正升煤矿采煤工艺的分析和选择

介绍了大采高一次采全高、人工假顶分层开采和综采放顶煤采煤工艺的适用特点,结合正升煤矿的采区布置、煤层赋存特点,通过分析正升煤矿煤层开采深度、煤层顶底板强度、煤层厚度及煤层结构条件,确定采用综采放顶煤采煤法作为该矿的采煤工艺,可为同等条件下煤矿选择采煤工艺提供借鉴。     

老君堂矿布置伪倾斜长壁炮采面的开采实践

结合老君堂煤矿21采区煤层赋存情况,分析了伪倾斜长壁炮采工作面布置对老君堂矿煤层赋存的适应性,通过21101工作面伪倾斜长壁布置开采实践,取得了良好的效果,对类似地质条件下的煤层开采,具有借鉴意义。     

麻黄梁煤矿采煤方法选择探讨

通过对麻黄梁煤矿3#煤层强度、埋藏深度、顶煤节理裂隙、煤层夹矸、顶板条件等各方面因素的分析,提出了人工假顶和综采放顶煤采煤法,分析了上述条件对3#煤层冒放性的影响,最后进行了综合评价,认为麻黄梁煤矿3#煤层适宜采用综采放顶煤开采技术。     

短孔煤层注水在炮采放顶煤工作面的应用

本文根据下峪口煤矿炮采放顶煤工作面煤层注水的实践经验,提出了短孔煤层注水既是炮采放顶煤工作面粉尘防治的一项根本性措施,也是炮采放顶煤工作面预防煤与瓦斯突出的一条有效途径     

碱沟煤矿超短壁急倾斜煤层综放开采实践

急倾斜煤层属难采煤层,碱沟煤矿对10 m左右厚的急倾斜煤层采用水平分层综采放顶煤回采工艺进行了研究,该矿采用综采放顶煤可以实现机械化,达到高产高效。     

不稳定煤层放顶煤开采技术研究与实践

煤层厚度变化大、地质构造复杂和煤层含有夹矸层是济宁二号煤矿煤层赋存的最大特点,而放顶煤开采所具有的对煤层厚度变化的适应性,为开采这类煤层提供了一种有效的开采方法.结合在济宁二号煤矿2301工作面实践放顶煤开采的经验,对影响放顶煤的煤层厚度、夹矸层等因素进行了分析,提出了适合不稳定煤层开来的放煤工艺.对相似条件下煤层开采方法的选择具有重要的参考价值.     

PVC塑料管在采煤工作面引水治水中的应用

<正>郑煤集团老君堂煤矿煤田地处滑动构造带,其首采21121采煤工作面采用单体液压支柱配2.4m长Π型钢梁支护,采取放顶煤一次采全高采煤方法炮采落煤。工作面俯采角为5°～13°,伪倾角为16°     

鹿洼煤矿3_下煤层放顶煤开采可行性分析

针对鹿洼煤矿的煤层赋存条件 ,从悬移支架放顶煤开采的技术性、安全性和经济性三个方面 ,分析论证了该矿3下 煤层放顶煤开采的可行性     

综采放顶煤开采大倾角煤层的技术措施

根据大同煤矿集团公司煤峪口矿综采放顶煤工作面的实践经验,分析了综采放顶煤开采大倾角煤层存在的问题,提出了技术对策。     

综采放顶煤上行开采的可行性分析

从五牧场煤矿的煤层条件、煤层倾角、层间岩性等方面,对综采放顶煤上行开采的条件进行了分析。着重论述了采用比值分析、"三带"分析、围岩平衡和类比分析等方法对综采放顶煤上行开采进行了可行性分析。分析认为,五牧场煤矿综采放顶煤上行开采具有较好的可行性、经济性和安全性。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。