进路宽度与边孔角对放矿效果的影响

无底柱分段崩落法广泛应用于国内地下铁矿山,具有 开采效率高、成本低等优势,但矿石损失贫化大。通过多组 进路宽度、边孔角放矿试验,从矿石贫化率、矿石回收率及结 合放出体形态发育特征探究放矿指标变化原因。结果表明: ①随着进路宽度边孔角的增加,矿石回收率随之增大,边孔 角每增加10°,矿石回收率平均增加约3.13个百分点;进路 宽度每增加0.5m,矿石回收率增加约0.82个百分点,当进 路宽度为5.5m、边孔角为55°时,矿石回收率最高;②贫化 率随着边孔角、进路宽度的增加呈先增加后减小的趋势,当 进路宽度为4m,边孔角为25°时贫化率最高,其中进路宽度 对贫化率影响明显;③进路宽度、边孔角越大,放出体形态高 度发育速度减慢,横向轴长发育速度增快,对纵向轴长发育 速度影响不大。放出体形态的变化导致顶部废石量减少,放 出矿岩量增加进而影响放矿指标。     

边孔角对各分段放矿效果的影响

为解决无底柱分段崩落法矿石损失和贫化大这一技术难题,改善放矿效果,采用多个分段的放矿模型,研究了6种边孔角对矿石残留情况、回采率和贫化率的影响。研究发现:第一分段脊部残留体随边孔角变大而变小,矿岩混杂区范围较小,而二、三分段矿石残留范围随之增大;受上分段残留矿石的影响,各分段的放矿效果不同,贫化率和回采率随边孔角变化呈规律性变化,整体放矿效果随边孔角增大呈"高、低、高"的变化趋势;边孔角影响放矿指标的主要因素是对脊部残留体矿石、上分段进路口内废石和本分段内矿石的回采量发生变化。研究结果表明:调整边孔角的大小可以改善放矿效果,同时小边孔角(5°)能够得到与大边孔角(55°)相同的放矿效果。     

司家营铁矿提高中深孔爆破效果实践

司家营铁矿Ⅲ采场无底拄分段崩落法中深孔爆破采矿过程中,按原有爆破参数中深孔爆破后,大块率高、成本高,矿石损失贫化大,易出现爆破生产事故。通过爆破参数优化研究,采用新型炸药、优化调整崩矿步距、加强中深孔施工管理等措施改善爆破效果,控制采场大块的产生,降低爆破成本,改善矿石的流动性,提高了矿石回收率。     

无底柱分段崩落法崩落矿石形态及其影响研究

本文针对无底柱分段崩落法存在的问题，从爆破入手，对放矿对象──崩落矿石的形态及其对矿石损失贫化的影响进行了理论分析、小型试验和工业试验，提出了矿石崩落体的概念，确定了崩落体的形态，指出放出体──松动体──崩落体是相互联系的整体，研究放矿问题应把放矿和爆破崩矿进行综合研究，通过爆破控制崩落体的形态和效果，使放出体与矿石崩落体和残留体构成的矿堆形态相吻合，以降低矿石损失贫化。     

边孔角对无底柱分段崩落法放矿效果的影响

无底柱分段崩落法采矿中,扇形炮孔的边孔角大小对凿岩爆破、采矿方法结构参数和放矿效果有着较大影响。基于单分段单进路放矿模型,进行了3种进路断面尺寸、6种边孔角的18组放矿物理模拟实验,研究了边孔角对放矿效果的影响。结果表明,边孔角和进路断面尺寸对放矿口上方两侧矿岩的流动性有较大影响,进而影响到放出体的形态;随着边孔角的降低,放矿效果也呈现出一定规律性的变化。     

群脉状铀矿床中铀矿石高柱浸出性能的研究

总结了某群脉状铀矿床原地爆破浸出采铀矿石高柱浸出条件试验结果。试验参考某铀矿原地爆破浸出采铀工业性试验的爆破参数，根据Rosin-Rammlar方程，调配了矿石粒度分布。对高柱内矿石不同粒度和不同高度浸出效果进行了研究，结果表明：该矿床矿石浸出性能较好，酸耗低，浸出周期短；铀金属质量浓度梯度变化规律明显；浸出一段时间后加少量氧化剂可明显加快矿石的浸出速率。该试验结果为该矿床原地爆破浸出工业性试验和研究有关技术参数的确定提供了参考和依据。     

正交试验在某铁矿爆破参数设计中的应用

为了降低阿根廷希拉格兰德铁矿采空区顶板的塌落率和采场爆落矿石的大块率,快速找出一套适宜于矿房中深孔回采爆破方案,采用正交试验方法进行中深孔回采爆破设计,经过系统完整的试验研究与分析,得出炮孔孔径为57 mm,炮孔密集度为1.25,孔底起爆的爆破方案。应用后,降低了铁矿采空区顶板的塌落率以及采场爆落矿石的大块率,提高了矿石回收率和生产效率,达到了预期效果。     

瑶岗仙钨矿倾斜极薄矿体爆破参数优选与采矿方法改进

分析瑶岗仙钨矿现采矿方法的特点与存在的问题,使用BP神经网络优选凿岩爆破参数,以总炸药单耗作为综合评价指标,选择合理的孔间距为0.9 m,排距为0.8 m,改进了现采矿方法底部结构,采用电动铲运机出矿代替电耙出矿,不留底柱开采。实践表明,优选出的爆破参数爆破效果良好,降低采矿成本,提高采场生产能力,改进后的采矿方法矿石损失率和贫化率小,回收率高。     

基于U-Net和改进分水岭算法的露天矿爆堆矿石图像分割方法

爆破大块率是反映爆破效果的关键指标,其统计精度主要依赖于爆堆矿石图像分割的准确性。由于爆堆矿石图像中存在矿石目标分布密集、边缘对比度低等问题,致使传统图像分割方法难以准确分割爆堆矿石图像。因此,提出了一种基于U-Net和改进分水岭算法的露天矿爆堆矿石图像分割方法,以实现大块率的精准统计。首先利用无人机在哑巴岭露天矿爆破现场拍摄爆堆矿石图像,制作爆堆矿石图像数据集;然后利用深度学习算法建立了UNet网络架构,同时融合了高级语义信息和低级语义信息,建立了爆堆矿石图像分割模型,再利用训练后的模型对爆堆矿石图像进行初步分割,进一步采用基于距离运算的分水岭算法优化了分割结果;最后评估了该方法的分割精度。试验结果表明:该算法可准确分割露天矿爆堆矿石图像,为露天矿爆破大块率统计、爆破效果智能评价提供技术支持。     

倾斜极薄矿体爆破参数优选与采矿方法改进

以瑶岗仙钨矿为背景,分析了现采矿方法的特点与存在的问题,使用BP神经网络对凿岩爆破参数进行优选,以总炸药单耗作为综合评价指标,选择合理的孔间距为0.9m,排距为0.8m;改进了现采矿方法底部结构,采用电动铲运机出矿代替电耙出矿,不留底柱。实践表明,优选出的爆破参数爆破效果良好,降低了采矿成本,改进后的采矿方法矿石损失贫化小,回收率高,提高了采场生产能力。     

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。