基于CO2水基压裂液的煤体软化及降尘技术应用

为解决坚硬煤层条件下，常规煤体注水方式效果不好，回采过程中顶煤可放性差、工作面截煤和放煤过程中粉尘大的难题，根据金川煤矿煤层的具体情况，基于煤体压裂软化-润渗除尘理论，利用CO₂活性水耦合液、液相与气相耦合液，代替传统注水和注气技术，在金川煤矿开展了煤体软化及降尘技术应用研究。CO₂活性水压裂软化润渗技术，能够使煤体中裂隙和孔隙的容积以及结构发生变化，造成煤体的破裂和松动，降低了煤炭强度，达到对硬煤最佳的软化效果。试验表明：煤层CO₂水基压裂后，放煤循环速度提高了5.6%，顶煤破碎块度均衡，顶煤平均采出率提高了3.2%；截割浮尘浓度降低45%，工作面能见度提高，工作面转载运输点煤尘降低23%，润渗作用有效降低了煤体产生浮尘的能力。     

煤层注水致裂技术原理及应用

煤层注水致裂技术是不同于传统煤层注水软化技术的新型技术,它改变了以往注水软化技术长孔、低压、稳流的特点,利用高压水所具有的切割、致裂特性,致裂破坏煤体,降低煤体硬度,提高煤炭可放性和回收率.     

浅析较坚硬煤层深孔高压注水

在中硬以上的较坚硬煤层进行煤体深孔高压注水 ,从而软化煤体硬度提高破煤速度 ,进而提高劳动生产率。它为解决较坚硬煤层中机械化开采开辟了有效的新技术途径     

屯宝煤矿顶煤超前注水软化技术应用研究

针对屯堡煤矿1192工作面放顶煤开采顶煤硬度大、冒落性差等难题,通过对注水软化顶煤机理的分析,提出了屯堡煤矿注水软化方案,并成功地进行了屯宝煤矿复杂难采煤层注水软化试验。屯堡煤矿1192工作面煤层注水后效果实测表明,对煤体进行预注水软化可以提高厚硬煤层的顶煤冒放性,减少了煤体中能量积聚,工作面顶煤含水率提高,工作面粉尘浓度显著降低,瓦斯相对涌出量降低。     

含硬结核薄煤层综采面煤体水力致裂弱化技术

田庄煤矿属薄煤层矿井,所主采的17煤,煤层厚度平均0.95 m,煤层中富含坚硬的硫化铁结核石,严重制约着薄煤层综采的高效安全生产。介绍了在采煤机割煤时,提前对煤体进行湿润软化来降低煤层的整体力学性能,对硫化铁结核石预先松动,减少采煤机截齿消耗,提高煤层的可采效率,实现薄煤层综采工作面的高效安全生产。     

千秋煤矿煤的单轴抗压强度与冲击能量指数关系

 为了搞清煤体强度对冲击地压防治的影响,通过试验研究了千秋煤矿二号煤层试样单轴抗压强度与冲击能量指数之间的关系。结果表明煤样的冲击能量指数与单轴抗压强度呈较显著的线性关系。煤样的浸水软化试验证明煤的冲击能量指数随单轴抗压强度降低而减小。降低煤层的煤体强度可以消减煤的冲击倾向性,是防治冲击地压发生内因的有效措施。     

煤层压裂卸压防冲机制研究

针对彬长矿区高地应力厚煤层开采时冲击动力灾害严重问题,采用理论分析和现场试验等方法,对压裂煤层卸压防冲机制进行了研究。研究表明：煤层压裂破碎后,煤体裂纹扩展表面能降低,产生碎块数量增多,耗散能占比越大,可释放弹性能减小;煤层压裂区应力存在往非压裂区转移现象,巷道侧煤体由压裂前的塑性-弹性2区变为压裂后的塑性-弹性-塑性-弹性4区分布;压裂煤层裂隙发育,应力集中系数降低,塑性区范围显著扩大,煤体弹性能得到释放,有效地预防了冲击地压的发生。     

矿井瓦斯煤尘爆炸事故预防技术研究

据煤层特性和瓦斯赋存状态,对煤层进行注水,把爆破范围内煤体中的瓦斯驱除、排净,利用压力水增加煤体的压力,降低煤层的透气性,阻止和隔离瓦斯释放,以达到防止瓦斯、煤尘爆炸事故的发生。     

“三软”煤层工作面注水技术探析

简要介绍了国投新集二矿1308工作面"三软"煤层开采,通过对煤层注水来增加煤体的湿润、粘结程度,降低煤体煤尘浮游能力。从而,保证工作面安全回采的先进经验,并对"三软"煤层注水技术进行探析。     

煤层注水技术应用中应注意的几个问题

随着放顶煤技术的推广应用和大型化综放工作面的发展,一系列诸如煤尘、自然发火、工作面瓦斯超限和坚硬顶煤的破碎等急待解决的安全问题也暴露出来,同时回采工作面采煤机割煤及后部放顶煤过程中煤尘产生量大,喷雾降尘只能部分解决煤尘,效果有限.国内外的实践证明,煤层注水是从根本上综合解决上述安全问题的行之有效的办法.理论上,压力水渗入煤细微孔隙湿润煤体,不断沟通煤体裂隙网,破坏了煤体结构的完整性,改变了煤体的物理力学性质而软化煤体,解决煤尘.同时,水又可以充当其它阻化剂的载体,防止煤体内部煤的氧化和自然发火.     

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。