高巷道风表移动路线的改良

矿井巷道风速的准确测定是通风管理的基础。针对高巷道,明确目前风表移动路线存在的问题,通过对巷道风速分布的分析,提出新的风表移动路线。新的风表移动路线提高了风速测量的精确度,在一定程度上解决了高巷道风速测量值偏低的问题。     

通风参数测量仪表的实验校准与应用

通风参数测量仪表的校准是煤矿通风安全仪器仪表使用与管理的一项重要工作。本文通过气压检定箱实现了精密气压计的校准,通过闭式环形风硐实现了风表的校准,并应用于实际矿井通风阻力测定提高了测量精度。实践证明,通风参数测量仪表的校准能够提高日常通风测量及通风阻力测定数据的准确性,更好地满足了安全生产的需要。     

煤矿通风参数测量方法与技术

针对目前煤矿测风手段人机共存、种类繁多的现象,通过对测风技术原理的理论分析,讨论现有测风技术的不足和改进之处。风速、风量测量面临精度不足和风速换算的问题,超声波风速传感器可实现更精准的测量。通风阻力测定面临误差和传感器适用性问题,可根据实际巷道情况合理搭配使用差压和绝压传感器。     

中速风表对风速测定的不确定度评定

在测量井下巷道风速时,不可避免地会引入误差,故风速的真值难以确定。为探究风速测定的准确性,在兖矿集团兴隆庄煤矿7302轨联巷用中速风表进行风速测量,并把测量过程中引入的各个误差进行了不确定度评定经分析评定,我矿的7302轨联巷风速符合《煤矿安全规程》的要求。     

巷道平均风速测定装置研究与应用测试

针对矿山走线法测风时人员手持风表所走轨迹速度差异致使风量测量误差较大的问题,研究设计出一种新型巷道平均风速测定装置,该装置采用在固定轨道上匀速走线方式测定风量,克服人工测量的弊端.同时对装置进行实际可靠性风量试验测试,测试结果显示在不同风速条件下,装置测定结果与实际风量误差均小于2％,精度远高于人工测量,可更准确地反映...     

提高巷道风量测定精度的最大风速法

采用测定巷道中心最大风速的方法获得巷道平均风量,首先推导出巷道最大风速与巷道平均风量的相关关系,给出了风速分布系数的测定与计算方法、适用范围。使用该方法测风可提高测风的速度与精度,减少测风误差,还可将风速传感器获得的风速直接转化成风量,实现对矿井风量的监测监控。     

全站仪三架法在长距离工作面贯通中的应用

煤矿井下作业环境复杂,巷道断面积大,且风速较高,导线点对中误差会受到很大影响。全站仪三架测量法可避免风速对测量精度的影响,有效提高测量精度。煤矿测量应用表明,该测量方法既提高了测量效率,又保证了测量精度,应用效果很好。     

用环缝板装置扩展单收缩段风洞的校验功能

<正> 矿用单收缩段风洞,一般只能校验机械式高、中速风表,对于低速风表是用热球式电风速计(以下简称电风速计)作相对校验。实践证明,由于电风速计的表头刻度和校准曲线座标均以对数划分,分辨率低,难以准确读数;表头读数随时间增长、电源消耗和风速加大而产生指针正向飘移累加;每校一台风表约需50min,按电风速计使用说明,每10min应使指针对零,实际上很难照说明行事,由于这些原因难以使校表误差达到应有的精度。为此,根据孔板流量计原理提出用“环缝板装置”改进原来的校表方法,使环缝板两侧在低速范围内产生较大的静压差,便可用刻度细、精度高的补偿式微压计准确读数,只要求得实际风速和压差值的函数关系,就能简便而精确地校验低速风表。     

使用MDH模型对凿岩台车标定方法研究

运用改进的D-H运动学建模方法,建立了台车误差模型,使用微分法对传递矩阵求出各参数的微分表达式,在运动学求得的位姿后调节各关节到实际位置,得到修正的各关节值,对得到的关节值进一步修正。得到各参数向实际位姿的方向收敛,提高了精度。通过试验验证,建立的模型提高了标定精度。     

烟雾管的制做

一般的风速表无法测定矿井巷道低于0.2m/s的风速(现使用的低速风表起动风速需大于0.2m/s)。为了准确的测定出巷道中的微弱风速,可采用烟雾测定方法.首先确定一段距离,然后压挤出烟雾管中的无水四氯化锡,与空气接触时产生烟雾,测出烟雾在这段距离所需的时间,就可以计算出微弱的风速,下面简单介绍一下制做方法。     

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。