, and ̄nd that smooth technical progress is exhibited by ...

2014
Mayo Sakai Daiji Kawaguchi Takashi Shimizu Susumu Cato Akifumi Ishihara Tomoya Nakamura

In the early 20 th century Japan, coal mining firms took an intermediary organization of labor, “dormitory system.” Given traditional technology that required high manual skills unknown to managements, firms relied on the intermediary organization both for screening and monitoring workers. This study focuses on referrers of miners, who took an essential role of signaling in the coal mining indu...

Journal: :International journal of environmental health research 2010
Yilan Liao Jinfeng Wang Jilei Wu Luke Driskell Wuyi Wang Ting Zhang Gu Xue Xiaoying Zheng

Shanxi province in northern China has one of the highest reported prevalence rates of neural tube defects (NTDs) in the world. The current study selected Heshun, the county with the highest rate of NTDs in Shanxi, as a study area and tested whether residence in a coal mining area was a contributing factor. A NTD cluster was detected in an area within 6 km of the coal mines for almost every year...

2015
Tianwei Lan Hongwei Zhang Sheng Li Jun Han Weihua Song A C Batugin Guoshui Tang

Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 fact...

2010
Peter B Reid Mark T Dunn David C Reid Jonathon C Ralston

This paper describes successful industrial research and development in the area of underground coal mining equipment automation. A brief background to underground coal mining is given, and the process of longwall mining is detailed. Some of the major limitations and issues impacting on the productivity and safety of the longwall mining process are highlighted, which serve to motivate the automa...

J. Shen J. Zou, K. Yang,

The mining chute is an important equipment in the process of coal transportation and coal screening preparation. During the working process, the mining chute will generate a lot of vibration and noise because of constantly friction and impact of gangue and coal blocks. In order to reduce the vibration and noise during the operation of the chute, a new type of foam aluminum laminated structure i...

Journal: Pollution 2019

Coal mining and related industry can increase heavy metals (HMs) concentrations in soil, atmosphere and wheat, thereby posing metal-associated human health risk via food ingestion.  In this study, 58 samples of soil, wheat, and dust were collected from Xuzhou coal mine eastern China, six kinds of HMs Pb, Cd, Cu, Zn, As and Cr were studied for their spatial distribution in wheat, enrichment in d...

Journal: :Central European journal of public health 2005
J Pesek V Bencko I Sýkorová M Vasícek O Michna K Martínek

Mining for coal and its utilization have various impacts on the surrounding environment. Huge volumes of waste materials which are by-products of both the underground and open cast coal mining, pose one of the major environmental hazards in addition to air pollution caused by coal burning in power plants in the Czech Republic. Some of these risks could be reduced when having accurate and compre...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید