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441.
根据对呼略矿采场围岩控制的研究 ,提出通过控制煤层底板来管理顶板 ,是采场围岩控制的重要方面。在矿压观测的基础上 ,经过科学分析与设计 ,增设单体支柱下的柱鞋 ,能有效地增强整个支护系统的刚度 ,达到控制和管理好顶板 ,实现安全生产的目的  相似文献   
442.
煤矿重大危险源辨识评价若干问题的研究与探讨   总被引:14,自引:8,他引:14  
重点对煤矿重大危险源辨识评价过程中的若干问题 ,进行了研究与探讨。其主要内容包括 :矿山重大危险源的定义与特性、评价单元的划分、危险等级的划分、煤矿重大危险源危险性与评价单元危险性之间的关系、煤矿重大危险源不同类型灾害的危险性的关系等。笔者认为对煤矿重大危险源辨识评价的研讨 ,为煤矿企业准确把握煤矿生产系统中的重大隐患和薄弱环节 ,通过对煤矿重大危险源的辨识评价 ,针对性的采取整改或预防措施 ,减少或消除事故的发生 ,促进煤矿安全生产 ,有重要参考价值。  相似文献   
443.
燃煤电厂烟气脱硫主要工艺   总被引:4,自引:0,他引:4  
简要介绍燃煤电厂烟气脱硫(FGD)的湿法,半干法,干法,可回收工艺和联合SO2/NOx工艺等五类主要工艺,并对我国烟气脱硫技术的进展进行了探讨,指出我国烟气脱硫技术的发展应走国产化的道路。  相似文献   
444.
煤与瓦斯突出起动过程的突变理论研究   总被引:12,自引:1,他引:11  
分析了煤与瓦斯突出的起动和发展机制,在此基础上,应用突变理论,采取拓扑变换的方法,得到了描述突出起动过程的突变势函数,讨论了突出起动过程的突变条件,并据此解释了防突措施的机理。所得结论与防突工程实践中的认识相一致,表明突变理论可望为研究煤与瓦斯突出机制提供一种新的方法  相似文献   
445.
湿式纤维栅除尘器是一种新型高效的湿式除尘器,其除尘效率高达98%以上,并且能有效地脱除锅炉燃煤烟气中的二氧化硫,排放烟气质量达到国家标准。除尘器结构简单,能耗少,便于构件更换与维修,是中小型锅炉适用的排烟除尘器。  相似文献   
446.
介绍了我国煤中汞含量与分布特征、煤中汞的赋存形态,分析了汞释放对环境的影响以及汞的脱除与控制技术。结果表明:我国(华南)晚三叠世(T3)煤中汞含量最高,平均含量为0.26μg/g;贫煤和无烟煤中汞含量最高,平均含量都超过0.20μg/g。含汞较高的晚三叠世、晚二叠世煤田主要分布于华南各地;多数煤中汞含量在0.300μg/g以下,但华南的江西、广西、贵州等地煤中汞含量总体水平较高;汞的赋存形态可分为有机结合态和无机结合态,煤中汞的控制方法可分为利用前脱汞、利用(燃烧)后脱汞和过程中汞形态转化。提出了煤炭洗选过程汞分布、脱除率和汞平衡等计算公式,指出了煤炭洗选过程中汞迁移行为的主要影响因素。  相似文献   
447.
测定了用不同量的CAM助滤剂对不同煤泥的助滤脱水效果,结果说明了助滤脱水效果与助滤剂用量、粒度组成和煤泥种类等相关。  相似文献   
448.
Coal production globally is projected to grow in the foreseeable future. Countries with heavy reliance on coal could reduce methane and other emissions through the capture and utilization of coal mine methane (CMM) in the short and medium term, while they pursue structural and long-term economic changes. Several countries have successfully implemented policies to promote CMM capture and utilization; however, some countries still struggle to implement projects. This paper outlines key factors to consider in adapting policies for CMM mitigation. The authors propose an approach for selecting adequate mechanisms for stimulating CMM mitigation that involves reviewing global best practices and categorizing them functionally either as mechanisms needed to improve the underlying conditions or as CMM-specific policies. It is important to understand local policy frameworks and to consider whether it is more feasible to improve underlying policy conditions or to provide targeted incentives as an interim measure.Using Kazakhstan as a case study, the authors demonstrate how policymakers could assess the overall policy framework to find the most promising options to facilitate CMM projects. Kazakhstan’s emissions from underground coal mines have been increasing both in total and per tonne of coal production, while overall production has been declining. CMM mitigation presents an opportunity for the country to reduce its greenhouse gas emissions in the near and medium term, while the government pursues sustainable development goals. Analysis shows that policymakers in Kazakhstan can leverage existing policies to stimulate utilization by extending feed-in tariffs to cover CMM and by developing working methodologies for companies to obtain emission reduction credits from CMM projects.  相似文献   
449.
In Finland, the new limit values for heavy metals in fertilizers used in agriculture and in forestry came into force in March 2007, and for materials used as earth construction agents, in June 2006. From the utilization point of view, it was notable that the total heavy metal concentrations (Cd, Cu, Pb, Cr, Mo, Zn, As, Ni, Ba, and Hg) in fly ash from a coal-fired power plant were lower than those limit values. The concentrations of the easily soluble elements Ca, Mg, Na, P, and Zn in the fly ash were between 3.5 and 35 times higher than those found in the coarse mineral soils of Finland. Fly ash is a potential agent for soil remediation and for improving soil fertility. If inorganic materials and by-products are utilized in earthworks, the content of harmful compounds must be low and the harmful components must be tightly bound to the matrix. Therefore, a five-stage sequential extraction procedure was used to evaluate the extractability of different elements in fly ash into the following fractions: (1) the water-soluble fraction, (2) the exchangeable fraction (CH3COOH), (3) the easily reduced fraction (NH2OH-HCl), (4) the oxidizable fraction (H2O2 + CH3COONH4), and (5) the residual fraction (HF + HNO3 + HCl).  相似文献   
450.
To understand the characteristics of atmospheric brown carbon (BrC), daily PM2.5 samples in Xingtai, a small city in North China Plain (NCP), during the four seasons of 2018-2019, were collected and analyzed for optical properties and chemical compositions. The light absorption at 365 nm (absλ=365 nm) displayed a strong seasonal variation with the highest value in winter (29.0±14.3 M/m), which was 3.2∼5.4-fold of that in other seasons. A strong correlation of absλ=365 nm with benzo(b)fluoranthene (BbF) was only observed in winter, indicating that coal combustion was the major source for BrC in the season due to the enhanced domestic heating. The mass absorbing efficiency of BrC also exhibited a similar seasonal pattern, and was found to correlate linearly with the aerosol pH, suggesting a positive effect of aerosol acidity on the optical properties and formation of BrC in the city. Positive matrix factorization (PMF) analysis further showed that on a yearly basis the major source for BrC was biomass burning, which accounted for 34% of the total BrC, followed by secondary formation (26.7%), coal combustion (21.3%) and fugitive dust (18%). However, the contribution from coal combustion was remarkably enhanced in winter, accounting for ∼40% of the total. Our work revealed that more efforts of “shifting coal to clean energy” are necessary in rural areas and small cities in NCP in order to further mitigate PM2.5 pollution in China.  相似文献   
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