基于熵权物元可拓的采空区自燃危险性评价

为了准确合理地对采空区自燃危险性进行评价,在传统的物元可拓评价模型基础上,融合了熵权法,建立了采空区自燃危险性评价的熵权物元可拓模型,通过熵权理论来确定权重,有效地克服了传统的物元可拓方法在评价的过程中选指标权重过于主观性的缺点,预测过程计算简便,将该方法应用于新集二矿采空区评价,研究结果表明:采空区自燃危险性评价结果与现场实际情况一致,为评价采空区自燃危险性提供了一条新的技术途径。     

基于模糊综合评价模型的煤自燃危险性评价研究

为了能够准确预测煤矿开采过程中采空区遗煤自燃的危险性，基于系统工程理论，运用层次分析法和模糊数学方法构建模糊综合评价模型，以此判断采空区遗煤自燃危险性。从“人-机-环-管”角度出发分析影响煤自燃的诸多因素，建立蕴含2层指标的煤自燃危险性评价体系，并进行了自燃危险性等级划分，分为很危险、危险、一般、较安全以及安全5个危险性等级。利用模糊综合评价模型对工程实例进行了危险性识别，得到的危险等级结果与工程实际情况相吻合，表明该模型应用到煤自燃危险性评价中具有良好的合理性与准确性，能够达到准确判别采空区遗煤自燃危险性的目的，以便提前制定防控措施。     

基于物元模型的采空区煤炭自燃危险性评价

基于可拓理论,建立了采空区煤炭自燃危险性评价物元模型,采用简单关联函数确定评价指标权重。确定了采空区煤炭自燃危险性评价指标及等级量值范围,依据山西某矿15101工作面实际,结合现场和实验室相关参数测定,获取了待评物元样本,对采空区自燃危险性进行了物元可拓评价。结果表明:该模型评价结果与实际情况相符,采用动态客观权重确定方法能有效避免主观因素的影响,将物元模型应用于采空区煤炭自燃危险性评价是合理可行的。     

采空区遗煤自然发火影响因素分析

结合煤自燃的理论和现场实际情况,归纳了影响采空区遗煤自然发火的因素,并分析了采空区遗煤自然发火因素对采空区遗煤自燃的影响程度。对预测、预防和防治采空区遗煤自然发火有一定指导意义。     

百灵煤矿10202工作面采空区自然“三带”影响因素分析

浅埋深综放开采自燃煤层具有采空区遗煤多、漏风严重、工作面推进速度慢等缺点,极易形成采空区浮煤自燃。以百灵煤矿10202工作面采空区为例,以采空区CO浓度随时间变化作为指标预测了预报自燃发火规律,开展了综放面采空区自燃发火研究,并采取了综合防治对策,可有效预防采空区煤矿自燃。     

大佛寺矿煤自燃多参数预报指标研究分析

高瓦斯矿井易自燃煤层工作面开采过程中,煤自燃指标及参考值的确定尤为重要。针对大佛寺煤矿工作面采空区实际情况,首先通过煤自燃程序升温实验研究煤自燃标志性气体,其次对采空区进行了现场观测,通过实验与现场数据联合分析,研究大佛寺煤矿工作面采空区遗煤自燃指标及参考值。     

数值模拟预测综放面采空区遗煤自燃程度

通过对宁夏灵武矿区枣泉煤矿2#煤层煤样进行程序升温实验,工作面上隅角CO浓度监测,得出了采空区遗煤的最高温度接近其自燃的临界温度,实现了早期预测采空区遗煤自燃程度,为治理工作面上隅角CO超限提供了科学依据.     

抽放条件下采空区煤自燃危险区域判定

瓦斯抽放不仅会增大采空区漏风,引起"三带"迁移,加大采空区煤自燃危险性;而且会造成采空区的紊乱及瓦斯积聚,致使采空区遗煤自燃危险区域更加复杂。针对建北矿4204工作面高瓦斯赋存实际情况,通过现场观测,得出采空区浮煤厚度、氧浓度和漏风强度的分布规律,并结合煤自然发火特性参数对采空区进行危险性分析,划分了抽采条件下采空区"三带"范围,确定了采空区自燃危险区域及预防采空区遗煤自燃的工作面安全推进速度。     

采空区煤炭自燃危险性模糊综合评价方法及应用

根据采空区煤炭自燃影响因素和自燃防治因素,建立采空区煤炭自燃危险性评价指标体系,其一级指标为煤的自燃倾向性、煤层地质赋存条件、开拓开采因素、通风因素和自燃防治因素。通过采用模糊综合评价法,确定了评价指标的权重和隶属度函数,建立了采空区煤炭自燃危险性评价模型。并采用该评价方法对顾桥煤矿1122(3)工作面自燃危险性进行了评价,评价的结果与实际情况基本一致。该评价方法为制定有效的采空区自燃防灭火措施有一定的指导意义。     

邹庄煤矿采空区CO涌出量预测模拟研究

为准确预测采空区CO涌出量,采用现场测试分析、数值模拟相结合的方法,以邹庄煤矿3103工作面采空区为研究对象,建立了CO涌出量预测数学模型,通过对工作面采空区漏风流场的数值模拟,得到采空区遗煤自燃漏风量,并以此对现场采空区中CO涌出量进行预测,结果表明,预测结果基本符合现场实际情况。     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

Brief news

正Corun invested another 50 million yuan in power battery for HEV Hunan Corun announced on 27 June that they had signed the cooperation agreement to jointly built Corun(Shaoxing)Autos Power Battery System Co.,Ltd.in Shaoxing Binhai New City.According to the announcement,total registered